Checkpoint

crates/gpui2/src/platform/keystroke.rs

@@ -0,0 +1,151 @@
+use anyhow::anyhow;
+use serde::Deserialize;
+use smallvec::SmallVec;
+use std::fmt::Write;
+
+#[derive(Clone, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
+pub struct Keystroke {
+    pub modifiers: Modifiers,
+    /// key is the character printed on the key that was pressed
+    /// e.g. for option-s, key is "s"
+    pub key: String,
+    /// ime_key is the character inserted by the IME engine when that key was pressed.
+    /// e.g. for option-s, ime_key is "ß"
+    pub ime_key: Option<String>,
+}
+
+impl Keystroke {
+    // When matching a key we cannot know whether the user intended to type
+    // the ime_key or the key. On some non-US keyboards keys we use in our
+    // bindings are behind option (for example `$` is typed `alt-ç` on a Czech keyboard),
+    // and on some keyboards the IME handler converts a sequence of keys into a
+    // specific character (for example `"` is typed as `" space` on a brazillian keyboard).
+    pub fn match_candidates(&self) -> SmallVec<[Keystroke; 2]> {
+        let mut possibilities = SmallVec::new();
+        match self.ime_key.as_ref() {
+            None => possibilities.push(self.clone()),
+            Some(ime_key) => {
+                possibilities.push(Keystroke {
+                    modifiers: Modifiers {
+                        control: self.modifiers.control,
+                        alt: false,
+                        shift: false,
+                        command: false,
+                        function: false,
+                    },
+                    key: ime_key.to_string(),
+                    ime_key: None,
+                });
+                possibilities.push(Keystroke {
+                    ime_key: None,
+                    ..self.clone()
+                });
+            }
+        }
+        possibilities
+    }
+
+    /// key syntax is:
+    /// [ctrl-][alt-][shift-][cmd-][fn-]key[->ime_key]
+    /// ime_key is only used for generating test events,
+    /// when matching a key with an ime_key set will be matched without it.
+    pub fn parse(source: &str) -> anyhow::Result<Self> {
+        let mut control = false;
+        let mut alt = false;
+        let mut shift = false;
+        let mut command = false;
+        let mut function = false;
+        let mut key = None;
+        let mut ime_key = None;
+
+        let mut components = source.split('-').peekable();
+        while let Some(component) = components.next() {
+            match component {
+                "ctrl" => control = true,
+                "alt" => alt = true,
+                "shift" => shift = true,
+                "cmd" => command = true,
+                "fn" => function = true,
+                _ => {
+                    if let Some(next) = components.peek() {
+                        if next.is_empty() && source.ends_with('-') {
+                            key = Some(String::from("-"));
+                            break;
+                        } else if next.len() > 1 && next.starts_with('>') {
+                            key = Some(String::from(component));
+                            ime_key = Some(String::from(&next[1..]));
+                            components.next();
+                        } else {
+                            return Err(anyhow!("Invalid keystroke `{}`", source));
+                        }
+                    } else {
+                        key = Some(String::from(component));
+                    }
+                }
+            }
+        }
+
+        let key = key.ok_or_else(|| anyhow!("Invalid keystroke `{}`", source))?;
+
+        Ok(Keystroke {
+            modifiers: Modifiers {
+                control,
+                alt,
+                shift,
+                command,
+                function,
+            },
+            key,
+            ime_key,
+        })
+    }
+}
+
+impl std::fmt::Display for Keystroke {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if self.modifiers.control {
+            f.write_char('^')?;
+        }
+        if self.modifiers.alt {
+            f.write_char('⌥')?;
+        }
+        if self.modifiers.command {
+            f.write_char('⌘')?;
+        }
+        if self.modifiers.shift {
+            f.write_char('⇧')?;
+        }
+        let key = match self.key.as_str() {
+            "backspace" => '⌫',
+            "up" => '↑',
+            "down" => '↓',
+            "left" => '←',
+            "right" => '→',
+            "tab" => '⇥',
+            "escape" => '⎋',
+            key => {
+                if key.len() == 1 {
+                    key.chars().next().unwrap().to_ascii_uppercase()
+                } else {
+                    return f.write_str(key);
+                }
+            }
+        };
+        f.write_char(key)
+    }
+}
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
+pub struct Modifiers {
+    pub control: bool,
+    pub alt: bool,
+    pub shift: bool,
+    pub command: bool,
+    pub function: bool,
+}
+
+impl Modifiers {
+    pub fn modified(&self) -> bool {
+        self.control || self.alt || self.shift || self.command || self.function
+    }
+}

crates/gpui2/src/platform/mac.rs

@@ -0,0 +1,165 @@
+///! Macos screen have a y axis that goings up from the bottom of the screen and
+///! an origin at the bottom left of the main display.
+mod dispatcher;
+mod display;
+mod display_linker;
+mod events;
+mod metal_atlas;
+mod metal_renderer;
+mod open_type;
+mod platform;
+mod text_system;
+mod window;
+mod window_appearence;
+
+use crate::{px, size, GlobalPixels, Pixels, Size};
+use anyhow::anyhow;
+use cocoa::{
+    base::{id, nil},
+    foundation::{NSAutoreleasePool, NSNotFound, NSRect, NSSize, NSString, NSUInteger, NSURL},
+};
+use metal_renderer::*;
+use objc::{
+    msg_send,
+    runtime::{BOOL, NO, YES},
+    sel, sel_impl,
+};
+use std::{
+    ffi::{c_char, CStr, OsStr},
+    ops::Range,
+    os::unix::prelude::OsStrExt,
+    path::PathBuf,
+};
+
+pub use dispatcher::*;
+pub use display::*;
+pub use display_linker::*;
+pub use metal_atlas::*;
+pub use platform::*;
+pub use text_system::*;
+pub use window::*;
+
+trait BoolExt {
+    fn to_objc(self) -> BOOL;
+}
+
+impl BoolExt for bool {
+    fn to_objc(self) -> BOOL {
+        if self {
+            YES
+        } else {
+            NO
+        }
+    }
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, Debug)]
+struct NSRange {
+    pub location: NSUInteger,
+    pub length: NSUInteger,
+}
+
+impl NSRange {
+    fn invalid() -> Self {
+        Self {
+            location: NSNotFound as NSUInteger,
+            length: 0,
+        }
+    }
+
+    fn is_valid(&self) -> bool {
+        self.location != NSNotFound as NSUInteger
+    }
+
+    fn to_range(self) -> Option<Range<usize>> {
+        if self.is_valid() {
+            let start = self.location as usize;
+            let end = start + self.length as usize;
+            Some(start..end)
+        } else {
+            None
+        }
+    }
+}
+
+impl From<Range<usize>> for NSRange {
+    fn from(range: Range<usize>) -> Self {
+        NSRange {
+            location: range.start as NSUInteger,
+            length: range.len() as NSUInteger,
+        }
+    }
+}
+
+unsafe impl objc::Encode for NSRange {
+    fn encode() -> objc::Encoding {
+        let encoding = format!(
+            "{{NSRange={}{}}}",
+            NSUInteger::encode().as_str(),
+            NSUInteger::encode().as_str()
+        );
+        unsafe { objc::Encoding::from_str(&encoding) }
+    }
+}
+
+unsafe fn ns_string(string: &str) -> id {
+    NSString::alloc(nil).init_str(string).autorelease()
+}
+
+impl From<NSSize> for Size<Pixels> {
+    fn from(value: NSSize) -> Self {
+        Size {
+            width: px(value.width as f32),
+            height: px(value.height as f32),
+        }
+    }
+}
+
+pub trait NSRectExt {
+    fn size(&self) -> Size<Pixels>;
+    fn intersects(&self, other: Self) -> bool;
+}
+
+impl From<NSRect> for Size<Pixels> {
+    fn from(rect: NSRect) -> Self {
+        let NSSize { width, height } = rect.size;
+        size(width.into(), height.into())
+    }
+}
+
+impl From<NSRect> for Size<GlobalPixels> {
+    fn from(rect: NSRect) -> Self {
+        let NSSize { width, height } = rect.size;
+        size(width.into(), height.into())
+    }
+}
+
+// impl NSRectExt for NSRect {
+//     fn intersects(&self, other: Self) -> bool {
+//         self.size.width > 0.
+//             && self.size.height > 0.
+//             && other.size.width > 0.
+//             && other.size.height > 0.
+//             && self.origin.x <= other.origin.x + other.size.width
+//             && self.origin.x + self.size.width >= other.origin.x
+//             && self.origin.y <= other.origin.y + other.size.height
+//             && self.origin.y + self.size.height >= other.origin.y
+//     }
+// }
+
+// todo!
+#[allow(unused)]
+unsafe fn ns_url_to_path(url: id) -> crate::Result<PathBuf> {
+    let path: *mut c_char = msg_send![url, fileSystemRepresentation];
+    if path.is_null() {
+        Err(anyhow!(
+            "url is not a file path: {}",
+            CStr::from_ptr(url.absoluteString().UTF8String()).to_string_lossy()
+        ))
+    } else {
+        Ok(PathBuf::from(OsStr::from_bytes(
+            CStr::from_ptr(path).to_bytes(),
+        )))
+    }
+}

crates/gpui2/src/platform/mac/dispatch.h

@@ -0,0 +1 @@
+#include <dispatch/dispatch.h>

crates/gpui2/src/platform/mac/dispatcher.rs

@@ -0,0 +1,73 @@
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+
+use crate::PlatformDispatcher;
+use async_task::Runnable;
+use objc::{
+    class, msg_send,
+    runtime::{BOOL, YES},
+    sel, sel_impl,
+};
+use std::ffi::c_void;
+
+include!(concat!(env!("OUT_DIR"), "/dispatch_sys.rs"));
+
+pub fn dispatch_get_main_queue() -> dispatch_queue_t {
+    unsafe { &_dispatch_main_q as *const _ as dispatch_queue_t }
+}
+
+pub struct MacDispatcher;
+
+impl PlatformDispatcher for MacDispatcher {
+    fn is_main_thread(&self) -> bool {
+        let is_main_thread: BOOL = unsafe { msg_send![class!(NSThread), isMainThread] };
+        is_main_thread == YES
+    }
+
+    fn dispatch(&self, runnable: Runnable) {
+        unsafe {
+            dispatch_async_f(
+                dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT.try_into().unwrap(), 0),
+                runnable.into_raw() as *mut c_void,
+                Some(trampoline),
+            );
+        }
+    }
+
+    fn dispatch_on_main_thread(&self, runnable: Runnable) {
+        unsafe {
+            dispatch_async_f(
+                dispatch_get_main_queue(),
+                runnable.into_raw() as *mut c_void,
+                Some(trampoline),
+            );
+        }
+    }
+}
+
+extern "C" fn trampoline(runnable: *mut c_void) {
+    let task = unsafe { Runnable::from_raw(runnable as *mut ()) };
+    task.run();
+}
+
+// #include <dispatch/dispatch.h>
+
+// int main(void) {
+
+//     dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+//         // Do some lengthy background work here...
+//         printf("Background Work\n");
+
+//         dispatch_async(dispatch_get_main_queue(), ^{
+//             // Once done, update your UI on the main queue here.
+//             printf("UI Updated\n");
+
+//         });
+//     });
+
+//     sleep(3);  // prevent the program from terminating immediately
+
+//     return 0;
+// }
+// ```

crates/gpui2/src/platform/mac/display.rs

@@ -0,0 +1,101 @@
+use crate::{point, size, Bounds, DisplayId, GlobalPixels, PlatformDisplay};
+use core_graphics::{
+    display::{CGDirectDisplayID, CGDisplayBounds, CGGetActiveDisplayList},
+    geometry::{CGPoint, CGRect, CGSize},
+};
+use std::any::Any;
+
+#[derive(Debug)]
+pub struct MacDisplay(pub(crate) CGDirectDisplayID);
+
+unsafe impl Send for MacDisplay {}
+
+impl MacDisplay {
+    /// Get the screen with the given UUID.
+    pub fn find_by_id(id: DisplayId) -> Option<Self> {
+        Self::all().find(|screen| screen.id() == id)
+    }
+
+    /// Get the primary screen - the one with the menu bar, and whose bottom left
+    /// corner is at the origin of the AppKit coordinate system.
+    pub fn primary() -> Self {
+        Self::all().next().unwrap()
+    }
+
+    pub fn all() -> impl Iterator<Item = Self> {
+        unsafe {
+            let mut display_count: u32 = 0;
+            let result = CGGetActiveDisplayList(0, std::ptr::null_mut(), &mut display_count);
+
+            if result == 0 {
+                let mut displays = Vec::with_capacity(display_count as usize);
+                CGGetActiveDisplayList(display_count, displays.as_mut_ptr(), &mut display_count);
+                displays.set_len(display_count as usize);
+
+                displays.into_iter().map(|display| MacDisplay(display))
+            } else {
+                panic!("Failed to get active display list");
+            }
+        }
+    }
+}
+
+/// Convert the given rectangle from CoreGraphics' native coordinate space to GPUI's coordinate space.
+///
+/// CoreGraphics' coordinate space has its origin at the bottom left of the primary screen,
+/// with the Y axis pointing upwards.
+///
+/// Conversely, in GPUI's coordinate system, the origin is placed at the top left of the primary
+/// screen, with the Y axis pointing downwards.
+pub(crate) fn display_bounds_from_native(rect: CGRect) -> Bounds<GlobalPixels> {
+    let primary_screen_size = unsafe { CGDisplayBounds(MacDisplay::primary().id().0) }.size;
+
+    Bounds {
+        origin: point(
+            GlobalPixels(rect.origin.x as f32),
+            GlobalPixels(
+                primary_screen_size.height as f32 - rect.origin.y as f32 - rect.size.height as f32,
+            ),
+        ),
+        size: size(
+            GlobalPixels(rect.size.width as f32),
+            GlobalPixels(rect.size.height as f32),
+        ),
+    }
+}
+
+/// Convert the given rectangle from GPUI's coordinate system to CoreGraphics' native coordinate space.
+///
+/// CoreGraphics' coordinate space has its origin at the bottom left of the primary screen,
+/// with the Y axis pointing upwards.
+///
+/// Conversely, in GPUI's coordinate system, the origin is placed at the top left of the primary
+/// screen, with the Y axis pointing downwards.
+pub(crate) fn display_bounds_to_native(bounds: Bounds<GlobalPixels>) -> CGRect {
+    let primary_screen_height = MacDisplay::primary().bounds().size.height;
+
+    CGRect::new(
+        &CGPoint::new(
+            bounds.origin.x.into(),
+            (primary_screen_height - bounds.origin.y - bounds.size.height).into(),
+        ),
+        &CGSize::new(bounds.size.width.into(), bounds.size.height.into()),
+    )
+}
+
+impl PlatformDisplay for MacDisplay {
+    fn id(&self) -> DisplayId {
+        DisplayId(self.0)
+    }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn bounds(&self) -> Bounds<GlobalPixels> {
+        unsafe {
+            let native_bounds = CGDisplayBounds(self.0);
+            display_bounds_from_native(native_bounds)
+        }
+    }
+}

