FontRenderer.cpp revision 16c88085255c71a1a8fc034129aa2dcc61e1ddd0 
1/*
2 * Copyright (C) 2010 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#define LOG_TAG "OpenGLRenderer"
18
19#include <SkUtils.h>
20
21#include <cutils/properties.h>
22
23#include <utils/Log.h>
24
25#include "Caches.h"
26#include "Debug.h"
27#include "FontRenderer.h"
28#include "Caches.h"
29
30namespace android {
31namespace uirenderer {
32
33///////////////////////////////////////////////////////////////////////////////
34// Defines
35///////////////////////////////////////////////////////////////////////////////
36
37#define DEFAULT_TEXT_CACHE_WIDTH 1024
38#define DEFAULT_TEXT_CACHE_HEIGHT 256
39#define MAX_TEXT_CACHE_WIDTH 2048
40#define TEXTURE_BORDER_SIZE 2
41
42#define AUTO_KERN(prev, next) (((next) - (prev) + 32) >> 6 << 16)
43
44///////////////////////////////////////////////////////////////////////////////
45// CacheTextureLine
46///////////////////////////////////////////////////////////////////////////////
47
48bool CacheTextureLine::fitBitmap(const SkGlyph& glyph, uint32_t *retOriginX, uint32_t *retOriginY) {
49    if (glyph.fHeight + TEXTURE_BORDER_SIZE > mMaxHeight) {
50        return false;
51    }
52
53    if (mCurrentCol + glyph.fWidth + TEXTURE_BORDER_SIZE < mMaxWidth) {
54        *retOriginX = mCurrentCol + 1;
55        *retOriginY = mCurrentRow + 1;
56        mCurrentCol += glyph.fWidth + TEXTURE_BORDER_SIZE;
57        mDirty = true;
58        return true;
59    }
60
61    return false;
62}
63
64///////////////////////////////////////////////////////////////////////////////
65// Font
66///////////////////////////////////////////////////////////////////////////////
67
68Font::Font(FontRenderer* state, uint32_t fontId, float fontSize,
69        int flags, uint32_t italicStyle, uint32_t scaleX,
70        SkPaint::Style style, uint32_t strokeWidth) :
71        mState(state), mFontId(fontId), mFontSize(fontSize),
72        mFlags(flags), mItalicStyle(italicStyle), mScaleX(scaleX),
73        mStyle(style), mStrokeWidth(mStrokeWidth) {
74}
75
76
77Font::~Font() {
78    for (uint32_t ct = 0; ct < mState->mActiveFonts.size(); ct++) {
79        if (mState->mActiveFonts[ct] == this) {
80            mState->mActiveFonts.removeAt(ct);
81            break;
82        }
83    }
84
85    for (uint32_t i = 0; i < mCachedGlyphs.size(); i++) {
86        delete mCachedGlyphs.valueAt(i);
87    }
88}
89
90void Font::invalidateTextureCache(CacheTextureLine *cacheLine) {
91    for (uint32_t i = 0; i < mCachedGlyphs.size(); i++) {
92        CachedGlyphInfo* cachedGlyph = mCachedGlyphs.valueAt(i);
93        if (cacheLine == NULL || cachedGlyph->mCachedTextureLine == cacheLine) {
94            cachedGlyph->mIsValid = false;
95        }
96    }
97}
98
99void Font::measureCachedGlyph(CachedGlyphInfo *glyph, int x, int y,
100        uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
101    int nPenX = x + glyph->mBitmapLeft;
102    int nPenY = y + glyph->mBitmapTop;
103
104    int width = (int) glyph->mBitmapWidth;
105    int height = (int) glyph->mBitmapHeight;
106
107    if (bounds->bottom > nPenY) {
108        bounds->bottom = nPenY;
109    }
110    if (bounds->left > nPenX) {
111        bounds->left = nPenX;
112    }
113    if (bounds->right < nPenX + width) {
114        bounds->right = nPenX + width;
115    }
116    if (bounds->top < nPenY + height) {
117        bounds->top = nPenY + height;
118    }
119}
120
121void Font::drawCachedGlyph(CachedGlyphInfo* glyph, int x, int y,
122        uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
123    int nPenX = x + glyph->mBitmapLeft;
124    int nPenY = y + glyph->mBitmapTop + glyph->mBitmapHeight;
125
126    float u1 = glyph->mBitmapMinU;
127    float u2 = glyph->mBitmapMaxU;
