1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/image/src/FrameBlender.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,192 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + *
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef mozilla_imagelib_FrameBlender_h_
1.11 +#define mozilla_imagelib_FrameBlender_h_
1.12 +
1.13 +#include "mozilla/MemoryReporting.h"
1.14 +#include "gfxTypes.h"
1.15 +#include "FrameSequence.h"
1.16 +#include "nsCOMPtr.h"
1.17 +
1.18 +class imgFrame;
1.19 +
1.20 +namespace mozilla {
1.21 +namespace image {
1.22 +
1.23 +/**
1.24 + * FrameBlender stores and gives access to imgFrames. It also knows how to
1.25 + * blend frames from previous to next, looping if necessary.
1.26 + *
1.27 + * All logic about when and whether to blend are external to FrameBlender.
1.28 + */
1.29 +class FrameBlender
1.30 +{
1.31 +public:
1.32 +
1.33 + /**
1.34 + * Create a new FrameBlender with a given frame sequence.
1.35 + *
1.36 + * If aSequenceToUse is not specified, it will be allocated automatically.
1.37 + */
1.38 + FrameBlender(FrameSequence* aSequenceToUse = nullptr);
1.39 + ~FrameBlender();
1.40 +
1.41 + bool DoBlend(nsIntRect* aDirtyRect, uint32_t aPrevFrameIndex,
1.42 + uint32_t aNextFrameIndex);
1.43 +
1.44 + already_AddRefed<FrameSequence> GetFrameSequence();
1.45 +
1.46 + /**
1.47 + * Get the @aIndex-th frame, including (if applicable) any results of
1.48 + * blending.
1.49 + */
1.50 + imgFrame* GetFrame(uint32_t aIndex) const;
1.51 +
1.52 + /**
1.53 + * Get the @aIndex-th frame in the frame index, ignoring results of blending.
1.54 + */
1.55 + imgFrame* RawGetFrame(uint32_t aIndex) const;
1.56 +
1.57 + void InsertFrame(uint32_t framenum, imgFrame* aFrame);
1.58 + void RemoveFrame(uint32_t framenum);
1.59 + imgFrame* SwapFrame(uint32_t framenum, imgFrame* aFrame);
1.60 + void ClearFrames();
1.61 +
1.62 + /* The total number of frames in this image. */
1.63 + uint32_t GetNumFrames() const;
1.64 +
1.65 + /*
1.66 + * Returns the frame's adjusted timeout. If the animation loops and the timeout
1.67 + * falls in between a certain range then the timeout is adjusted so that
1.68 + * it's never 0. If the animation does not loop then no adjustments are made.
1.69 + */
1.70 + int32_t GetTimeoutForFrame(uint32_t framenum) const;
1.71 +
1.72 + /*
1.73 + * Set number of times to loop the image.
1.74 + * @note -1 means loop forever.
1.75 + */
1.76 + void SetLoopCount(int32_t aLoopCount);
1.77 + int32_t GetLoopCount() const;
1.78 +
1.79 + void Discard();
1.80 +
1.81 + void SetSize(nsIntSize aSize) { mSize = aSize; }
1.82 +
1.83 + size_t SizeOfDecodedWithComputedFallbackIfHeap(gfxMemoryLocation aLocation,
1.84 + mozilla::MallocSizeOf aMallocSizeOf) const;
1.85 +
1.86 + void ResetAnimation();
1.87 +
1.88 + // "Blend" method indicates how the current image is combined with the
1.89 + // previous image.
1.90 + enum FrameBlendMethod {
1.91 + // All color components of the frame, including alpha, overwrite the current
1.92 + // contents of the frame's output buffer region
1.93 + kBlendSource = 0,
1.94 +
1.95 + // The frame should be composited onto the output buffer based on its alpha,
1.96 + // using a simple OVER operation
1.97 + kBlendOver
1.98 + };
1.99 +
1.100 + enum FrameDisposalMethod {
1.101 + kDisposeClearAll = -1, // Clear the whole image, revealing
1.102 + // what was there before the gif displayed
1.103 + kDisposeNotSpecified, // Leave frame, let new frame draw on top
1.104 + kDisposeKeep, // Leave frame, let new frame draw on top
1.105 + kDisposeClear, // Clear the frame's area, revealing bg
1.106 + kDisposeRestorePrevious // Restore the previous (composited) frame
1.107 + };
1.108 +
1.109 + // A hint as to whether an individual frame is entirely opaque, or requires
1.110 + // alpha blending.
