/* * Copyright (C) 2006 Apple Computer, 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 * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef ImageDecoder_h #define ImageDecoder_h #include "IntRect.h" #include "ImageSource.h" #include "PlatformString.h" #include "SharedBuffer.h" #include <wtf/Assertions.h> #include <wtf/RefPtr.h> #include <wtf/Vector.h> #if PLATFORM(SKIA) #include "NativeImageSkia.h" #include "SkBitmap.h" #endif namespace WebCore { // The RGBA32Buffer object represents the decoded image data in RGBA32 format. This buffer is what all // decoders write a single frame into. Frames are then instantiated for drawing by being handed this buffer. class RGBA32Buffer { public: enum FrameStatus { FrameEmpty, FramePartial, FrameComplete }; enum FrameDisposalMethod { // If you change the numeric values of these, make sure you audit all // users, as some users may cast raw values to/from these constants. DisposeNotSpecified, // Leave frame in framebuffer DisposeKeep, // Leave frame in framebuffer DisposeOverwriteBgcolor, // Clear frame to transparent DisposeOverwritePrevious, // Clear frame to previous framebuffer contents }; #if PLATFORM(SKIA) typedef uint32_t PixelData; #else typedef unsigned PixelData; #endif RGBA32Buffer(); // For backends which refcount their data, this constructor doesn't need // to create a new copy of the image data, only increase the ref count. // // This exists because ImageDecoder keeps a Vector<RGBA32Buffer>, and // Vector requires this constructor. RGBA32Buffer(const RGBA32Buffer& other) { operator=(other); } // Deletes the pixel data entirely; used by ImageDecoder to save memory // when we no longer need to display a frame and only need its metadata. void clear(); // Zeroes the pixel data in the buffer, setting it to fully-transparent. void zeroFill(); // Creates a new copy of the image data in |other|, so the two images // can be modified independently. void copyBitmapData(const RGBA32Buffer& other); // Copies the pixel data at [(startX, startY), (endX, startY)) to the // same X-coordinates on each subsequent row up to but not including // endY. void copyRowNTimes(int startX, int endX, int startY, int endY) { ASSERT(startX < width()); 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. Will return true on success, false if the memory // allocation fails. Calling this multiple times is undefined and may // leak memory. bool setSize(int newWidth, int newHeight); // To be used by ImageSource::createFrameAtIndex(). Returns a pointer // to the underlying native image data. This pointer will be owned by // the BitmapImage and freed in FrameData::clear(). NativeImagePtr asNewNativeImage() const; bool hasAlpha() const; const IntRect& rect() const { return m_rect; } FrameStatus status() const { return m_status; } unsigned duration() const { return m_duration; } FrameDisposalMethod disposalMethod() const { return m_disposalMethod; } void setHasAlpha(bool alpha); void setRect(const IntRect& r) { m_rect = r; } void setStatus(FrameStatus status); void setDuration(unsigned duration) { m_duration = duration; } void setDisposalMethod(FrameDisposalMethod method) { m_disposalMethod = method; } inline void setRGBA(int x, int y, unsigned r, unsigned g, unsigned b, unsigned a) { setRGBA(getAddr(x, y), r, g, b, a); } private: RGBA32Buffer& operator=(const RGBA32Buffer& other); int width() const; int height() const; inline PixelData* getAddr(int x, int y) { #if PLATFORM(CAIRO) || PLATFORM(WX) return m_bytes.data() + (y * width()) + x; #elif PLATFORM(SKIA) return m_bitmap.getAddr32(x, y); #else ASSERT_NOT_REACHED(); return 0; #endif } inline void setRGBA(PixelData* dest, unsigned r, unsigned g, unsigned b, unsigned a) { // We store this data pre-multiplied. if (a == 0) *dest = 0; else { if (a < 255) { float alphaPercent = a / 255.0f; r = static_cast<unsigned>(r * alphaPercent); g = static_cast<unsigned>(g * alphaPercent); b = static_cast<unsigned>(b * alphaPercent); } *dest = (a << 24 | r << 16 | g << 8 | b); } } #if PLATFORM(CAIRO) || PLATFORM(WX) Vector<PixelData> m_bytes; IntSize m_size; // The size of the buffer. This