Support EXT_color_buffer_half_float on WebGL 2.0 contexts

src/libANGLE/Context.cpp

@@ -3196,8 +3196,9 @@ Extensions Context::generateSupportedExtensions() const
         // can be blit onto each other if the format is available.
         // We require colorBufferFloat to be present in order to enable colorBufferHalfFloat, so
         // that blitting is always allowed if the requested formats are exposed and have the correct
-        // feature capabilities
-        if (!supportedExtensions.colorBufferFloat)
+        // feature capabilities.
+        // WebGL 2 wants to support colorBufferHalfFloat without colorBufferFloat.
+        if (!supportedExtensions.colorBufferFloat && !mWebGLContext)
         {
             supportedExtensions.colorBufferHalfFloat = false;
         }

src/libANGLE/formatutils.cpp

@@ -186,7 +186,9 @@ static bool SizedHalfFloatRGTextureAttachmentSupport(const Version &clientVersio
     // HALF_FLOAT
     if (clientVersion >= Version(3, 0))
     {
-        return extensions.colorBufferFloat;
+        // WebGL 2 supports EXT_color_buffer_half_float.
+        return extensions.colorBufferFloat ||
+               (extensions.webglCompatibility && extensions.colorBufferHalfFloat);
     }
     // HALF_FLOAT_OES
     else
@@ -253,7 +255,8 @@ static bool SizedHalfFloatRGBTextureAttachmentSupport(const Version &clientVersi
         // It is unclear how EXT_color_buffer_half_float applies to ES3.0 and above, however,
         // dEQP GLES3 es3fFboColorbufferTests.cpp verifies that texture attachment of GL_RGB16F
         // is possible, so assume that all GLES implementations support it.
-        return extensions.colorBufferHalfFloat;
+        // The WebGL version of the extension explicitly forbids RGB formats.
+        return extensions.colorBufferHalfFloat && !extensions.webglCompatibility;
     }
     // HALF_FLOAT_OES
     else
@@ -265,8 +268,9 @@ static bool SizedHalfFloatRGBTextureAttachmentSupport(const Version &clientVersi
 static bool SizedHalfFloatRGBRenderbufferSupport(const Version &clientVersion,
                                                  const Extensions &extensions)
 {
-    return (clientVersion >= Version(3, 0) || extensions.textureHalfFloat) &&
-           extensions.colorBufferHalfFloat;
+    return !extensions.webglCompatibility &&
+           ((clientVersion >= Version(3, 0) || extensions.textureHalfFloat) &&
+            extensions.colorBufferHalfFloat);
 }
 
 static bool SizedHalfFloatRGBATextureAttachmentSupport(const Version &clientVersion,
@@ -275,7 +279,9 @@ static bool SizedHalfFloatRGBATextureAttachmentSupport(const Version &clientVers
     // HALF_FLOAT
     if (clientVersion >= Version(3, 0))
     {
-        return extensions.colorBufferFloat;
+        // WebGL 2 supports EXT_color_buffer_half_float.
+        return extensions.colorBufferFloat ||
+               (extensions.webglCompatibility && extensions.colorBufferHalfFloat);
     }
     // HALF_FLOAT_OES
     else

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -289,6 +289,18 @@ static gl::TextureCaps GenerateTextureFormatCaps(const FunctionsGL *functions,
     textureCaps.blendable         = textureCaps.renderbuffer || textureCaps.textureAttachment;
 
     // Do extra renderability validation for some formats.
+    if (internalFormat == GL_R16F || internalFormat == GL_RG16F || internalFormat == GL_RGB16F)
+    {
+        // SupportRequirement can't currently express a condition of the form (version && extension)
+        // || other extensions, so do the (version && extension) part here.
+        if (functions->isAtLeastGLES(gl::Version(3, 0)) &&
+            functions->hasGLESExtension("GL_EXT_color_buffer_half_float"))
+        {
+            textureCaps.textureAttachment = true;
+            textureCaps.renderbuffer      = true;
+        }
+    }
+
     // We require GL_RGBA16F is renderable to expose EXT_color_buffer_half_float but we can't know
     // if the format is supported unless we try to create a framebuffer.
     if (internalFormat == GL_RGBA16F)

src/tests/gl_tests/WebGLCompatibilityTest.cpp

@@ -3619,7 +3619,8 @@ TEST_P(WebGLCompatibilityTest, R16FTextures)
             // Sized R 16F
             bool texture = true;
             bool filter  = true;
-            bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
+            bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
+                          IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
             TestFloatTextureFormat(GL_R16F, GL_RED, GL_HALF_FLOAT, texture, filter, render,
                                    textureData, readPixelsData);
         }
@@ -3675,7 +3676,8 @@ TEST_P(WebGLCompatibilityTest, RG16FTextures)
             // Sized RG 16F
             bool texture = true;
             bool filter  = true;
-            bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
+            bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
+                          IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
             TestFloatTextureFormat(GL_RG16F, GL_RG, GL_HALF_FLOAT, texture, filter, render,
                                    textureData, readPixelsData);
         }
@@ -3737,10 +3739,8 @@ TEST_P(WebGLCompatibilityTest, RGB16FTextures)
             // Sized RGB 16F
             bool texture = true;
             bool filter  = true;
-            // It is unclear how EXT_color_buffer_half_float applies to ES3.0 and above, however,
-            // dEQP GLES3 es3fFboColorbufferTests.cpp verifies that texture attachment of GL_RGB16F
-            // is possible, so assume that all GLES implementations support it.
-            bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
+            // Renderability of RGB is forbidden by GL_EXT_color_buffer_half_float in WebGL 2.
+            bool render = false;
             TestFloatTextureFormat(GL_RGB16F, GL_RGB, GL_HALF_FLOAT, texture, filter, render,
                                    textureData, readPixelsData);
         }
@@ -3796,7 +3796,8 @@ TEST_P(WebGLCompatibilityTest, RGBA16FTextures)
             // Sized RGBA 16F
             bool texture = true;
             bool filter  = true;
-            bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
+            bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
+                          IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
             TestFloatTextureFormat(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT, texture, filter, render,
                                    textureData, readPixelsData);
         }