JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/image-decoders/ImageFrame.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2009-2010. 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
@@ skipping 48 matching lines @@
     enum AlphaBlendSource {
         // Blend non-opaque pixels atop the corresponding pixels in the
         // initial buffer state (i.e. any previous frame buffer after having
         // been properly disposed).
         BlendAtopPreviousFrame,
 
         // Blend non-opaque pixels against fully transparent (i.e. simply
         // overwrite the corresponding pixels).
         BlendAtopBgcolor,
     };
+
+    enum ColorType {
+        RGBA8888 = kN32_SkColorType,
+        RGB565 = kRGB_565_SkColorType
+    };
+
     typedef uint32_t PixelData;
+    typedef uint16_t PixelData16;
 
     ImageFrame();
 
     // The assignment operator reads m_hasAlpha (inside setStatus()) before it
     // sets it (in setHasAlpha()).  This doesn't cause any problems, since the
     // setHasAlpha() call ensures all state is set correctly, but it means we
     // need to initialize m_hasAlpha to some value before calling the operator
     // lest any tools complain about using an uninitialized value.
     ImageFrame(const ImageFrame& other) : m_hasAlpha(false) { operator=(other); }
 
@@ skipping 20 matching lines @@
         ASSERT(endX <= width());
         ASSERT(startY < height());
         ASSERT(endY <= height());
         const int rowBytes = (endX - startX) * sizeof(PixelData);
         const PixelData* const startAddr = getAddr(startX, startY);
         for (int destY = startY + 1; destY < endY; ++destY)
             memcpy(getAddr(startX, destY), startAddr, rowBytes);
     }
 
     // Allocates space for the pixel data.  Must be called before any pixels
-    // are written.  Must only be called once.  Returns whether allocation
-    // succeeded.
-    bool setSize(int newWidth, int newHeight);
+    // are written. Returns whether allocation succeeded.
+    bool setSize(int newWidth, int newHeight, ColorType bitmapType = RGBA8888);
+    inline bool hasSize(const IntSize& size, ColorType bitmapType) const
+    {
+        // skip checking height, no stretching involved
+        return (m_bitmap.width() == size.width()) && (bitmapType == static_cast<ColorType>(m_bitmap.colorType()));
+    }
 
     // Returns a caller-owned pointer to the underlying native image data.
     // (Actual use: This pointer will be owned by BitmapImage and freed in
     // FrameData::clear()).
     const SkBitmap& bitmap() const;
 
     bool hasAlpha() const;
     const IntRect& originalFrameRect() const { return m_originalFrameRect; }
     Status status() const { return m_status; }
     unsigned duration() const { return m_duration; }
@@ skipping 16 matching lines @@
     // The pixelsChanged flag needs to be set when the raw pixel data was directly modified
     // (e.g. through a pointer or setRGBA). The flag is usually set after a batch of changes was made.
     void setPixelsChanged(bool pixelsChanged) { m_pixelsChanged = pixelsChanged; }
     void setRequiredPreviousFrameIndex(size_t previousFrameIndex) { m_requiredPreviousFrameIndex = previousFrameIndex; }
 
     inline PixelData* getAddr(int x, int y)
     {
         return m_bitmap.getAddr32(x, y);
     }
 
+    template<class T>
+    inline T* getAddrT(int x, int y)
+    {
+        ASSERT_NOT_REACHED();
+    }
+
     inline void setRGBA(int x, int y, unsigned r, unsigned g, unsigned b, unsigned a)
     {
         setRGBA(getAddr(x, y), r, g, b, a);
     }
 
     inline void setRGBA(PixelData* dest, unsigned r, unsigned g, unsigned b, unsigned a)
     {
         if (m_premultiplyAlpha)
             setRGBAPremultiply(dest, r, g, b, a);
         else
@@ skipping 12 matching lines @@
         }
 
         *dest = SkPackARGB32NoCheck(a, r, g, b);
     }
 
     static inline void setRGBARaw(PixelData* dest, unsigned r, unsigned g, unsigned b, unsigned a)
     {
         *dest = SkPackARGB32NoCheck(a, r, g, b);
     }
 
+    static inline void setRGB565(PixelData16* dest, unsigned r, unsigned g, unsigned b)
+    {
+        *dest = SkDitherPack888ToRGB16(r, g, b);
+    }
+
     // Notifies the SkBitmap if any pixels changed and resets the flag.
     inline void notifyBitmapIfPixelsChanged()
     {
         if (m_pixelsChanged)
             m_bitmap.notifyPixelsChanged();
         m_pixelsChanged = false;
     }
 
 private:
     int width() const
@@ skipping 20 matching lines @@
     // True if the pixels changed, but the bitmap has not yet been notified.
     bool m_pixelsChanged;
 
     // The frame that must be decoded before this frame can be decoded.
     // WTF::kNotFound if this frame doesn't require any previous frame.
     // This is used by ImageDecoder::clearCacheExceptFrame(), and will never
     // be read for image formats that do not have multiple frames.
     size_t m_requiredPreviousFrameIndex;
 };
 
+template<>
+inline ImageFrame::PixelData* ImageFrame::getAddrT<ImageFrame::PixelData>(int x, int y)
+{
+    return m_bitmap.getAddr32(x, y);
+}
+
+template<>
+inline ImageFrame::PixelData16* ImageFrame::getAddrT<ImageFrame::PixelData16>(int x, int y)
+{
+    return m_bitmap.getAddr16(x, y);
+}
+
 } // namespace blink
 
 #endif