From 04665800c0b18cab84b151692dbbda93726d3e51 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathansobo@gmail.com>
Date: Sun, 21 Mar 2021 09:19:12 -0600
Subject: [PATCH] Scale quads by scale factor before writing to Metal buffer

Co-Authored-By: Antonio Scandurra <me@as-cii.com>
---
 gpui/src/platform/mac/renderer.rs | 22 ++++++++++++----------
 gpui/src/scene.rs                 |  6 ++++++
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/gpui/src/platform/mac/renderer.rs b/gpui/src/platform/mac/renderer.rs
index 733a719426..ba207544db 100644
--- a/gpui/src/platform/mac/renderer.rs
+++ b/gpui/src/platform/mac/renderer.rs
@@ -65,11 +65,11 @@ impl Renderer {
         });
 
         for layer in scene.layers() {
-            self.render_quads(layer, ctx);
+            self.render_quads(scene, layer, ctx);
         }
     }
 
-    fn render_quads(&mut self, layer: &Layer, ctx: &RenderContext) {
+    fn render_quads(&mut self, scene: &Scene, layer: &Layer, ctx: &RenderContext) {
         ctx.command_encoder
             .set_render_pipeline_state(&self.quad_pipeline_state);
         ctx.command_encoder.set_vertex_buffer(
@@ -96,15 +96,17 @@ impl Renderer {
         let buffer_contents = self.instances.contents() as *mut shaders::GPUIQuad;
         for quad_batch in layer.quads().chunks(batch_size) {
             for (ix, quad) in quad_batch.iter().enumerate() {
+                let bounds = quad.bounds * scene.scale_factor();
+                let shader_quad = shaders::GPUIQuad {
+                    origin: bounds.origin().to_float2(),
+                    size: bounds.size().to_float2(),
+                    background_color: quad
+                        .background
+                        .unwrap_or(ColorU::transparent_black())
+                        .to_uchar4(),
+                };
                 unsafe {
-                    *(buffer_contents.offset(ix as isize)) = shaders::GPUIQuad {
-                        origin: quad.bounds.origin().to_float2(),
-                        size: quad.bounds.size().to_float2(),
-                        background_color: quad
-                            .background
-                            .unwrap_or(ColorU::transparent_black())
-                            .to_uchar4(),
-                    };
+                    *(buffer_contents.offset(ix as isize)) = shader_quad;
                 }
             }
             self.instances.did_modify_range(NSRange {
diff --git a/gpui/src/scene.rs b/gpui/src/scene.rs
index 6f5daaf750..62d074a472 100644
--- a/gpui/src/scene.rs
+++ b/gpui/src/scene.rs
@@ -1,3 +1,5 @@
+use core::f32;
+
 use crate::{color::ColorU, geometry::rect::RectF};
 pub struct Scene {
     scale_factor: f32,
@@ -38,6 +40,10 @@ impl Scene {
         }
     }
 
+    pub fn scale_factor(&self) -> f32 {
+        self.scale_factor
+    }
+
     pub fn layers(&self) -> &[Layer] {
         self.layers.as_slice()
     }