GL: Make GL_EXT_texture_format_BGRA8888 enableable.

src/libANGLE/Caps.cpp

@@ -776,7 +776,7 @@ const ExtensionInfoMap &GetExtensionInfoMap()
         map["GL_OES_rgb8_rgba8"] = enableableExtension(&Extensions::rgb8rgba8);
         map["GL_EXT_texture_format_BGRA8888"] = enableableExtension(&Extensions::textureFormatBGRA8888);
         map["GL_EXT_texture_type_2_10_10_10_REV"] = enableableExtension(&Extensions::textureFormat2101010REV);
-        map["GL_EXT_read_format_bgra"] = esOnlyExtension(&Extensions::readFormatBGRA);
+        map["GL_EXT_read_format_bgra"] = enableableExtension(&Extensions::readFormatBGRA);
         map["GL_NV_pixel_buffer_object"] = enableableExtension(&Extensions::pixelBufferObject);
         map["GL_OES_mapbuffer"] = enableableExtension(&Extensions::mapBuffer);
         map["GL_EXT_map_buffer_range"] = enableableExtension(&Extensions::mapBufferRange);

src/libANGLE/formatutils.cpp

@@ -360,9 +360,26 @@ bool InternalFormat::isLUMA() const
             (luminanceBits + alphaBits) > 0);
 }
 
-GLenum InternalFormat::getReadPixelsFormat() const
+GLenum InternalFormat::getReadPixelsFormat(const Extensions &extensions) const
 {
-    return format;
+    switch (format)
+    {
+        case GL_BGRA_EXT:
+            // BGRA textures may be enabled but calling glReadPixels with BGRA is disallowed without
+            // GL_EXT_texture_format_BGRA8888.  Read as RGBA instead.
+            if (!extensions.readFormatBGRA)
+            {
+                return GL_RGBA;
+            }
+            else
+            {
+                return GL_BGRA_EXT;
+            }
+            break;
+
+        default:
+            return format;
+    }
 }
 
 GLenum InternalFormat::getReadPixelsType(const Version &version) const

src/libANGLE/formatutils.h

@@ -117,7 +117,7 @@ struct InternalFormat
                                                    GLuint *resultOut) const;
 
     bool isLUMA() const;
-    GLenum getReadPixelsFormat() const;
+    GLenum getReadPixelsFormat(const Extensions &extensions) const;
     GLenum getReadPixelsType(const Version &version) const;
 
     // Support upload a portion of image?

src/libANGLE/renderer/d3d/FramebufferD3D.cpp

@@ -212,7 +212,7 @@ GLenum FramebufferD3D::getImplementationColorReadFormat(const gl::Context *conte
     const gl::InternalFormat &implementationFormatInfo =
         gl::GetSizedInternalFormatInfo(implementationFormat);
 
-    return implementationFormatInfo.getReadPixelsFormat();
+    return implementationFormatInfo.getReadPixelsFormat(context->getExtensions());
 }
 
 GLenum FramebufferD3D::getImplementationColorReadType(const gl::Context *context) const

src/libANGLE/renderer/gl/FramebufferGL.cpp

@@ -461,7 +461,7 @@ GLenum FramebufferGL::getImplementationColorReadFormat(const gl::Context *contex
 {
     const auto *readAttachment = mState.getReadAttachment();
     const Format &format       = readAttachment->getFormat();
-    return format.info->getReadPixelsFormat();
+    return format.info->getReadPixelsFormat(context->getExtensions());
 }
 
 GLenum FramebufferGL::getImplementationColorReadType(const gl::Context *context) const

src/libANGLE/renderer/null/FramebufferNULL.cpp

@@ -92,7 +92,7 @@ GLenum FramebufferNULL::getImplementationColorReadFormat(const gl::Context *cont
 
     const gl::Format &format = readAttachment->getFormat();
     ASSERT(format.info != nullptr);
-    return format.info->getReadPixelsFormat();
+    return format.info->getReadPixelsFormat(context->getExtensions());
 }
 
 GLenum FramebufferNULL::getImplementationColorReadType(const gl::Context *context) const