128    float v1 = glyph->mBitmapMinV;
129    float v2 = glyph->mBitmapMaxV;
130
131    int width = (int) glyph->mBitmapWidth;
132    int height = (int) glyph->mBitmapHeight;
133
134    mState->appendMeshQuad(nPenX, nPenY, u1, v2,
135            nPenX + width, nPenY, u2, v2,
136            nPenX + width, nPenY - height, u2, v1,
137            nPenX, nPenY - height, u1, v1, glyph->mCachedTextureLine->mCacheTexture);
138}
139
140void Font::drawCachedGlyphBitmap(CachedGlyphInfo* glyph, int x, int y,
141        uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
142    int nPenX = x + glyph->mBitmapLeft;
143    int nPenY = y + glyph->mBitmapTop;
144
145    uint32_t endX = glyph->mStartX + glyph->mBitmapWidth;
146    uint32_t endY = glyph->mStartY + glyph->mBitmapHeight;
147
148    CacheTexture *cacheTexture = glyph->mCachedTextureLine->mCacheTexture;
149    uint32_t cacheWidth = cacheTexture->mWidth;
150    const uint8_t* cacheBuffer = cacheTexture->mTexture;
151
152    uint32_t cacheX = 0, cacheY = 0;
153    int32_t bX = 0, bY = 0;
154    for (cacheX = glyph->mStartX, bX = nPenX; cacheX < endX; cacheX++, bX++) {
155        for (cacheY = glyph->mStartY, bY = nPenY; cacheY < endY; cacheY++, bY++) {
156#if DEBUG_FONT_RENDERER
157            if (bX < 0 || bY < 0 || bX >= (int32_t) bitmapW || bY >= (int32_t) bitmapH) {
158                ALOGE("Skipping invalid index");
159                continue;
160            }
161#endif
162            uint8_t tempCol = cacheBuffer[cacheY * cacheWidth + cacheX];
163            bitmap[bY * bitmapW + bX] = tempCol;
164        }
165    }
166}
167
168void Font::drawCachedGlyph(CachedGlyphInfo* glyph, float x, float hOffset, float vOffset,
169        SkPathMeasure& measure, SkPoint* position, SkVector* tangent) {
170    const float halfWidth = glyph->mBitmapWidth * 0.5f;
171    const float height = glyph->mBitmapHeight;
172
173    vOffset += glyph->mBitmapTop + height;
174
175    SkPoint destination[4];
176    measure.getPosTan(x + hOffset +  glyph->mBitmapLeft + halfWidth, position, tangent);
177
178    // Move along the tangent and offset by the normal
179    destination[0].set(-tangent->fX * halfWidth - tangent->fY * vOffset,
180            -tangent->fY * halfWidth + tangent->fX * vOffset);
181    destination[1].set(tangent->fX * halfWidth - tangent->fY * vOffset,
182            tangent->fY * halfWidth + tangent->fX * vOffset);
183    destination[2].set(destination[1].fX + tangent->fY * height,
184            destination[1].fY - tangent->fX * height);
185    destination[3].set(destination[0].fX + tangent->fY * height,
186            destination[0].fY - tangent->fX * height);
187
188    const float u1 = glyph->mBitmapMinU;
189    const float u2 = glyph->mBitmapMaxU;
190    const float v1 = glyph->mBitmapMinV;
191    const float v2 = glyph->mBitmapMaxV;
192
193    mState->appendRotatedMeshQuad(
194            position->fX + destination[0].fX,
195            position->fY + destination[0].fY, u1, v2,
196            position->fX + destination[1].fX,
197            position->fY + destination[1].fY, u2, v2,
198            position->fX + destination[2].fX,
199            position->fY + destination[2].fY, u2, v1,
200            position->fX + destination[3].fX,
201            position->fY + destination[3].fY, u1, v1,
202            glyph->mCachedTextureLine->mCacheTexture);
203}
204
205CachedGlyphInfo* Font::getCachedGlyph(SkPaint* paint, glyph_t textUnit) {
206    CachedGlyphInfo* cachedGlyph = NULL;
207    ssize_t index = mCachedGlyphs.indexOfKey(textUnit);
208    if (index >= 0) {
209        cachedGlyph = mCachedGlyphs.valueAt(index);
210    } else {
211        cachedGlyph = cacheGlyph(paint, textUnit);
212    }
213
214    // Is the glyph still in texture cache?