crates/gpui2/src/platform/mac/display_linker.rs

@@ -0,0 +1,274 @@
+use std::{
+    ffi::c_void,
+    mem,
+    sync::{Arc, Weak},
+};
+
+use crate::DisplayId;
+use collections::HashMap;
+use parking_lot::Mutex;
+pub use sys::CVTimeStamp as VideoTimestamp;
+
+pub(crate) struct MacDisplayLinker {
+    links: HashMap<DisplayId, MacDisplayLink>,
+}
+
+struct MacDisplayLink {
+    system_link: sys::DisplayLink,
+    _output_callback: Arc<OutputCallback>,
+}
+
+impl MacDisplayLinker {
+    pub fn new() -> Self {
+        MacDisplayLinker {
+            links: Default::default(),
+        }
+    }
+}
+
+type OutputCallback = Mutex<Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp)>>;
+
+impl MacDisplayLinker {
+    pub fn set_output_callback(
+        &mut self,
+        display_id: DisplayId,
+        output_callback: Box<dyn FnMut(&VideoTimestamp, &VideoTimestamp)>,
+    ) {
+        if let Some(mut system_link) = unsafe { sys::DisplayLink::on_display(display_id.0) } {
+            let callback = Arc::new(Mutex::new(output_callback));
+            let weak_callback_ptr: *const OutputCallback = Arc::downgrade(&callback).into_raw();
+            unsafe { system_link.set_output_callback(trampoline, weak_callback_ptr as *mut c_void) }
+
+            self.links.insert(
+                display_id,
+                MacDisplayLink {
+                    _output_callback: callback,
+                    system_link,
+                },
+            );
+        } else {
+            log::warn!("DisplayLink could not be obtained for {:?}", display_id);
+            return;
+        }
+    }
+
+    pub fn start(&mut self, display_id: DisplayId) {
+        if let Some(link) = self.links.get_mut(&display_id) {
+            unsafe {
+                link.system_link.start();
+            }
+        } else {
+            log::warn!("No DisplayLink callback registered for {:?}", display_id)
+        }
+    }
+
+    pub fn stop(&mut self, display_id: DisplayId) {
+        if let Some(link) = self.links.get_mut(&display_id) {
+            unsafe {
+                link.system_link.stop();
+            }
+        } else {
+            log::warn!("No DisplayLink callback registered for {:?}", display_id)
+        }
+    }
+}
+
+unsafe extern "C" fn trampoline(
+    _display_link_out: *mut sys::CVDisplayLink,
+    current_time: *const sys::CVTimeStamp,
+    output_time: *const sys::CVTimeStamp,
+    _flags_in: i64,
+    _flags_out: *mut i64,
+    user_data: *mut c_void,
+) -> i32 {
+    if let Some((current_time, output_time)) = current_time.as_ref().zip(output_time.as_ref()) {
+        let output_callback: Weak<OutputCallback> =
+            Weak::from_raw(user_data as *mut OutputCallback);
+        if let Some(output_callback) = output_callback.upgrade() {
+            (output_callback.lock())(current_time, output_time)
+        }
+        mem::forget(output_callback);
+    }
+    0
+}
+
+mod sys {
+    //! Derived from display-link crate under the fololwing license:
+    //! https://github.com/BrainiumLLC/display-link/blob/master/LICENSE-MIT
+    //! Apple docs: [CVDisplayLink](https://developer.apple.com/documentation/corevideo/cvdisplaylinkoutputcallback?language=objc)
+    #![allow(dead_code, non_upper_case_globals)]
+
+    use foreign_types::{foreign_type, ForeignType};
+    use std::{
+        ffi::c_void,
+        fmt::{Debug, Formatter, Result},
+    };
+
+    #[derive(Debug)]
+    pub enum CVDisplayLink {}
+
+    foreign_type! {
+        type CType = CVDisplayLink;
+        fn drop = CVDisplayLinkRelease;
+        fn clone = CVDisplayLinkRetain;
+        pub struct DisplayLink;
+        pub struct DisplayLinkRef;
+    }
+
+    impl Debug for DisplayLink {
+        fn fmt(&self, formatter: &mut Formatter) -> Result {
+            formatter
+                .debug_tuple("DisplayLink")
+                .field(&self.as_ptr())
+                .finish()
+        }
+    }
+
+    #[repr(C)]
+    #[derive(Clone, Copy)]
+    pub struct CVTimeStamp {
+        pub version: u32,
+        pub video_time_scale: i32,
+        pub video_time: i64,
+        pub host_time: u64,
+        pub rate_scalar: f64,
+        pub video_refresh_period: i64,
+        pub smpte_time: CVSMPTETime,
+        pub flags: u64,
+        pub reserved: u64,
+    }
+
+    pub type CVTimeStampFlags = u64;
+
+    pub const kCVTimeStampVideoTimeValid: CVTimeStampFlags = 1 << 0;
+    pub const kCVTimeStampHostTimeValid: CVTimeStampFlags = 1 << 1;
+    pub const kCVTimeStampSMPTETimeValid: CVTimeStampFlags = 1 << 2;
+    pub const kCVTimeStampVideoRefreshPeriodValid: CVTimeStampFlags = 1 << 3;
+    pub const kCVTimeStampRateScalarValid: CVTimeStampFlags = 1 << 4;
+    pub const kCVTimeStampTopField: CVTimeStampFlags = 1 << 16;
+    pub const kCVTimeStampBottomField: CVTimeStampFlags = 1 << 17;
+    pub const kCVTimeStampVideoHostTimeValid: CVTimeStampFlags =
+        kCVTimeStampVideoTimeValid | kCVTimeStampHostTimeValid;
+    pub const kCVTimeStampIsInterlaced: CVTimeStampFlags =
+        kCVTimeStampTopField | kCVTimeStampBottomField;
+
+    #[repr(C)]
+    #[derive(Clone, Copy)]
+    pub struct CVSMPTETime {
+        pub subframes: i16,
+        pub subframe_divisor: i16,
+        pub counter: u32,
+        pub time_type: u32,
+        pub flags: u32,
+        pub hours: i16,
+        pub minutes: i16,
+        pub seconds: i16,
+        pub frames: i16,
+    }
+
+    pub type CVSMPTETimeType = u32;
+
+    pub const kCVSMPTETimeType24: CVSMPTETimeType = 0;
+    pub const kCVSMPTETimeType25: CVSMPTETimeType = 1;
+    pub const kCVSMPTETimeType30Drop: CVSMPTETimeType = 2;
+    pub const kCVSMPTETimeType30: CVSMPTETimeType = 3;
+    pub const kCVSMPTETimeType2997: CVSMPTETimeType = 4;
+    pub const kCVSMPTETimeType2997Drop: CVSMPTETimeType = 5;
+    pub const kCVSMPTETimeType60: CVSMPTETimeType = 6;
+    pub const kCVSMPTETimeType5994: CVSMPTETimeType = 7;
+
+    pub type CVSMPTETimeFlags = u32;
+
+    pub const kCVSMPTETimeValid: CVSMPTETimeFlags = 1 << 0;
+    pub const kCVSMPTETimeRunning: CVSMPTETimeFlags = 1 << 1;
+
+    pub type CVDisplayLinkOutputCallback = unsafe extern "C" fn(
+        display_link_out: *mut CVDisplayLink,
+        // A pointer to the current timestamp. This represents the timestamp when the callback is called.
+        current_time: *const CVTimeStamp,
+        // A pointer to the output timestamp. This represents the timestamp for when the frame will be displayed.
+        output_time: *const CVTimeStamp,
+        // Unused
+        flags_in: i64,
+        // Unused
+        flags_out: *mut i64,
+        // A pointer to app-defined data.
+        display_link_context: *mut c_void,
+    ) -> i32;
+
+    #[link(name = "CoreFoundation", kind = "framework")]
+    #[link(name = "CoreVideo", kind = "framework")]
+    #[allow(improper_ctypes)]
+    extern "C" {
+        pub fn CVDisplayLinkCreateWithActiveCGDisplays(
+            display_link_out: *mut *mut CVDisplayLink,
+        ) -> i32;
+        pub fn CVDisplayLinkCreateWithCGDisplay(
+            display_id: u32,
+            display_link_out: *mut *mut CVDisplayLink,
+        ) -> i32;
+        pub fn CVDisplayLinkSetOutputCallback(
+            display_link: &mut DisplayLinkRef,
+            callback: CVDisplayLinkOutputCallback,
+            user_info: *mut c_void,
+        ) -> i32;
+        pub fn CVDisplayLinkSetCurrentCGDisplay(
+            display_link: &mut DisplayLinkRef,
+            display_id: u32,
+        ) -> i32;
+        pub fn CVDisplayLinkStart(display_link: &mut DisplayLinkRef) -> i32;
+        pub fn CVDisplayLinkStop(display_link: &mut DisplayLinkRef) -> i32;
+        pub fn CVDisplayLinkRelease(display_link: *mut CVDisplayLink);
+        pub fn CVDisplayLinkRetain(display_link: *mut CVDisplayLink) -> *mut CVDisplayLink;
+    }
+
+    impl DisplayLink {
+        /// Apple docs: [CVDisplayLinkCreateWithActiveCGDisplays](https://developer.apple.com/documentation/corevideo/1456863-cvdisplaylinkcreatewithactivecgd?language=objc)
+        pub unsafe fn new() -> Option<Self> {
+            let mut display_link: *mut CVDisplayLink = 0 as _;
+            let code = CVDisplayLinkCreateWithActiveCGDisplays(&mut display_link);
+            if code == 0 {
+                Some(DisplayLink::from_ptr(display_link))
+            } else {
+                None
+            }
+        }
+
+        /// Apple docs: [CVDisplayLinkCreateWithCGDisplay](https://developer.apple.com/documentation/corevideo/1456981-cvdisplaylinkcreatewithcgdisplay?language=objc)
+        pub unsafe fn on_display(display_id: u32) -> Option<Self> {
+            let mut display_link: *mut CVDisplayLink = 0 as _;
+            let code = CVDisplayLinkCreateWithCGDisplay(display_id, &mut display_link);
+            if code == 0 {
+                Some(DisplayLink::from_ptr(display_link))
+            } else {
+                None
+            }
+        }
+    }
+
+    impl DisplayLinkRef {
+        /// Apple docs: [CVDisplayLinkSetOutputCallback](https://developer.apple.com/documentation/corevideo/1457096-cvdisplaylinksetoutputcallback?language=objc)
+        pub unsafe fn set_output_callback(
+            &mut self,
+            callback: CVDisplayLinkOutputCallback,
+            user_info: *mut c_void,
+        ) {
+            assert_eq!(CVDisplayLinkSetOutputCallback(self, callback, user_info), 0);
+        }
+
+        /// Apple docs: [CVDisplayLinkSetCurrentCGDisplay](https://developer.apple.com/documentation/corevideo/1456768-cvdisplaylinksetcurrentcgdisplay?language=objc)
+        pub unsafe fn set_current_display(&mut self, display_id: u32) {
+            assert_eq!(CVDisplayLinkSetCurrentCGDisplay(self, display_id), 0);
+        }
+
+        /// Apple docs: [CVDisplayLinkStart](https://developer.apple.com/documentation/corevideo/1457193-cvdisplaylinkstart?language=objc)
+        pub unsafe fn start(&mut self) {
+            assert_eq!(CVDisplayLinkStart(self), 0);
+        }
+
+        /// Apple docs: [CVDisplayLinkStop](https://developer.apple.com/documentation/corevideo/1457281-cvdisplaylinkstop?language=objc)
+        pub unsafe fn stop(&mut self) {
+            assert_eq!(CVDisplayLinkStop(self), 0);
+        }
+    }
+}

crates/gpui2/src/platform/mac/events.rs

@@ -0,0 +1,357 @@
+use crate::{
+    point, px, InputEvent, KeyDownEvent, KeyUpEvent, Keystroke, Modifiers, ModifiersChangedEvent,
+    MouseButton, MouseDownEvent, MouseExitEvent, MouseMoveEvent, MouseUpEvent, NavigationDirection,
+    Pixels, ScrollDelta, ScrollWheelEvent, TouchPhase,
+};
+use cocoa::{
+    appkit::{NSEvent, NSEventModifierFlags, NSEventPhase, NSEventType},
+    base::{id, YES},
+    foundation::NSString as _,
+};
+use core_graphics::{
+    event::{CGEvent, CGEventFlags, CGKeyCode},
+    event_source::{CGEventSource, CGEventSourceStateID},
+};
+use ctor::ctor;
+use foreign_types::ForeignType;
+use objc::{class, msg_send, sel, sel_impl};
+use std::{borrow::Cow, ffi::CStr, mem, os::raw::c_char, ptr};
+
+const BACKSPACE_KEY: u16 = 0x7f;
+const SPACE_KEY: u16 = b' ' as u16;
+const ENTER_KEY: u16 = 0x0d;
+const NUMPAD_ENTER_KEY: u16 = 0x03;
+const ESCAPE_KEY: u16 = 0x1b;
+const TAB_KEY: u16 = 0x09;
+const SHIFT_TAB_KEY: u16 = 0x19;
+
+static mut EVENT_SOURCE: core_graphics::sys::CGEventSourceRef = ptr::null_mut();
+
+#[ctor]
+unsafe fn build_event_source() {
+    let source = CGEventSource::new(CGEventSourceStateID::Private).unwrap();
+    EVENT_SOURCE = source.as_ptr();
+    mem::forget(source);
+}
+
+// todo!
+#[allow(unused)]
+pub fn key_to_native(key: &str) -> Cow<str> {
+    use cocoa::appkit::*;
+    let code = match key {
+        "space" => SPACE_KEY,
+        "backspace" => BACKSPACE_KEY,
+        "up" => NSUpArrowFunctionKey,
+        "down" => NSDownArrowFunctionKey,
+        "left" => NSLeftArrowFunctionKey,
+        "right" => NSRightArrowFunctionKey,
+        "pageup" => NSPageUpFunctionKey,
+        "pagedown" => NSPageDownFunctionKey,
+        "home" => NSHomeFunctionKey,
+        "end" => NSEndFunctionKey,
+        "delete" => NSDeleteFunctionKey,
+        "f1" => NSF1FunctionKey,
+        "f2" => NSF2FunctionKey,
+        "f3" => NSF3FunctionKey,
+        "f4" => NSF4FunctionKey,
+        "f5" => NSF5FunctionKey,
+        "f6" => NSF6FunctionKey,
+        "f7" => NSF7FunctionKey,
+        "f8" => NSF8FunctionKey,
+        "f9" => NSF9FunctionKey,
+        "f10" => NSF10FunctionKey,
+        "f11" => NSF11FunctionKey,
+        "f12" => NSF12FunctionKey,
+        _ => return Cow::Borrowed(key),
+    };
+    Cow::Owned(String::from_utf16(&[code]).unwrap())
+}
+
+unsafe fn read_modifiers(native_event: id) -> Modifiers {
+    let modifiers = native_event.modifierFlags();
+    let control = modifiers.contains(NSEventModifierFlags::NSControlKeyMask);
+    let alt = modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask);
+    let shift = modifiers.contains(NSEventModifierFlags::NSShiftKeyMask);
+    let command = modifiers.contains(NSEventModifierFlags::NSCommandKeyMask);
+    let function = modifiers.contains(NSEventModifierFlags::NSFunctionKeyMask);
+
+    Modifiers {
+        control,
+        alt,
+        shift,
+        command,
+        function,
+    }
+}
+
+impl InputEvent {
+    pub unsafe fn from_native(native_event: id, window_height: Option<Pixels>) -> Option<Self> {
+        let event_type = native_event.eventType();
+
+        // Filter out event types that aren't in the NSEventType enum.
+        // See https://github.com/servo/cocoa-rs/issues/155#issuecomment-323482792 for details.
+        match event_type as u64 {
+            0 | 21 | 32 | 33 | 35 | 36 | 37 => {
+                return None;
+            }
+            _ => {}
+        }
+
+        match event_type {
+            NSEventType::NSFlagsChanged => Some(Self::ModifiersChanged(ModifiersChangedEvent {
+                modifiers: read_modifiers(native_event),
+            })),
+            NSEventType::NSKeyDown => Some(Self::KeyDown(KeyDownEvent {
+                keystroke: parse_keystroke(native_event),
+                is_held: native_event.isARepeat() == YES,
+            })),
+            NSEventType::NSKeyUp => Some(Self::KeyUp(KeyUpEvent {
+                keystroke: parse_keystroke(native_event),
+            })),
+            NSEventType::NSLeftMouseDown
+            | NSEventType::NSRightMouseDown
+            | NSEventType::NSOtherMouseDown => {
+                let button = match native_event.buttonNumber() {
+                    0 => MouseButton::Left,
+                    1 => MouseButton::Right,
+                    2 => MouseButton::Middle,
+                    3 => MouseButton::Navigate(NavigationDirection::Back),
+                    4 => MouseButton::Navigate(NavigationDirection::Forward),
+                    // Other mouse buttons aren't tracked currently
+                    _ => return None,
+                };
+                window_height.map(|window_height| {
+                    Self::MouseDown(MouseDownEvent {
+                        button,
+                        position: point(
+                            px(native_event.locationInWindow().x as f32),
+                            // MacOS screen coordinates are relative to bottom left
+                            window_height - px(native_event.locationInWindow().y as f32),
+                        ),
+                        modifiers: read_modifiers(native_event),
+                        click_count: native_event.clickCount() as usize,
+                    })
+                })
+            }
+            NSEventType::NSLeftMouseUp
+            | NSEventType::NSRightMouseUp
+            | NSEventType::NSOtherMouseUp => {
+                let button = match native_event.buttonNumber() {
+                    0 => MouseButton::Left,
+                    1 => MouseButton::Right,
+                    2 => MouseButton::Middle,
+                    3 => MouseButton::Navigate(NavigationDirection::Back),
+                    4 => MouseButton::Navigate(NavigationDirection::Forward),
+                    // Other mouse buttons aren't tracked currently
+                    _ => return None,
+                };
+
+                window_height.map(|window_height| {
+                    Self::MouseUp(MouseUpEvent {
+                        button,
+                        position: point(
+                            px(native_event.locationInWindow().x as f32),
+                            window_height - px(native_event.locationInWindow().y as f32),
+                        ),
+                        modifiers: read_modifiers(native_event),
+                        click_count: native_event.clickCount() as usize,
+                    })
+                })
+            }
+            NSEventType::NSScrollWheel => window_height.map(|window_height| {
+                let phase = match native_event.phase() {
+                    NSEventPhase::NSEventPhaseMayBegin | NSEventPhase::NSEventPhaseBegan => {
+                        TouchPhase::Started
+                    }
+                    NSEventPhase::NSEventPhaseEnded => TouchPhase::Ended,
+                    _ => TouchPhase::Moved,
+                };
+
+                let raw_data = point(
+                    native_event.scrollingDeltaX() as f32,
+                    native_event.scrollingDeltaY() as f32,
+                );
+
+                let delta = if native_event.hasPreciseScrollingDeltas() == YES {
+                    ScrollDelta::Pixels(raw_data.map(px))
+                } else {
+                    ScrollDelta::Lines(raw_data)
+                };
+
+                Self::ScrollWheel(ScrollWheelEvent {
+                    position: point(
+                        px(native_event.locationInWindow().x as f32),
+                        window_height - px(native_event.locationInWindow().y as f32),
+                    ),
+                    delta,
+                    touch_phase: phase,
+                    modifiers: read_modifiers(native_event),
+                })
+            }),
+            NSEventType::NSLeftMouseDragged
+            | NSEventType::NSRightMouseDragged
+            | NSEventType::NSOtherMouseDragged => {
+                let pressed_button = match native_event.buttonNumber() {
+                    0 => MouseButton::Left,
+                    1 => MouseButton::Right,
+                    2 => MouseButton::Middle,
+                    3 => MouseButton::Navigate(NavigationDirection::Back),
+                    4 => MouseButton::Navigate(NavigationDirection::Forward),
+                    // Other mouse buttons aren't tracked currently
+                    _ => return None,
+                };
+
+                window_height.map(|window_height| {
+                    Self::MouseMoved(MouseMoveEvent {
+                        pressed_button: Some(pressed_button),
+                        position: point(
+                            px(native_event.locationInWindow().x as f32),
+                            window_height - px(native_event.locationInWindow().y as f32),
+                        ),
+                        modifiers: read_modifiers(native_event),
+                    })
+                })
+            }
+            NSEventType::NSMouseMoved => window_height.map(|window_height| {
+                Self::MouseMoved(MouseMoveEvent {
+                    position: point(
+                        px(native_event.locationInWindow().x as f32),
+                        window_height - px(native_event.locationInWindow().y as f32),
+                    ),
+                    pressed_button: None,
+                    modifiers: read_modifiers(native_event),
+                })
+            }),
+            NSEventType::NSMouseExited => window_height.map(|window_height| {
+                Self::MouseExited(MouseExitEvent {
+                    position: point(
+                        px(native_event.locationInWindow().x as f32),
+                        window_height - px(native_event.locationInWindow().y as f32),
+                    ),
+
+                    pressed_button: None,
+                    modifiers: read_modifiers(native_event),
+                })
+            }),
+            _ => None,
+        }
+    }
+}
+
+unsafe fn parse_keystroke(native_event: id) -> Keystroke {
+    use cocoa::appkit::*;
+
+    let mut chars_ignoring_modifiers =
+        CStr::from_ptr(native_event.charactersIgnoringModifiers().UTF8String() as *mut c_char)
+            .to_str()
+            .unwrap()
+            .to_string();
+    let first_char = chars_ignoring_modifiers.chars().next().map(|ch| ch as u16);
+    let modifiers = native_event.modifierFlags();
+
+    let control = modifiers.contains(NSEventModifierFlags::NSControlKeyMask);
+    let alt = modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask);
+    let mut shift = modifiers.contains(NSEventModifierFlags::NSShiftKeyMask);
+    let command = modifiers.contains(NSEventModifierFlags::NSCommandKeyMask);
+    let function = modifiers.contains(NSEventModifierFlags::NSFunctionKeyMask)
+        && first_char.map_or(true, |ch| {
+            !(NSUpArrowFunctionKey..=NSModeSwitchFunctionKey).contains(&ch)
+        });
+
+    #[allow(non_upper_case_globals)]
+    let key = match first_char {
+        Some(SPACE_KEY) => "space".to_string(),
+        Some(BACKSPACE_KEY) => "backspace".to_string(),
+        Some(ENTER_KEY) | Some(NUMPAD_ENTER_KEY) => "enter".to_string(),
+        Some(ESCAPE_KEY) => "escape".to_string(),
+        Some(TAB_KEY) => "tab".to_string(),
+        Some(SHIFT_TAB_KEY) => "tab".to_string(),
+        Some(NSUpArrowFunctionKey) => "up".to_string(),
+        Some(NSDownArrowFunctionKey) => "down".to_string(),
+        Some(NSLeftArrowFunctionKey) => "left".to_string(),
+        Some(NSRightArrowFunctionKey) => "right".to_string(),
+        Some(NSPageUpFunctionKey) => "pageup".to_string(),
+        Some(NSPageDownFunctionKey) => "pagedown".to_string(),
+        Some(NSHomeFunctionKey) => "home".to_string(),
+        Some(NSEndFunctionKey) => "end".to_string(),
+        Some(NSDeleteFunctionKey) => "delete".to_string(),
+        Some(NSF1FunctionKey) => "f1".to_string(),
+        Some(NSF2FunctionKey) => "f2".to_string(),
+        Some(NSF3FunctionKey) => "f3".to_string(),
+        Some(NSF4FunctionKey) => "f4".to_string(),
+        Some(NSF5FunctionKey) => "f5".to_string(),
+        Some(NSF6FunctionKey) => "f6".to_string(),
+        Some(NSF7FunctionKey) => "f7".to_string(),
+        Some(NSF8FunctionKey) => "f8".to_string(),
+        Some(NSF9FunctionKey) => "f9".to_string(),
+        Some(NSF10FunctionKey) => "f10".to_string(),
+        Some(NSF11FunctionKey) => "f11".to_string(),
+        Some(NSF12FunctionKey) => "f12".to_string(),
+        _ => {
+            let mut chars_ignoring_modifiers_and_shift =
+                chars_for_modified_key(native_event.keyCode(), false, false);
+
+            // Honor ⌘ when Dvorak-QWERTY is used.
+            let chars_with_cmd = chars_for_modified_key(native_event.keyCode(), true, false);
+            if command && chars_ignoring_modifiers_and_shift != chars_with_cmd {
+                chars_ignoring_modifiers =
+                    chars_for_modified_key(native_event.keyCode(), true, shift);
+                chars_ignoring_modifiers_and_shift = chars_with_cmd;
+            }
+
+            if shift {
+                if chars_ignoring_modifiers_and_shift
+                    == chars_ignoring_modifiers.to_ascii_lowercase()
+                {
+                    chars_ignoring_modifiers_and_shift
+                } else if chars_ignoring_modifiers_and_shift != chars_ignoring_modifiers {
+                    shift = false;
+                    chars_ignoring_modifiers
+                } else {
+                    chars_ignoring_modifiers
+                }
+            } else {
+                chars_ignoring_modifiers
+            }
+        }
+    };
+
+    Keystroke {
+        modifiers: Modifiers {
+            control,
+            alt,
+            shift,
+            command,
+            function,
+        },
+        key,
+        ime_key: None,
+    }
+}
+
+fn chars_for_modified_key(code: CGKeyCode, cmd: bool, shift: bool) -> String {
+    // Ideally, we would use `[NSEvent charactersByApplyingModifiers]` but that
+    // always returns an empty string with certain keyboards, e.g. Japanese. Synthesizing
+    // an event with the given flags instead lets us access `characters`, which always
+    // returns a valid string.
+    let source = unsafe { core_graphics::event_source::CGEventSource::from_ptr(EVENT_SOURCE) };
+    let event = CGEvent::new_keyboard_event(source.clone(), code, true).unwrap();
+    mem::forget(source);
+
+    let mut flags = CGEventFlags::empty();
+    if cmd {
+        flags |= CGEventFlags::CGEventFlagCommand;
+    }
+    if shift {
+        flags |= CGEventFlags::CGEventFlagShift;
+    }
+    event.set_flags(flags);
+
+    unsafe {
+        let event: id = msg_send![class!(NSEvent), eventWithCGEvent: &*event];
+        CStr::from_ptr(event.characters().UTF8String())
+            .to_str()
+            .unwrap()
+            .to_string()
+    }
+}

