Create util functions to convert Color <-> uint8_t RGBA values

packages/react-native/ReactCommon/react/renderer/graphics/Color.cpp

@@ -17,10 +17,12 @@ bool isColorMeaningful(const SharedColor& color) noexcept {
   return colorComponentsFromColor(color).alpha > 0;
 }
 
+// Create Color from float RGBA values in [0, 1] range
 SharedColor colorFromComponents(ColorComponents components) {
   return {hostPlatformColorFromComponents(components)};
 }
 
+// Read Color components in [0, 1] range
 ColorComponents colorComponentsFromColor(SharedColor sharedColor) {
   return colorComponentsFromHostPlatformColor(*sharedColor);
 }

packages/react-native/ReactCommon/react/renderer/graphics/platform/cxx/react/renderer/graphics/HostPlatformColor.h

@@ -9,6 +9,7 @@
 
 #include <react/renderer/graphics/ColorComponents.h>
 #include <cmath>
+#include <cstdint>
 
 namespace facebook::react {
 
@@ -19,21 +20,43 @@ static const facebook::react::Color UndefinedColor =
     std::numeric_limits<facebook::react::Color>::max();
 }
 
+inline Color
+hostPlatformColorFromRGBA(uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
+  return (a & 0xff) << 24 | (r & 0xff) << 16 | (g & 0xff) << 8 | (b & 0xff);
+}
+
 inline Color hostPlatformColorFromComponents(ColorComponents components) {
   float ratio = 255;
-  return ((int)std::round(components.alpha * ratio) & 0xff) << 24 |
-      ((int)std::round(components.red * ratio) & 0xff) << 16 |
-      ((int)std::round(components.green * ratio) & 0xff) << 8 |
-      ((int)std::round(components.blue * ratio) & 0xff);
+  return hostPlatformColorFromRGBA(
+      static_cast<uint8_t>(std::round(components.red * ratio)),
+      static_cast<uint8_t>(std::round(components.green * ratio)),
+      static_cast<uint8_t>(std::round(components.blue * ratio)),
+      static_cast<uint8_t>(std::round(components.alpha * ratio)));
+}
+
+inline uint8_t alphaFromHostPlatformColor(Color color) {
+  return static_cast<uint8_t>((color >> 24) & 0xff);
+}
+
+inline uint8_t redFromHostPlatformColor(Color color) {
+  return static_cast<uint8_t>((color >> 16) & 0xff);
+}
+
+inline uint8_t greenFromHostPlatformColor(Color color) {
+  return static_cast<uint8_t>((color >> 8) & 0xff);
+}
+
+inline uint8_t blueFromHostPlatformColor(Color color) {
+  return static_cast<uint8_t>((color >> 0) & 0xff);
 }
 
 inline ColorComponents colorComponentsFromHostPlatformColor(Color color) {
   float ratio = 255;
   return ColorComponents{
-      (float)((color >> 16) & 0xff) / ratio,
-      (float)((color >> 8) & 0xff) / ratio,
-      (float)((color >> 0) & 0xff) / ratio,
-      (float)((color >> 24) & 0xff) / ratio};
+      static_cast<float>(redFromHostPlatformColor(color)) / ratio,
+      static_cast<float>(greenFromHostPlatformColor(color)) / ratio,
+      static_cast<float>(blueFromHostPlatformColor(color)) / ratio,
+      static_cast<float>(alphaFromHostPlatformColor(color)) / ratio};
 }
 
 } // namespace facebook::react