215    if (!cachedGlyph->mIsValid) {
216        const SkGlyph& skiaGlyph = GET_METRICS(paint, textUnit);
217        updateGlyphCache(paint, skiaGlyph, cachedGlyph);
218    }
219
220    return cachedGlyph;
221}
222
223void Font::render(SkPaint* paint, const char* text, uint32_t start, uint32_t len,
224        int numGlyphs, int x, int y, uint8_t *bitmap, uint32_t bitmapW, uint32_t bitmapH) {
225    if (bitmap != NULL && bitmapW > 0 && bitmapH > 0) {
226        render(paint, text, start, len, numGlyphs, x, y, BITMAP, bitmap,
227                bitmapW, bitmapH, NULL, NULL);
228    } else {
229        render(paint, text, start, len, numGlyphs, x, y, FRAMEBUFFER, NULL,
230                0, 0, NULL, NULL);
231    }
232}
233
234void Font::render(SkPaint* paint, const char *text, uint32_t start, uint32_t len,
235            int numGlyphs, int x, int y, const float* positions) {
236    render(paint, text, start, len, numGlyphs, x, y, FRAMEBUFFER, NULL,
237            0, 0, NULL, positions);
238}
239
240void Font::render(SkPaint* paint, const char *text, uint32_t start, uint32_t len,
241        int numGlyphs, SkPath* path, float hOffset, float vOffset) {
242    if (numGlyphs == 0 || text == NULL || len == 0) {
243        return;
244    }
245
246    text += start;
247
248    int glyphsCount = 0;
249    SkFixed prevRsbDelta = 0;
250
251    float penX = 0.0f;
252
253    SkPoint position;
254    SkVector tangent;
255
256    SkPathMeasure measure(*path, false);
257    float pathLength = SkScalarToFloat(measure.getLength());
258
259    if (paint->getTextAlign() != SkPaint::kLeft_Align) {
260        float textWidth = SkScalarToFloat(paint->measureText(text, len));
261        float pathOffset = pathLength;
262        if (paint->getTextAlign() == SkPaint::kCenter_Align) {
263            textWidth *= 0.5f;
264            pathOffset *= 0.5f;
265        }
266        penX += pathOffset - textWidth;
267    }
268
269    while (glyphsCount < numGlyphs && penX < pathLength) {
270        glyph_t glyph = GET_GLYPH(text);
271
272        if (IS_END_OF_STRING(glyph)) {
273            break;
274        }
275
276        CachedGlyphInfo* cachedGlyph = getCachedGlyph(paint, glyph);
277        penX += SkFixedToFloat(AUTO_KERN(prevRsbDelta, cachedGlyph->mLsbDelta));
278        prevRsbDelta = cachedGlyph->mRsbDelta;
279
280        if (cachedGlyph->mIsValid) {
281            drawCachedGlyph(cachedGlyph, penX, hOffset, vOffset, measure, &position, &tangent);
282        }
283
284        penX += SkFixedToFloat(cachedGlyph->mAdvanceX);
285
286        glyphsCount++;
287    }
288}
289
290void Font::measure(SkPaint* paint, const char* text, uint32_t start, uint32_t len,
291        int numGlyphs, Rect *bounds) {
292    if (bounds == NULL) {
293        ALOGE("No return rectangle provided to measure text");
294        return;
295    }
296    bounds->set(1e6, -1e6, -1e6, 1e6);
297    render(paint, text, start, len, numGlyphs, 0, 0, MEASURE, NULL, 0, 0, bounds, NULL);
298}
299
300void Font::render(SkPaint* paint, const char* text, uint32_t start, uint32_t len,
301        int numGlyphs, int x, int y, RenderMode mode, uint8_t *bitmap,
302        uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* positions) {
303    if (numGlyphs == 0 || text == NULL || len == 0) {
304        return;
305    }
306
307    static RenderGlyph gRenderGlyph[] = {
308            &android::uirenderer::Font::drawCachedGlyph,
309            &android::uirenderer::Font::drawCachedGlyphBitmap,
310            &android::uirenderer::Font::measureCachedGlyph
311    };
312    RenderGlyph render = gRenderGlyph[mode];
313
314    text += start;
315    int glyphsCount = 0;
316
317    if (CC_LIKELY(positions == NULL)) {
318        SkFixed prevRsbDelta = 0;
319
320        float penX = x + 0.5f;
321        int penY = y;
322
323        while (glyphsCount < numGlyphs) {
324            glyph_t glyph = GET_GLYPH(text);
325
326            // Reached the end of the string
327            if (IS_END_OF_STRING(glyph)) {
328                break;
329            }
330
331            CachedGlyphInfo* cachedGlyph = getCachedGlyph(paint, glyph);
332            penX += SkFixedToFloat(AUTO_KERN(prevRsbDelta, cachedGlyph->mLsbDelta));
333            prevRsbDelta = cachedGlyph->mRsbDelta;
334
335            // If it's still not valid, we couldn't cache it, so we shouldn't draw garbage
336            if (cachedGlyph->mIsValid) {
337                (*this.*render)(cachedGlyph, (int) floorf(penX), penY,
338                        bitmap, bitmapW, bitmapH, bounds, positions);
339            }
340
341            penX += SkFixedToFloat(cachedGlyph->mAdvanceX);
342
343            glyphsCount++;
344        }
345    } else {
346        const SkPaint::Align align = paint->getTextAlign();
347
348        // This is for renderPosText()
349        while (glyphsCount < numGlyphs) {
350            glyph_t glyph = GET_GLYPH(text);
351
352            // Reached the end of the string
