Avoid GPU readback in tex(Sub)Image2D(ImageBitmap)

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

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 4123 matching lines @@
     if (!imageForRender || !validateTexFunc("texImage2D", TexImage, SourceHTMLImageElement, target, level, internalformat, imageForRender->width(), imageForRender->height(), 1, 0, format, type, 0, 0, 0))
         return;
 
     if (type == GL_UNSIGNED_INT_10F_11F_11F_REV) {
         // The UNSIGNED_INT_10F_11F_11F_REV type pack/unpack isn't implemented.
         type = GL_FLOAT;
     }
     texImage2DImpl(target, level, internalformat, format, type, imageForRender.get(), WebGLImageConversion::HtmlDomImage, m_unpackFlipY, m_unpackPremultiplyAlpha);
 }
 
-bool WebGLRenderingContextBase::canUseTexImageCanvasByGPU(GLint internalformat, GLenum type)
+bool WebGLRenderingContextBase::canUseTexImageByGPU(GLint internalformat, GLenum type)
 {
     if (isFloatType(type) || isIntegerFormat(internalformat) || isSRGBFormat(internalformat))
         return false;
     return true;
 }
 
-void WebGLRenderingContextBase::texImageCanvasByGPU(TexImageByGPUType functionType, WebGLTexture* texture, GLenum target,
-    GLint level, GLint internalformat, GLenum type, GLint xoffset, GLint yoffset, GLint zoffset, HTMLCanvasElement* canvas)
+void WebGLRenderingContextBase::texImageCanvasByGPU(HTMLCanvasElement* canvas, GLuint targetTexture, GLenum targetInternalformat, GLenum targetType, GLint targetLevel)
 {
+    if (!canvas->is3D()) {
+        ImageBuffer* buffer = canvas->buffer();
+        if (!buffer->copyToPlatformTexture(contextGL(), targetTexture, targetInternalformat, targetType,
+            targetLevel, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
+            NOTREACHED();
+        }
+    } else {
+        WebGLRenderingContextBase* gl = toWebGLRenderingContextBase(canvas->renderingContext());
+        ScopedTexture2DRestorer restorer(gl);
+        if (!gl->drawingBuffer()->copyToPlatformTexture(contextGL(), targetTexture, targetInternalformat, targetType,
+            targetLevel, m_unpackPremultiplyAlpha, !m_unpackFlipY, BackBuffer)) {
+            NOTREACHED();
+        }
+    }
+}
+
+void WebGLRenderingContextBase::texImageByGPU(TexImageByGPUType functionType, WebGLTexture* texture, GLenum target,
+    GLint level, GLint internalformat, GLenum type, GLint xoffset, GLint yoffset, GLint zoffset, HTMLCanvasElement* canvas, ImageBitmap* bitmap)
+{
+    DCHECK((!canvas || !bitmap) && (canvas || bitmap));
     ScopedTexture2DRestorer restorer(this);
 
     GLuint targetTexture = texture->object();
     GLenum targetType = type;
     GLenum targetInternalformat = internalformat;
     GLint targetLevel = level;
     bool possibleDirectCopy = false;
+    // TODO: Make this function support more cases in texSubImage calls.
     if (functionType == TexImage2DByGPU) {
         possibleDirectCopy = Extensions3DUtil::canUseCopyTextureCHROMIUM(target, internalformat, type, level);
     }
 
     // if direct copy is not possible, create a temporary texture and then copy from canvas to temporary texture to target texture.
     if (!possibleDirectCopy) {
         targetLevel = 0;
         targetInternalformat = GL_RGBA;
         targetType = GL_UNSIGNED_BYTE;
         contextGL()->GenTextures(1, &targetTexture);
         contextGL()->BindTexture(GL_TEXTURE_2D, targetTexture);
         contextGL()->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
         contextGL()->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
         contextGL()->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
         contextGL()->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
         contextGL()->TexImage2D(GL_TEXTURE_2D, 0, targetInternalformat, canvas->width(),
             canvas->height(), 0, GL_RGBA, targetType, 0);
     }
 