crates/gpui2/src/platform/mac/metal_atlas.rs

@@ -0,0 +1,256 @@
+use crate::{
+    AtlasKey, AtlasTextureId, AtlasTextureKind, AtlasTile, Bounds, DevicePixels, PlatformAtlas,
+    Point, Size,
+};
+use anyhow::Result;
+use collections::HashMap;
+use derive_more::{Deref, DerefMut};
+use etagere::BucketedAtlasAllocator;
+use metal::Device;
+use parking_lot::Mutex;
+use std::borrow::Cow;
+
+pub struct MetalAtlas(Mutex<MetalAtlasState>);
+
+impl MetalAtlas {
+    pub fn new(device: Device) -> Self {
+        MetalAtlas(Mutex::new(MetalAtlasState {
+            device: AssertSend(device),
+            monochrome_textures: Default::default(),
+            polychrome_textures: Default::default(),
+            path_textures: Default::default(),
+            tiles_by_key: Default::default(),
+        }))
+    }
+
+    pub(crate) fn metal_texture(&self, id: AtlasTextureId) -> metal::Texture {
+        self.0.lock().texture(id).metal_texture.clone()
+    }
+
+    pub(crate) fn allocate(
+        &self,
+        size: Size<DevicePixels>,
+        texture_kind: AtlasTextureKind,
+    ) -> AtlasTile {
+        self.0.lock().allocate(size, texture_kind)
+    }
+
+    pub(crate) fn clear_textures(&self, texture_kind: AtlasTextureKind) {
+        let mut lock = self.0.lock();
+        let textures = match texture_kind {
+            AtlasTextureKind::Monochrome => &mut lock.monochrome_textures,
+            AtlasTextureKind::Polychrome => &mut lock.polychrome_textures,
+            AtlasTextureKind::Path => &mut lock.path_textures,
+        };
+        for texture in textures {
+            texture.clear();
+        }
+    }
+}
+
+struct MetalAtlasState {
+    device: AssertSend<Device>,
+    monochrome_textures: Vec<MetalAtlasTexture>,
+    polychrome_textures: Vec<MetalAtlasTexture>,
+    path_textures: Vec<MetalAtlasTexture>,
+    tiles_by_key: HashMap<AtlasKey, AtlasTile>,
+}
+
+impl PlatformAtlas for MetalAtlas {
+    fn get_or_insert_with<'a>(
+        &self,
+        key: &AtlasKey,
+        build: &mut dyn FnMut() -> Result<(Size<DevicePixels>, Cow<'a, [u8]>)>,
+    ) -> Result<AtlasTile> {
+        let mut lock = self.0.lock();
+        if let Some(tile) = lock.tiles_by_key.get(key) {
+            return Ok(tile.clone());
+        } else {
+            let (size, bytes) = build()?;
+            let tile = lock.allocate(size, key.texture_kind());
+            let texture = lock.texture(tile.texture_id);
+            texture.upload(tile.bounds, &bytes);
+            lock.tiles_by_key.insert(key.clone(), tile.clone());
+            Ok(tile)
+        }
+    }
+
+    fn clear(&self) {
+        let mut lock = self.0.lock();
+        lock.tiles_by_key.clear();
+        for texture in &mut lock.monochrome_textures {
+            texture.clear();
+        }
+        for texture in &mut lock.polychrome_textures {
+            texture.clear();
+        }
+        for texture in &mut lock.path_textures {
+            texture.clear();
+        }
+    }
+}
+
+impl MetalAtlasState {
+    fn allocate(&mut self, size: Size<DevicePixels>, texture_kind: AtlasTextureKind) -> AtlasTile {
+        let textures = match texture_kind {
+            AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
+            AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
+            AtlasTextureKind::Path => &mut self.path_textures,
+        };
+        textures
+            .iter_mut()
+            .rev()
+            .find_map(|texture| texture.allocate(size))
+            .unwrap_or_else(|| {
+                let texture = self.push_texture(size, texture_kind);
+                texture.allocate(size).unwrap()
+            })
+    }
+
+    fn push_texture(
+        &mut self,
+        min_size: Size<DevicePixels>,
+        kind: AtlasTextureKind,
+    ) -> &mut MetalAtlasTexture {
+        const DEFAULT_ATLAS_SIZE: Size<DevicePixels> = Size {
+            width: DevicePixels(1024),
+            height: DevicePixels(1024),
+        };
+
+        let size = min_size.max(&DEFAULT_ATLAS_SIZE);
+        let texture_descriptor = metal::TextureDescriptor::new();
+        texture_descriptor.set_width(size.width.into());
+        texture_descriptor.set_height(size.height.into());
+        let pixel_format;
+        let usage;
+        match kind {
+            AtlasTextureKind::Monochrome => {
+                pixel_format = metal::MTLPixelFormat::A8Unorm;
+                usage = metal::MTLTextureUsage::ShaderRead;
+            }
+            AtlasTextureKind::Polychrome => {
+                pixel_format = metal::MTLPixelFormat::BGRA8Unorm;
+                usage = metal::MTLTextureUsage::ShaderRead;
+            }
+            AtlasTextureKind::Path => {
+                pixel_format = metal::MTLPixelFormat::R16Float;
+                usage = metal::MTLTextureUsage::RenderTarget | metal::MTLTextureUsage::ShaderRead;
+            }
+        }
+        texture_descriptor.set_pixel_format(pixel_format);
+        texture_descriptor.set_usage(usage);
+        let metal_texture = self.device.new_texture(&texture_descriptor);
+
+        let textures = match kind {
+            AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
+            AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
+            AtlasTextureKind::Path => &mut self.path_textures,
+        };
+        let atlas_texture = MetalAtlasTexture {
+            id: AtlasTextureId {
+                index: textures.len() as u32,
+                kind,
+            },
+            allocator: etagere::BucketedAtlasAllocator::new(size.into()),
+            metal_texture: AssertSend(metal_texture),
+        };
+        textures.push(atlas_texture);
+        textures.last_mut().unwrap()
+    }
+
+    fn texture(&self, id: AtlasTextureId) -> &MetalAtlasTexture {
+        let textures = match id.kind {
+            crate::AtlasTextureKind::Monochrome => &self.monochrome_textures,
+            crate::AtlasTextureKind::Polychrome => &self.polychrome_textures,
+            crate::AtlasTextureKind::Path => &self.path_textures,
+        };
+        &textures[id.index as usize]
+    }
+}
+
+struct MetalAtlasTexture {
+    id: AtlasTextureId,
+    allocator: BucketedAtlasAllocator,
+    metal_texture: AssertSend<metal::Texture>,
+}
+
+impl MetalAtlasTexture {
+    fn clear(&mut self) {
+        self.allocator.clear();
+    }
+
+    fn allocate(&mut self, size: Size<DevicePixels>) -> Option<AtlasTile> {
+        let allocation = self.allocator.allocate(size.into())?;
+        let tile = AtlasTile {
+            texture_id: self.id,
+            tile_id: allocation.id.into(),
+            bounds: Bounds {
+                origin: allocation.rectangle.min.into(),
+                size,
+            },
+        };
+        Some(tile)
+    }
+
+    fn upload(&self, bounds: Bounds<DevicePixels>, bytes: &[u8]) {
+        let region = metal::MTLRegion::new_2d(
+            bounds.origin.x.into(),
+            bounds.origin.y.into(),
+            bounds.size.width.into(),
+            bounds.size.height.into(),
+        );
+        self.metal_texture.replace_region(
+            region,
+            0,
+            bytes.as_ptr() as *const _,
+            u32::from(bounds.size.width.to_bytes(self.bytes_per_pixel())) as u64,
+        );
+    }
+
+    fn bytes_per_pixel(&self) -> u8 {
+        use metal::MTLPixelFormat::*;
+        match self.metal_texture.pixel_format() {
+            A8Unorm | R8Unorm => 1,
+            RGBA8Unorm | BGRA8Unorm => 4,
+            _ => unimplemented!(),
+        }
+    }
+}
+
+impl From<Size<DevicePixels>> for etagere::Size {
+    fn from(size: Size<DevicePixels>) -> Self {
+        etagere::Size::new(size.width.into(), size.height.into())
+    }
+}
+
+impl From<etagere::Point> for Point<DevicePixels> {
+    fn from(value: etagere::Point) -> Self {
+        Point {
+            x: DevicePixels::from(value.x),
+            y: DevicePixels::from(value.y),
+        }
+    }
+}
+
+impl From<etagere::Size> for Size<DevicePixels> {
+    fn from(size: etagere::Size) -> Self {
+        Size {
+            width: DevicePixels::from(size.width),
+            height: DevicePixels::from(size.height),
+        }
+    }
+}
+
+impl From<etagere::Rectangle> for Bounds<DevicePixels> {
+    fn from(rectangle: etagere::Rectangle) -> Self {
+        Bounds {
+            origin: rectangle.min.into(),
+            size: rectangle.size().into(),
+        }
+    }
+}
+
+#[derive(Deref, DerefMut)]
+struct AssertSend<T>(T);
+
+unsafe impl<T> Send for AssertSend<T> {}

