support uploading sub-rectangles of ImageData

third_party/WebKit/Source/platform/graphics/gpu/WebGLImageConversion.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/graphics/gpu/WebGLImageConversion.h"
 
 #include "platform/graphics/ImageObserver.h"
 #include "platform/graphics/cpu/arm/WebGLImageConversionNEON.h"
 #include "platform/graphics/cpu/mips/WebGLImageConversionMSA.h"
 #include "platform/graphics/cpu/x86/WebGLImageConversionSSE.h"
@@ skipping 2879 matching lines @@
                   flipY))
     return false;
   if (ImageObserver* observer = image->getImageObserver())
     observer->didDraw(image);
   return true;
 }
 
 bool WebGLImageConversion::extractImageData(const uint8_t* imageData,
                                             DataFormat sourceDataFormat,
                                             const IntSize& imageDataSize,
+                                            const IntRect& sourceImageSubRect,
                                             GLenum format,
                                             GLenum type,
                                             bool flipY,
                                             bool premultiplyAlpha,
                                             Vector<uint8_t>& data) {
   if (!imageData)
     return false;
   int width = imageDataSize.width();
   int height = imageDataSize.height();
 
   unsigned packedSize;
   // Output data is tightly packed (alignment == 1).
   PixelStoreParams params;
   params.alignment = 1;
-  if (computeImageSizeInBytes(format, type, width, height, 1, params,
+  if (computeImageSizeInBytes(format, type, sourceImageSubRect.width(),
+                              sourceImageSubRect.height(), 1, params,
                               &packedSize, 0, 0) != GL_NO_ERROR)
     return false;
   data.resize(packedSize);
 
   if (!packPixels(imageData, sourceDataFormat, width, height,
-                  IntRect(0, 0, width, height), 0, format, type,
+                  sourceImageSubRect, 0, format, type,
                   premultiplyAlpha ? AlphaDoPremultiply : AlphaDoNothing,
                   data.data(), flipY))
     return false;
 
   return true;
 }
 
 bool WebGLImageConversion::extractTextureData(unsigned width,
                                               unsigned height,
                                               GLenum format,
@@ skipping 173 matching lines @@
       pack<WebGLImageConversion::DataFormatRGB565,
            WebGLImageConversion::AlphaDoNothing>(srcRowStart, dstRowStart,
                                                  pixelsPerRow);
     } break;
     default:
       break;
   }
 }
 
 }  // namespace blink