-    if (!canvas->is3D()) {
-        ImageBuffer* buffer = canvas->buffer();
-        if (!buffer->copyToPlatformTexture(contextGL(), targetTexture, targetInternalformat, targetType,
-            targetLevel, m_unpackPremultiplyAlpha, m_unpackFlipY)) {
-            ASSERT_NOT_REACHED();
-        }
-    } else {
-        WebGLRenderingContextBase* gl = toWebGLRenderingContextBase(canvas->renderingContext());
-        ScopedTexture2DRestorer restorer(gl);
-        if (!gl->drawingBuffer()->copyToPlatformTexture(contextGL(), targetTexture, targetInternalformat, targetType,
-            targetLevel, m_unpackPremultiplyAlpha, !m_unpackFlipY, BackBuffer)) {
-            ASSERT_NOT_REACHED();
-        }
-    }
+    if (canvas)
+        texImageCanvasByGPU(canvas, targetTexture, targetInternalformat, targetType, targetLevel);
+    else
+        texImageBitmapByGPU(bitmap, targetTexture, targetInternalformat, targetType, targetLevel);
 
     if (!possibleDirectCopy) {
         GLuint tmpFBO;
         contextGL()->GenFramebuffers(1, &tmpFBO);
         contextGL()->BindFramebuffer(GL_FRAMEBUFFER, tmpFBO);
         contextGL()->FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, targetTexture, 0);
         contextGL()->BindTexture(texture->getTarget(), texture->object());
         if (functionType == TexImage2DByGPU) {
             contextGL()->CopyTexSubImage2D(target, level, 0, 0, 0, 0, canvas->width(), canvas->height());
         } else if (functionType == TexSubImage2DByGPU) {
@@ skipping 14 matching lines @@
     if (isContextLost())
         return;
     if (!validateHTMLCanvasElement("texImage2D", canvas, exceptionState))
         return;
     WebGLTexture* texture = validateTexture2DBinding("texImage2D", target);
     if (!texture)
         return;
     if (!validateTexFunc("texImage2D", TexImage, SourceHTMLCanvasElement, target, level, internalformat, canvas->width(), canvas->height(), 1, 0, format, type, 0, 0, 0))
         return;
 
-    // texImageCanvasByGPU relies on copyTextureCHROMIUM which doesn't support float/integer/sRGB internal format.
+    // texImageByGPU relies on copyTextureCHROMIUM which doesn't support float/integer/sRGB internal format.
     // FIXME: relax the constrains if copyTextureCHROMIUM is upgraded to handle more formats.
-    if (!canvas->renderingContext() || !canvas->renderingContext()->isAccelerated() || !canUseTexImageCanvasByGPU(internalformat, type)) {
+    if (!canvas->renderingContext() || !canvas->renderingContext()->isAccelerated() || !canUseTexImageByGPU(internalformat, type)) {
         // 2D canvas has only FrontBuffer.
         texImage2DImpl(target, level, internalformat, format, type, canvas->copiedImage(FrontBuffer, PreferAcceleration).get(),
             WebGLImageConversion::HtmlDomCanvas, m_unpackFlipY, m_unpackPremultiplyAlpha);
         return;
     }
 
     texImage2DBase(target, level, internalformat, canvas->width(), canvas->height(), 0, format, type, 0);
-    texImageCanvasByGPU(TexImage2DByGPU, texture, target, level, internalformat, type, 0, 0, 0, canvas);
+    texImageByGPU(TexImage2DByGPU, texture, target, level, internalformat, type, 0, 0, 0, canvas, nullptr);
 }
 
 PassRefPtr<Image> WebGLRenderingContextBase::videoFrameToImage(HTMLVideoElement* video)
 {
     IntSize size(video->videoWidth(), video->videoHeight());
     ImageBuffer* buf = m_generatedImageCache.imageBuffer(size);
     if (!buf) {
         synthesizeGLError(GL_OUT_OF_MEMORY, "texImage2D", "out of memory");
         return nullptr;
     }
@@ skipping 42 matching lines @@
         }
     }
 
     // Normal pure SW path.
     RefPtr<Image> image = videoFrameToImage(video);
     if (!image)
         return;
     texImage2DImpl(target, level, internalformat, format, type, image.get(), WebGLImageConversion::HtmlDomVideo, m_unpackFlipY, m_unpackPremultiplyAlpha);
 }
 