crates/gpui2/src/platform/mac/metal_renderer.rs

@@ -0,0 +1,880 @@
+use crate::{
+    point, size, AtlasTextureId, AtlasTextureKind, AtlasTile, Bounds, ContentMask, DevicePixels,
+    Hsla, MetalAtlas, MonochromeSprite, Path, PathId, PathVertex, PolychromeSprite, PrimitiveBatch,
+    Quad, ScaledPixels, Scene, Shadow, Size, Underline,
+};
+use cocoa::{
+    base::{NO, YES},
+    foundation::NSUInteger,
+    quartzcore::AutoresizingMask,
+};
+use collections::HashMap;
+use metal::{CommandQueue, MTLPixelFormat, MTLResourceOptions, NSRange};
+use objc::{self, msg_send, sel, sel_impl};
+use smallvec::SmallVec;
+use std::{ffi::c_void, mem, ptr, sync::Arc};
+
+const SHADERS_METALLIB: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/shaders.metallib"));
+const INSTANCE_BUFFER_SIZE: usize = 8192 * 1024; // This is an arbitrary decision. There's probably a more optimal value.
+
+pub(crate) struct MetalRenderer {
+    layer: metal::MetalLayer,
+    command_queue: CommandQueue,
+    paths_rasterization_pipeline_state: metal::RenderPipelineState,
+    path_sprites_pipeline_state: metal::RenderPipelineState,
+    shadows_pipeline_state: metal::RenderPipelineState,
+    quads_pipeline_state: metal::RenderPipelineState,
+    underlines_pipeline_state: metal::RenderPipelineState,
+    monochrome_sprites_pipeline_state: metal::RenderPipelineState,
+    polychrome_sprites_pipeline_state: metal::RenderPipelineState,
+    unit_vertices: metal::Buffer,
+    instances: metal::Buffer,
+    sprite_atlas: Arc<MetalAtlas>,
+}
+
+impl MetalRenderer {
+    pub fn new(is_opaque: bool) -> Self {
+        let device: metal::Device = if let Some(device) = metal::Device::system_default() {
+            device
+        } else {
+            log::error!("unable to access a compatible graphics device");
+            std::process::exit(1);
+        };
+
+        let layer = metal::MetalLayer::new();
+        layer.set_device(&device);
+        layer.set_pixel_format(MTLPixelFormat::BGRA8Unorm);
+        layer.set_presents_with_transaction(true);
+        layer.set_opaque(is_opaque);
+        unsafe {
+            let _: () = msg_send![&*layer, setAllowsNextDrawableTimeout: NO];
+            let _: () = msg_send![&*layer, setNeedsDisplayOnBoundsChange: YES];
+            let _: () = msg_send![
+                &*layer,
+                setAutoresizingMask: AutoresizingMask::WIDTH_SIZABLE
+                    | AutoresizingMask::HEIGHT_SIZABLE
+            ];
+        }
+
+        let library = device
+            .new_library_with_data(SHADERS_METALLIB)
+            .expect("error building metal library");
+
+        fn to_float2_bits(point: crate::PointF) -> u64 {
+            unsafe {
+                let mut output = mem::transmute::<_, u32>(point.y.to_bits()) as u64;
+                output <<= 32;
+                output |= mem::transmute::<_, u32>(point.x.to_bits()) as u64;
+                output
+            }
+        }
+
+        let unit_vertices = [
+            to_float2_bits(point(0., 0.)),
+            to_float2_bits(point(1., 0.)),
+            to_float2_bits(point(0., 1.)),
+            to_float2_bits(point(0., 1.)),
+            to_float2_bits(point(1., 0.)),
+            to_float2_bits(point(1., 1.)),
+        ];
+        let unit_vertices = device.new_buffer_with_data(
+            unit_vertices.as_ptr() as *const c_void,
+            (unit_vertices.len() * mem::size_of::<u64>()) as u64,
+            MTLResourceOptions::StorageModeManaged,
+        );
+        let instances = device.new_buffer(
+            INSTANCE_BUFFER_SIZE as u64,
+            MTLResourceOptions::StorageModeManaged,
+        );
+
+        let paths_rasterization_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "paths_rasterization",
+            "path_rasterization_vertex",
+            "path_rasterization_fragment",
+            MTLPixelFormat::R16Float,
+        );
+        let path_sprites_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "path_sprites",
+            "path_sprite_vertex",
+            "path_sprite_fragment",
+            MTLPixelFormat::BGRA8Unorm,
+        );
+        let shadows_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "shadows",
+            "shadow_vertex",
+            "shadow_fragment",
+            MTLPixelFormat::BGRA8Unorm,
+        );
+        let quads_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "quads",
+            "quad_vertex",
+            "quad_fragment",
+            MTLPixelFormat::BGRA8Unorm,
+        );
+        let underlines_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "underlines",
+            "underline_vertex",
+            "underline_fragment",
+            MTLPixelFormat::BGRA8Unorm,
+        );
+        let monochrome_sprites_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "monochrome_sprites",
+            "monochrome_sprite_vertex",
+            "monochrome_sprite_fragment",
+            MTLPixelFormat::BGRA8Unorm,
+        );
+        let polychrome_sprites_pipeline_state = build_pipeline_state(
+            &device,
+            &library,
+            "polychrome_sprites",
+            "polychrome_sprite_vertex",
+            "polychrome_sprite_fragment",
+            MTLPixelFormat::BGRA8Unorm,
+        );
+
+        let command_queue = device.new_command_queue();
+        let sprite_atlas = Arc::new(MetalAtlas::new(device.clone()));
+
+        Self {
+            layer,
+            command_queue,
+            paths_rasterization_pipeline_state,
+            path_sprites_pipeline_state,
+            shadows_pipeline_state,
+            quads_pipeline_state,
+            underlines_pipeline_state,
+            monochrome_sprites_pipeline_state,
+            polychrome_sprites_pipeline_state,
+            unit_vertices,
+            instances,
+            sprite_atlas,
+        }
+    }
+
+    pub fn layer(&self) -> &metal::MetalLayerRef {
+        &*self.layer
+    }
+
+    pub fn sprite_atlas(&self) -> &Arc<MetalAtlas> {
+        &self.sprite_atlas
+    }
+
+    pub fn draw(&mut self, scene: &Scene) {
+        let layer = self.layer.clone();
+        let viewport_size = layer.drawable_size();
+        let viewport_size: Size<DevicePixels> = size(
+            (viewport_size.width.ceil() as i32).into(),
+            (viewport_size.height.ceil() as i32).into(),
+        );
+        let drawable = if let Some(drawable) = layer.next_drawable() {
+            drawable
+        } else {
+            log::error!(
+                "failed to retrieve next drawable, drawable size: {:?}",
+                viewport_size
+            );
+            return;
+        };
+        let command_queue = self.command_queue.clone();
+        let command_buffer = command_queue.new_command_buffer();
+        let mut instance_offset = 0;
+
+        let path_tiles = self.rasterize_paths(scene.paths(), &mut instance_offset, &command_buffer);
+
+        let render_pass_descriptor = metal::RenderPassDescriptor::new();
+        let color_attachment = render_pass_descriptor
+            .color_attachments()
+            .object_at(0)
+            .unwrap();
+
+        color_attachment.set_texture(Some(drawable.texture()));
+        color_attachment.set_load_action(metal::MTLLoadAction::Clear);
+        color_attachment.set_store_action(metal::MTLStoreAction::Store);
+        let alpha = if self.layer.is_opaque() { 1. } else { 0. };
+        color_attachment.set_clear_color(metal::MTLClearColor::new(0., 0., 0., alpha));
+        let command_encoder = command_buffer.new_render_command_encoder(render_pass_descriptor);
+
+        command_encoder.set_viewport(metal::MTLViewport {
+            originX: 0.0,
+            originY: 0.0,
+            width: i32::from(viewport_size.width) as f64,
+            height: i32::from(viewport_size.height) as f64,
+            znear: 0.0,
+            zfar: 1.0,
+        });
+        for batch in scene.batches() {
+            match batch {
+                PrimitiveBatch::Shadows(shadows) => {
+                    self.draw_shadows(
+                        shadows,
+                        &mut instance_offset,
+                        viewport_size,
+                        command_encoder,
+                    );
+                }
+                PrimitiveBatch::Quads(quads) => {
+                    self.draw_quads(quads, &mut instance_offset, viewport_size, command_encoder);
+                }
+                PrimitiveBatch::Paths(paths) => {
+                    self.draw_paths(
+                        paths,
+                        &path_tiles,
+                        &mut instance_offset,
+                        viewport_size,
+                        command_encoder,
+                    );
+                }
+                PrimitiveBatch::Underlines(underlines) => {
+                    self.draw_underlines(
+                        underlines,
+                        &mut instance_offset,
+                        viewport_size,
+                        command_encoder,
+                    );
+                }
+                PrimitiveBatch::MonochromeSprites {
+                    texture_id,
+                    sprites,
+                } => {
+                    self.draw_monochrome_sprites(
+                        texture_id,
+                        sprites,
+                        &mut instance_offset,
+                        viewport_size,
+                        command_encoder,
+                    );
+                }
+                PrimitiveBatch::PolychromeSprites {
+                    texture_id,
+                    sprites,
+                } => {
+                    self.draw_polychrome_sprites(
+                        texture_id,
+                        sprites,
+                        &mut instance_offset,
+                        viewport_size,
+                        command_encoder,
+                    );
+                }
+            }
+        }
+
+        command_encoder.end_encoding();
+
+        self.instances.did_modify_range(NSRange {
+            location: 0,
+            length: instance_offset as NSUInteger,
+        });
+
+        command_buffer.commit();
+        self.sprite_atlas.clear_textures(AtlasTextureKind::Path);
+        command_buffer.wait_until_completed();
+        drawable.present();
+    }
+
+    fn rasterize_paths(
+        &mut self,
+        paths: &[Path<ScaledPixels>],
+        offset: &mut usize,
+        command_buffer: &metal::CommandBufferRef,
+    ) -> HashMap<PathId, AtlasTile> {
+        let mut tiles = HashMap::default();
+        let mut vertices_by_texture_id = HashMap::default();
+        for path in paths {
+            let clipped_bounds = path.bounds.intersect(&path.content_mask.bounds);
+
+            let tile = self
+                .sprite_atlas
+                .allocate(clipped_bounds.size.map(Into::into), AtlasTextureKind::Path);
+            vertices_by_texture_id
+                .entry(tile.texture_id)
+                .or_insert(Vec::new())
+                .extend(path.vertices.iter().map(|vertex| PathVertex {
+                    xy_position: vertex.xy_position - path.bounds.origin
+                        + tile.bounds.origin.map(Into::into),
+                    st_position: vertex.st_position,
+                    content_mask: ContentMask {
+                        bounds: tile.bounds.map(Into::into),
+                    },
+                }));
+            tiles.insert(path.id, tile);
+        }
+
+        for (texture_id, vertices) in vertices_by_texture_id {
+            align_offset(offset);
+            let next_offset = *offset + vertices.len() * mem::size_of::<PathVertex<ScaledPixels>>();
+            assert!(
+                next_offset <= INSTANCE_BUFFER_SIZE,
+                "instance buffer exhausted"
+            );
+
+            let render_pass_descriptor = metal::RenderPassDescriptor::new();
+            let color_attachment = render_pass_descriptor
+                .color_attachments()
+                .object_at(0)
+                .unwrap();
+
+            let texture = self.sprite_atlas.metal_texture(texture_id);
+            color_attachment.set_texture(Some(&texture));
+            color_attachment.set_load_action(metal::MTLLoadAction::Clear);
+            color_attachment.set_store_action(metal::MTLStoreAction::Store);
+            color_attachment.set_clear_color(metal::MTLClearColor::new(0., 0., 0., 1.));
+            let command_encoder = command_buffer.new_render_command_encoder(render_pass_descriptor);
+            command_encoder.set_render_pipeline_state(&self.paths_rasterization_pipeline_state);
+            command_encoder.set_vertex_buffer(
+                PathRasterizationInputIndex::Vertices as u64,
+                Some(&self.instances),
+                *offset as u64,
+            );
+            let texture_size = Size {
+                width: DevicePixels::from(texture.width()),
+                height: DevicePixels::from(texture.height()),
+            };
+            command_encoder.set_vertex_bytes(
+                PathRasterizationInputIndex::AtlasTextureSize as u64,
+                mem::size_of_val(&texture_size) as u64,
+                &texture_size as *const Size<DevicePixels> as *const _,
+            );
+
+            let vertices_bytes_len = mem::size_of::<PathVertex<ScaledPixels>>() * vertices.len();
+            let buffer_contents = unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+            unsafe {
+                ptr::copy_nonoverlapping(
+                    vertices.as_ptr() as *const u8,
+                    buffer_contents,
+                    vertices_bytes_len,
+                );
+            }
+
+            command_encoder.draw_primitives(
+                metal::MTLPrimitiveType::Triangle,
+                0,
+                vertices.len() as u64,
+            );
+            command_encoder.end_encoding();
+            *offset = next_offset;
+        }
+
+        tiles
+    }
+
+    fn draw_shadows(
+        &mut self,
+        shadows: &[Shadow],
+        offset: &mut usize,
+        viewport_size: Size<DevicePixels>,
+        command_encoder: &metal::RenderCommandEncoderRef,
+    ) {
+        if shadows.is_empty() {
+            return;
+        }
+        align_offset(offset);
+
+        command_encoder.set_render_pipeline_state(&self.shadows_pipeline_state);
+        command_encoder.set_vertex_buffer(
+            ShadowInputIndex::Vertices as u64,
+            Some(&self.unit_vertices),
+            0,
+        );
+        command_encoder.set_vertex_buffer(
+            ShadowInputIndex::Shadows as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_fragment_buffer(
+            ShadowInputIndex::Shadows as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+
+        command_encoder.set_vertex_bytes(
+            ShadowInputIndex::ViewportSize as u64,
+            mem::size_of_val(&viewport_size) as u64,
+            &viewport_size as *const Size<DevicePixels> as *const _,
+        );
+
+        let shadow_bytes_len = mem::size_of::<Shadow>() * shadows.len();
+        let buffer_contents = unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+        unsafe {
+            ptr::copy_nonoverlapping(
+                shadows.as_ptr() as *const u8,
+                buffer_contents,
+                shadow_bytes_len,
+            );
+        }
+
+        let next_offset = *offset + shadow_bytes_len;
+        assert!(
+            next_offset <= INSTANCE_BUFFER_SIZE,
+            "instance buffer exhausted"
+        );
+
+        command_encoder.draw_primitives_instanced(
+            metal::MTLPrimitiveType::Triangle,
+            0,
+            6,
+            shadows.len() as u64,
+        );
+        *offset = next_offset;
+    }
+
+    fn draw_quads(
+        &mut self,
+        quads: &[Quad],
+        offset: &mut usize,
+        viewport_size: Size<DevicePixels>,
+        command_encoder: &metal::RenderCommandEncoderRef,
+    ) {
+        if quads.is_empty() {
+            return;
+        }
+        align_offset(offset);
+
+        command_encoder.set_render_pipeline_state(&self.quads_pipeline_state);
+        command_encoder.set_vertex_buffer(
+            QuadInputIndex::Vertices as u64,
+            Some(&self.unit_vertices),
+            0,
+        );
+        command_encoder.set_vertex_buffer(
+            QuadInputIndex::Quads as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_fragment_buffer(
+            QuadInputIndex::Quads as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+
+        command_encoder.set_vertex_bytes(
+            QuadInputIndex::ViewportSize as u64,
+            mem::size_of_val(&viewport_size) as u64,
+            &viewport_size as *const Size<DevicePixels> as *const _,
+        );
+
+        let quad_bytes_len = mem::size_of::<Quad>() * quads.len();
+        let buffer_contents = unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+        unsafe {
+            ptr::copy_nonoverlapping(quads.as_ptr() as *const u8, buffer_contents, quad_bytes_len);
+        }
+
+        let next_offset = *offset + quad_bytes_len;
+        assert!(
+            next_offset <= INSTANCE_BUFFER_SIZE,
+            "instance buffer exhausted"
+        );
+
+        command_encoder.draw_primitives_instanced(
+            metal::MTLPrimitiveType::Triangle,
+            0,
+            6,
+            quads.len() as u64,
+        );
+        *offset = next_offset;
+    }
+
+    fn draw_paths(
+        &mut self,
+        paths: &[Path<ScaledPixels>],
+        tiles_by_path_id: &HashMap<PathId, AtlasTile>,
+        offset: &mut usize,
+        viewport_size: Size<DevicePixels>,
+        command_encoder: &metal::RenderCommandEncoderRef,
+    ) {
+        if paths.is_empty() {
+            return;
+        }
+
+        command_encoder.set_render_pipeline_state(&self.path_sprites_pipeline_state);
+        command_encoder.set_vertex_buffer(
+            SpriteInputIndex::Vertices as u64,
+            Some(&self.unit_vertices),
+            0,
+        );
+        command_encoder.set_vertex_bytes(
+            SpriteInputIndex::ViewportSize as u64,
+            mem::size_of_val(&viewport_size) as u64,
+            &viewport_size as *const Size<DevicePixels> as *const _,
+        );
+
+        let mut prev_texture_id = None;
+        let mut sprites = SmallVec::<[_; 1]>::new();
+        let mut paths_and_tiles = paths
+            .into_iter()
+            .map(|path| (path, tiles_by_path_id.get(&path.id).unwrap()))
+            .peekable();
+
+        loop {
+            if let Some((path, tile)) = paths_and_tiles.peek() {
+                if prev_texture_id.map_or(true, |texture_id| texture_id == tile.texture_id) {
+                    prev_texture_id = Some(tile.texture_id);
+                    sprites.push(PathSprite {
+                        bounds: Bounds {
+                            origin: path.bounds.origin.map(|p| p.floor()),
+                            size: tile.bounds.size.map(Into::into),
+                        },
+                        color: path.color,
+                        tile: (*tile).clone(),
+                    });
+                    paths_and_tiles.next();
+                    continue;
+                }
+            }
+
+            if sprites.is_empty() {
+                break;
+            } else {
+                align_offset(offset);
+                let texture_id = prev_texture_id.take().unwrap();
+                let texture: metal::Texture = self.sprite_atlas.metal_texture(texture_id);
+                let texture_size = size(
+                    DevicePixels(texture.width() as i32),
+                    DevicePixels(texture.height() as i32),
+                );
+
+                command_encoder.set_vertex_buffer(
+                    SpriteInputIndex::Sprites as u64,
+                    Some(&self.instances),
+                    *offset as u64,
+                );
+                command_encoder.set_vertex_bytes(
+                    SpriteInputIndex::AtlasTextureSize as u64,
+                    mem::size_of_val(&texture_size) as u64,
+                    &texture_size as *const Size<DevicePixels> as *const _,
+                );
+                command_encoder.set_fragment_buffer(
+                    SpriteInputIndex::Sprites as u64,
+                    Some(&self.instances),
+                    *offset as u64,
+                );
+                command_encoder
+                    .set_fragment_texture(SpriteInputIndex::AtlasTexture as u64, Some(&texture));
+
+                let sprite_bytes_len = mem::size_of::<MonochromeSprite>() * sprites.len();
+                let buffer_contents =
+                    unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+                unsafe {
+                    ptr::copy_nonoverlapping(
+                        sprites.as_ptr() as *const u8,
+                        buffer_contents,
+                        sprite_bytes_len,
+                    );
+                }
+
+                let next_offset = *offset + sprite_bytes_len;
+                assert!(
+                    next_offset <= INSTANCE_BUFFER_SIZE,
+                    "instance buffer exhausted"
+                );
+
+                command_encoder.draw_primitives_instanced(
+                    metal::MTLPrimitiveType::Triangle,
+                    0,
+                    6,
+                    sprites.len() as u64,
+                );
+                *offset = next_offset;
+                sprites.clear();
+            }
+        }
+    }
+
+    fn draw_underlines(
+        &mut self,
+        underlines: &[Underline],
+        offset: &mut usize,
+        viewport_size: Size<DevicePixels>,
+        command_encoder: &metal::RenderCommandEncoderRef,
+    ) {
+        if underlines.is_empty() {
+            return;
+        }
+        align_offset(offset);
+
+        command_encoder.set_render_pipeline_state(&self.underlines_pipeline_state);
+        command_encoder.set_vertex_buffer(
+            UnderlineInputIndex::Vertices as u64,
+            Some(&self.unit_vertices),
+            0,
+        );
+        command_encoder.set_vertex_buffer(
+            UnderlineInputIndex::Underlines as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_fragment_buffer(
+            UnderlineInputIndex::Underlines as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+
+        command_encoder.set_vertex_bytes(
+            UnderlineInputIndex::ViewportSize as u64,
+            mem::size_of_val(&viewport_size) as u64,
+            &viewport_size as *const Size<DevicePixels> as *const _,
+        );
+
+        let quad_bytes_len = mem::size_of::<Underline>() * underlines.len();
+        let buffer_contents = unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+        unsafe {
+            ptr::copy_nonoverlapping(
+                underlines.as_ptr() as *const u8,
+                buffer_contents,
+                quad_bytes_len,
+            );
+        }
+
+        let next_offset = *offset + quad_bytes_len;
+        assert!(
+            next_offset <= INSTANCE_BUFFER_SIZE,
+            "instance buffer exhausted"
+        );
+
+        command_encoder.draw_primitives_instanced(
+            metal::MTLPrimitiveType::Triangle,
+            0,
+            6,
+            underlines.len() as u64,
+        );
+        *offset = next_offset;
+    }
+
+    fn draw_monochrome_sprites(
+        &mut self,
+        texture_id: AtlasTextureId,
+        sprites: &[MonochromeSprite],
+        offset: &mut usize,
+        viewport_size: Size<DevicePixels>,
+        command_encoder: &metal::RenderCommandEncoderRef,
+    ) {
+        if sprites.is_empty() {
+            return;
+        }
+        align_offset(offset);
+
+        let texture = self.sprite_atlas.metal_texture(texture_id);
+        let texture_size = size(
+            DevicePixels(texture.width() as i32),
+            DevicePixels(texture.height() as i32),
+        );
+        command_encoder.set_render_pipeline_state(&self.monochrome_sprites_pipeline_state);
+        command_encoder.set_vertex_buffer(
+            SpriteInputIndex::Vertices as u64,
+            Some(&self.unit_vertices),
+            0,
+        );
+        command_encoder.set_vertex_buffer(
+            SpriteInputIndex::Sprites as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_vertex_bytes(
+            SpriteInputIndex::ViewportSize as u64,
+            mem::size_of_val(&viewport_size) as u64,
+            &viewport_size as *const Size<DevicePixels> as *const _,
+        );
+        command_encoder.set_vertex_bytes(
+            SpriteInputIndex::AtlasTextureSize as u64,
+            mem::size_of_val(&texture_size) as u64,
+            &texture_size as *const Size<DevicePixels> as *const _,
+        );
+        command_encoder.set_fragment_buffer(
+            SpriteInputIndex::Sprites as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_fragment_texture(SpriteInputIndex::AtlasTexture as u64, Some(&texture));
+
+        let sprite_bytes_len = mem::size_of::<MonochromeSprite>() * sprites.len();
+        let buffer_contents = unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+        unsafe {
+            ptr::copy_nonoverlapping(
+                sprites.as_ptr() as *const u8,
+                buffer_contents,
+                sprite_bytes_len,
+            );
+        }
+
+        let next_offset = *offset + sprite_bytes_len;
+        assert!(
+            next_offset <= INSTANCE_BUFFER_SIZE,
+            "instance buffer exhausted"
+        );
+
+        command_encoder.draw_primitives_instanced(
+            metal::MTLPrimitiveType::Triangle,
+            0,
+            6,
+            sprites.len() as u64,
+        );
+        *offset = next_offset;
+    }
+
+    fn draw_polychrome_sprites(
+        &mut self,
+        texture_id: AtlasTextureId,
+        sprites: &[PolychromeSprite],
+        offset: &mut usize,
+        viewport_size: Size<DevicePixels>,
+        command_encoder: &metal::RenderCommandEncoderRef,
+    ) {
+        if sprites.is_empty() {
+            return;
+        }
+        align_offset(offset);
+
+        let texture = self.sprite_atlas.metal_texture(texture_id);
+        let texture_size = size(
+            DevicePixels(texture.width() as i32),
+            DevicePixels(texture.height() as i32),
+        );
+        command_encoder.set_render_pipeline_state(&self.polychrome_sprites_pipeline_state);
+        command_encoder.set_vertex_buffer(
+            SpriteInputIndex::Vertices as u64,
+            Some(&self.unit_vertices),
+            0,
+        );
+        command_encoder.set_vertex_buffer(
+            SpriteInputIndex::Sprites as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_vertex_bytes(
+            SpriteInputIndex::ViewportSize as u64,
+            mem::size_of_val(&viewport_size) as u64,
+            &viewport_size as *const Size<DevicePixels> as *const _,
+        );
+        command_encoder.set_vertex_bytes(
+            SpriteInputIndex::AtlasTextureSize as u64,
+            mem::size_of_val(&texture_size) as u64,
+            &texture_size as *const Size<DevicePixels> as *const _,
+        );
+        command_encoder.set_fragment_buffer(
+            SpriteInputIndex::Sprites as u64,
+            Some(&self.instances),
+            *offset as u64,
+        );
+        command_encoder.set_fragment_texture(SpriteInputIndex::AtlasTexture as u64, Some(&texture));
+
+        let sprite_bytes_len = mem::size_of::<PolychromeSprite>() * sprites.len();
+        let buffer_contents = unsafe { (self.instances.contents() as *mut u8).add(*offset) };
+        unsafe {
+            ptr::copy_nonoverlapping(
+                sprites.as_ptr() as *const u8,
+                buffer_contents,
+                sprite_bytes_len,
+            );
+        }
+
+        let next_offset = *offset + sprite_bytes_len;
+        assert!(
+            next_offset <= INSTANCE_BUFFER_SIZE,
+            "instance buffer exhausted"
+        );
+
+        command_encoder.draw_primitives_instanced(
+            metal::MTLPrimitiveType::Triangle,
+            0,
+            6,
+            sprites.len() as u64,
+        );
+        *offset = next_offset;
+    }
+}
+
+fn build_pipeline_state(
+    device: &metal::DeviceRef,
+    library: &metal::LibraryRef,
+    label: &str,
+    vertex_fn_name: &str,
+    fragment_fn_name: &str,
+    pixel_format: metal::MTLPixelFormat,
+) -> metal::RenderPipelineState {
+    let vertex_fn = library
+        .get_function(vertex_fn_name, None)
+        .expect("error locating vertex function");
+    let fragment_fn = library
+        .get_function(fragment_fn_name, None)
+        .expect("error locating fragment function");
+
+    let descriptor = metal::RenderPipelineDescriptor::new();
+    descriptor.set_label(label);
+    descriptor.set_vertex_function(Some(vertex_fn.as_ref()));
+    descriptor.set_fragment_function(Some(fragment_fn.as_ref()));
+    let color_attachment = descriptor.color_attachments().object_at(0).unwrap();
+    color_attachment.set_pixel_format(pixel_format);
+    color_attachment.set_blending_enabled(true);
+    color_attachment.set_rgb_blend_operation(metal::MTLBlendOperation::Add);
+    color_attachment.set_alpha_blend_operation(metal::MTLBlendOperation::Add);
+    color_attachment.set_source_rgb_blend_factor(metal::MTLBlendFactor::SourceAlpha);
+    color_attachment.set_source_alpha_blend_factor(metal::MTLBlendFactor::One);
+    color_attachment.set_destination_rgb_blend_factor(metal::MTLBlendFactor::OneMinusSourceAlpha);
+    color_attachment.set_destination_alpha_blend_factor(metal::MTLBlendFactor::One);
+    descriptor.set_depth_attachment_pixel_format(MTLPixelFormat::Invalid);
+
+    device
+        .new_render_pipeline_state(&descriptor)
+        .expect("could not create render pipeline state")
+}
+
+// Align to multiples of 256 make Metal happy.
+fn align_offset(offset: &mut usize) {
+    *offset = ((*offset + 255) / 256) * 256;
+}
+
+#[repr(C)]
+enum ShadowInputIndex {
+    Vertices = 0,
+    Shadows = 1,
+    ViewportSize = 2,
+}
+
+#[repr(C)]
+enum QuadInputIndex {
+    Vertices = 0,
+    Quads = 1,
+    ViewportSize = 2,
+}
+
+#[repr(C)]
+enum UnderlineInputIndex {
+    Vertices = 0,
+    Underlines = 1,
+    ViewportSize = 2,
+}
+
+#[repr(C)]
+enum SpriteInputIndex {
+    Vertices = 0,
+    Sprites = 1,
+    ViewportSize = 2,
+    AtlasTextureSize = 3,
+    AtlasTexture = 4,
+}
+
+#[repr(C)]
+enum PathRasterizationInputIndex {
+    Vertices = 0,
+    AtlasTextureSize = 1,
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+#[repr(C)]
+pub struct PathSprite {
+    pub bounds: Bounds<ScaledPixels>,
+    pub color: Hsla,
+    pub tile: AtlasTile,
+}

