webgl: optimize webgl.texSubImage2D(video) path.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
index 40794bb8a10cd65ab8710f2250454db70d7990a0..e58b10d5d2145831fc887598233c368848d95b16 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
@@ -4385,7 +4385,7 @@ void WebGLRenderingContextBase::texImageCanvasByGPU(TexImageByGPUType functionTy
 
     if (!canvas->is3D()) {
         ImageBuffer* buffer = canvas->buffer();
-        if (!buffer->copyToPlatformTexture(webContext(), targetTexture, targetInternalformat, targetType,
+        if (!buffer->copyToPlatformTexture(webContext(), GL_TEXTURE_2D, targetTexture, targetInternalformat, targetType,
             targetLevel, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
             ASSERT_NOT_REACHED();
         }
@@ -4417,6 +4417,51 @@ void WebGLRenderingContextBase::texImageCanvasByGPU(TexImageByGPUType functionTy
     }
 }
 
+bool WebGLRenderingContextBase::texImage2DVideoByGPU(TexImageFunctionType functionType, WebGLTexture* texture, GLenum target,
+    GLint level, GLenum internalformat, GLenum type, GLint xoffset, GLint yoffset, HTMLVideoElement* video)
+{
+    typedef WebMediaPlayer::CopyVideoTextureParams CopyParams;
+    if (video->copyVideoTextureToPlatformTexture(webContext(),
+        CopyParams(
+            functionType == NotTexSubImage2D ? CopyParams::FullCopy : CopyParams::SubCopy,
+            target, texture->object(), internalformat, type, level, xoffset,
+            yoffset, m_unpackPremultiplyAlpha, m_unpackFlipY))) {
+        if (functionType == NotTexSubImage2D)
+            texture->setLevelInfo(target, level, internalformat, video->videoWidth(), video->videoHeight(), 1, type);
+        return true;
+    }
+
+    // Try using an accelerated image buffer, this allows YUV conversion to be done on the GPU.
+    OwnPtr<ImageBufferSurface> surface = adoptPtr(new AcceleratedImageBufferSurface(IntSize(video->videoWidth(), video->videoHeight())));
+    if (surface->isValid()) {
+        OwnPtr<ImageBuffer> imageBuffer(ImageBuffer::create(surface.release()));
+        if (imageBuffer) {
+            // The video element paints an RGBA frame into our surface here. By using an AcceleratedImageBufferSurface,
+            // we enable the WebMediaPlayer implementation to do any necessary color space conversion on the GPU (though it
+            // may still do a CPU conversion and upload the results).
+            video->paintCurrentFrame(imageBuffer->canvas(), IntRect(0, 0, video->videoWidth(), video->videoHeight()), nullptr);
+
+            // This is a straight GPU-GPU copy, any necessary color space conversion was handled in the paintCurrentFrameInContext() call.
+            switch (functionType) {
+            case NotTexSubImage2D:
+                if (imageBuffer->copyToPlatformTexture(webContext(), target, texture->object(), internalformat, type,
+                    level, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
+                    texture->setLevelInfo(target, level, internalformat, video->videoWidth(), video->videoHeight(), 1, type);
+                    return true;
+                }
+                break;
+            case TexSubImage2D:
+                if (imageBuffer->copySubToPlatformTexture(webContext(), target, texture->object(), level,
+                    xoffset, yoffset, video->videoWidth(), video->videoHeight(), m_unpackPremultiplyAlpha, m_unpackFlipY)) {
+                    return true;
+                }
+                break;
+            }
+        }
+    }
+    return false;
+}
+
 void WebGLRenderingContextBase::texImage2D(GLenum target, GLint level, GLenum internalformat,
     GLenum format, GLenum type, HTMLCanvasElement* canvas, ExceptionState& exceptionState)
 {
@@ -4463,31 +4508,9 @@ void WebGLRenderingContextBase::texImage2D(GLenum target, GLint level, GLenum in
     // Otherwise, it will fall back to the normal SW path.
     WebGLTexture* texture = validateTextureBinding("texImage2D", target, true);
     ASSERT(texture);
-    if (GL_TEXTURE_2D == target) {
-        if (Extensions3DUtil::canUseCopyTextureCHROMIUM(target, internalformat, type, level)
-            && video->copyVideoTextureToPlatformTexture(webContext(), texture->object(), internalformat, type, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
-            texture->setLevelInfo(target, level, internalformat, video->videoWidth(), video->videoHeight(), 1, type);
+    if (Extensions3DUtil::canUseCopyTextureCHROMIUM(target, internalformat, type, level)) {
+        if (texImage2DVideoByGPU(NotTexSubImage2D, texture, target, level, internalformat, type, 0, 0, video))
             return;
-        }
-
-        // Try using an accelerated image buffer, this allows YUV conversion to be done on the GPU.
-        OwnPtr<ImageBufferSurface> surface = adoptPtr(new AcceleratedImageBufferSurface(IntSize(video->videoWidth(), video->videoHeight())));
-        if (surface->isValid()) {
-            OwnPtr<ImageBuffer> imageBuffer(ImageBuffer::create(surface.release()));
-            if (imageBuffer) {
-                // The video element paints an RGBA frame into our surface here. By using an AcceleratedImageBufferSurface,
-                // we enable the WebMediaPlayer implementation to do any necessary color space conversion on the GPU (though it
-                // may still do a CPU conversion and upload the results).
-                video->paintCurrentFrame(imageBuffer->canvas(), IntRect(0, 0, video->videoWidth(), video->videoHeight()), nullptr);
-
-                // This is a straight GPU-GPU copy, any necessary color space conversion was handled in the paintCurrentFrameInContext() call.
-                if (imageBuffer->copyToPlatformTexture(webContext(), texture->object(), internalformat, type,
-                    level, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
-                    texture->setLevelInfo(target, level, internalformat, video->videoWidth(), video->videoHeight(), 1, type);
-                    return;
-                }
-            }
-        }
     }
 
     // Normal pure SW path.
@@ -4703,6 +4726,16 @@ void WebGLRenderingContextBase::texSubImage2D(GLenum target, GLint level, GLint
         || !validateTexFunc("texSubImage2D", TexSubImage2D, SourceHTMLVideoElement, target, level, 0, video->videoWidth(), video->videoHeight(), 0, format, type, xoffset, yoffset))
         return;
 
+    // Go through the fast path doing a GPU-GPU textures copy without a readback to system memory if possible.
+    // Otherwise, it will fall back to the normal SW path.
+    WebGLTexture* texture = validateTextureBinding("texSubImage2D", target, true);
+    ASSERT(texture);
+    if (Extensions3DUtil::canUseCopyTextureCHROMIUM(target, GL_RGBA, type, level)) {
+        if (texImage2DVideoByGPU(TexSubImage2D, texture, target, level, GL_FALSE,
+            GL_FALSE, xoffset, yoffset, video))
+            return;
+    }
+
     RefPtr<Image> image = videoFrameToImage(video);
     if (!image)
         return;