+void WebGLRenderingContextBase::texImageBitmapByGPU(ImageBitmap* bitmap, GLuint targetTexture, GLenum targetInternalformat, GLenum targetType, GLint targetLevel)
+{
+    RefPtr<SkImage> skImage = bitmap->bitmapImage()->imageForCurrentFrame(drawingBuffer()->contextProvider());
+    bitmap->bitmapImage()->copyTexture(drawingBuffer()->contextProvider(), targetTexture, targetInternalformat, targetType);
+}
+
 void WebGLRenderingContextBase::texImage2D(GLenum target, GLint level, GLint internalformat,
     GLenum format, GLenum type, ImageBitmap* bitmap, ExceptionState& exceptionState)
 {
     if (isContextLost())
         return;
     if (!validateImageBitmap("texImage2D", bitmap, exceptionState))
         return;
-    if (!validateTexture2DBinding("texImage2D", target))
+    WebGLTexture* texture = validateTexture2DBinding("texImage2D", target);
+    if (!texture)
         return;
     if (!validateTexFunc("texImage2D", TexImage, SourceImageBitmap, target, level, internalformat, bitmap->width(), bitmap->height(), 1, 0, format, type, 0, 0, 0))
         return;
     ASSERT(bitmap->bitmapImage());
+    if (bitmap->isTextureBacked() && canUseTexImageByGPU(internalformat, type)) {
+        texImage2DBase(target, level, internalformat, bitmap->width(), bitmap->height(), 0, format, type, 0);
+        texImageByGPU(TexImage2DByGPU, texture, target, level, internalformat, type, 0, 0, 0, nullptr, bitmap);
+        return;
+    }
     RefPtr<SkImage> skImage = bitmap->bitmapImage()->imageForCurrentFrame();
     SkPixmap pixmap;
     OwnPtr<uint8_t[]> pixelData;
     uint8_t* pixelDataPtr = nullptr;
-    // TODO(crbug.com/613411): peekPixels fails if the SkImage is texture-backed

[Stephen White, 2016/06/03 17:59:13]

Is the mailbox case now handled by the copyTexture() case above? I.e., is this
bug fixed?

-    // Use texture mailbox in that case.
+    // In the case where an ImageBitmap is not texture backed, peekPixels() always succeed.
+    // However, when it is texture backed and !canUseTexImageByGPU, we do a GPU read back.
     bool peekSucceed = skImage->peekPixels(&pixmap);
     if (peekSucceed) {
         pixelDataPtr = static_cast<uint8_t*>(pixmap.writable_addr());
-    } else if (skImage->isTextureBacked()) {
+    } else {
         pixelData = bitmap->copyBitmapData(bitmap->isPremultiplied() ? PremultiplyAlpha : DontPremultiplyAlpha);
         pixelDataPtr = pixelData.get();
     }
     Vector<uint8_t> data;
     bool needConversion = true;
     bool havePeekableRGBA = (peekSucceed && pixmap.colorType() == SkColorType::kRGBA_8888_SkColorType);
-    bool isPixelDataRBGA = (havePeekableRGBA || !peekSucceed);
-    if (isPixelDataRBGA && format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
+    bool isPixelDataRGBA = (havePeekableRGBA || !peekSucceed);
+    if (isPixelDataRGBA && format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
         needConversion = false;
     } else {
         if (type == GL_UNSIGNED_INT_10F_11F_11F_REV) {
             // The UNSIGNED_INT_10F_11F_11F_REV type pack/unpack isn't implemented.
             type = GL_FLOAT;
         }
         // In the case of ImageBitmap, we do not need to apply flipY or premultiplyAlpha.
-        bool isPixelDataBGRA = (peekSucceed && pixmap.colorType() == SkColorType::kBGRA_8888_SkColorType);
+        bool isPixelDataBGRA = pixmap.colorType() == SkColorType::kBGRA_8888_SkColorType;
         if ((isPixelDataBGRA && !WebGLImageConversion::extractImageData(pixelDataPtr, WebGLImageConversion::DataFormat::DataFormatBGRA8, bitmap->size(), format, type, false, false, data))
-            || (isPixelDataRBGA && !WebGLImageConversion::extractImageData(pixelDataPtr, WebGLImageConversion::DataFormat::DataFormatRGBA8, bitmap->size(), format, type, false, false, data))) {
+            || (isPixelDataRGBA && !WebGLImageConversion::extractImageData(pixelDataPtr, WebGLImageConversion::DataFormat::DataFormatRGBA8, bitmap->size(), format, type, false, false, data))) {
             synthesizeGLError(GL_INVALID_VALUE, "texImage2D", "bad image data");
             return;
         }
     }
     resetUnpackParameters();
     texImage2DBase(target, level, internalformat, bitmap->width(), bitmap->height(), 0, format, type, needConversion ? data.data() : pixelDataPtr);
     restoreUnpackParameters();
 }
 