353            if (IS_END_OF_STRING(glyph)) {
354                break;
355            }
356
357            CachedGlyphInfo* cachedGlyph = getCachedGlyph(paint, glyph);
358
359            // If it's still not valid, we couldn't cache it, so we shouldn't draw garbage
360            if (cachedGlyph->mIsValid) {
361                int penX = x + positions[(glyphsCount << 1)];
362                int penY = y + positions[(glyphsCount << 1) + 1];
363
364                switch (align) {
365                    case SkPaint::kRight_Align:
366                        penX -= SkFixedToFloat(cachedGlyph->mAdvanceX);
367                        penY -= SkFixedToFloat(cachedGlyph->mAdvanceY);
368                        break;
369                    case SkPaint::kCenter_Align:
370                        penX -= SkFixedToFloat(cachedGlyph->mAdvanceX >> 1);
371                        penY -= SkFixedToFloat(cachedGlyph->mAdvanceY >> 1);
372                    default:
373                        break;
374                }
375
376                (*this.*render)(cachedGlyph, penX, penY,
377                        bitmap, bitmapW, bitmapH, bounds, positions);
378            }
379
380            glyphsCount++;
381        }
382    }
383}
384
385void Font::updateGlyphCache(SkPaint* paint, const SkGlyph& skiaGlyph, CachedGlyphInfo* glyph) {
386    glyph->mAdvanceX = skiaGlyph.fAdvanceX;
387    glyph->mAdvanceY = skiaGlyph.fAdvanceY;
388    glyph->mBitmapLeft = skiaGlyph.fLeft;
389    glyph->mBitmapTop = skiaGlyph.fTop;
390    glyph->mLsbDelta = skiaGlyph.fLsbDelta;
391    glyph->mRsbDelta = skiaGlyph.fRsbDelta;
392
393    uint32_t startX = 0;
394    uint32_t startY = 0;
395
396    // Get the bitmap for the glyph
397    paint->findImage(skiaGlyph);
398    mState->cacheBitmap(skiaGlyph, glyph, &startX, &startY);
399
400    if (!glyph->mIsValid) {
401        return;
402    }
403
404    uint32_t endX = startX + skiaGlyph.fWidth;
405    uint32_t endY = startY + skiaGlyph.fHeight;
406
407    glyph->mStartX = startX;
408    glyph->mStartY = startY;
409    glyph->mBitmapWidth = skiaGlyph.fWidth;
410    glyph->mBitmapHeight = skiaGlyph.fHeight;
411
412    uint32_t cacheWidth = glyph->mCachedTextureLine->mCacheTexture->mWidth;
413    uint32_t cacheHeight = glyph->mCachedTextureLine->mCacheTexture->mHeight;
414
415    glyph->mBitmapMinU = (float) startX / (float) cacheWidth;
416    glyph->mBitmapMinV = (float) startY / (float) cacheHeight;
417    glyph->mBitmapMaxU = (float) endX / (float) cacheWidth;
418    glyph->mBitmapMaxV = (float) endY / (float) cacheHeight;
419
420    mState->mUploadTexture = true;
421}
422
423CachedGlyphInfo* Font::cacheGlyph(SkPaint* paint, glyph_t glyph) {
424    CachedGlyphInfo* newGlyph = new CachedGlyphInfo();
425    mCachedGlyphs.add(glyph, newGlyph);
426
427    const SkGlyph& skiaGlyph = GET_METRICS(paint, glyph);
428    newGlyph->mGlyphIndex = skiaGlyph.fID;
429    newGlyph->mIsValid = false;
430
431    updateGlyphCache(paint, skiaGlyph, newGlyph);
432
433    return newGlyph;
434}
435
436Font* Font::create(FontRenderer* state, uint32_t fontId, float fontSize,
437        int flags, uint32_t italicStyle, uint32_t scaleX,
438        SkPaint::Style style, uint32_t strokeWidth) {
439    Vector<Font*> &activeFonts = state->mActiveFonts;
440
441    for (uint32_t i = 0; i < activeFonts.size(); i++) {
442        Font* font = activeFonts[i];
443        if (font->mFontId == fontId && font->mFontSize == fontSize &&
444                font->mFlags == flags && font->mItalicStyle == italicStyle &&
445                font->mScaleX == scaleX && font->mStyle == style &&
446                (style == SkPaint::kFill_Style || font->mStrokeWidth == strokeWidth)) {
447            return font;
448        }
449    }
450
451    Font* newFont = new Font(state, fontId, fontSize, flags, italicStyle,
452            scaleX, style, strokeWidth);
453    activeFonts.push(newFont);
454    return newFont;
455}
456
457///////////////////////////////////////////////////////////////////////////////
458// FontRenderer
459///////////////////////////////////////////////////////////////////////////////
460
461static bool sLogFontRendererCreate = true;
462
463FontRenderer::FontRenderer() {
464    if (sLogFontRendererCreate) {
465        INIT_LOGD("Creating FontRenderer");
466    }
467
468    mGammaTable = NULL;
469    mInitialized = false;
470    mMaxNumberOfQuads = 1024;
471    mCurrentQuadIndex = 0;
472
473    mTextMeshPtr = NULL;
474    mCurrentCacheTexture = NULL;
475    mLastCacheTexture = NULL;
476    mCacheTextureSmall = NULL;
477    mCacheTexture128 = NULL;
478    mCacheTexture256 = NULL;
479    mCacheTexture512 = NULL;
480
481    mLinearFiltering = false;
482
483    mIndexBufferID = 0;
484
485    mSmallCacheWidth = DEFAULT_TEXT_CACHE_WIDTH;
486    mSmallCacheHeight = DEFAULT_TEXT_CACHE_HEIGHT;
487
488    char property[PROPERTY_VALUE_MAX];
489    if (property_get(PROPERTY_TEXT_CACHE_WIDTH, property, NULL) > 0) {