crates/gpui2/src/platform/mac/open_type.rs

@@ -0,0 +1,394 @@
+#![allow(unused, non_upper_case_globals)]
+
+use crate::FontFeatures;
+use cocoa::appkit::CGFloat;
+use core_foundation::{base::TCFType, number::CFNumber};
+use core_graphics::geometry::CGAffineTransform;
+use core_text::{
+    font::{CTFont, CTFontRef},
+    font_descriptor::{
+        CTFontDescriptor, CTFontDescriptorCreateCopyWithFeature, CTFontDescriptorRef,
+    },
+};
+use font_kit::font::Font;
+use std::ptr;
+
+const kCaseSensitiveLayoutOffSelector: i32 = 1;
+const kCaseSensitiveLayoutOnSelector: i32 = 0;
+const kCaseSensitiveLayoutType: i32 = 33;
+const kCaseSensitiveSpacingOffSelector: i32 = 3;
+const kCaseSensitiveSpacingOnSelector: i32 = 2;
+const kCharacterAlternativesType: i32 = 17;
+const kCommonLigaturesOffSelector: i32 = 3;
+const kCommonLigaturesOnSelector: i32 = 2;
+const kContextualAlternatesOffSelector: i32 = 1;
+const kContextualAlternatesOnSelector: i32 = 0;
+const kContextualAlternatesType: i32 = 36;
+const kContextualLigaturesOffSelector: i32 = 19;
+const kContextualLigaturesOnSelector: i32 = 18;
+const kContextualSwashAlternatesOffSelector: i32 = 5;
+const kContextualSwashAlternatesOnSelector: i32 = 4;
+const kDefaultLowerCaseSelector: i32 = 0;
+const kDefaultUpperCaseSelector: i32 = 0;
+const kDiagonalFractionsSelector: i32 = 2;
+const kFractionsType: i32 = 11;
+const kHistoricalLigaturesOffSelector: i32 = 21;
+const kHistoricalLigaturesOnSelector: i32 = 20;
+const kHojoCharactersSelector: i32 = 12;
+const kInferiorsSelector: i32 = 2;
+const kJIS2004CharactersSelector: i32 = 11;
+const kLigaturesType: i32 = 1;
+const kLowerCasePetiteCapsSelector: i32 = 2;
+const kLowerCaseSmallCapsSelector: i32 = 1;
+const kLowerCaseType: i32 = 37;
+const kLowerCaseNumbersSelector: i32 = 0;
+const kMathematicalGreekOffSelector: i32 = 11;
+const kMathematicalGreekOnSelector: i32 = 10;
+const kMonospacedNumbersSelector: i32 = 0;
+const kNLCCharactersSelector: i32 = 13;
+const kNoFractionsSelector: i32 = 0;
+const kNormalPositionSelector: i32 = 0;
+const kNoStyleOptionsSelector: i32 = 0;
+const kNumberCaseType: i32 = 21;
+const kNumberSpacingType: i32 = 6;
+const kOrdinalsSelector: i32 = 3;
+const kProportionalNumbersSelector: i32 = 1;
+const kQuarterWidthTextSelector: i32 = 4;
+const kScientificInferiorsSelector: i32 = 4;
+const kSlashedZeroOffSelector: i32 = 5;
+const kSlashedZeroOnSelector: i32 = 4;
+const kStyleOptionsType: i32 = 19;
+const kStylisticAltEighteenOffSelector: i32 = 37;
+const kStylisticAltEighteenOnSelector: i32 = 36;
+const kStylisticAltEightOffSelector: i32 = 17;
+const kStylisticAltEightOnSelector: i32 = 16;
+const kStylisticAltElevenOffSelector: i32 = 23;
+const kStylisticAltElevenOnSelector: i32 = 22;
+const kStylisticAlternativesType: i32 = 35;
+const kStylisticAltFifteenOffSelector: i32 = 31;
+const kStylisticAltFifteenOnSelector: i32 = 30;
+const kStylisticAltFiveOffSelector: i32 = 11;
+const kStylisticAltFiveOnSelector: i32 = 10;
+const kStylisticAltFourOffSelector: i32 = 9;
+const kStylisticAltFourOnSelector: i32 = 8;
+const kStylisticAltFourteenOffSelector: i32 = 29;
+const kStylisticAltFourteenOnSelector: i32 = 28;
+const kStylisticAltNineOffSelector: i32 = 19;
+const kStylisticAltNineOnSelector: i32 = 18;
+const kStylisticAltNineteenOffSelector: i32 = 39;
+const kStylisticAltNineteenOnSelector: i32 = 38;
+const kStylisticAltOneOffSelector: i32 = 3;
+const kStylisticAltOneOnSelector: i32 = 2;
+const kStylisticAltSevenOffSelector: i32 = 15;
+const kStylisticAltSevenOnSelector: i32 = 14;
+const kStylisticAltSeventeenOffSelector: i32 = 35;
+const kStylisticAltSeventeenOnSelector: i32 = 34;
+const kStylisticAltSixOffSelector: i32 = 13;
+const kStylisticAltSixOnSelector: i32 = 12;
+const kStylisticAltSixteenOffSelector: i32 = 33;
+const kStylisticAltSixteenOnSelector: i32 = 32;
+const kStylisticAltTenOffSelector: i32 = 21;
+const kStylisticAltTenOnSelector: i32 = 20;
+const kStylisticAltThirteenOffSelector: i32 = 27;
+const kStylisticAltThirteenOnSelector: i32 = 26;
+const kStylisticAltThreeOffSelector: i32 = 7;
+const kStylisticAltThreeOnSelector: i32 = 6;
+const kStylisticAltTwelveOffSelector: i32 = 25;
+const kStylisticAltTwelveOnSelector: i32 = 24;
+const kStylisticAltTwentyOffSelector: i32 = 41;
+const kStylisticAltTwentyOnSelector: i32 = 40;
+const kStylisticAltTwoOffSelector: i32 = 5;
+const kStylisticAltTwoOnSelector: i32 = 4;
+const kSuperiorsSelector: i32 = 1;
+const kSwashAlternatesOffSelector: i32 = 3;
+const kSwashAlternatesOnSelector: i32 = 2;
+const kTitlingCapsSelector: i32 = 4;
+const kTypographicExtrasType: i32 = 14;
+const kVerticalFractionsSelector: i32 = 1;
+const kVerticalPositionType: i32 = 10;
+
+pub fn apply_features(font: &mut Font, features: FontFeatures) {
+    // See https://chromium.googlesource.com/chromium/src/+/66.0.3359.158/third_party/harfbuzz-ng/src/hb-coretext.cc
+    // for a reference implementation.
+    toggle_open_type_feature(
+        font,
+        features.calt(),
+        kContextualAlternatesType,
+        kContextualAlternatesOnSelector,
+        kContextualAlternatesOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.case(),
+        kCaseSensitiveLayoutType,
+        kCaseSensitiveLayoutOnSelector,
+        kCaseSensitiveLayoutOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.cpsp(),
+        kCaseSensitiveLayoutType,
+        kCaseSensitiveSpacingOnSelector,
+        kCaseSensitiveSpacingOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.frac(),
+        kFractionsType,
+        kDiagonalFractionsSelector,
+        kNoFractionsSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.liga(),
+        kLigaturesType,
+        kCommonLigaturesOnSelector,
+        kCommonLigaturesOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.onum(),
+        kNumberCaseType,
+        kLowerCaseNumbersSelector,
+        2,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ordn(),
+        kVerticalPositionType,
+        kOrdinalsSelector,
+        kNormalPositionSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.pnum(),
+        kNumberSpacingType,
+        kProportionalNumbersSelector,
+        4,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss01(),
+        kStylisticAlternativesType,
+        kStylisticAltOneOnSelector,
+        kStylisticAltOneOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss02(),
+        kStylisticAlternativesType,
+        kStylisticAltTwoOnSelector,
+        kStylisticAltTwoOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss03(),
+        kStylisticAlternativesType,
+        kStylisticAltThreeOnSelector,
+        kStylisticAltThreeOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss04(),
+        kStylisticAlternativesType,
+        kStylisticAltFourOnSelector,
+        kStylisticAltFourOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss05(),
+        kStylisticAlternativesType,
+        kStylisticAltFiveOnSelector,
+        kStylisticAltFiveOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss06(),
+        kStylisticAlternativesType,
+        kStylisticAltSixOnSelector,
+        kStylisticAltSixOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss07(),
+        kStylisticAlternativesType,
+        kStylisticAltSevenOnSelector,
+        kStylisticAltSevenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss08(),
+        kStylisticAlternativesType,
+        kStylisticAltEightOnSelector,
+        kStylisticAltEightOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss09(),
+        kStylisticAlternativesType,
+        kStylisticAltNineOnSelector,
+        kStylisticAltNineOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss10(),
+        kStylisticAlternativesType,
+        kStylisticAltTenOnSelector,
+        kStylisticAltTenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss11(),
+        kStylisticAlternativesType,
+        kStylisticAltElevenOnSelector,
+        kStylisticAltElevenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss12(),
+        kStylisticAlternativesType,
+        kStylisticAltTwelveOnSelector,
+        kStylisticAltTwelveOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss13(),
+        kStylisticAlternativesType,
+        kStylisticAltThirteenOnSelector,
+        kStylisticAltThirteenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss14(),
+        kStylisticAlternativesType,
+        kStylisticAltFourteenOnSelector,
+        kStylisticAltFourteenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss15(),
+        kStylisticAlternativesType,
+        kStylisticAltFifteenOnSelector,
+        kStylisticAltFifteenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss16(),
+        kStylisticAlternativesType,
+        kStylisticAltSixteenOnSelector,
+        kStylisticAltSixteenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss17(),
+        kStylisticAlternativesType,
+        kStylisticAltSeventeenOnSelector,
+        kStylisticAltSeventeenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss18(),
+        kStylisticAlternativesType,
+        kStylisticAltEighteenOnSelector,
+        kStylisticAltEighteenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss19(),
+        kStylisticAlternativesType,
+        kStylisticAltNineteenOnSelector,
+        kStylisticAltNineteenOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.ss20(),
+        kStylisticAlternativesType,
+        kStylisticAltTwentyOnSelector,
+        kStylisticAltTwentyOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.subs(),
+        kVerticalPositionType,
+        kInferiorsSelector,
+        kNormalPositionSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.sups(),
+        kVerticalPositionType,
+        kSuperiorsSelector,
+        kNormalPositionSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.swsh(),
+        kContextualAlternatesType,
+        kSwashAlternatesOnSelector,
+        kSwashAlternatesOffSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.titl(),
+        kStyleOptionsType,
+        kTitlingCapsSelector,
+        kNoStyleOptionsSelector,
+    );
+    toggle_open_type_feature(
+        font,
+        features.tnum(),
+        kNumberSpacingType,
+        kMonospacedNumbersSelector,
+        4,
+    );
+    toggle_open_type_feature(
+        font,
+        features.zero(),
+        kTypographicExtrasType,
+        kSlashedZeroOnSelector,
+        kSlashedZeroOffSelector,
+    );
+}
+
+fn toggle_open_type_feature(
+    font: &mut Font,
+    enabled: Option<bool>,
+    type_identifier: i32,
+    on_selector_identifier: i32,
+    off_selector_identifier: i32,
+) {
+    if let Some(enabled) = enabled {
+        let native_font = font.native_font();
+        unsafe {
+            let selector_identifier = if enabled {
+                on_selector_identifier
+            } else {
+                off_selector_identifier
+            };
+            let new_descriptor = CTFontDescriptorCreateCopyWithFeature(
+                native_font.copy_descriptor().as_concrete_TypeRef(),
+                CFNumber::from(type_identifier).as_concrete_TypeRef(),
+                CFNumber::from(selector_identifier).as_concrete_TypeRef(),
+            );
+            let new_descriptor = CTFontDescriptor::wrap_under_create_rule(new_descriptor);
+            let new_font = CTFontCreateCopyWithAttributes(
+                font.native_font().as_concrete_TypeRef(),
+                0.0,
+                ptr::null(),
+                new_descriptor.as_concrete_TypeRef(),
+            );
+            let new_font = CTFont::wrap_under_create_rule(new_font);
+            *font = Font::from_native_font(new_font);
+        }
+    }
+}
+
+#[link(name = "CoreText", kind = "framework")]
+extern "C" {
+    fn CTFontCreateCopyWithAttributes(
+        font: CTFontRef,
+        size: CGFloat,
+        matrix: *const CGAffineTransform,
+        attributes: CTFontDescriptorRef,
+    ) -> CTFontRef;
+}