 void WebGLRenderingContextBase::texParameter(GLenum target, GLenum pname, GLfloat paramf, GLint parami, bool isFloat)
@@ skipping 192 matching lines @@
     if (!texture)
         return;
     if (!validateTexFunc("texSubImage2D", TexSubImage, SourceHTMLCanvasElement, target, level, 0, canvas->width(), canvas->height(), 1, 0, format, type, xoffset, yoffset, 0))
         return;
 
     // FIXME: Implement GPU-to-GPU path for WebGL 2 and more internal formats.
     bool useReadBackPath = isWebGL2OrHigher()
         || extensionEnabled(OESTextureFloatName)
         || extensionEnabled(OESTextureHalfFloatName)
         || extensionEnabled(EXTsRGBName);
-    // texImageCanvasByGPU relies on copyTextureCHROMIUM which doesn't support float/integer/sRGB internal format.
+    // texImageByGPU relies on copyTextureCHROMIUM which doesn't support float/integer/sRGB internal format.
     // FIXME: relax the constrains if copyTextureCHROMIUM is upgraded to handle more formats.
     if (!canvas->renderingContext() || !canvas->renderingContext()->isAccelerated() || useReadBackPath) {
         // 2D canvas has only FrontBuffer.
         texSubImage2DImpl(target, level, xoffset, yoffset, format, type, canvas->copiedImage(FrontBuffer, PreferAcceleration).get(),
             WebGLImageConversion::HtmlDomCanvas, m_unpackFlipY, m_unpackPremultiplyAlpha);
         return;
     }
 
-    texImageCanvasByGPU(TexSubImage2DByGPU, texture, target, level, GL_RGBA, type, xoffset, yoffset, 0, canvas);
+    texImageByGPU(TexSubImage2DByGPU, texture, target, level, GL_RGBA, type, xoffset, yoffset, 0, canvas, nullptr);
 }
 
 void WebGLRenderingContextBase::texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
     GLenum format, GLenum type, HTMLVideoElement* video, ExceptionState& exceptionState)
 {
     if (isContextLost())
         return;
     if (!validateHTMLVideoElement("texSubImage2D", video, exceptionState))
         return;
     if (!validateTexture2DBinding("texSubImage2D", target))
         return;
     if (!validateTexFunc("texSubImage2D", TexSubImage, SourceHTMLVideoElement, target, level, 0, video->videoWidth(), video->videoHeight(), 1, 0, format, type, xoffset, yoffset, 0))
         return;
 
     RefPtr<Image> image = videoFrameToImage(video);
     if (!image)
         return;
     texSubImage2DImpl(target, level, xoffset, yoffset, format, type, image.get(), WebGLImageConversion::HtmlDomVideo, m_unpackFlipY, m_unpackPremultiplyAlpha);
 }
 
 void WebGLRenderingContextBase::texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
     GLenum format, GLenum type, ImageBitmap* bitmap, ExceptionState& exceptionState)
 {
     if (isContextLost())
         return;
     if (!validateImageBitmap("texSubImage2D", bitmap, exceptionState))
         return;
-    if (!validateTexture2DBinding("texSubImage2D", target))
+    WebGLTexture* texture = validateTexture2DBinding("texSubImage2D", target);
+    if (!texture)
         return;
-    if (!validateTexFunc("texSubImage2D", TexSubImage, SourceImageBitmap, target, level, 0, bitmap->width(), bitmap->height(), 1, 0, format, type, 0, 0, 0))
+    if (!validateTexFunc("texSubImage2D", TexSubImage, SourceImageBitmap, target, level, 0, bitmap->width(), bitmap->height(), 1, 0, format, type, xoffset, yoffset, 0))
         return;
-    if (type == GL_UNSIGNED_INT_10F_11F_11F_REV) {
-        // The UNSIGNED_INT_10F_11F_11F_REV type pack/unpack isn't implemented.
-        type = GL_FLOAT;
+    bool useReadBackPath = isWebGL2OrHigher()

[Stephen White, 2016/06/03 17:59:13]

Seems to be copied from line 4570. Could you refactor this into a helper
function, and include the FIXME above? I was a little confused as to where these
restrictions came from.

