Don't blend alpha channels

Antonio Scandurra and Nathan Sobo created 

We want to use the source alpha to determine the color of the final
pixel, but we want the final pixels to be fully opaque.

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

Change summary

gpui/src/platform/mac/renderer.rs | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

Detailed changes

gpui/src/platform/mac/renderer.rs 🔗 

@@ -709,9 +709,9 @@ fn build_pipeline_state(
     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::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::OneMinusSourceAlpha);
+    color_attachment.set_destination_alpha_blend_factor(metal::MTLBlendFactor::One);
 
     device
         .new_render_pipeline_state(&descriptor)