490        if (sLogFontRendererCreate) {
491            INIT_LOGD("  Setting text cache width to %s pixels", property);
492        }
493        mSmallCacheWidth = atoi(property);
494    } else {
495        if (sLogFontRendererCreate) {
496            INIT_LOGD("  Using default text cache width of %i pixels", mSmallCacheWidth);
497        }
498    }
499
500    if (property_get(PROPERTY_TEXT_CACHE_HEIGHT, property, NULL) > 0) {
501        if (sLogFontRendererCreate) {
502            INIT_LOGD("  Setting text cache width to %s pixels", property);
503        }
504        mSmallCacheHeight = atoi(property);
505    } else {
506        if (sLogFontRendererCreate) {
507            INIT_LOGD("  Using default text cache height of %i pixels", mSmallCacheHeight);
508        }
509    }
510
511    sLogFontRendererCreate = false;
512}
513
514FontRenderer::~FontRenderer() {
515    for (uint32_t i = 0; i < mCacheLines.size(); i++) {
516        delete mCacheLines[i];
517    }
518    mCacheLines.clear();
519
520    if (mInitialized) {
521        // Unbinding the buffer shouldn't be necessary but it crashes with some drivers
522        Caches::getInstance().unbindIndicesBuffer();
523        glDeleteBuffers(1, &mIndexBufferID);
524
525        delete[] mTextMeshPtr;
526        delete mCacheTextureSmall;
527        delete mCacheTexture128;
528        delete mCacheTexture256;
529        delete mCacheTexture512;
530    }
531
532    Vector<Font*> fontsToDereference = mActiveFonts;
533    for (uint32_t i = 0; i < fontsToDereference.size(); i++) {
534        delete fontsToDereference[i];
535    }
536}
537
538void FontRenderer::flushAllAndInvalidate() {
539    if (mCurrentQuadIndex != 0) {
540        issueDrawCommand();
541        mCurrentQuadIndex = 0;
542    }
543
544    for (uint32_t i = 0; i < mActiveFonts.size(); i++) {
545        mActiveFonts[i]->invalidateTextureCache();
546    }
547
548    for (uint32_t i = 0; i < mCacheLines.size(); i++) {
549        mCacheLines[i]->mCurrentCol = 0;
550    }
551}
552
553void FontRenderer::deallocateTextureMemory(CacheTexture *cacheTexture) {
554    if (cacheTexture && cacheTexture->mTexture) {
555        glDeleteTextures(1, &cacheTexture->mTextureId);
556        delete[] cacheTexture->mTexture;
557        cacheTexture->mTexture = NULL;
558        cacheTexture->mTextureId = 0;
559    }
560}
561
562void FontRenderer::flushLargeCaches() {
563    if ((!mCacheTexture128 || !mCacheTexture128->mTexture) &&
564            (!mCacheTexture256 || !mCacheTexture256->mTexture) &&
565            (!mCacheTexture512 || !mCacheTexture512->mTexture)) {
566        // Typical case; no large glyph caches allocated
567        return;
568    }
569
570    for (uint32_t i = 0; i < mCacheLines.size(); i++) {
571        CacheTextureLine* cacheLine = mCacheLines[i];
572        if ((cacheLine->mCacheTexture == mCacheTexture128 ||
573                cacheLine->mCacheTexture == mCacheTexture256 ||
574                cacheLine->mCacheTexture == mCacheTexture512) &&
575                cacheLine->mCacheTexture->mTexture != NULL) {
576            cacheLine->mCurrentCol = 0;
577            for (uint32_t i = 0; i < mActiveFonts.size(); i++) {
578                mActiveFonts[i]->invalidateTextureCache(cacheLine);
579            }
580        }
581    }
582
583    deallocateTextureMemory(mCacheTexture128);
584    deallocateTextureMemory(mCacheTexture256);
585    deallocateTextureMemory(mCacheTexture512);
586}
587
588void FontRenderer::allocateTextureMemory(CacheTexture* cacheTexture) {
589    int width = cacheTexture->mWidth;
590    int height = cacheTexture->mHeight;
591
592    cacheTexture->mTexture = new uint8_t[width * height];
593#if DEBUG_FONT_RENDERER
594    memset(cacheTexture->mTexture, 0, width * height * sizeof(uint8_t));
595#endif
596
597    if (!cacheTexture->mTextureId) {
598        glGenTextures(1, &cacheTexture->mTextureId);
599    }
600
601    Caches::getInstance().activeTexture(0);
602    glBindTexture(GL_TEXTURE_2D, cacheTexture->mTextureId);
603    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
604    // Initialize texture dimensions
605    glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0,
606            GL_ALPHA, GL_UNSIGNED_BYTE, 0);
607
608    const GLenum filtering = cacheTexture->mLinearFiltering ? GL_LINEAR : GL_NEAREST;
609    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filtering);
610    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filtering);
611
612    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
613    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
614}
615
616void FontRenderer::cacheBitmap(const SkGlyph& glyph, CachedGlyphInfo* cachedGlyph,
617        uint32_t* retOriginX, uint32_t* retOriginY) {
618    cachedGlyph->mIsValid = false;
619    // If the glyph is too tall, don't cache it
620    if (glyph.fHeight + TEXTURE_BORDER_SIZE > mCacheLines[mCacheLines.size() - 1]->mMaxHeight) {
