support uploading sub-rectangles of ImageData

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

 /*
  * 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 1004 matching lines @@
                     GLint zoffset,
                     GLenum format,
                     GLenum type,
                     Image*,
                     WebGLImageConversion::ImageHtmlDomSource,
                     bool flipY,
                     bool premultiplyAlpha,
                     const IntRect&,
                     GLsizei depth,
                     GLint unpackImageHeight);
+  template <typename T>
+  bool validateTexImageSubRectangle(const char* functionName,
+                                    T* image,
+                                    const IntRect& subRect,
+                                    bool* selectingSubRectangle) {
+    *selectingSubRectangle = image &&
+                             !(subRect.x() == 0 && subRect.y() == 0 &&
+                               subRect.width() == image->width() &&
+                               subRect.height() == image->height());
+    // If the source image rect selects anything except the entire
+    // contents of the image, assert that we're running WebGL 2.0 or
+    // higher, since this should never happen for WebGL 1.0 (even though
+    // the code could support it). If the image is null, that will be
+    // signaled as an error later.
+    DCHECK(!*selectingSubRectangle || isWebGL2OrHigher())
+        << "subRect = (" << subRect.width() << " x " << subRect.height()
+        << ") @ (" << subRect.x() << ", " << subRect.y() << "), image = ("
+        << (image ? image->width() : -1) << " x "
+        << (image ? image->height() : -1) << ")";
+
+    if (subRect.x() < 0 || subRect.y() < 0 || subRect.maxX() > image->width() ||
+        subRect.maxY() > image->height() || subRect.width() < 0 ||
+        subRect.height() < 0) {
+      synthesizeGLError(GL_INVALID_OPERATION, functionName,
+                        "source sub-rectangle specified via pixel unpack "
+                        "parameters is invalid");
+      return false;
+    }
+    return true;
+  }
 
   // Copy from the source directly to the texture via the gpu, without a
   // read-back to system memory.  Souce could be canvas or imageBitmap.
   void texImageByGPU(TexImageByGPUType,
                      WebGLTexture*,
                      GLenum target,
                      GLint level,
                      GLint internalformat,
                      GLenum type,
                      GLint xoffset,
@@ skipping 438 matching lines @@
                                GLenum,
                                GLint,
                                GLint,
                                GLint,
                                GLenum,
                                GLenum,
                                GLsizei,
                                GLint,
                                GLint,
                                GLint,
-                               ImageData*);
+                               ImageData*,
+                               const IntRect&);
   void texImageHelperHTMLImageElement(TexImageFunctionID,
                                       GLenum,
                                       GLint,
                                       GLint,
                                       GLenum,
                                       GLenum,
                                       GLint,
                                       GLint,
                                       GLint,
                                       HTMLImageElement*,
@@ skipping 30 matching lines @@
                                  GLenum,
                                  GLenum,
                                  GLint,
                                  GLint,
                                  GLint,
                                  ImageBitmap*,
                                  ExceptionState&);
   static const char* getTexImageFunctionName(TexImageFunctionID);
   IntRect sentinelEmptyRect();
   IntRect safeGetImageSize(Image*);
+  IntRect getImageDataSize(ImageData*);
 
   // Helper implementing readPixels for WebGL 1.0 and 2.0.
   void readPixelsHelper(GLint x,
                         GLint y,
                         GLsizei width,
                         GLsizei height,
                         GLenum format,
                         GLenum type,
                         DOMArrayBufferView* pixels,
                         GLuint offset);
@@ skipping 22 matching lines @@
                   context,
                   context->is3d(),
                   context.is3d());
 
 }  // namespace blink
 
 WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(
     blink::WebGLRenderingContextBase::TextureUnitState);
 
 #endif  // WebGLRenderingContextBase_h