Check alpha in ColorMask for YUV target

ColorMask is used to mask the writing of R, G, B and A values to all
active draw buffers. r, g, b, and a indicate whether R, G, B, or A
values, respectively, are written or not (a value of TRUE means that
the corresponding value is written) except when the color buffer is
in YUV color space, in that case setting any one of the r, g, b, and
a values as false would generate draw time INVALID_OPERATION error.

Bug: angleproject:383174962
Change-Id: I38c2510c307dd8158e71c920986cb497ca923ff9
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6083471
Reviewed-by: Shahbaz Youssefi <[email protected]>
Reviewed-by: Charlie Lao <[email protected]>
Commit-Queue: Charlie Lao <[email protected]>

Author: Shufen Ma

CONTRIBUTORS

@@ -207,6 +207,7 @@ Arm Ltd.
  Guoxing Wu
  Min Zhang
  Yuxiang Qian
+ Shufen Ma
 
 Broadcom Inc.
  Gary Sweet

src/libANGLE/ErrorStrings.h

@@ -265,7 +265,7 @@ MSG kInvalidBufferUsageFlags = "Invalid buffer usage flags.";
 MSG kInvalidClearMask = "Invalid mask bits.";
 MSG kInvalidClientState = "Invalid client vertex array type.";
 MSG kInvalidClipPlane = "Invalid clip plane.";
-MSG kInvalidColorMaskForYUV = "Red, green and blue color writes must be enabled when writing to YUV framebuffers.";
+MSG kInvalidColorMaskForYUV = "Red, green, blue color and alpha writes must be enabled when writing to YUV framebuffers.";
 MSG kInvalidCombinedImageUnit = "Specified unit must be in [GL_TEXTURE0, GL_TEXTURE0 + GL_MAX_COMBINED_IMAGE_UNITS)";
 MSG kInvalidComponents = "Invalid components.";
 MSG kInvalidCompressedFormat = "Not a valid compressed texture format.";

src/libANGLE/validationES.cpp

@@ -4313,10 +4313,11 @@ const char *ValidateDrawStates(const Context *context, GLenum *outErrorCode)
     if (framebufferIsYUV)
     {
         const BlendState &blendState = state.getBlendState();
-        if (!blendState.colorMaskRed || !blendState.colorMaskGreen || !blendState.colorMaskBlue)
+        if (!blendState.colorMaskRed || !blendState.colorMaskGreen || !blendState.colorMaskBlue ||
+            !blendState.colorMaskAlpha)
         {
-            // When rendering into a YUV framebuffer, the color mask must have r g and b set to
-            // true.
+            // When rendering into a YUV framebuffer, the color mask must have r g b and alpha set
+            // to true.
             return kInvalidColorMaskForYUV;
         }
 

src/tests/gl_tests/ImageTest.cpp

@@ -3737,6 +3737,11 @@ TEST_P(ImageTestES3, RenderToYUVAHB)
     glUseProgram(mRenderYUVProgram);
     glUniform4f(mRenderYUVUniformLocation, drawColor[0] / 255.0f, drawColor[1] / 255.0f,
                 drawColor[2] / 255.0f, drawColor[3] / 255.0f);
+
+    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_FALSE);
+    drawQuad(mRenderYUVProgram, "position", 0.0f);
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
     drawQuad(mRenderYUVProgram, "position", 0.0f);
     ASSERT_GL_NO_ERROR();