Metal: fix max point size and RGB565 renderbuffer bug.

src/libANGLE/renderer/metal/DisplayMtl.mm

@@ -435,7 +435,11 @@ void DisplayMtl::ensureCapsInitialized() const
     mNativeCaps.maxCubeMapTextureSize = mNativeCaps.max2DTextureSize;
     mNativeCaps.maxRenderbufferSize   = mNativeCaps.max2DTextureSize;
     mNativeCaps.minAliasedPointSize   = 1;
-    mNativeCaps.maxAliasedPointSize   = 511;
+    // NOTE(hqle): Metal has some problems drawing big point size even though
+    // Metal-Feature-Set-Tables.pdf says that max supported point size is 511. We limit it to 64 for
+    // now.
+    // http://anglebug.com/4816
+    mNativeCaps.maxAliasedPointSize = 64;
 
     mNativeCaps.minAliasedLineWidth = 1.0f;
     mNativeCaps.maxAliasedLineWidth = 1.0f;
@@ -588,8 +592,7 @@ void DisplayMtl::initializeExtensions() const
     mNativeExtensions.textureFilterAnisotropic = true;
     mNativeExtensions.maxTextureAnisotropy     = 16;
 
-    // NOTE(hqle): Support true NPOT textures.
-    mNativeExtensions.textureNPOTOES = false;
+    mNativeExtensions.textureNPOTOES = true;
 
     mNativeExtensions.texture3DOES = false;
 

src/libANGLE/renderer/metal/RenderBufferMtl.mm

@@ -64,6 +64,19 @@ angle::Result RenderbufferMtl::setStorageImpl(const gl::Context *context,
                                               &mTexture));
 
         mRenderTarget.set(mTexture, 0, 0, mFormat);
+
+        // For emulated channels that GL texture intends to not have,
+        // we need to initialize their content.
+        bool emulatedChannels;
+        mTexture->setColorWritableMask(mtl::GetEmulatedColorWriteMask(mFormat, &emulatedChannels));
+        if (emulatedChannels)
+        {
+            gl::ImageIndex index;
+
+            index = gl::ImageIndex::Make2D(0);
+
+            ANGLE_TRY(mtl::InitializeTextureContents(context, mTexture, mFormat, index));
+        }
     }
 
     return angle::Result::Continue;

src/libANGLE/renderer/metal/TextureMtl.mm

@@ -28,45 +28,6 @@ namespace rx
 namespace
 {
 
-MTLColorWriteMask GetColorWriteMask(const mtl::Format &mtlFormat, bool *emulatedChannelsOut)
-{
-    const angle::Format &intendedFormat = mtlFormat.intendedAngleFormat();
-    const angle::Format &actualFormat   = mtlFormat.actualAngleFormat();
-    bool emulatedChannels               = false;
-    MTLColorWriteMask colorWritableMask = MTLColorWriteMaskAll;
-    if (intendedFormat.alphaBits == 0 && actualFormat.alphaBits)
-    {
-        emulatedChannels = true;
-        // Disable alpha write to this texture
-        colorWritableMask = colorWritableMask & (~MTLColorWriteMaskAlpha);
-    }
-    if (intendedFormat.luminanceBits == 0)
-    {
-        if (intendedFormat.redBits == 0 && actualFormat.redBits)
-        {
-            emulatedChannels = true;
-            // Disable red write to this texture
-            colorWritableMask = colorWritableMask & (~MTLColorWriteMaskRed);
-        }
-        if (intendedFormat.greenBits == 0 && actualFormat.greenBits)
-        {
-            emulatedChannels = true;
-            // Disable green write to this texture
-            colorWritableMask = colorWritableMask & (~MTLColorWriteMaskGreen);
-        }
-        if (intendedFormat.blueBits == 0 && actualFormat.blueBits)
-        {
-            emulatedChannels = true;
-            // Disable blue write to this texture
-            colorWritableMask = colorWritableMask & (~MTLColorWriteMaskBlue);
-        }
-    }
-
-    *emulatedChannelsOut = emulatedChannels;
-
-    return colorWritableMask;
-}
-
 gl::ImageIndex GetImageBaseLevelIndex(const mtl::TextureRef &image)
 {
     gl::ImageIndex imageBaseIndex;
@@ -1067,8 +1028,9 @@ angle::Result TextureMtl::checkForEmulatedChannels(const gl::Context *context,
                                                    const mtl::Format &mtlFormat,
                                                    const mtl::TextureRef &texture)
 {
-    bool emulatedChannels               = false;
-    MTLColorWriteMask colorWritableMask = GetColorWriteMask(mtlFormat, &emulatedChannels);
+    bool emulatedChannels = false;
+    MTLColorWriteMask colorWritableMask =
+        mtl::GetEmulatedColorWriteMask(mtlFormat, &emulatedChannels);
     texture->setColorWritableMask(colorWritableMask);
 
