summaryrefslogtreecommitdiffstats
path: root/Source/WebCore/platform/graphics/android/BaseTile.h
blob: d336ae2cbb5eeaf982954502471113c944e3df27 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/*
 * Copyright 2010, The Android Open Source Project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * 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 THE COPYRIGHT HOLDERS ``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 THE COPYRIGHT OWNER 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 BaseTile_h
#define BaseTile_h

#if USE(ACCELERATED_COMPOSITING)

#include "BaseRenderer.h"
#include "SkRect.h"
#include "SkRegion.h"
#include "TextureOwner.h"

#include <utils/threads.h>

namespace WebCore {

class TextureInfo;
class TiledPage;
class BaseTileTexture;

/**
 * An individual tile that is used to construct part of a webpage's BaseLayer of
 * content.  Each tile is assigned to a TiledPage and is responsible for drawing
 * and displaying their section of the page.  The lifecycle of a tile is:
 *
 * 1. Each tile is created on the main GL thread and assigned to a specific
 *    location within a TiledPage.
 * 2. When needed the tile is passed to the background thread where it paints
 *    the BaseLayer's most recent PictureSet to a bitmap which is then uploaded
 *    to the GPU.
 * 3. After the bitmap is uploaded to the GPU the main GL thread then uses the
 *    tile's draw() function to display the tile to the screen.
 * 4. Steps 2-3 are repeated as necessary.
 * 5. The tile is destroyed when the user navigates to a new page.
 *
 */
class BaseTile : public TextureOwner {
public:
    BaseTile();
    ~BaseTile();

    void setContents(TiledPage* page, int x, int y);
    bool isAvailable() const { return !m_texture; }

    void reserveTexture();
    void setUsedLevel(int);
    int usedLevel();
    bool isTileReady();
    void draw(float transparency, SkRect& rect, float scale);

    // the only thread-safe function called by the background thread
    void paintBitmap();
    int paintPartialBitmap(SkIRect rect, float tx, float ty,
                            float scale, BaseTileTexture* texture,
                            TextureInfo* textureInfo,
                            TiledPage* tiledPage,
                            bool fullRepaint = false);

    void markAsDirty(const unsigned int pictureCount,
                     const SkRegion& dirtyArea);
    bool isDirty();
    bool isRepaintPending();
    void setRepaintPending(bool pending);
    void setUsable(bool usable);
    float scale() const { return m_scale; }
    void setScale(float scale);
    void fullInval();

    int x() const { return m_x; }
    int y() const { return m_y; }
    unsigned int lastPaintedPicture() const { return m_lastPaintedPicture; }
    BaseTileTexture* texture() { return m_texture; }

    // TextureOwner implementation
    virtual bool removeTexture(BaseTileTexture* texture);
    virtual TiledPage* page() { return m_page; }

private:
    // these variables are only set when the object is constructed
    TiledPage* m_page;
    int m_x;
    int m_y;

    // The remaining variables can be updated throughout the lifetime of the object
    BaseTileTexture* m_texture;
    float m_scale;
    // used to signal that the that the tile is out-of-date and needs to be redrawn
    bool m_dirty;
    // used to signal that a repaint is pending
    bool m_repaintPending;
    // used to signal whether or not the draw can use this tile.
    bool m_usable;
    // stores the id of the latest picture from webkit that caused this tile to
    // become dirty. A tile is no longer dirty when it has been painted with a
    // picture that is newer than this value.
    unsigned int m_lastDirtyPicture;

    // store the dirty region
    SkRegion m_dirtyAreaA;
    SkRegion m_dirtyAreaB;
    bool m_fullRepaintA;
    bool m_fullRepaintB;
    SkRegion* m_currentDirtyArea;

    // stores the id of the latest picture painted to the tile. If the id is 0
    // then we know that the picture has not yet been painted an there is nothing
    // to display (dirty or otherwise).
    unsigned int m_lastPaintedPicture;

    // This mutex serves two purposes. (1) It ensures that certain operations
    // happen atomically and (2) it makes sure those operations are synchronized
    // across all threads and cores.
    android::Mutex m_atomicSync;

    BaseRenderer* m_renderer;
};

} // namespace WebCore

#endif // USE(ACCELERATED_COMPOSITING)
#endif // BaseTile_h