1/*
2 * Copyright (C) 2012 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 ANDROID_HWUI_CACHE_TEXTURE_H
18#define ANDROID_HWUI_CACHE_TEXTURE_H
19
20#include "PixelBuffer.h"
21#include "Rect.h"
22#include "Texture.h"
23#include "Vertex.h"
24
25#include <GLES3/gl3.h>
26#include <SkGlyph.h>
27#include <utils/Log.h>
28
29
30namespace android {
31namespace uirenderer {
32
33class Caches;
34
35/**
36 * CacheBlock is a node in a linked list of current free space areas in a CacheTexture.
37 * Using CacheBlocks enables us to pack the cache from top to bottom as well as left to right.
38 * When we add a glyph to the cache, we see if it fits within one of the existing columns that
39 * have already been started (this is the case if the glyph fits vertically as well as
40 * horizontally, and if its width is sufficiently close to the column width to avoid
41 * sub-optimal packing of small glyphs into wide columns). If there is no column in which the
42 * glyph fits, we check the final node, which is the remaining space in the cache, creating
43 * a new column as appropriate.
44 *
45 * As columns fill up, we remove their CacheBlock from the list to avoid having to check
46 * small blocks in the future.
47 */
48struct CacheBlock {
49    uint16_t mX;
50    uint16_t mY;
51    uint16_t mWidth;
52    uint16_t mHeight;
53    CacheBlock* mNext;
54    CacheBlock* mPrev;
55
56    CacheBlock(uint16_t x, uint16_t y, uint16_t width, uint16_t height):
57            mX(x), mY(y), mWidth(width), mHeight(height), mNext(nullptr), mPrev(nullptr) {
58    }
59
60    static CacheBlock* insertBlock(CacheBlock* head, CacheBlock* newBlock);
61    static CacheBlock* removeBlock(CacheBlock* head, CacheBlock* blockToRemove);
62
63    void output() {
64        CacheBlock* currBlock = this;
65        while (currBlock) {
66            ALOGD("Block: this, x, y, w, h = %p, %d, %d, %d, %d",
67                    currBlock, currBlock->mX, currBlock->mY,
68                    currBlock->mWidth, currBlock->mHeight);
69            currBlock = currBlock->mNext;
70        }
71    }
72};
73
74class CacheTexture {
75public:
76    CacheTexture(uint16_t width, uint16_t height, GLenum format, uint32_t maxQuadCount);
77    ~CacheTexture();
78
79    void reset();
80    void init();
81
82    void releaseMesh();
83    void releasePixelBuffer();
84
85    void allocatePixelBuffer();
86    void allocateMesh();
87
88    // Returns true if glPixelStorei(GL_UNPACK_ROW_LENGTH) must be reset
89    // This method will also call setDirty(false)
90    bool upload();
91
92    bool fitBitmap(const SkGlyph& glyph, uint32_t* retOriginX, uint32_t* retOriginY);
93
94    inline uint16_t getWidth() const {
95        return mWidth;
96    }
97
98    inline uint16_t getHeight() const {
99        return mHeight;
100    }
101
102    inline GLenum getFormat() const {
103        return mFormat;
104    }
105
106    inline uint32_t getOffset(uint16_t x, uint16_t y) const {
107        return (y * getWidth() + x) * PixelBuffer::formatSize(mFormat);
108    }
109
110    inline const Rect* getDirtyRect() const {
111        return &mDirtyRect;
112    }
113
114    inline PixelBuffer* getPixelBuffer() const {
115        return mPixelBuffer;
116    }
117
118    Texture& getTexture() {
119        allocatePixelBuffer();
120        return mTexture;
121    }
122
123    GLuint getTextureId() {
124        allocatePixelBuffer();
125        return mTexture.id();
126    }
127
128    inline bool isDirty() const {
129        return mDirty;
130    }
131
132    inline bool getLinearFiltering() const {
133        return mLinearFiltering;
134    }
135
136    /**
137     * This method assumes that the proper texture unit is active.
138     */
139    void setLinearFiltering(bool linearFiltering);
140
141    inline uint16_t getGlyphCount() const {
142        return mNumGlyphs;
143    }
144
145    TextureVertex* mesh() const {
146        return mMesh;
147    }
148
149    uint32_t meshElementCount() const {
150        return mCurrentQuad * 6;
151    }
152
153    uint16_t* indices() const {
154        return (uint16_t*) nullptr;
155    }
156
157    void resetMesh() {
158        mCurrentQuad = 0;
159    }
160
161    inline void addQuad(float x1, float y1, float u1, float v1,
162            float x2, float y2, float u2, float v2,
163            float x3, float y3, float u3, float v3,
164            float x4, float y4, float u4, float v4) {
165        TextureVertex* mesh = mMesh + mCurrentQuad * 4;
166        TextureVertex::set(mesh++, x2, y2, u2, v2);
167        TextureVertex::set(mesh++, x3, y3, u3, v3);
168        TextureVertex::set(mesh++, x1, y1, u1, v1);
169        TextureVertex::set(mesh++, x4, y4, u4, v4);
170        mCurrentQuad++;
171    }
172
173    bool canDraw() const {
174        return mCurrentQuad > 0;
175    }
176
177    bool endOfMesh() const {
178        return mCurrentQuad == mMaxQuadCount;
179    }
180
181private:
182    void setDirty(bool dirty);
183
184    PixelBuffer* mPixelBuffer = nullptr;
185    Texture mTexture;
186    uint32_t mWidth, mHeight;
187    GLenum mFormat;
188    bool mLinearFiltering = false;
189    bool mDirty = false;
190    uint16_t mNumGlyphs = 0;
191    TextureVertex* mMesh = nullptr;
192    uint32_t mCurrentQuad = 0;
193    uint32_t mMaxQuadCount;
194    Caches& mCaches;
195    CacheBlock* mCacheBlocks;
196    bool mHasUnpackRowLength;
197    Rect mDirtyRect;
198};
199
200}; // namespace uirenderer
201}; // namespace android
202
203#endif // ANDROID_HWUI_CACHE_TEXTURE_H
204