crates/gpui2/src/platform/mac/shaders.metal

@@ -0,0 +1,553 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+float4 hsla_to_rgba(Hsla hsla);
+float4 to_device_position(float2 unit_vertex, Bounds_ScaledPixels bounds,
+                          Bounds_ScaledPixels clip_bounds,
+                          constant Size_DevicePixels *viewport_size);
+float2 to_tile_position(float2 unit_vertex, AtlasTile tile,
+                        constant Size_DevicePixels *atlas_size);
+float quad_sdf(float2 point, Bounds_ScaledPixels bounds,
+               Corners_ScaledPixels corner_radii);
+float gaussian(float x, float sigma);
+float2 erf(float2 x);
+float blur_along_x(float x, float y, float sigma, float corner,
+                   float2 half_size);
+
+struct QuadVertexOutput {
+  float4 position [[position]];
+  float4 background_color [[flat]];
+  float4 border_color [[flat]];
+  uint quad_id [[flat]];
+};
+
+vertex QuadVertexOutput quad_vertex(uint unit_vertex_id [[vertex_id]],
+                                    uint quad_id [[instance_id]],
+                                    constant float2 *unit_vertices
+                                    [[buffer(QuadInputIndex_Vertices)]],
+                                    constant Quad *quads
+                                    [[buffer(QuadInputIndex_Quads)]],
+                                    constant Size_DevicePixels *viewport_size
+                                    [[buffer(QuadInputIndex_ViewportSize)]]) {
+  float2 unit_vertex = unit_vertices[unit_vertex_id];
+  Quad quad = quads[quad_id];
+  float4 device_position = to_device_position(
+      unit_vertex, quad.bounds, quad.content_mask.bounds, viewport_size);
+  float4 background_color = hsla_to_rgba(quad.background);
+  float4 border_color = hsla_to_rgba(quad.border_color);
+  return QuadVertexOutput{device_position, background_color, border_color,
+                          quad_id};
+}
+
+fragment float4 quad_fragment(QuadVertexOutput input [[stage_in]],
+                              constant Quad *quads
+                              [[buffer(QuadInputIndex_Quads)]]) {
+  Quad quad = quads[input.quad_id];
+  float2 half_size =
+      float2(quad.bounds.size.width, quad.bounds.size.height) / 2.;
+  float2 center =
+      float2(quad.bounds.origin.x, quad.bounds.origin.y) + half_size;
+  float2 center_to_point = input.position.xy - center;
+  float corner_radius;
+  if (center_to_point.x < 0.) {
+    if (center_to_point.y < 0.) {
+      corner_radius = quad.corner_radii.top_left;
+    } else {
+      corner_radius = quad.corner_radii.bottom_left;
+    }
+  } else {
+    if (center_to_point.y < 0.) {
+      corner_radius = quad.corner_radii.top_right;
+    } else {
+      corner_radius = quad.corner_radii.bottom_right;
+    }
+  }
+
+  float2 rounded_edge_to_point =
+      fabs(center_to_point) - half_size + corner_radius;
+  float distance =
+      length(max(0., rounded_edge_to_point)) +
+      min(0., max(rounded_edge_to_point.x, rounded_edge_to_point.y)) -
+      corner_radius;
+
+  float vertical_border = center_to_point.x <= 0. ? quad.border_widths.left
+                                                  : quad.border_widths.right;
+  float horizontal_border = center_to_point.y <= 0. ? quad.border_widths.top
+                                                    : quad.border_widths.bottom;
+  float2 inset_size =
+      half_size - corner_radius - float2(vertical_border, horizontal_border);
+  float2 point_to_inset_corner = fabs(center_to_point) - inset_size;
+  float border_width;
+  if (point_to_inset_corner.x < 0. && point_to_inset_corner.y < 0.) {
+    border_width = 0.;
+  } else if (point_to_inset_corner.y > point_to_inset_corner.x) {
+    border_width = horizontal_border;
+  } else {
+    border_width = vertical_border;
+  }
+
+  float4 color;
+  if (border_width == 0.) {
+    color = input.background_color;
+  } else {
+    float inset_distance = distance + border_width;
+
+    // Decrease border's opacity as we move inside the background.
+    input.border_color.a *= 1. - saturate(0.5 - inset_distance);
+
+    // Alpha-blend the border and the background.
+    float output_alpha =
+        quad.border_color.a + quad.background.a * (1. - quad.border_color.a);
+    float3 premultiplied_border_rgb =
+        input.border_color.rgb * quad.border_color.a;
+    float3 premultiplied_background_rgb =
+        input.background_color.rgb * input.background_color.a;
+    float3 premultiplied_output_rgb =
+        premultiplied_border_rgb +
+        premultiplied_background_rgb * (1. - input.border_color.a);
+    color = float4(premultiplied_output_rgb, output_alpha);
+  }
+
+  return color * float4(1., 1., 1., saturate(0.5 - distance));
+}
+
+struct ShadowVertexOutput {
+  float4 position [[position]];
+  float4 color [[flat]];
+  uint shadow_id [[flat]];
+};
+
+vertex ShadowVertexOutput shadow_vertex(
+    uint unit_vertex_id [[vertex_id]], uint shadow_id [[instance_id]],
+    constant float2 *unit_vertices [[buffer(ShadowInputIndex_Vertices)]],
+    constant Shadow *shadows [[buffer(ShadowInputIndex_Shadows)]],
+    constant Size_DevicePixels *viewport_size
+    [[buffer(ShadowInputIndex_ViewportSize)]]) {
+  float2 unit_vertex = unit_vertices[unit_vertex_id];
+  Shadow shadow = shadows[shadow_id];
+
+  float margin = 3. * shadow.blur_radius;
+  // Set the bounds of the shadow and adjust its size based on the shadow's
+  // spread radius to achieve the spreading effect
+  Bounds_ScaledPixels bounds = shadow.bounds;
+  bounds.origin.x -= margin;
+  bounds.origin.y -= margin;
+  bounds.size.width += 2. * margin;
+  bounds.size.height += 2. * margin;
+
+  float4 device_position = to_device_position(
+      unit_vertex, bounds, shadow.content_mask.bounds, viewport_size);
+  float4 color = hsla_to_rgba(shadow.color);
+
+  return ShadowVertexOutput{
+      device_position,
+      color,
+      shadow_id,
+  };
+}
+
+fragment float4 shadow_fragment(ShadowVertexOutput input [[stage_in]],
+                                constant Shadow *shadows
+                                [[buffer(ShadowInputIndex_Shadows)]]) {
+  Shadow shadow = shadows[input.shadow_id];
+
+  float2 origin = float2(shadow.bounds.origin.x, shadow.bounds.origin.y);
+  float2 size = float2(shadow.bounds.size.width, shadow.bounds.size.height);
+  float2 half_size = size / 2.;
+  float2 center = origin + half_size;
+  float2 point = input.position.xy - center;
+  float corner_radius;
+  if (point.x < 0.) {
+    if (point.y < 0.) {
+      corner_radius = shadow.corner_radii.top_left;
+    } else {
+      corner_radius = shadow.corner_radii.bottom_left;
+    }
+  } else {
+    if (point.y < 0.) {
+      corner_radius = shadow.corner_radii.top_right;
+    } else {
+      corner_radius = shadow.corner_radii.bottom_right;
+    }
+  }
+
+  // The signal is only non-zero in a limited range, so don't waste samples
+  float low = point.y - half_size.y;
+  float high = point.y + half_size.y;
+  float start = clamp(-3. * shadow.blur_radius, low, high);
+  float end = clamp(3. * shadow.blur_radius, low, high);
+
+  // Accumulate samples (we can get away with surprisingly few samples)
+  float step = (end - start) / 4.;
+  float y = start + step * 0.5;
+  float alpha = 0.;
+  for (int i = 0; i < 4; i++) {
+    alpha += blur_along_x(point.x, point.y - y, shadow.blur_radius,
+                          corner_radius, half_size) *
+             gaussian(y, shadow.blur_radius) * step;
+    y += step;
+  }
+
+  return input.color * float4(1., 1., 1., alpha);
+}
+
+struct UnderlineVertexOutput {
+  float4 position [[position]];
+  float4 color [[flat]];
+  uint underline_id [[flat]];
+};
+
+vertex UnderlineVertexOutput underline_vertex(
+    uint unit_vertex_id [[vertex_id]], uint underline_id [[instance_id]],
+    constant float2 *unit_vertices [[buffer(UnderlineInputIndex_Vertices)]],
+    constant Underline *underlines [[buffer(UnderlineInputIndex_Underlines)]],
+    constant Size_DevicePixels *viewport_size
+    [[buffer(ShadowInputIndex_ViewportSize)]]) {
+  float2 unit_vertex = unit_vertices[unit_vertex_id];
+  Underline underline = underlines[underline_id];
+  float4 device_position =
+      to_device_position(unit_vertex, underline.bounds,
+                         underline.content_mask.bounds, viewport_size);
+  float4 color = hsla_to_rgba(underline.color);
+  return UnderlineVertexOutput{device_position, color, underline_id};
+}
+
+fragment float4 underline_fragment(UnderlineVertexOutput input [[stage_in]],
+                                   constant Underline *underlines
+                                   [[buffer(UnderlineInputIndex_Underlines)]]) {
+  Underline underline = underlines[input.underline_id];
+  if (underline.wavy) {
+    float half_thickness = underline.thickness * 0.5;
+    float2 origin =
+        float2(underline.bounds.origin.x, underline.bounds.origin.y);
+    float2 st = ((input.position.xy - origin) / underline.bounds.size.height) -
+                float2(0., 0.5);
+    float frequency = (M_PI_F * (3. * underline.thickness)) / 8.;
+    float amplitude = 1. / (2. * underline.thickness);
+    float sine = sin(st.x * frequency) * amplitude;
+    float dSine = cos(st.x * frequency) * amplitude * frequency;
+    float distance = (st.y - sine) / sqrt(1. + dSine * dSine);
+    float distance_in_pixels = distance * underline.bounds.size.height;
+    float distance_from_top_border = distance_in_pixels - half_thickness;
+    float distance_from_bottom_border = distance_in_pixels + half_thickness;
+    float alpha = saturate(
+        0.5 - max(-distance_from_bottom_border, distance_from_top_border));
+    return input.color * float4(1., 1., 1., alpha);
+  } else {
+    return input.color;
+  }
+}
+
+struct MonochromeSpriteVertexOutput {
+  float4 position [[position]];
+  float2 tile_position;
+  float4 color [[flat]];
+  uint sprite_id [[flat]];
+};
+
+vertex MonochromeSpriteVertexOutput monochrome_sprite_vertex(
+    uint unit_vertex_id [[vertex_id]], uint sprite_id [[instance_id]],
+    constant float2 *unit_vertices [[buffer(SpriteInputIndex_Vertices)]],
+    constant MonochromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
+    constant Size_DevicePixels *viewport_size
+    [[buffer(SpriteInputIndex_ViewportSize)]],
+    constant Size_DevicePixels *atlas_size
+    [[buffer(SpriteInputIndex_AtlasTextureSize)]]) {
+
+  float2 unit_vertex = unit_vertices[unit_vertex_id];
+  MonochromeSprite sprite = sprites[sprite_id];
+  // Don't apply content mask at the vertex level because we don't have time
+  // to make sampling from the texture match the mask.
+  float4 device_position = to_device_position(unit_vertex, sprite.bounds,
+                                              sprite.bounds, viewport_size);
+  float2 tile_position = to_tile_position(unit_vertex, sprite.tile, atlas_size);
+  float4 color = hsla_to_rgba(sprite.color);
+  return MonochromeSpriteVertexOutput{device_position, tile_position, color,
+                                      sprite_id};
+}
+
+fragment float4 monochrome_sprite_fragment(
+    MonochromeSpriteVertexOutput input [[stage_in]],
+    constant MonochromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
+    texture2d<float> atlas_texture [[texture(SpriteInputIndex_AtlasTexture)]]) {
+  MonochromeSprite sprite = sprites[input.sprite_id];
+  constexpr sampler atlas_texture_sampler(mag_filter::linear,
+                                          min_filter::linear);
+  float4 sample =
+      atlas_texture.sample(atlas_texture_sampler, input.tile_position);
+  float clip_distance = quad_sdf(input.position.xy, sprite.content_mask.bounds,
+                                 Corners_ScaledPixels{0., 0., 0., 0.});
+  float4 color = input.color;
+  color.a *= sample.a * saturate(0.5 - clip_distance);
+  return color;
+}
+
+struct PolychromeSpriteVertexOutput {
+  float4 position [[position]];
+  float2 tile_position;
+  uint sprite_id [[flat]];
+};
+
+vertex PolychromeSpriteVertexOutput polychrome_sprite_vertex(
+    uint unit_vertex_id [[vertex_id]], uint sprite_id [[instance_id]],
+    constant float2 *unit_vertices [[buffer(SpriteInputIndex_Vertices)]],
+    constant PolychromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
+    constant Size_DevicePixels *viewport_size
+    [[buffer(SpriteInputIndex_ViewportSize)]],
+    constant Size_DevicePixels *atlas_size
+    [[buffer(SpriteInputIndex_AtlasTextureSize)]]) {
+
+  float2 unit_vertex = unit_vertices[unit_vertex_id];
+  PolychromeSprite sprite = sprites[sprite_id];
+  // Don't apply content mask at the vertex level because we don't have time
+  // to make sampling from the texture match the mask.
+  float4 device_position = to_device_position(unit_vertex, sprite.bounds,
+                                              sprite.bounds, viewport_size);
+  float2 tile_position = to_tile_position(unit_vertex, sprite.tile, atlas_size);
+  return PolychromeSpriteVertexOutput{device_position, tile_position,
+                                      sprite_id};
+}
+
+fragment float4 polychrome_sprite_fragment(
+    PolychromeSpriteVertexOutput input [[stage_in]],
+    constant PolychromeSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
+    texture2d<float> atlas_texture [[texture(SpriteInputIndex_AtlasTexture)]]) {
+  PolychromeSprite sprite = sprites[input.sprite_id];
+  constexpr sampler atlas_texture_sampler(mag_filter::linear,
+                                          min_filter::linear);
+  float4 sample =
+      atlas_texture.sample(atlas_texture_sampler, input.tile_position);
+  float quad_distance =
+      quad_sdf(input.position.xy, sprite.bounds, sprite.corner_radii);
+  float clip_distance = quad_sdf(input.position.xy, sprite.content_mask.bounds,
+                                 Corners_ScaledPixels{0., 0., 0., 0.});
+  float distance = max(quad_distance, clip_distance);
+
+  float4 color = sample;
+  if (sprite.grayscale) {
+    float grayscale = 0.2126 * color.r + 0.7152 * color.g + 0.0722 * color.b;
+    color.r = grayscale;
+    color.g = grayscale;
+    color.b = grayscale;
+  }
+  color.a *= saturate(0.5 - distance);
+  return color;
+}
+
+struct PathRasterizationVertexOutput {
+  float4 position [[position]];
+  float2 st_position;
+  float clip_rect_distance [[clip_distance]][4];
+};
+
+struct PathRasterizationFragmentInput {
+  float4 position [[position]];
+  float2 st_position;
+};
+
+vertex PathRasterizationVertexOutput path_rasterization_vertex(
+    uint vertex_id [[vertex_id]],
+    constant PathVertex_ScaledPixels *vertices
+    [[buffer(PathRasterizationInputIndex_Vertices)]],
+    constant Size_DevicePixels *atlas_size
+    [[buffer(PathRasterizationInputIndex_AtlasTextureSize)]]) {
+  PathVertex_ScaledPixels v = vertices[vertex_id];
+  float2 vertex_position = float2(v.xy_position.x, v.xy_position.y);
+  float2 viewport_size = float2(atlas_size->width, atlas_size->height);
+  return PathRasterizationVertexOutput{
+      float4(vertex_position / viewport_size * float2(2., -2.) +
+                 float2(-1., 1.),
+             0., 1.),
+      float2(v.st_position.x, v.st_position.y),
+      {v.xy_position.x - v.content_mask.bounds.origin.x,
+       v.content_mask.bounds.origin.x + v.content_mask.bounds.size.width -
+           v.xy_position.x,
+       v.xy_position.y - v.content_mask.bounds.origin.y,
+       v.content_mask.bounds.origin.y + v.content_mask.bounds.size.height -
+           v.xy_position.y}};
+}
+
+fragment float4 path_rasterization_fragment(PathRasterizationFragmentInput input
+                                            [[stage_in]]) {
+  float2 dx = dfdx(input.st_position);
+  float2 dy = dfdy(input.st_position);
+  float2 gradient = float2((2. * input.st_position.x) * dx.x - dx.y,
+                           (2. * input.st_position.x) * dy.x - dy.y);
+  float f = (input.st_position.x * input.st_position.x) - input.st_position.y;
+  float distance = f / length(gradient);
+  float alpha = saturate(0.5 - distance);
+  return float4(alpha, 0., 0., 1.);
+}
+
+struct PathSpriteVertexOutput {
+  float4 position [[position]];
+  float2 tile_position;
+  float4 color [[flat]];
+  uint sprite_id [[flat]];
+};
+
+vertex PathSpriteVertexOutput path_sprite_vertex(
+    uint unit_vertex_id [[vertex_id]], uint sprite_id [[instance_id]],
+    constant float2 *unit_vertices [[buffer(SpriteInputIndex_Vertices)]],
+    constant PathSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
+    constant Size_DevicePixels *viewport_size
+    [[buffer(SpriteInputIndex_ViewportSize)]],
+    constant Size_DevicePixels *atlas_size
+    [[buffer(SpriteInputIndex_AtlasTextureSize)]]) {
+
+  float2 unit_vertex = unit_vertices[unit_vertex_id];
+  PathSprite sprite = sprites[sprite_id];
+  // Don't apply content mask because it was already accounted for when
+  // rasterizing the path.
+  float4 device_position = to_device_position(unit_vertex, sprite.bounds,
+                                              sprite.bounds, viewport_size);
+  float2 tile_position = to_tile_position(unit_vertex, sprite.tile, atlas_size);
+  float4 color = hsla_to_rgba(sprite.color);
+  return PathSpriteVertexOutput{device_position, tile_position, color,
+                                sprite_id};
+}
+
+fragment float4 path_sprite_fragment(
+    PathSpriteVertexOutput input [[stage_in]],
+    constant PathSprite *sprites [[buffer(SpriteInputIndex_Sprites)]],
+    texture2d<float> atlas_texture [[texture(SpriteInputIndex_AtlasTexture)]]) {
+  PathSprite sprite = sprites[input.sprite_id];
+  constexpr sampler atlas_texture_sampler(mag_filter::linear,
+                                          min_filter::linear);
+  float4 sample =
+      atlas_texture.sample(atlas_texture_sampler, input.tile_position);
+  float mask = 1. - abs(1. - fmod(sample.r, 2.));
+  float4 color = input.color;
+  color.a *= mask;
+  return color;
+}
+
+float4 hsla_to_rgba(Hsla hsla) {
+  float h = hsla.h * 6.0; // Now, it's an angle but scaled in [0, 6) range
+  float s = hsla.s;
+  float l = hsla.l;
+  float a = hsla.a;
+
+  float c = (1.0 - fabs(2.0 * l - 1.0)) * s;
+  float x = c * (1.0 - fabs(fmod(h, 2.0) - 1.0));
+  float m = l - c / 2.0;
+
+  float r = 0.0;
+  float g = 0.0;
+  float b = 0.0;
+
+  if (h >= 0.0 && h < 1.0) {
+    r = c;
+    g = x;
+    b = 0.0;
+  } else if (h >= 1.0 && h < 2.0) {
+    r = x;
+    g = c;
+    b = 0.0;
+  } else if (h >= 2.0 && h < 3.0) {
+    r = 0.0;
+    g = c;
+    b = x;
+  } else if (h >= 3.0 && h < 4.0) {
+    r = 0.0;
+    g = x;
+    b = c;
+  } else if (h >= 4.0 && h < 5.0) {
+    r = x;
+    g = 0.0;
+    b = c;
+  } else {
+    r = c;
+    g = 0.0;
+    b = x;
+  }
+
+  float4 rgba;
+  rgba.x = (r + m);
+  rgba.y = (g + m);
+  rgba.z = (b + m);
+  rgba.w = a;
+  return rgba;
+}
+
+float4 to_device_position(float2 unit_vertex, Bounds_ScaledPixels bounds,
+                          Bounds_ScaledPixels clip_bounds,
+                          constant Size_DevicePixels *input_viewport_size) {
+  float2 position =
+      unit_vertex * float2(bounds.size.width, bounds.size.height) +
+      float2(bounds.origin.x, bounds.origin.y);
+  position.x = max(clip_bounds.origin.x, position.x);
+  position.x = min(clip_bounds.origin.x + clip_bounds.size.width, position.x);
+  position.y = max(clip_bounds.origin.y, position.y);
+  position.y = min(clip_bounds.origin.y + clip_bounds.size.height, position.y);
+
+  float2 viewport_size = float2((float)input_viewport_size->width,
+                                (float)input_viewport_size->height);
+  float2 device_position =
+      position / viewport_size * float2(2., -2.) + float2(-1., 1.);
+  return float4(device_position, 0., 1.);
+}
+
+float2 to_tile_position(float2 unit_vertex, AtlasTile tile,
+                        constant Size_DevicePixels *atlas_size) {
+  float2 tile_origin = float2(tile.bounds.origin.x, tile.bounds.origin.y);
+  float2 tile_size = float2(tile.bounds.size.width, tile.bounds.size.height);
+  return (tile_origin + unit_vertex * tile_size) /
+         float2((float)atlas_size->width, (float)atlas_size->height);
+}
+
+float quad_sdf(float2 point, Bounds_ScaledPixels bounds,
+               Corners_ScaledPixels corner_radii) {
+  float2 half_size = float2(bounds.size.width, bounds.size.height) / 2.;
+  float2 center = float2(bounds.origin.x, bounds.origin.y) + half_size;
+  float2 center_to_point = point - center;
+  float corner_radius;
+  if (center_to_point.x < 0.) {
+    if (center_to_point.y < 0.) {
+      corner_radius = corner_radii.top_left;
+    } else {
+      corner_radius = corner_radii.bottom_left;
+    }
+  } else {
+    if (center_to_point.y < 0.) {
+      corner_radius = corner_radii.top_right;
+    } else {
+      corner_radius = corner_radii.bottom_right;
+    }
+  }
+
+  float2 rounded_edge_to_point =
+      abs(center_to_point) - half_size + corner_radius;
+  float distance =
+      length(max(0., rounded_edge_to_point)) +
+      min(0., max(rounded_edge_to_point.x, rounded_edge_to_point.y)) -
+      corner_radius;
+
+  return distance;
+}
+
+// A standard gaussian function, used for weighting samples
+float gaussian(float x, float sigma) {
+  return exp(-(x * x) / (2. * sigma * sigma)) / (sqrt(2. * M_PI_F) * sigma);
+}
+
+// This approximates the error function, needed for the gaussian integral
+float2 erf(float2 x) {
+  float2 s = sign(x);
+  float2 a = abs(x);
+  x = 1. + (0.278393 + (0.230389 + 0.078108 * (a * a)) * a) * a;
+  x *= x;
+  return s - s / (x * x);
+}
+
+float blur_along_x(float x, float y, float sigma, float corner,
+                   float2 half_size) {
+  float delta = min(half_size.y - corner - abs(y), 0.);
+  float curved =
+      half_size.x - corner + sqrt(max(0., corner * corner - delta * delta));
+  float2 integral =
+      0.5 + 0.5 * erf((x + float2(-curved, curved)) * (sqrt(0.5) / sigma));
+  return integral.y - integral.x;
+}