1.111 + enum FrameAlpha {
1.112 + kFrameHasAlpha,
1.113 + kFrameOpaque
1.114 + };
1.115 +
1.116 +private:
1.117 +
1.118 + struct Anim
1.119 + {
1.120 + //! Track the last composited frame for Optimizations (See DoComposite code)
1.121 + int32_t lastCompositedFrameIndex;
1.122 +
1.123 + /** For managing blending of frames
1.124 + *
1.125 + * Some animations will use the compositingFrame to composite images
1.126 + * and just hand this back to the caller when it is time to draw the frame.
1.127 + * NOTE: When clearing compositingFrame, remember to set
1.128 + * lastCompositedFrameIndex to -1. Code assume that if
1.129 + * lastCompositedFrameIndex >= 0 then compositingFrame exists.
1.130 + */
1.131 + FrameDataPair compositingFrame;
1.132 +
1.133 + /** the previous composited frame, for DISPOSE_RESTORE_PREVIOUS
1.134 + *
1.135 + * The Previous Frame (all frames composited up to the current) needs to be
1.136 + * stored in cases where the image specifies it wants the last frame back
1.137 + * when it's done with the current frame.
1.138 + */
1.139 + FrameDataPair compositingPrevFrame;
1.140 +
1.141 + Anim() :
1.142 + lastCompositedFrameIndex(-1)
1.143 + {}
1.144 + };
1.145 +
1.146 + void EnsureAnimExists();
1.147 +
1.148 + /** Clears an area of <aFrame> with transparent black.
1.149 + *
1.150 + * @param aFrameData Target Frame data
1.151 + * @param aFrameRect The rectangle of the data pointed ot by aFrameData
1.152 + *
1.153 + * @note Does also clears the transparancy mask
1.154 + */
1.155 + static void ClearFrame(uint8_t* aFrameData, const nsIntRect& aFrameRect);
1.156 +
1.157 + //! @overload
1.158 + static void ClearFrame(uint8_t* aFrameData, const nsIntRect& aFrameRect, const nsIntRect &aRectToClear);
1.159 +
1.160 + //! Copy one frames's image and mask into another
1.161 + static bool CopyFrameImage(const uint8_t *aDataSrc, const nsIntRect& aRectSrc,
1.162 + uint8_t *aDataDest, const nsIntRect& aRectDest);
1.163 +
1.164 + /**
1.165 + * Draws one frames's image to into another, at the position specified by
1.166 + * aSrcRect.
1.167 + *
1.168 + * @aSrcData the raw data of the current frame being drawn
1.169 + * @aSrcRect the size of the source frame, and the position of that frame in
1.170 + * the composition frame
1.171 + * @aSrcPaletteLength the length (in bytes) of the palette at the beginning
1.172 + * of the source data (0 if image is not paletted)
1.173 + * @aSrcHasAlpha whether the source data represents an image with alpha
1.174 + * @aDstPixels the raw data of the composition frame where the current frame
1.175 + * is drawn into (32-bit ARGB)
1.176 + * @aDstRect the size of the composition frame
1.177 + * @aBlendMethod the blend method for how to blend src on the composition frame.
1.178 + */
1.179 + static nsresult DrawFrameTo(const uint8_t *aSrcData, const nsIntRect& aSrcRect,
1.180 + uint32_t aSrcPaletteLength, bool aSrcHasAlpha,
1.181 + uint8_t *aDstPixels, const nsIntRect& aDstRect,
1.182 + FrameBlendMethod aBlendMethod);
1.183 +
1.184 +private: // data
1.185 + //! All the frames of the image
1.186 + nsRefPtr<FrameSequence> mFrames;
1.187 + nsIntSize mSize;
1.188 + Anim* mAnim;
1.189 + int32_t mLoopCount;
1.190 +};
1.191 +
1.192 +} // namespace image
1.193 +} // namespace mozilla
1.194 +
1.195 +#endif /* mozilla_imagelib_FrameBlender_h_ */