621        ALOGE("Font size to large to fit in cache. width, height = %i, %i",
622                (int) glyph.fWidth, (int) glyph.fHeight);
623        return;
624    }
625
626    // Now copy the bitmap into the cache texture
627    uint32_t startX = 0;
628    uint32_t startY = 0;
629
630    bool bitmapFit = false;
631    CacheTextureLine *cacheLine;
632    for (uint32_t i = 0; i < mCacheLines.size(); i++) {
633        bitmapFit = mCacheLines[i]->fitBitmap(glyph, &startX, &startY);
634        if (bitmapFit) {
635            cacheLine = mCacheLines[i];
636            break;
637        }
638    }
639
640    // If the new glyph didn't fit, flush the state so far and invalidate everything
641    if (!bitmapFit) {
642        flushAllAndInvalidate();
643
644        // Try to fit it again
645        for (uint32_t i = 0; i < mCacheLines.size(); i++) {
646            bitmapFit = mCacheLines[i]->fitBitmap(glyph, &startX, &startY);
647            if (bitmapFit) {
648                cacheLine = mCacheLines[i];
649                break;
650            }
651        }
652
653        // if we still don't fit, something is wrong and we shouldn't draw
654        if (!bitmapFit) {
655            return;
656        }
657    }
658
659    cachedGlyph->mCachedTextureLine = cacheLine;
660
661    *retOriginX = startX;
662    *retOriginY = startY;
663
664    uint32_t endX = startX + glyph.fWidth;
665    uint32_t endY = startY + glyph.fHeight;
666
667    uint32_t cacheWidth = cacheLine->mMaxWidth;
668
669    CacheTexture* cacheTexture = cacheLine->mCacheTexture;
670    if (!cacheTexture->mTexture) {
671        // Large-glyph texture memory is allocated only as needed
672        allocateTextureMemory(cacheTexture);
673    }
674
675    uint8_t* cacheBuffer = cacheTexture->mTexture;
676    uint8_t* bitmapBuffer = (uint8_t*) glyph.fImage;
677    unsigned int stride = glyph.rowBytes();
678
679    uint32_t cacheX = 0, bX = 0, cacheY = 0, bY = 0;
680    for (cacheX = startX, bX = 0; cacheX < endX; cacheX++, bX++) {
681        for (cacheY = startY, bY = 0; cacheY < endY; cacheY++, bY++) {
682            uint8_t tempCol = bitmapBuffer[bY * stride + bX];
683            cacheBuffer[cacheY * cacheWidth + cacheX] = mGammaTable[tempCol];
684        }
685    }
686
687    cachedGlyph->mIsValid = true;
688}
689
690CacheTexture* FontRenderer::createCacheTexture(int width, int height, bool allocate) {
691    uint8_t* textureMemory = NULL;
692    CacheTexture* cacheTexture = new CacheTexture(textureMemory, width, height);
693
694    if (allocate) {
695        allocateTextureMemory(cacheTexture);
696    }
697
698    return cacheTexture;
699}
700
701void FontRenderer::initTextTexture() {
702    for (uint32_t i = 0; i < mCacheLines.size(); i++) {
703        delete mCacheLines[i];
704    }
705    mCacheLines.clear();
706
707    if (mCacheTextureSmall) {
708        delete mCacheTextureSmall;
709        delete mCacheTexture128;
710        delete mCacheTexture256;
711        delete mCacheTexture512;
712    }
713
714    // Next, use other, separate caches for large glyphs.
715    uint16_t maxWidth = 0;
716    if (Caches::hasInstance()) {
717        maxWidth = Caches::getInstance().maxTextureSize;
718    }
719
720    if (maxWidth > MAX_TEXT_CACHE_WIDTH || maxWidth == 0) {
721        maxWidth = MAX_TEXT_CACHE_WIDTH;
722    }
723
724    mCacheTextureSmall = createCacheTexture(mSmallCacheWidth, mSmallCacheHeight, true);
725    mCacheTexture128 = createCacheTexture(maxWidth, 256, false);
726    mCacheTexture256 = createCacheTexture(maxWidth, 256, false);
727    mCacheTexture512 = createCacheTexture(maxWidth, 512, false);
728    mCurrentCacheTexture = mCacheTextureSmall;
729
730    mUploadTexture = false;
731    // Split up our default cache texture into lines of certain widths
732    int nextLine = 0;
733    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, 18, nextLine, 0, mCacheTextureSmall));
734    nextLine += mCacheLines.top()->mMaxHeight;
735    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, 26, nextLine, 0, mCacheTextureSmall));
736    nextLine += mCacheLines.top()->mMaxHeight;
737    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, 26, nextLine, 0, mCacheTextureSmall));
738    nextLine += mCacheLines.top()->mMaxHeight;
739    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, 34, nextLine, 0, mCacheTextureSmall));
740    nextLine += mCacheLines.top()->mMaxHeight;
741    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, 34, nextLine, 0, mCacheTextureSmall));
742    nextLine += mCacheLines.top()->mMaxHeight;
743    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, 42, nextLine, 0, mCacheTextureSmall));
744    nextLine += mCacheLines.top()->mMaxHeight;
745    mCacheLines.push(new CacheTextureLine(mSmallCacheWidth, mSmallCacheHeight - nextLine,
746            nextLine, 0, mCacheTextureSmall));
747
748    //  The first cache is split into 2 lines of height 128, the rest have just one cache line.
