| /* |
| * 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 IMAGE_DECODER_H_ |
| #define IMAGE_DECODER_H_ |
| |
| #include "IntRect.h" |
| #include "ImageSource.h" |
| #include "SharedBuffer.h" |
| #include <wtf/Vector.h> |
| |
| namespace WebCore { |
| |
| typedef Vector<unsigned> RGBA32Array; |
| |
| // 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 = 0, // Leave frame in framebuffer |
| DisposeKeep = 1, // Leave frame in framebuffer |
| DisposeOverwriteBgcolor = 2, // Clear frame to transparent |
| DisposeOverwritePrevious = 3, // Clear frame to previous framebuffer contents |
| }; |
| |
| RGBA32Buffer() : m_height(0), m_status(FrameEmpty), m_duration(0), |
| m_disposalMethod(DisposeNotSpecified), m_hasAlpha(false) |
| {} |
| |
| const RGBA32Array& bytes() const { return m_bytes; } |
| RGBA32Array& bytes() { return m_bytes; } |
| const IntRect& rect() const { return m_rect; } |
| unsigned height() const { return m_height; } |
| FrameStatus status() const { return m_status; } |
| unsigned duration() const { return m_duration; } |
| FrameDisposalMethod disposalMethod() const { return m_disposalMethod; } |
| bool hasAlpha() const { return m_hasAlpha; } |
| |
| void setRect(const IntRect& r) { m_rect = r; } |
| void ensureHeight(unsigned rowIndex) { if (rowIndex > m_height) m_height = rowIndex; } |
| void setStatus(FrameStatus s) { m_status = s; } |
| void setDuration(unsigned duration) { m_duration = duration; } |
| void setDisposalMethod(FrameDisposalMethod method) { m_disposalMethod = method; } |
| void setHasAlpha(bool alpha) { m_hasAlpha = alpha; } |
| |
| static void setRGBA(unsigned& pos, unsigned r, unsigned g, unsigned b, unsigned a) |
| { |
| // We store this data pre-multiplied. |
| if (a == 0) |
| pos = 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); |
| } |
| pos = (a << 24 | r << 16 | g << 8 | b); |
| } |
| } |
| |
| private: |
| RGBA32Array m_bytes; |
| 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. |
| unsigned m_height; // The height (the number of rows we've fully decoded). |
| 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. |
| bool m_hasAlpha; // Whether or not any of the pixels in the buffer have transparency. |
| }; |
| |
| // 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_sizeAvailable(false), m_failed(false) {} |
| virtual ~ImageDecoder() {} |
| |
| // 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. |
| virtual bool isSizeAvailable() const = 0; |
| |
| // Requests the size. |
| virtual IntSize size() const { return m_size; } |
| |
| // 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; } |
| |
| protected: |
| RefPtr<SharedBuffer> m_data; // The encoded data. |
| Vector<RGBA32Buffer> m_frameBufferCache; |
| bool m_sizeAvailable; |
| mutable bool m_failed; |
| IntSize m_size; |
| }; |
| |
| } |
| |
| #endif |