rsFont.h revision 09c67356bbeee0a97a20a06c95b66756838cb541 
1/*
2 * Copyright (C) 2009 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_RS_FONT_H
18#define ANDROID_RS_FONT_H
19
20#include "RenderScript.h"
21#include "rsStream.h"
22#include <utils/String8.h>
23#include <utils/Vector.h>
24#include <utils/KeyedVector.h>
25
26#include <ft2build.h>
27#include FT_FREETYPE_H
28
29// ---------------------------------------------------------------------------
30namespace android {
31
32namespace renderscript {
33
34// Gamma (>= 1.0, <= 10.0)
35#define PROPERTY_TEXT_GAMMA "ro.text_gamma"
36#define PROPERTY_TEXT_BLACK_GAMMA_THRESHOLD "ro.text_gamma.black_threshold"
37#define PROPERTY_TEXT_WHITE_GAMMA_THRESHOLD "ro.text_gamma.white_threshold"
38
39#define DEFAULT_TEXT_GAMMA 1.4f
40#define DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD 64
41#define DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD 192
42
43class FontState;
44
45class Font : public ObjectBase
46{
47public:
48    enum RenderMode {
49        FRAMEBUFFER,
50        BITMAP,
51        MEASURE,
52    };
53
54    struct Rect {
55        int32_t left;
56        int32_t top;
57        int32_t right;
58        int32_t bottom;
59        void set(int32_t l, int32_t r, int32_t t, int32_t b) {
60            left = l;
61            right = r;
62            top = t;
63            bottom = b;
64        }
65    };
66
67    ~Font();
68
69    // Currently files do not get serialized,
70    // but we need to inherit from ObjectBase for ref tracking
71    virtual void serialize(OStream *stream) const {
72    }
73    virtual RsA3DClassID getClassId() const {
74        return RS_A3D_CLASS_ID_UNKNOWN;
75    }
76
77    static Font * create(Context *rsc, const char *name, uint32_t fontSize, uint32_t dpi);
78
79protected:
80
81    friend class FontState;
82
83    // Pointer to the utf data, length of data, where to start, number of glyphs ot read
84    // (each glyph may be longer than a char because we are dealing with utf data)
85    // Last two variables are the initial pen position
86    void renderUTF(const char *text, uint32_t len, int32_t x, int32_t y,
87                   uint32_t start, int32_t numGlyphs,
88                   RenderMode mode = FRAMEBUFFER, Rect *bounds = NULL,
89                   uint8_t *bitmap = NULL, uint32_t bitmapW = 0, uint32_t bitmapH = 0);
90
91    void invalidateTextureCache();
92    struct CachedGlyphInfo
93    {
94        // Has the cache been invalidated?
95        bool mIsValid;
96        // Location of the cached glyph in the bitmap
97        // in case we need to resize the texture
98        uint32_t mBitmapMinX;
99        uint32_t mBitmapMinY;
100        uint32_t mBitmapWidth;
101        uint32_t mBitmapHeight;
102        // Also cache texture coords for the quad
103        float mBitmapMinU;
104        float mBitmapMinV;
105        float mBitmapMaxU;
106        float mBitmapMaxV;
107        // Minimize how much we call freetype
108        FT_UInt mGlyphIndex;
109        FT_Vector mAdvance;
110        // Values below contain a glyph's origin in the bitmap
111        FT_Int mBitmapLeft;
112        FT_Int mBitmapTop;
113    };
114
115    String8 mFontName;
116    uint32_t mFontSize;
117    uint32_t mDpi;
118
119    Font(Context *rsc);
120    bool init(const char *name, uint32_t fontSize, uint32_t dpi);
121
122    FT_Face mFace;
123    bool mInitialized;
124    bool mHasKerning;
125
126    DefaultKeyedVector<uint32_t, CachedGlyphInfo* > mCachedGlyphs;
127    CachedGlyphInfo* getCachedUTFChar(int32_t utfChar);
128
129    CachedGlyphInfo *cacheGlyph(uint32_t glyph);
130    void updateGlyphCache(CachedGlyphInfo *glyph);
131    void measureCachedGlyph(CachedGlyphInfo *glyph, int32_t x, int32_t y, Rect *bounds);
132    void drawCachedGlyph(CachedGlyphInfo *glyph, int32_t x, int32_t y);
133    void drawCachedGlyph(CachedGlyphInfo *glyph, int32_t x, int32_t y,
134                         uint8_t *bitmap, uint32_t bitmapW, uint32_t bitmapH);
135};
136
137class FontState
138{
139public:
