FrameSequence_gif.h revision a3ac0a2df64dcfb8b0b01f1cf05e9afd1439e1f4 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef RASTERMILL_FRAMESQUENCE_GIF_H
18#define RASTERMILL_FRAMESQUENCE_GIF_H
19
20#include "config.h"
21#include "gif_lib.h"
22
23#include "Stream.h"
24#include "Color.h"
25#include "FrameSequence.h"
26
27class FrameSequence_gif : public FrameSequence {
28public:
29    FrameSequence_gif(Stream* stream);
30    virtual ~FrameSequence_gif();
31
32    virtual int getWidth() const {
33        return mGif ? mGif->SWidth : 0;
34    }
35
36    virtual int getHeight() const {
37        return mGif ? mGif->SHeight : 0;
38    }
39
40    virtual int getFrameCount() const {
41        return mGif ? mGif->ImageCount : 0;
42    }
43
44    virtual bool isOpaque() const {
45        return (mBgColor & COLOR_8888_ALPHA_MASK) == COLOR_8888_ALPHA_MASK;
46    }
47
48    virtual FrameSequenceState* createState() const;
49
50    GifFileType* getGif() const { return mGif; }
51    Color8888 getBackgroundColor() const { return mBgColor; }
52    bool getPreservedFrame(int frameIndex) const { return mPreservedFrames[frameIndex]; }
53    int getRestoringFrame(int frameIndex) const { return mRestoringFrames[frameIndex]; }
54
55private:
56    GifFileType* mGif;
57    Color8888 mBgColor;
58
59    // array of bool per frame - if true, frame data is used by a later DISPOSE_PREVIOUS frame
60    bool* mPreservedFrames;
61
62    // array of ints per frame - if >= 0, points to the index of the preserve that frame needs
63    int* mRestoringFrames;
64};
65
66class FrameSequenceState_gif : public FrameSequenceState {
67public:
68    FrameSequenceState_gif(const FrameSequence_gif& frameSequence);
69    virtual ~FrameSequenceState_gif();
70
71    // returns frame's delay time in ms
72    virtual long drawFrame(int frameNr,
73            Color8888* outputPtr, int outputPixelStride, int previousFrameNr);
74
75private:
76    void savePreserveBuffer(Color8888* outputPtr, int outputPixelStride, int frameNr);
77    void restorePreserveBuffer(Color8888* outputPtr, int outputPixelStride);
78
79    const FrameSequence_gif& mFrameSequence;
80    Color8888* mPreserveBuffer;
81    int mPreserveBufferFrame;
82};
83
84#endif //RASTERMILL_FRAMESQUENCE_GIF_H
85