POSIX: bitmap data on the wire

skia/ext/platform_canvas_mac.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef SKIA_EXT_PLATFORM_CANVAS_MAC_H_
 #define SKIA_EXT_PLATFORM_CANVAS_MAC_H_
 
 #include "skia/ext/platform_device_mac.h"
 
 #include "SkCanvas.h"
@@ skipping 39 matching lines @@
   // bottommost device.
   //
   // Danger: the resulting device should not be saved. It will be invalidated
   // by the next call to save() or restore().
   PlatformDeviceMac& getTopPlatformDevice() const;
 
   // Allow callers to see the non-virtual function even though we have an
   // override of a virtual one.
   using SkCanvas::clipRect;
 
+  // Return the stride (length of a line in bytes) for the given width. Because
+  // we use 32-bits per pixel, this will be roughly 4*width. However, for
+  // alignment reasons we may wish to increase that.
+  static size_t StrideForWidth(unsigned width);
+
  protected:
   // Creates a device store for use by the canvas. We override this so that
   // the device is always our own so we know that we can use GDI operations
   // on it. Simply calls into createPlatformDevice().
   virtual SkDevice* createDevice(SkBitmap::Config, int width, int height,
                                  bool is_opaque, bool isForLayer);
 
   // Creates a device store for use by the canvas. By default, it creates a
   // BitmapPlatformDevice object. Can be overridden to change the object type.
   virtual SkDevice* createPlatformDevice(int width, int height, bool is_opaque,
                                          CGContextRef context);
 
  private:
   // Unimplemented. This is to try to prevent people from calling this function
   // on SkCanvas. SkCanvas' version is not virtual, so we can't prevent this
   // 100%, but hopefully this will make people notice and not use the function.
   // Calling SkCanvas' version will create a new device which is not compatible
   // with us and we will crash if somebody tries to draw into it with
   // CoreGraphics.
   SkDevice* setBitmapDevice(const SkBitmap& bitmap);
 
   // Disallow copy and assign.
   PlatformCanvasMac(const PlatformCanvasMac&);
   PlatformCanvasMac& operator=(const PlatformCanvasMac&);
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_MAC_H_