crates/gpui2/src/platform/mac/text_system.rs

@@ -0,0 +1,752 @@
+use crate::{
+    point, px, size, Bounds, DevicePixels, Font, FontFeatures, FontId, FontMetrics, FontRun,
+    FontStyle, FontWeight, GlyphId, LineLayout, Pixels, PlatformTextSystem, Point,
+    RenderGlyphParams, Result, ShapedGlyph, ShapedRun, SharedString, Size, SUBPIXEL_VARIANTS,
+};
+use anyhow::anyhow;
+use cocoa::appkit::{CGFloat, CGPoint};
+use collections::HashMap;
+use core_foundation::{
+    array::CFIndex,
+    attributed_string::{CFAttributedStringRef, CFMutableAttributedString},
+    base::{CFRange, TCFType},
+    string::CFString,
+};
+use core_graphics::{
+    base::{kCGImageAlphaPremultipliedLast, CGGlyph},
+    color_space::CGColorSpace,
+    context::CGContext,
+};
+use core_text::{font::CTFont, line::CTLine, string_attributes::kCTFontAttributeName};
+use font_kit::{
+    font::Font as FontKitFont,
+    handle::Handle,
+    hinting::HintingOptions,
+    metrics::Metrics,
+    properties::{Style as FontkitStyle, Weight as FontkitWeight},
+    source::SystemSource,
+    sources::mem::MemSource,
+};
+use parking_lot::{RwLock, RwLockUpgradableReadGuard};
+use pathfinder_geometry::{
+    rect::{RectF, RectI},
+    transform2d::Transform2F,
+    vector::{Vector2F, Vector2I},
+};
+use smallvec::SmallVec;
+use std::{char, cmp, convert::TryFrom, ffi::c_void, sync::Arc};
+
+use super::open_type;
+
+#[allow(non_upper_case_globals)]
+const kCGImageAlphaOnly: u32 = 7;
+
+pub struct MacTextSystem(RwLock<MacTextSystemState>);
+
+struct MacTextSystemState {
+    memory_source: MemSource,
+    system_source: SystemSource,
+    fonts: Vec<FontKitFont>,
+    font_selections: HashMap<Font, FontId>,
+    font_ids_by_postscript_name: HashMap<String, FontId>,
+    font_ids_by_family_name: HashMap<SharedString, SmallVec<[FontId; 4]>>,
+    postscript_names_by_font_id: HashMap<FontId, String>,
+}
+
+impl MacTextSystem {
+    pub fn new() -> Self {
+        Self(RwLock::new(MacTextSystemState {
+            memory_source: MemSource::empty(),
+            system_source: SystemSource::new(),
+            fonts: Vec::new(),
+            font_selections: HashMap::default(),
+            font_ids_by_postscript_name: HashMap::default(),
+            font_ids_by_family_name: HashMap::default(),
+            postscript_names_by_font_id: HashMap::default(),
+        }))
+    }
+}
+
+impl Default for MacTextSystem {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl PlatformTextSystem for MacTextSystem {
+    fn add_fonts(&self, fonts: &[Arc<Vec<u8>>]) -> Result<()> {
+        self.0.write().add_fonts(fonts)
+    }
+
+    fn all_font_families(&self) -> Vec<String> {
+        self.0
+            .read()
+            .system_source
+            .all_families()
+            .expect("core text should never return an error")
+    }
+
+    fn font_id(&self, font: &Font) -> Result<FontId> {
+        let lock = self.0.upgradable_read();
+        if let Some(font_id) = lock.font_selections.get(font) {
+            Ok(*font_id)
+        } else {
+            let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
+            let candidates = if let Some(font_ids) = lock.font_ids_by_family_name.get(&font.family)
+            {
+                font_ids.as_slice()
+            } else {
+                let font_ids = lock.load_family(&font.family, font.features)?;
+                lock.font_ids_by_family_name
+                    .insert(font.family.clone(), font_ids);
+                lock.font_ids_by_family_name[&font.family].as_ref()
+            };
+
+            let candidate_properties = candidates
+                .iter()
+                .map(|font_id| lock.fonts[font_id.0].properties())
+                .collect::<SmallVec<[_; 4]>>();
+
+            let ix = font_kit::matching::find_best_match(
+                &candidate_properties,
+                &font_kit::properties::Properties {
+                    style: font.style.into(),
+                    weight: font.weight.into(),
+                    stretch: Default::default(),
+                },
+            )?;
+
+            Ok(candidates[ix])
+        }
+    }
+
+    fn font_metrics(&self, font_id: FontId) -> FontMetrics {
+        self.0.read().fonts[font_id.0].metrics().into()
+    }
+
+    fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
+        Ok(self.0.read().fonts[font_id.0]
+            .typographic_bounds(glyph_id.into())?
+            .into())
+    }
+
+    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
+        self.0.read().advance(font_id, glyph_id)
+    }
+
+    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
+        self.0.read().glyph_for_char(font_id, ch)
+    }
+
+    fn glyph_raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
+        self.0.read().raster_bounds(params)
+    }
+
+    fn rasterize_glyph(
+        &self,
+        glyph_id: &RenderGlyphParams,
+    ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
+        self.0.read().rasterize_glyph(glyph_id)
+    }
+
+    fn layout_line(&self, text: &str, font_size: Pixels, font_runs: &[FontRun]) -> LineLayout {
+        self.0.write().layout_line(text, font_size, font_runs)
+    }
+
+    fn wrap_line(
+        &self,
+        text: &str,
+        font_id: FontId,
+        font_size: Pixels,
+        width: Pixels,
+    ) -> Vec<usize> {
+        self.0.read().wrap_line(text, font_id, font_size, width)
+    }
+}
+
+impl MacTextSystemState {
+    fn add_fonts(&mut self, fonts: &[Arc<Vec<u8>>]) -> Result<()> {
+        self.memory_source.add_fonts(
+            fonts
+                .iter()
+                .map(|bytes| Handle::from_memory(bytes.clone(), 0)),
+        )?;
+        Ok(())
+    }
+
+    fn load_family(
+        &mut self,
+        name: &SharedString,
+        features: FontFeatures,
+    ) -> Result<SmallVec<[FontId; 4]>> {
+        let mut font_ids = SmallVec::new();
+        let family = self
+            .memory_source
+            .select_family_by_name(name.as_ref())
+            .or_else(|_| self.system_source.select_family_by_name(name.as_ref()))?;
+        for font in family.fonts() {
+            let mut font = font.load()?;
+            open_type::apply_features(&mut font, features);
+            let font_id = FontId(self.fonts.len());
+            font_ids.push(font_id);
+            let postscript_name = font.postscript_name().unwrap();
+            self.font_ids_by_postscript_name
+                .insert(postscript_name.clone(), font_id);
+            self.postscript_names_by_font_id
+                .insert(font_id, postscript_name);
+            self.fonts.push(font);
+        }
+        Ok(font_ids)
+    }
+
+    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
+        Ok(self.fonts[font_id.0].advance(glyph_id.into())?.into())
+    }
+
+    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
+        self.fonts[font_id.0].glyph_for_char(ch).map(Into::into)
+    }
+
+    fn id_for_native_font(&mut self, requested_font: CTFont) -> FontId {
+        let postscript_name = requested_font.postscript_name();
+        if let Some(font_id) = self.font_ids_by_postscript_name.get(&postscript_name) {
+            *font_id
+        } else {
+            let font_id = FontId(self.fonts.len());
+            self.font_ids_by_postscript_name
+                .insert(postscript_name.clone(), font_id);
+            self.postscript_names_by_font_id
+                .insert(font_id, postscript_name);
+            self.fonts
+                .push(font_kit::font::Font::from_core_graphics_font(
+                    requested_font.copy_to_CGFont(),
+                ));
+            font_id
+        }
+    }
+
+    fn is_emoji(&self, font_id: FontId) -> bool {
+        self.postscript_names_by_font_id
+            .get(&font_id)
+            .map_or(false, |postscript_name| {
+                postscript_name == "AppleColorEmoji"
+            })
+    }
+
+    fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
+        let font = &self.fonts[params.font_id.0];
+        let scale = Transform2F::from_scale(params.scale_factor);
+        Ok(font
+            .raster_bounds(
+                params.glyph_id.into(),
+                params.font_size.into(),
+                scale,
+                HintingOptions::None,
+                font_kit::canvas::RasterizationOptions::GrayscaleAa,
+            )?
+            .into())
+    }
+
+    fn rasterize_glyph(&self, params: &RenderGlyphParams) -> Result<(Size<DevicePixels>, Vec<u8>)> {
+        let glyph_bounds = self.raster_bounds(params)?;
+        if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
+            Err(anyhow!("glyph bounds are empty"))
+        } else {
+            // Add an extra pixel when the subpixel variant isn't zero to make room for anti-aliasing.
+            let mut bitmap_size = glyph_bounds.size;
+            if params.subpixel_variant.x > 0 {
+                bitmap_size.width += DevicePixels(1);
+            }
+            if params.subpixel_variant.y > 0 {
+                bitmap_size.height += DevicePixels(1);
+            }
+
+            let mut bytes;
+            let cx;
+            if params.is_emoji {
+                bytes = vec![0; bitmap_size.width.0 as usize * 4 * bitmap_size.height.0 as usize];
+                cx = CGContext::create_bitmap_context(
+                    Some(bytes.as_mut_ptr() as *mut _),
+                    bitmap_size.width.0 as usize,
+                    bitmap_size.height.0 as usize,
+                    8,
+                    bitmap_size.width.0 as usize * 4,
+                    &CGColorSpace::create_device_rgb(),
+                    kCGImageAlphaPremultipliedLast,
+                );
+            } else {
+                bytes = vec![0; bitmap_size.width.0 as usize * bitmap_size.height.0 as usize];
+                cx = CGContext::create_bitmap_context(
+                    Some(bytes.as_mut_ptr() as *mut _),
+                    bitmap_size.width.0 as usize,
+                    bitmap_size.height.0 as usize,
+                    8,
+                    bitmap_size.width.0 as usize,
+                    &CGColorSpace::create_device_gray(),
+                    kCGImageAlphaOnly,
+                );
+            }
+
+            // Move the origin to bottom left and account for scaling, this
+            // makes drawing text consistent with the font-kit's raster_bounds.
+            cx.translate(
+                -glyph_bounds.origin.x.0 as CGFloat,
+                (glyph_bounds.origin.y.0 + glyph_bounds.size.height.0) as CGFloat,
+            );
+            cx.scale(
+                params.scale_factor as CGFloat,
+                params.scale_factor as CGFloat,
+            );
+
+            let subpixel_shift = params
+                .subpixel_variant
+                .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
+            cx.set_allows_font_subpixel_positioning(true);
+            cx.set_should_subpixel_position_fonts(true);
+            cx.set_allows_font_subpixel_quantization(false);
+            cx.set_should_subpixel_quantize_fonts(false);
+            self.fonts[params.font_id.0]
+                .native_font()
+                .clone_with_font_size(f32::from(params.font_size) as CGFloat)
+                .draw_glyphs(
+                    &[u32::from(params.glyph_id) as CGGlyph],
+                    &[CGPoint::new(
+                        (subpixel_shift.x / params.scale_factor) as CGFloat,
+                        (subpixel_shift.y / params.scale_factor) as CGFloat,
+                    )],
+                    cx,
+                );
+
+            if params.is_emoji {
+                // Convert from RGBA with premultiplied alpha to BGRA with straight alpha.
+                for pixel in bytes.chunks_exact_mut(4) {
+                    pixel.swap(0, 2);
+                    let a = pixel[3] as f32 / 255.;
+                    pixel[0] = (pixel[0] as f32 / a) as u8;
+                    pixel[1] = (pixel[1] as f32 / a) as u8;
+                    pixel[2] = (pixel[2] as f32 / a) as u8;
+                }
+            }
+
+            Ok((bitmap_size.into(), bytes))
+        }
+    }
+
+    fn layout_line(&mut self, text: &str, font_size: Pixels, font_runs: &[FontRun]) -> LineLayout {
+        // Construct the attributed string, converting UTF8 ranges to UTF16 ranges.
+        let mut string = CFMutableAttributedString::new();
+        {
+            string.replace_str(&CFString::new(text), CFRange::init(0, 0));
+            let utf16_line_len = string.char_len() as usize;
+
+            let mut ix_converter = StringIndexConverter::new(text);
+            for run in font_runs {
+                let utf8_end = ix_converter.utf8_ix + run.len;
+                let utf16_start = ix_converter.utf16_ix;
+
+                if utf16_start >= utf16_line_len {
+                    break;
+                }
+
+                ix_converter.advance_to_utf8_ix(utf8_end);
+                let utf16_end = cmp::min(ix_converter.utf16_ix, utf16_line_len);
+
+                let cf_range =
+                    CFRange::init(utf16_start as isize, (utf16_end - utf16_start) as isize);
+
+                let font: &FontKitFont = &self.fonts[run.font_id.0];
+                unsafe {
+                    string.set_attribute(
+                        cf_range,
+                        kCTFontAttributeName,
+                        &font.native_font().clone_with_font_size(font_size.into()),
+                    );
+                }
+
+                if utf16_end == utf16_line_len {
+                    break;
+                }
+            }
+        }
+
+        // Retrieve the glyphs from the shaped line, converting UTF16 offsets to UTF8 offsets.
+        let line = CTLine::new_with_attributed_string(string.as_concrete_TypeRef());
+
+        let mut runs = Vec::new();
+        for run in line.glyph_runs().into_iter() {
+            let attributes = run.attributes().unwrap();
+            let font = unsafe {
+                attributes
+                    .get(kCTFontAttributeName)
+                    .downcast::<CTFont>()
+                    .unwrap()
+            };
+            let font_id = self.id_for_native_font(font);
+
+            let mut ix_converter = StringIndexConverter::new(text);
+            let mut glyphs = SmallVec::new();
+            for ((glyph_id, position), glyph_utf16_ix) in run
+                .glyphs()
+                .iter()
+                .zip(run.positions().iter())
+                .zip(run.string_indices().iter())
+            {
+                let glyph_utf16_ix = usize::try_from(*glyph_utf16_ix).unwrap();
+                ix_converter.advance_to_utf16_ix(glyph_utf16_ix);
+                glyphs.push(ShapedGlyph {
+                    id: (*glyph_id).into(),
+                    position: point(position.x as f32, position.y as f32).map(px),
+                    index: ix_converter.utf8_ix,
+                    is_emoji: self.is_emoji(font_id),
+                });
+            }
+
+            runs.push(ShapedRun { font_id, glyphs })
+        }
+
+        let typographic_bounds = line.get_typographic_bounds();
+        LineLayout {
+            width: typographic_bounds.width.into(),
+            ascent: typographic_bounds.ascent.into(),
+            descent: typographic_bounds.descent.into(),
+            runs,
+            font_size,
+        }
+    }
+
+    fn wrap_line(
+        &self,
+        text: &str,
+        font_id: FontId,
+        font_size: Pixels,
+        width: Pixels,
+    ) -> Vec<usize> {
+        let mut string = CFMutableAttributedString::new();
+        string.replace_str(&CFString::new(text), CFRange::init(0, 0));
+        let cf_range = CFRange::init(0, text.encode_utf16().count() as isize);
+        let font = &self.fonts[font_id.0];
+        unsafe {
+            string.set_attribute(
+                cf_range,
+                kCTFontAttributeName,
+                &font.native_font().clone_with_font_size(font_size.into()),
+            );
+
+            let typesetter = CTTypesetterCreateWithAttributedString(string.as_concrete_TypeRef());
+            let mut ix_converter = StringIndexConverter::new(text);
+            let mut break_indices = Vec::new();
+            while ix_converter.utf8_ix < text.len() {
+                let utf16_len = CTTypesetterSuggestLineBreak(
+                    typesetter,
+                    ix_converter.utf16_ix as isize,
+                    width.into(),
+                ) as usize;
+                ix_converter.advance_to_utf16_ix(ix_converter.utf16_ix + utf16_len);
+                if ix_converter.utf8_ix >= text.len() {
+                    break;
+                }
+                break_indices.push(ix_converter.utf8_ix as usize);
+            }
+            break_indices
+        }
+    }
+}
+
+#[derive(Clone)]
+struct StringIndexConverter<'a> {
+    text: &'a str,
+    utf8_ix: usize,
+    utf16_ix: usize,
+}
+
+impl<'a> StringIndexConverter<'a> {
+    fn new(text: &'a str) -> Self {
+        Self {
+            text,
+            utf8_ix: 0,
+            utf16_ix: 0,
+        }
+    }
+
+    fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
+        for (ix, c) in self.text[self.utf8_ix..].char_indices() {
+            if self.utf8_ix + ix >= utf8_target {
+                self.utf8_ix += ix;
+                return;
+            }
+            self.utf16_ix += c.len_utf16();
+        }
+        self.utf8_ix = self.text.len();
+    }
+
+    fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
+        for (ix, c) in self.text[self.utf8_ix..].char_indices() {
+            if self.utf16_ix >= utf16_target {
+                self.utf8_ix += ix;
+                return;
+            }
+            self.utf16_ix += c.len_utf16();
+        }
+        self.utf8_ix = self.text.len();
+    }
+}
+
+#[repr(C)]
+pub struct __CFTypesetter(c_void);
+
+pub type CTTypesetterRef = *const __CFTypesetter;
+
+#[link(name = "CoreText", kind = "framework")]
+extern "C" {
+    fn CTTypesetterCreateWithAttributedString(string: CFAttributedStringRef) -> CTTypesetterRef;
+
+    fn CTTypesetterSuggestLineBreak(
+        typesetter: CTTypesetterRef,
+        start_index: CFIndex,
+        width: f64,
+    ) -> CFIndex;
+}
+
+impl From<Metrics> for FontMetrics {
+    fn from(metrics: Metrics) -> Self {
+        FontMetrics {
+            units_per_em: metrics.units_per_em,
+            ascent: metrics.ascent,
+            descent: metrics.descent,
+            line_gap: metrics.line_gap,
+            underline_position: metrics.underline_position,
+            underline_thickness: metrics.underline_thickness,
+            cap_height: metrics.cap_height,
+            x_height: metrics.x_height,
+            bounding_box: metrics.bounding_box.into(),
+        }
+    }
+}
+
+impl From<RectF> for Bounds<f32> {
+    fn from(rect: RectF) -> Self {
+        Bounds {
+            origin: point(rect.origin_x(), rect.origin_y()),
+            size: size(rect.width(), rect.height()),
+        }
+    }
+}
+
+impl From<RectI> for Bounds<DevicePixels> {
+    fn from(rect: RectI) -> Self {
+        Bounds {
+            origin: point(DevicePixels(rect.origin_x()), DevicePixels(rect.origin_y())),
+            size: size(DevicePixels(rect.width()), DevicePixels(rect.height())),
+        }
+    }
+}
+
+impl From<Vector2I> for Size<DevicePixels> {
+    fn from(value: Vector2I) -> Self {
+        size(value.x().into(), value.y().into())
+    }
+}
+
+impl From<RectI> for Bounds<i32> {
+    fn from(rect: RectI) -> Self {
+        Bounds {
+            origin: point(rect.origin_x(), rect.origin_y()),
+            size: size(rect.width(), rect.height()),
+        }
+    }
+}
+
+impl From<Point<u32>> for Vector2I {
+    fn from(size: Point<u32>) -> Self {
+        Vector2I::new(size.x as i32, size.y as i32)
+    }
+}
+
+impl From<Vector2F> for Size<f32> {
+    fn from(vec: Vector2F) -> Self {
+        size(vec.x(), vec.y())
+    }
+}
+
+impl From<FontWeight> for FontkitWeight {
+    fn from(value: FontWeight) -> Self {
+        FontkitWeight(value.0)
+    }
+}
+
+impl From<FontStyle> for FontkitStyle {
+    fn from(style: FontStyle) -> Self {
+        match style {
+            FontStyle::Normal => FontkitStyle::Normal,
+            FontStyle::Italic => FontkitStyle::Italic,
+            FontStyle::Oblique => FontkitStyle::Oblique,
+        }
+    }
+}
+
+// #[cfg(test)]
+// mod tests {
+//     use super::*;
+//     use crate::AppContext;
+//     use font_kit::properties::{Style, Weight};
+//     use platform::FontSystem as _;
+
+//     #[crate::test(self, retries = 5)]
+//     fn test_layout_str(_: &mut AppContext) {
+//         // This is failing intermittently on CI and we don't have time to figure it out
+//         let fonts = FontSystem::new();
+//         let menlo = fonts.load_family("Menlo", &Default::default()).unwrap();
+//         let menlo_regular = RunStyle {
+//             font_id: fonts.select_font(&menlo, &Properties::new()).unwrap(),
+//             color: Default::default(),
+//             underline: Default::default(),
+//         };
+//         let menlo_italic = RunStyle {
+//             font_id: fonts
+//                 .select_font(&menlo, Properties::new().style(Style::Italic))
+//                 .unwrap(),
+//             color: Default::default(),
+//             underline: Default::default(),
+//         };
+//         let menlo_bold = RunStyle {
+//             font_id: fonts
+//                 .select_font(&menlo, Properties::new().weight(Weight::BOLD))
+//                 .unwrap(),
+//             color: Default::default(),
+//             underline: Default::default(),
+//         };
+//         assert_ne!(menlo_regular, menlo_italic);
+//         assert_ne!(menlo_regular, menlo_bold);
+//         assert_ne!(menlo_italic, menlo_bold);
+
+//         let line = fonts.layout_line(
+//             "hello world",
+//             16.0,
+//             &[(2, menlo_bold), (4, menlo_italic), (5, menlo_regular)],
+//         );
+//         assert_eq!(line.runs.len(), 3);
+//         assert_eq!(line.runs[0].font_id, menlo_bold.font_id);
+//         assert_eq!(line.runs[0].glyphs.len(), 2);
+//         assert_eq!(line.runs[1].font_id, menlo_italic.font_id);
+//         assert_eq!(line.runs[1].glyphs.len(), 4);
+//         assert_eq!(line.runs[2].font_id, menlo_regular.font_id);
+//         assert_eq!(line.runs[2].glyphs.len(), 5);
+//     }
+
+//     #[test]
+//     fn test_glyph_offsets() -> crate::Result<()> {
+//         let fonts = FontSystem::new();
+//         let zapfino = fonts.load_family("Zapfino", &Default::default())?;
+//         let zapfino_regular = RunStyle {
+//             font_id: fonts.select_font(&zapfino, &Properties::new())?,
+//             color: Default::default(),
+//             underline: Default::default(),
+//         };
+//         let menlo = fonts.load_family("Menlo", &Default::default())?;
+//         let menlo_regular = RunStyle {
+//             font_id: fonts.select_font(&menlo, &Properties::new())?,
+//             color: Default::default(),
+//             underline: Default::default(),
+//         };
+
+//         let text = "This is, m𐍈re 𐍈r less, Zapfino!𐍈";
+//         let line = fonts.layout_line(
+//             text,
+//             16.0,
+//             &[
+//                 (9, zapfino_regular),
+//                 (13, menlo_regular),
+//                 (text.len() - 22, zapfino_regular),
+//             ],
+//         );
+//         assert_eq!(
+//             line.runs
+//                 .iter()
+//                 .flat_map(|r| r.glyphs.iter())
+//                 .map(|g| g.index)
+//                 .collect::<Vec<_>>(),
+//             vec![0, 2, 4, 5, 7, 8, 9, 10, 14, 15, 16, 17, 21, 22, 23, 24, 26, 27, 28, 29, 36, 37],
+//         );
+//         Ok(())
+//     }
+
+//     #[test]
+//     #[ignore]
+//     fn test_rasterize_glyph() {
+//         use std::{fs::File, io::BufWriter, path::Path};
+
+//         let fonts = FontSystem::new();
+//         let font_ids = fonts.load_family("Fira Code", &Default::default()).unwrap();
+//         let font_id = fonts.select_font(&font_ids, &Default::default()).unwrap();
+//         let glyph_id = fonts.glyph_for_char(font_id, 'G').unwrap();
+
+//         const VARIANTS: usize = 1;
+//         for i in 0..VARIANTS {
+//             let variant = i as f32 / VARIANTS as f32;
+//             let (bounds, bytes) = fonts
+//                 .rasterize_glyph(
+//                     font_id,
+//                     16.0,
+//                     glyph_id,
+//                     vec2f(variant, variant),
+//                     2.,
+//                     RasterizationOptions::Alpha,
+//                 )
+//                 .unwrap();
+
+//             let name = format!("/Users/as-cii/Desktop/twog-{}.png", i);
+//             let path = Path::new(&name);
+//             let file = File::create(path).unwrap();
+//             let w = &mut BufWriter::new(file);
+
+//             let mut encoder = png::Encoder::new(w, bounds.width() as u32, bounds.height() as u32);
+//             encoder.set_color(png::ColorType::Grayscale);
+//             encoder.set_depth(png::BitDepth::Eight);
+//             let mut writer = encoder.write_header().unwrap();
+//             writer.write_image_data(&bytes).unwrap();
+//         }
+//     }
+
+//     #[test]
+//     fn test_wrap_line() {
+//         let fonts = FontSystem::new();
+//         let font_ids = fonts.load_family("Helvetica", &Default::default()).unwrap();
+//         let font_id = fonts.select_font(&font_ids, &Default::default()).unwrap();
+
+//         let line = "one two three four five\n";
+//         let wrap_boundaries = fonts.wrap_line(line, font_id, 16., 64.0);
+//         assert_eq!(wrap_boundaries, &["one two ".len(), "one two three ".len()]);
+
+//         let line = "aaa ααα ✋✋✋ 🎉🎉🎉\n";
+//         let wrap_boundaries = fonts.wrap_line(line, font_id, 16., 64.0);
+//         assert_eq!(
+//             wrap_boundaries,
+//             &["aaa ααα ".len(), "aaa ααα ✋✋✋ ".len(),]
+//         );
+//     }
+
+//     #[test]
+//     fn test_layout_line_bom_char() {
+//         let fonts = FontSystem::new();
+//         let font_ids = fonts.load_family("Helvetica", &Default::default()).unwrap();
+//         let style = RunStyle {
+//             font_id: fonts.select_font(&font_ids, &Default::default()).unwrap(),
+//             color: Default::default(),
+//             underline: Default::default(),
+//         };
+
+//         let line = "\u{feff}";
+//         let layout = fonts.layout_line(line, 16., &[(line.len(), style)]);
+//         assert_eq!(layout.len, line.len());
+//         assert!(layout.runs.is_empty());
+
+//         let line = "a\u{feff}b";
+//         let layout = fonts.layout_line(line, 16., &[(line.len(), style)]);
+//         assert_eq!(layout.len, line.len());
+//         assert_eq!(layout.runs.len(), 1);
+//         assert_eq!(layout.runs[0].glyphs.len(), 2);
+//         assert_eq!(layout.runs[0].glyphs[0].id, 68); // a
+//                                                      // There's no glyph for \u{feff}
+//         assert_eq!(layout.runs[0].glyphs[1].id, 69); // b
+//     }
+// }