+        || extensionEnabled(OESTextureFloatName)
+        || extensionEnabled(OESTextureHalfFloatName)
+        || extensionEnabled(EXTsRGBName);
+    if (bitmap->isTextureBacked() && !useReadBackPath) {

[Stephen White, 2016/06/03 17:59:13]

Are there tests which cover all these possible conditions?

+        texImageByGPU(TexSubImage2DByGPU, texture, target, level, GL_RGBA, type, xoffset, yoffset, 0, nullptr, bitmap);
+        return;
     }
-    ASSERT(bitmap->bitmapImage());
     RefPtr<SkImage> skImage = bitmap->bitmapImage()->imageForCurrentFrame();
     SkPixmap pixmap;
     OwnPtr<uint8_t[]> pixelData;
     uint8_t* pixelDataPtr = nullptr;
+    // In the case where an ImageBitmap is not texture backed, peekPixels() always succeed.
+    // However, when it is texture backed and !canUseTexImageByGPU, we do a GPU read back.
     bool peekSucceed = skImage->peekPixels(&pixmap);
     if (peekSucceed) {
         pixelDataPtr = static_cast<uint8_t*>(pixmap.writable_addr());
-    } else if (skImage->isTextureBacked()) {
+    } else {
         pixelData = bitmap->copyBitmapData(bitmap->isPremultiplied() ? PremultiplyAlpha : DontPremultiplyAlpha);
         pixelDataPtr = pixelData.get();
     }
     Vector<uint8_t> data;
     bool needConversion = true;
     bool havePeekableRGBA = (peekSucceed && pixmap.colorType() == SkColorType::kRGBA_8888_SkColorType);
-    bool isPixelDataRBGA = (havePeekableRGBA || !peekSucceed);
-    if (isPixelDataRBGA && format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
+    bool isPixelDataRGBA = (havePeekableRGBA || !peekSucceed);
+    if (isPixelDataRGBA && format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
         needConversion = false;
     } else {
+        if (type == GL_UNSIGNED_INT_10F_11F_11F_REV) {

[Stephen White, 2016/06/03 17:59:13]

Is there a 10_11_11 test somewhere?

+            // The UNSIGNED_INT_10F_11F_11F_REV type pack/unpack isn't implemented.
+            type = GL_FLOAT;
+        }
         // In the case of ImageBitmap, we do not need to apply flipY or premultiplyAlpha.
-        bool isPixelDataBGRA = (peekSucceed && pixmap.colorType() == SkColorType::kBGRA_8888_SkColorType);
+        bool isPixelDataBGRA = pixmap.colorType() == SkColorType::kBGRA_8888_SkColorType;
         if ((isPixelDataBGRA && !WebGLImageConversion::extractImageData(pixelDataPtr, WebGLImageConversion::DataFormat::DataFormatBGRA8, bitmap->size(), format, type, false, false, data))
-            || (isPixelDataRBGA && !WebGLImageConversion::extractImageData(pixelDataPtr, WebGLImageConversion::DataFormat::DataFormatRGBA8, bitmap->size(), format, type, false, false, data))) {
+            || (isPixelDataRGBA && !WebGLImageConversion::extractImageData(pixelDataPtr, WebGLImageConversion::DataFormat::DataFormatRGBA8, bitmap->size(), format, type, false, false, data))) {
             synthesizeGLError(GL_INVALID_VALUE, "texSubImage2D", "bad image data");
             return;
         }
     }
     resetUnpackParameters();
     contextGL()->TexSubImage2D(target, level, xoffset, yoffset, bitmap->width(), bitmap->height(), format, type, needConversion ? data.data() : pixelDataPtr);
     restoreUnpackParameters();
 }
 
 void WebGLRenderingContextBase::uniform1f(const WebGLUniformLocation* location, GLfloat x)
@@ skipping 1793 matching lines @@
         contextGL()->PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 }
 
 void WebGLRenderingContextBase::restoreUnpackParameters()
 {
     if (m_unpackAlignment != 1)
         contextGL()->PixelStorei(GL_UNPACK_ALIGNMENT, m_unpackAlignment);
 }
 
 } // namespace blink