Merge "Change the dither texture's swizzling" into jb-mr2-dev

libs/hwui/Dither.cpp

@@ -38,6 +38,10 @@ void Dither::bindDitherTexture() {
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 
         if (useFloatTexture) {
+            // We use a R16F texture, let's remap the alpha channel to the
+            // red channel to avoid changing the shader sampling code on GL ES 3.0+
+            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_A, GL_RED);
+
             float dither = 1.0f / (255.0f * DITHER_KERNEL_SIZE * DITHER_KERNEL_SIZE);
             const GLfloat pattern[] = {
                  0 * dither,  8 * dither,  2 * dither, 10 * dither,

libs/hwui/ProgramCache.cpp

@@ -186,7 +186,7 @@ const char* gFS_Main_Dither[2] = {
         // ES 2.0
         "texture2D(ditherSampler, ditherTexCoords).a * " STR(DITHER_KERNEL_SIZE_INV_SQUARE),
         // ES 3.0
-        "texture2D(ditherSampler, ditherTexCoords).r"
+        "texture2D(ditherSampler, ditherTexCoords).a"
 };
 const char* gFS_Main_AddDitherToGradient =
         "    gradientColor += %s;\n";