WIP

crates/gpui3/src/window.rs

@@ -2,8 +2,8 @@ use crate::{
     px, AnyView, AppContext, AvailableSpace, BorrowAppContext, Bounds, Context, Corners,
     DevicePixels, Effect, Element, EntityId, FontId, GlyphId, Handle, Hsla, IsZero, LayerId,
     LayoutId, MainThread, MainThreadOnly, MonochromeSprite, Pixels, PlatformAtlas, PlatformWindow,
-    Point, Reference, RenderGlyphParams, RenderSvgParams, ScaledPixels, Scene, SharedString, Size,
-    Style, TaffyLayoutEngine, WeakHandle, WindowOptions, SUBPIXEL_VARIANTS,
+    Point, PolychromeSprite, Reference, RenderGlyphParams, RenderSvgParams, ScaledPixels, Scene,
+    SharedString, Size, Style, TaffyLayoutEngine, WeakHandle, WindowOptions, SUBPIXEL_VARIANTS,
 };
 use anyhow::Result;
 use futures::Future;
@@ -17,6 +17,7 @@ pub struct Window {
     handle: AnyWindowHandle,
     platform_window: MainThreadOnly<Box<dyn PlatformWindow>>,
     monochrome_sprite_atlas: Arc<dyn PlatformAtlas>,
+    polychrome_sprite_atlas: Arc<dyn PlatformAtlas>,
     rem_size: Pixels,
     content_size: Size<Pixels>,
     layout_engine: TaffyLayoutEngine,
@@ -36,6 +37,7 @@ impl Window {
     ) -> Self {
         let platform_window = cx.platform().open_window(handle, options);
         let monochrome_sprite_atlas = platform_window.monochrome_sprite_atlas();
+        let polychrome_sprite_atlas = platform_window.polychrome_sprite_atlas();
         let mouse_position = platform_window.mouse_position();
         let content_size = platform_window.content_size();
         let scale_factor = platform_window.scale_factor();
@@ -59,6 +61,7 @@ impl Window {
             handle,
             platform_window,
             monochrome_sprite_atlas,
+            polychrome_sprite_atlas,
             rem_size: px(16.),
             content_size,
             layout_engine: TaffyLayoutEngine::new(),
@@ -300,6 +303,52 @@ impl<'a, 'w> WindowContext<'a, 'w> {
         Ok(())
     }
 
+    pub fn paint_emoji(
+        &mut self,
+        origin: Point<Pixels>,
+        order: u32,
+        font_id: FontId,
+        glyph_id: GlyphId,
+        font_size: Pixels,
+    ) -> Result<()> {
+        let scale_factor = self.scale_factor();
+        let glyph_origin = origin.scale(scale_factor);
+        let params = RenderGlyphParams {
+            font_id,
+            glyph_id,
+            font_size,
+            subpixel_variant: Default::default(),
+            scale_factor,
+        };
+
+        let raster_bounds = self.text_system().raster_bounds(&params)?;
+        if !raster_bounds.is_zero() {
+            let layer_id = self.current_layer_id();
+            let tile = self
+                .window
+                .polychrome_sprite_atlas
+                .get_or_insert_with(&params.clone().into(), &mut || {
+                    self.text_system().rasterize_glyph(&params)
+                })?;
+            let bounds = Bounds {
+                origin: glyph_origin.map(|px| px.floor()) + raster_bounds.origin.map(Into::into),
+                size: tile.bounds.size.map(Into::into),
+            };
+            let content_mask = self.content_mask().scale(scale_factor);
+
+            self.window.scene.insert(
+                layer_id,
+                PolychromeSprite {
+                    order,
+                    bounds,
+                    content_mask,
+                    tile,
+                },
+            );
+        }
+        Ok(())
+    }
+
     pub(crate) fn draw(&mut self) -> Result<()> {
         let unit_entity = self.unit_entity.clone();
         self.update_entity(&unit_entity, |_, cx| {