140    FontState();
141    ~FontState();
142
143    void init(Context *rsc);
144    void deinit(Context *rsc);
145
146    ObjectBaseRef<Font> mDefault;
147    ObjectBaseRef<Font> mLast;
148
149    void renderText(const char *text, uint32_t len, int32_t x, int32_t y,
150                    uint32_t startIndex = 0, int numGlyphs = -1,
151                    Font::RenderMode mode = Font::FRAMEBUFFER,
152                    Font::Rect *bounds = NULL,
153                    uint8_t *bitmap = NULL, uint32_t bitmapW = 0, uint32_t bitmapH = 0);
154
155    void measureText(const char *text, uint32_t len, Font::Rect *bounds);
156
157    void setFontColor(float r, float g, float b, float a);
158    void getFontColor(float *r, float *g, float *b, float *a) const;
159
160protected:
161
162    friend class Font;
163
164    struct CacheTextureLine
165    {
166        uint32_t mMaxHeight;
167        uint32_t mMaxWidth;
168        uint32_t mCurrentRow;
169        uint32_t mCurrentCol;
170        bool mDirty;
171
172        CacheTextureLine(uint32_t maxHeight, uint32_t maxWidth, uint32_t currentRow, uint32_t currentCol) :
173            mMaxHeight(maxHeight), mMaxWidth(maxWidth), mCurrentRow(currentRow), mCurrentCol(currentCol),
174            mDirty(false)  {
175        }
176
177        bool fitBitmap(FT_Bitmap *bitmap, uint32_t *retOriginX, uint32_t *retOriginY) {
178            if((uint32_t)bitmap->rows > mMaxHeight) {
179                return false;
180            }
181
182            if(mCurrentCol + (uint32_t)bitmap->width < mMaxWidth) {
183               *retOriginX = mCurrentCol;
184               *retOriginY = mCurrentRow;
185               mCurrentCol += bitmap->width;
186               mDirty = true;
187               return true;
188            }
189
190            return false;
191        }
192    };
193
194    Vector<CacheTextureLine*> mCacheLines;
195    uint32_t getRemainingCacheCapacity();
196
197    void precacheLatin(Font *font);
198    String8 mLatinPrecache;
199
200    Context *mRSC;
201
202    struct {
203        float mFontColor[4];
204        float mGamma;
205    } mConstants;
206    bool mConstantsDirty;
207
208    float mBlackGamma;
209    float mWhiteGamma;
210
211    float mBlackThreshold;
212    float mWhiteThreshold;
213
214    // Free type library, we only need one copy
215    FT_Library mLibrary;
216    FT_Library getLib();
217    Vector<Font*> mActiveFonts;
218
219    // Render state for the font
220    ObjectBaseRef<Allocation> mFontShaderFConstant;
221    ObjectBaseRef<ProgramFragment> mFontShaderF;
222    ObjectBaseRef<Sampler> mFontSampler;
223    ObjectBaseRef<ProgramStore> mFontProgramStore;
224    void initRenderState();
225
226    // Texture to cache glyph bitmaps
227    ObjectBaseRef<Allocation> mTextTexture;
228    void initTextTexture();
229    const uint8_t* getTextTextureData() const {
230        return (uint8_t*)mTextTexture->getPtr();
231    }
232
233    bool cacheBitmap(FT_Bitmap *bitmap, uint32_t *retOriginX, uint32_t *retOriginY);
234    const Type* getCacheTextureType() {
235        return mTextTexture->getType();
236    }
237
238    void flushAllAndInvalidate();
239
240    // Pointer to vertex data to speed up frame to frame work
241    float *mTextMeshPtr;
242    uint32_t mCurrentQuadIndex;
243    uint32_t mMaxNumberOfQuads;
244
245    void initVertexArrayBuffers();
246    ObjectBaseRef<Allocation> mIndexBuffer;
247    ObjectBaseRef<Allocation> mVertexArray;
248
249
250    bool mInitialized;
251
252    void checkInit();
253
254    void issueDrawCommand();
255
256    void appendMeshQuad(float x1, float y1, float z1,
257                          float u1, float v1,
258                          float x2, float y2, float z2,
259                          float u2, float v2,
260                          float x3, float y3, float z3,
261                          float u3, float v3,
262                          float x4, float y4, float z4,
263                          float u4, float v4);
264
265};
266
267
268}
269}
270
271#endif
272