749    mCacheLines.push(new CacheTextureLine(maxWidth, 128, 0, 0, mCacheTexture128));
750    mCacheLines.push(new CacheTextureLine(maxWidth, 128, 128, 0, mCacheTexture128));
751    mCacheLines.push(new CacheTextureLine(maxWidth, 256, 0, 0, mCacheTexture256));
752    mCacheLines.push(new CacheTextureLine(maxWidth, 512, 0, 0, mCacheTexture512));
753}
754
755// Avoid having to reallocate memory and render quad by quad
756void FontRenderer::initVertexArrayBuffers() {
757    uint32_t numIndices = mMaxNumberOfQuads * 6;
758    uint32_t indexBufferSizeBytes = numIndices * sizeof(uint16_t);
759    uint16_t* indexBufferData = (uint16_t*) malloc(indexBufferSizeBytes);
760
761    // Four verts, two triangles , six indices per quad
762    for (uint32_t i = 0; i < mMaxNumberOfQuads; i++) {
763        int i6 = i * 6;
764        int i4 = i * 4;
765
766        indexBufferData[i6 + 0] = i4 + 0;
767        indexBufferData[i6 + 1] = i4 + 1;
768        indexBufferData[i6 + 2] = i4 + 2;
769
770        indexBufferData[i6 + 3] = i4 + 0;
771        indexBufferData[i6 + 4] = i4 + 2;
772        indexBufferData[i6 + 5] = i4 + 3;
773    }
774
775    glGenBuffers(1, &mIndexBufferID);
776    Caches::getInstance().bindIndicesBuffer(mIndexBufferID);
777    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indexBufferSizeBytes, indexBufferData, GL_STATIC_DRAW);
778
779    free(indexBufferData);
780
781    uint32_t coordSize = 2;
782    uint32_t uvSize = 2;
783    uint32_t vertsPerQuad = 4;
784    uint32_t vertexBufferSize = mMaxNumberOfQuads * vertsPerQuad * coordSize * uvSize;
785    mTextMeshPtr = new float[vertexBufferSize];
786}
787
788// We don't want to allocate anything unless we actually draw text
789void FontRenderer::checkInit() {
790    if (mInitialized) {
791        return;
792    }
793
794    initTextTexture();
795    initVertexArrayBuffers();
796
797    mInitialized = true;
798}
799
800void FontRenderer::checkTextureUpdate() {
801    if (!mUploadTexture && mLastCacheTexture == mCurrentCacheTexture) {
802        return;
803    }
804
805    Caches& caches = Caches::getInstance();
806    GLuint lastTextureId = 0;
807    // Iterate over all the cache lines and see which ones need to be updated
808    for (uint32_t i = 0; i < mCacheLines.size(); i++) {
809        CacheTextureLine* cl = mCacheLines[i];
810        if (cl->mDirty && cl->mCacheTexture->mTexture != NULL) {
811            CacheTexture* cacheTexture = cl->mCacheTexture;
812            uint32_t xOffset = 0;
813            uint32_t yOffset = cl->mCurrentRow;
814            uint32_t width   = cl->mMaxWidth;
815            uint32_t height  = cl->mMaxHeight;
816            void* textureData = cacheTexture->mTexture + (yOffset * width);
817
818            if (cacheTexture->mTextureId != lastTextureId) {
819                caches.activeTexture(0);
820                glBindTexture(GL_TEXTURE_2D, cacheTexture->mTextureId);
821                lastTextureId = cacheTexture->mTextureId;
822            }
823            glTexSubImage2D(GL_TEXTURE_2D, 0, xOffset, yOffset, width, height,
824                    GL_ALPHA, GL_UNSIGNED_BYTE, textureData);
825
826            cl->mDirty = false;
827        }
828    }
829
830    caches.activeTexture(0);
831    glBindTexture(GL_TEXTURE_2D, mCurrentCacheTexture->mTextureId);
832    if (mLinearFiltering != mCurrentCacheTexture->mLinearFiltering) {
833        const GLenum filtering = mLinearFiltering ? GL_LINEAR : GL_NEAREST;
834        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filtering);
835        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filtering);
836        mCurrentCacheTexture->mLinearFiltering = mLinearFiltering;
837    }
838    mLastCacheTexture = mCurrentCacheTexture;
839
840    mUploadTexture = false;
841}
842
843void FontRenderer::issueDrawCommand() {
844    checkTextureUpdate();
845
846    Caches& caches = Caches::getInstance();
847    caches.bindIndicesBuffer(mIndexBufferID);
848    if (!mDrawn) {
849        float* buffer = mTextMeshPtr;
850        int offset = 2;
851
852        bool force = caches.unbindMeshBuffer();
853        caches.bindPositionVertexPointer(force, caches.currentProgram->position, buffer);
854        caches.bindTexCoordsVertexPointer(force, caches.currentProgram->texCoords,
855                buffer + offset);