     // For emulated channels that GL texture intends to not have,

src/libANGLE/renderer/metal/mtl_utils.h

@@ -92,6 +92,13 @@ PrimitiveTopologyClass GetPrimitiveTopologyClass(gl::PrimitiveMode mode);
 MTLPrimitiveType GetPrimitiveType(gl::PrimitiveMode mode);
 MTLIndexType GetIndexType(gl::DrawElementsType type);
 
+// Get color write mask for a specified format. Some formats such as RGB565 doesn't have alpha
+// channel but is emulated by a RGBA8 format, we need to disable alpha write for this format.
+// - isFormatEmulated: if the format is emulated, this pointer will store a true value.
+MTLColorWriteMask GetEmulatedColorWriteMask(const mtl::Format &mtlFormat, bool *isFormatEmulated);
+MTLColorWriteMask GetEmulatedColorWriteMask(const mtl::Format &mtlFormat);
+bool IsFormatEmulated(const mtl::Format &mtlFormat);
+
 // Useful to set clear color for texture originally having no alpha in GL, but backend's format
 // has alpha channel.
 MTLClearColor EmulatedAlphaClearColor(MTLClearColor color, MTLColorWriteMask colorMask);

src/libANGLE/renderer/metal/mtl_utils.mm

@@ -433,6 +433,59 @@ MTLIndexType GetIndexType(gl::DrawElementsType type)
     }
 }
 
+MTLColorWriteMask GetEmulatedColorWriteMask(const mtl::Format &mtlFormat, bool *isEmulatedOut)
+{
+    const angle::Format &intendedFormat = mtlFormat.intendedAngleFormat();
+    const angle::Format &actualFormat   = mtlFormat.actualAngleFormat();
+    bool isFormatEmulated               = false;
+    MTLColorWriteMask colorWritableMask = MTLColorWriteMaskAll;
+    if (intendedFormat.alphaBits == 0 && actualFormat.alphaBits)
+    {
+        isFormatEmulated = true;
+        // Disable alpha write to this texture
+        colorWritableMask = colorWritableMask & (~MTLColorWriteMaskAlpha);
+    }
+    if (intendedFormat.luminanceBits == 0)
+    {
+        if (intendedFormat.redBits == 0 && actualFormat.redBits)
+        {
+            isFormatEmulated = true;
+            // Disable red write to this texture
+            colorWritableMask = colorWritableMask & (~MTLColorWriteMaskRed);
+        }
+        if (intendedFormat.greenBits == 0 && actualFormat.greenBits)
+        {
+            isFormatEmulated = true;
+            // Disable green write to this texture
+            colorWritableMask = colorWritableMask & (~MTLColorWriteMaskGreen);
+        }
+        if (intendedFormat.blueBits == 0 && actualFormat.blueBits)
+        {
+            isFormatEmulated = true;
+            // Disable blue write to this texture
+            colorWritableMask = colorWritableMask & (~MTLColorWriteMaskBlue);
+        }
+    }
+
+    *isEmulatedOut = isFormatEmulated;
+
+    return colorWritableMask;
+}
+
+MTLColorWriteMask GetEmulatedColorWriteMask(const mtl::Format &mtlFormat)
+{
+    // Ignore isFormatEmulated boolean value
+    bool isFormatEmulated;
+    return GetEmulatedColorWriteMask(mtlFormat, &isFormatEmulated);
+}
+
+bool IsFormatEmulated(const mtl::Format &mtlFormat)
+{
+    bool isFormatEmulated;
+    (void)GetEmulatedColorWriteMask(mtlFormat, &isFormatEmulated);
+    return isFormatEmulated;
+}
+
 MTLClearColor EmulatedAlphaClearColor(MTLClearColor color, MTLColorWriteMask colorMask)
 {
     MTLClearColor re = color;

src/tests/gl_tests/FramebufferTest.cpp

@@ -362,6 +362,28 @@ TEST_P(FramebufferFormatsTest, ReadDrawCompleteness)
     EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
 }
 
+// Test that a renderbuffer with RGB565 format works as expected. This test is intended for some
+// back-end having no support for native RGB565 renderbuffer and thus having to emulate using RGBA
+// format.
+TEST_P(FramebufferFormatsTest, RGB565Renderbuffer)
+{
+    GLRenderbuffer rbo;
+    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB565, 1, 1);
+
+    GLFramebuffer completeFBO;
+    glBindFramebuffer(GL_FRAMEBUFFER, completeFBO);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbo);
+
+    EXPECT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
+
+    ASSERT_GL_NO_ERROR();
+
+    glClearColor(1, 0, 0, 0.5f);
+    glClear(GL_COLOR_BUFFER_BIT);
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
+}
+
 class FramebufferTest_ES3 : public ANGLETest
 {};