Support uploads of sub-rectangles of canvases to 2D and 3D textures.

third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
@@ skipping 196 matching lines @@
 WebLayer* ImageBuffer::platformLayer() const {
   return m_surface->layer();
 }
 
 bool ImageBuffer::copyToPlatformTexture(gpu::gles2::GLES2Interface* gl,
                                         GLuint texture,
                                         GLenum internalFormat,
                                         GLenum destType,
                                         GLint level,
                                         bool premultiplyAlpha,
-                                        bool flipY) {
+                                        bool flipY,
+                                        const IntPoint& destPoint,
+                                        const IntRect& sourceSubRectangle) {
   if (!Extensions3DUtil::canUseCopyTextureCHROMIUM(
           GL_TEXTURE_2D, internalFormat, destType, level))
     return false;
 
   if (!isSurfaceValid())
     return false;
 
   sk_sp<const SkImage> textureImage = m_surface->newImageSnapshot(
       PreferAcceleration, SnapshotReasonCopyToWebGLTexture);
   if (!textureImage)
@@ skipping 29 matching lines @@
   gpu::SyncToken produceSyncToken;
   sharedGL->GenSyncTokenCHROMIUM(sharedFenceSync, produceSyncToken.GetData());
   gl->WaitSyncTokenCHROMIUM(produceSyncToken.GetConstData());
 
   GLuint sourceTexture =
       gl->CreateAndConsumeTextureCHROMIUM(textureInfo->fTarget, mailbox.name);
 
   // The canvas is stored in a premultiplied format, so unpremultiply if
   // necessary. The canvas is also stored in an inverted position, so the flip
   // semantics are reversed.
-  gl->CopyTextureCHROMIUM(sourceTexture, texture, internalFormat, destType,
-                          flipY ? GL_FALSE : GL_TRUE, GL_FALSE,
-                          premultiplyAlpha ? GL_FALSE : GL_TRUE);
+  // It is expected that callers of this method have already allocated
+  // the platform texture with the appropriate size.
+  gl->CopySubTextureCHROMIUM(sourceTexture, texture, destPoint.x(),
+                             destPoint.y(), sourceSubRectangle.x(),
+                             sourceSubRectangle.y(), sourceSubRectangle.width(),
+                             sourceSubRectangle.height(),
+                             flipY ? GL_FALSE : GL_TRUE, GL_FALSE,
+                             premultiplyAlpha ? GL_FALSE : GL_TRUE);
 
   gl->DeleteTextures(1, &sourceTexture);
 
   const GLuint64 contextFenceSync = gl->InsertFenceSyncCHROMIUM();
 
   gl->Flush();
 
   gpu::SyncToken copySyncToken;
   gl->GenSyncTokenCHROMIUM(contextFenceSync, copySyncToken.GetData());
   sharedGL->WaitSyncTokenCHROMIUM(copySyncToken.GetConstData());
@@ skipping 19 matching lines @@
   if (!provider)
     return false;
   gpu::gles2::GLES2Interface* gl = provider->contextGL();
   GLuint textureId = m_surface->getBackingTextureHandleForOverwrite();
   if (!textureId)
     return false;
 
   gl->Flush();
 
   return drawingBuffer->copyToPlatformTexture(
-      gl, textureId, GL_RGBA, GL_UNSIGNED_BYTE, 0, true, false, sourceBuffer);
+      gl, textureId, GL_RGBA, GL_UNSIGNED_BYTE, 0, true, false, IntPoint(0, 0),
+      IntRect(IntPoint(0, 0), drawingBuffer->size()), sourceBuffer);
 }
 
 void ImageBuffer::draw(GraphicsContext& context,
                        const FloatRect& destRect,
                        const FloatRect* srcPtr,
                        SkBlendMode op) {
   if (!isSurfaceValid())
     return;
 
   FloatRect srcRect =
@@ skipping 234 matching lines @@
   ASSERT(MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType));
 
   Vector<unsigned char> result;
   if (!encodeImage(mimeType, quality, &result))
     return "data:,";
 
   return "data:" + mimeType + ";base64," + base64Encode(result);
 }
 
 }  // namespace blink