crates/gpui2/src/platform/mac/window_appearence.rs

@@ -0,0 +1,35 @@
+use crate::WindowAppearance;
+use cocoa::{
+    appkit::{NSAppearanceNameVibrantDark, NSAppearanceNameVibrantLight},
+    base::id,
+    foundation::NSString,
+};
+use objc::{msg_send, sel, sel_impl};
+use std::ffi::CStr;
+
+impl WindowAppearance {
+    pub unsafe fn from_native(appearance: id) -> Self {
+        let name: id = msg_send![appearance, name];
+        if name == NSAppearanceNameVibrantLight {
+            Self::VibrantLight
+        } else if name == NSAppearanceNameVibrantDark {
+            Self::VibrantDark
+        } else if name == NSAppearanceNameAqua {
+            Self::Light
+        } else if name == NSAppearanceNameDarkAqua {
+            Self::Dark
+        } else {
+            println!(
+                "unknown appearance: {:?}",
+                CStr::from_ptr(name.UTF8String())
+            );
+            Self::Light
+        }
+    }
+}
+
+#[link(name = "AppKit", kind = "framework")]
+extern "C" {
+    pub static NSAppearanceNameAqua: id;
+    pub static NSAppearanceNameDarkAqua: id;
+}

crates/gpui2/src/platform/test.rs

@@ -0,0 +1,188 @@
+use super::Platform;
+use crate::{DisplayId, Executor};
+
+pub struct TestPlatform;
+
+impl TestPlatform {
+    pub fn new() -> Self {
+        TestPlatform
+    }
+}
+
+// todo!("implement out what our tests needed in GPUI 1")
+impl Platform for TestPlatform {
+    fn executor(&self) -> Executor {
+        unimplemented!()
+    }
+
+    fn text_system(&self) -> std::sync::Arc<dyn crate::PlatformTextSystem> {
+        unimplemented!()
+    }
+
+    fn run(&self, _on_finish_launching: Box<dyn FnOnce()>) {
+        unimplemented!()
+    }
+
+    fn quit(&self) {
+        unimplemented!()
+    }
+
+    fn restart(&self) {
+        unimplemented!()
+    }
+
+    fn activate(&self, _ignoring_other_apps: bool) {
+        unimplemented!()
+    }
+
+    fn hide(&self) {
+        unimplemented!()
+    }
+
+    fn hide_other_apps(&self) {
+        unimplemented!()
+    }
+
+    fn unhide_other_apps(&self) {
+        unimplemented!()
+    }
+
+    fn displays(&self) -> Vec<std::rc::Rc<dyn crate::PlatformDisplay>> {
+        unimplemented!()
+    }
+
+    fn display(&self, _id: DisplayId) -> Option<std::rc::Rc<dyn crate::PlatformDisplay>> {
+        unimplemented!()
+    }
+
+    fn main_window(&self) -> Option<crate::AnyWindowHandle> {
+        unimplemented!()
+    }
+
+    fn open_window(
+        &self,
+        _handle: crate::AnyWindowHandle,
+        _options: crate::WindowOptions,
+    ) -> Box<dyn crate::PlatformWindow> {
+        unimplemented!()
+    }
+
+    fn set_display_link_output_callback(
+        &self,
+        _display_id: DisplayId,
+        _callback: Box<dyn FnMut(&crate::VideoTimestamp, &crate::VideoTimestamp)>,
+    ) {
+        unimplemented!()
+    }
+
+    fn start_display_link(&self, _display_id: DisplayId) {
+        unimplemented!()
+    }
+
+    fn stop_display_link(&self, _display_id: DisplayId) {
+        unimplemented!()
+    }
+
+    fn open_url(&self, _url: &str) {
+        unimplemented!()
+    }
+
+    fn on_open_urls(&self, _callback: Box<dyn FnMut(Vec<String>)>) {
+        unimplemented!()
+    }
+
+    fn prompt_for_paths(
+        &self,
+        _options: crate::PathPromptOptions,
+    ) -> futures::channel::oneshot::Receiver<Option<Vec<std::path::PathBuf>>> {
+        unimplemented!()
+    }
+
+    fn prompt_for_new_path(
+        &self,
+        _directory: &std::path::Path,
+    ) -> futures::channel::oneshot::Receiver<Option<std::path::PathBuf>> {
+        unimplemented!()
+    }
+
+    fn reveal_path(&self, _path: &std::path::Path) {
+        unimplemented!()
+    }
+
+    fn on_become_active(&self, _callback: Box<dyn FnMut()>) {
+        unimplemented!()
+    }
+
+    fn on_resign_active(&self, _callback: Box<dyn FnMut()>) {
+        unimplemented!()
+    }
+
+    fn on_quit(&self, _callback: Box<dyn FnMut()>) {
+        unimplemented!()
+    }
+
+    fn on_reopen(&self, _callback: Box<dyn FnMut()>) {
+        unimplemented!()
+    }
+
+    fn on_event(&self, _callback: Box<dyn FnMut(crate::InputEvent) -> bool>) {
+        unimplemented!()
+    }
+
+    fn os_name(&self) -> &'static str {
+        unimplemented!()
+    }
+
+    fn os_version(&self) -> anyhow::Result<crate::SemanticVersion> {
+        unimplemented!()
+    }
+
+    fn app_version(&self) -> anyhow::Result<crate::SemanticVersion> {
+        unimplemented!()
+    }
+
+    fn app_path(&self) -> anyhow::Result<std::path::PathBuf> {
+        unimplemented!()
+    }
+
+    fn local_timezone(&self) -> time::UtcOffset {
+        unimplemented!()
+    }
+
+    fn path_for_auxiliary_executable(&self, _name: &str) -> anyhow::Result<std::path::PathBuf> {
+        unimplemented!()
+    }
+
+    fn set_cursor_style(&self, _style: crate::CursorStyle) {
+        unimplemented!()
+    }
+
+    fn should_auto_hide_scrollbars(&self) -> bool {
+        unimplemented!()
+    }
+
+    fn write_to_clipboard(&self, _item: crate::ClipboardItem) {
+        unimplemented!()
+    }
+
+    fn read_from_clipboard(&self) -> Option<crate::ClipboardItem> {
+        unimplemented!()
+    }
+
+    fn write_credentials(
+        &self,
+        _url: &str,
+        _username: &str,
+        _password: &[u8],
+    ) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+
+    fn read_credentials(&self, _url: &str) -> anyhow::Result<Option<(String, Vec<u8>)>> {
+        unimplemented!()
+    }
+
+    fn delete_credentials(&self, _url: &str) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+}