diff options
Diffstat (limited to 'WebCore/platform/image-decoders/ImageDecoder.h')
| -rw-r--r-- | WebCore/platform/image-decoders/ImageDecoder.h | 269 |
1 files changed, 139 insertions, 130 deletions
diff --git a/WebCore/platform/image-decoders/ImageDecoder.h b/WebCore/platform/image-decoders/ImageDecoder.h index 17756ac..ca27b37 100644 --- a/WebCore/platform/image-decoders/ImageDecoder.h +++ b/WebCore/platform/image-decoders/ImageDecoder.h @@ -23,8 +23,8 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ -#ifndef IMAGE_DECODER_H_ -#define IMAGE_DECODER_H_ +#ifndef ImageDecoder_h +#define ImageDecoder_h #include "IntRect.h" #include "ImageSource.h" @@ -34,136 +34,145 @@ 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 - }; + 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, // Leave frame in framebuffer + DisposeKeep, // Leave frame in framebuffer + DisposeOverwriteBgcolor, // Clear frame to transparent + DisposeOverwritePrevious, // Clear frame to previous framebuffer contents + }; + + RGBA32Buffer() + : m_height(0) + , m_status(FrameEmpty) + , m_duration(0) + , m_disposalMethod(DisposeNotSpecified) + , m_hasAlpha(false) + { + } + + void clear() { + m_bytes.clear(); + m_status = FrameEmpty; + // NOTE: Do not reset other members here; clearFrameBufferCache() calls + // this to free the bitmap data, but other functions like + // initFrameBuffer() and frameComplete() may still need to read other + // metadata out of this frame later. + } - RGBA32Buffer() : m_height(0), m_status(FrameEmpty), m_duration(0), - m_disposalMethod(DisposeNotSpecified), m_hasAlpha(false) - {} - - void clear() { - m_bytes.clear(); - m_status = FrameEmpty; - // NOTE: Do not reset other members here; clearFrameBufferCache() calls - // this to free the bitmap data, but other functions like - // initFrameBuffer() and frameComplete() may still need to read other - // metadata out of this frame later. - } - - 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); + 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); } - 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() {} - - // 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. - 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; } - - // 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_sizeAvailable; - mutable bool m_failed; - IntSize m_size; -}; - -} + + 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() {} + + // 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. + 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; } + + // 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_sizeAvailable; + mutable bool m_failed; + IntSize m_size; + }; + +} // namespace WebCore #endif |