should be the // same as ImageDecoder::m_size. bool m_hasAlpha; // Whether or not any of the pixels in the buffer have transparency. #elif PLATFORM(SKIA) NativeImageSkia m_bitmap; #endif IntRect m_rect; // The rect of the original specified frame within the overall buffer. // This will always just be the entire buffer except for GIF frames // whose original rect was smaller than the overall image size. FrameStatus m_status; // Whether or not this frame is completely finished decoding. unsigned m_duration; // The animation delay. FrameDisposalMethod m_disposalMethod; // What to do with this frame's data when initializing the next frame. }; // The ImageDecoder class represents a base class for specific image format decoders // (e.g., GIF, JPG, PNG, ICO) to derive from. All decoders decode into RGBA32 format // and the base class manages the RGBA32 frame cache. class ImageDecoder { public: ImageDecoder() : m_failed(false) , m_sizeAvailable(false) { } virtual ~ImageDecoder() {} // The the filename extension usually associated with an undecoded image of this type. virtual String filenameExtension() const = 0; // All specific decoder plugins must do something with the data they are given. virtual void setData(SharedBuffer* data, bool allDataReceived) { m_data = data; } // Whether or not the size information has been decoded yet. This default // implementation just returns true if the size has been set and we have not // seen a failure. Decoders may want to override this to lazily decode // enough of the image to get the size. virtual bool isSizeAvailable() { return !m_failed && m_sizeAvailable; } // Requests the size. virtual IntSize size() const { // Requesting the size of an invalid bitmap is meaningless. ASSERT(!m_failed); return m_size; } // Called by the image decoders to set their decoded size, this also check // the size for validity. It will return true if the size was set, or false // if there is an error. On error, the m_failed flag will be set and the // caller should immediately stop decoding. virtual bool setSize(unsigned width, unsigned height) { if (isOverSize(width, height)) { m_failed = true; return false; } m_size = IntSize(width, height); m_sizeAvailable = true; return true; } // The total number of frames for the image. Classes that support multiple frames // will scan the image data for the answer if they need to (without necessarily // decoding all of the individual frames). virtual int frameCount() { return 1; } // The number of repetitions to perform for an animation loop. virtual int repetitionCount() const { return cAnimationNone; } // Called to obtain the RGBA32Buffer full of decoded data for rendering. The // decoder plugin will decode as much of the frame as it can before handing // back the buffer. virtual RGBA32Buffer* frameBufferAtIndex(size_t index) = 0; // Whether or not the underlying image format even supports alpha transparency. virtual bool supportsAlpha() const { return true; } bool failed() const { return m_failed; } void setFailed() { m_failed = true; } // Wipe out frames in the frame buffer cache before |clearBeforeFrame|, // assuming this can be done without breaking decoding. Different decoders // place different restrictions on what frames are safe to destroy, so this // is left to them to implement. // For convenience's sake, we provide a default (empty) implementation, // since in practice only GIFs will ever use this. virtual void clearFrameBufferCache(size_t clearBeforeFrame) { } protected: RefPtr<SharedBuffer> m_data; // The encoded data. Vector<RGBA32Buffer> m_frameBufferCache; bool m_failed; private: // Some code paths compute the size of the image as "width * height * 4" // and return it as a (signed) int. Avoid overflow. static bool isOverSize(unsigned width, unsigned height) { // width * height must not exceed (2 ^ 29) - 1, so that we don't // overflow when we multiply by 4. unsigned long long total_size = static_cast<unsigned long long>(width) * static_cast<unsigned long long>(height); return total_size > ((1 << 29) - 1); } IntSize m_size; bool m_sizeAvailable; }; } // namespace WebCore #endif