Reland: Framework wide color (#54415) (#54737)

lib/gpu/lib/src/render_pass.dart

@@ -95,6 +95,15 @@ base class RenderTarget {
   final DepthStencilAttachment? depthStencilAttachment;
 }
 
+// TODO(gaaclarke): Refactor this to support wide gamut colors.
+int _colorToInt(ui.Color color) {
+  assert(color.colorSpace == ui.ColorSpace.sRGB);
+  return ((color.a * 255.0).round() << 24) |
+      ((color.r * 255.0).round() << 16) |
+      ((color.g * 255.0).round() << 8) |
+      ((color.b * 255.0).round() << 0);
+}
+
 base class RenderPass extends NativeFieldWrapperClass1 {
   /// Creates a new RenderPass.
   RenderPass._(CommandBuffer commandBuffer, RenderTarget renderTarget) {
@@ -105,7 +114,7 @@ base class RenderPass extends NativeFieldWrapperClass1 {
           index,
           color.loadAction.index,
           color.storeAction.index,
-          color.clearValue.value,
+          _colorToInt(color.clearValue),
           color.texture,
           color.resolveTexture);
       if (error != null) {

lib/ui/lerp.dart

@@ -26,6 +26,8 @@ double? lerpDouble(num? a, num? b, double t) {
 ///
 /// Same as [lerpDouble] but specialized for non-null `double` type.
 double _lerpDouble(double a, double b, double t) {
+  // This doesn't match _lerpInt to preserve specific behaviors when dealing
+  // with infinity and nan.
   return a * (1.0 - t) + b * t;
 }