856    }
857
858    glDrawElements(GL_TRIANGLES, mCurrentQuadIndex * 6, GL_UNSIGNED_SHORT, NULL);
859
860    mDrawn = true;
861}
862
863void FontRenderer::appendMeshQuadNoClip(float x1, float y1, float u1, float v1,
864        float x2, float y2, float u2, float v2, float x3, float y3, float u3, float v3,
865        float x4, float y4, float u4, float v4, CacheTexture* texture) {
866    if (texture != mCurrentCacheTexture) {
867        if (mCurrentQuadIndex != 0) {
868            // First, draw everything stored already which uses the previous texture
869            issueDrawCommand();
870            mCurrentQuadIndex = 0;
871        }
872        // Now use the new texture id
873        mCurrentCacheTexture = texture;
874    }
875
876    const uint32_t vertsPerQuad = 4;
877    const uint32_t floatsPerVert = 4;
878    float* currentPos = mTextMeshPtr + mCurrentQuadIndex * vertsPerQuad * floatsPerVert;
879
880    (*currentPos++) = x1;
881    (*currentPos++) = y1;
882    (*currentPos++) = u1;
883    (*currentPos++) = v1;
884
885    (*currentPos++) = x2;
886    (*currentPos++) = y2;
887    (*currentPos++) = u2;
888    (*currentPos++) = v2;
889
890    (*currentPos++) = x3;
891    (*currentPos++) = y3;
892    (*currentPos++) = u3;
893    (*currentPos++) = v3;
894
895    (*currentPos++) = x4;
896    (*currentPos++) = y4;
897    (*currentPos++) = u4;
898    (*currentPos++) = v4;
899
900    mCurrentQuadIndex++;
901}
902
903void FontRenderer::appendMeshQuad(float x1, float y1, float u1, float v1,
904        float x2, float y2, float u2, float v2, float x3, float y3, float u3, float v3,
905        float x4, float y4, float u4, float v4, CacheTexture* texture) {
906
907    if (mClip &&
908            (x1 > mClip->right || y1 < mClip->top || x2 < mClip->left || y4 > mClip->bottom)) {
909        return;
910    }
911
912    appendMeshQuadNoClip(x1, y1, u1, v1, x2, y2, u2, v2, x3, y3, u3, v3, x4, y4, u4, v4, texture);
913
914    if (mBounds) {
915        mBounds->left = fmin(mBounds->left, x1);
916        mBounds->top = fmin(mBounds->top, y3);
917        mBounds->right = fmax(mBounds->right, x3);
918        mBounds->bottom = fmax(mBounds->bottom, y1);
919    }
920
921    if (mCurrentQuadIndex == mMaxNumberOfQuads) {
922        issueDrawCommand();
923        mCurrentQuadIndex = 0;
924    }
925}
926
927void FontRenderer::appendRotatedMeshQuad(float x1, float y1, float u1, float v1,
928        float x2, float y2, float u2, float v2, float x3, float y3, float u3, float v3,
929        float x4, float y4, float u4, float v4, CacheTexture* texture) {
930
931    appendMeshQuadNoClip(x1, y1, u1, v1, x2, y2, u2, v2, x3, y3, u3, v3, x4, y4, u4, v4, texture);
932
933    if (mBounds) {
934        mBounds->left = fmin(mBounds->left, fmin(x1, fmin(x2, fmin(x3, x4))));
935        mBounds->top = fmin(mBounds->top, fmin(y1, fmin(y2, fmin(y3, y4))));
936        mBounds->right = fmax(mBounds->right, fmax(x1, fmax(x2, fmax(x3, x4))));
937        mBounds->bottom = fmax(mBounds->bottom, fmax(y1, fmax(y2, fmax(y3, y4))));
938    }
939
940    if (mCurrentQuadIndex == mMaxNumberOfQuads) {
941        issueDrawCommand();
942        mCurrentQuadIndex = 0;
943    }
944}
945
946uint32_t FontRenderer::getRemainingCacheCapacity() {
947    uint32_t remainingCapacity = 0;
948    float totalPixels = 0;
949    for(uint32_t i = 0; i < mCacheLines.size(); i ++) {
950         remainingCapacity += (mCacheLines[i]->mMaxWidth - mCacheLines[i]->mCurrentCol);
951         totalPixels += mCacheLines[i]->mMaxWidth;
952    }
953    remainingCapacity = (remainingCapacity * 100) / totalPixels;
954    return remainingCapacity;
955}
956
957void FontRenderer::precacheLatin(SkPaint* paint) {
958    // Remaining capacity is measured in %
959    uint32_t remainingCapacity = getRemainingCacheCapacity();
960    uint32_t precacheIndex = 0;
961
962    // We store a string with letters in a rough frequency of occurrence
963    String16 l("eisarntolcdugpmhbyfvkwzxjq EISARNTOLCDUGPMHBYFVKWZXJQ,.?!()-+@;:'0123456789");
964
965    size_t size = l.size();
966    uint16_t latin[size];
967    paint->utfToGlyphs(l.string(), SkPaint::kUTF16_TextEncoding, size * sizeof(char16_t), latin);
968
969    while (remainingCapacity > 25 && precacheIndex < size) {
970        mCurrentFont->getCachedGlyph(paint, TO_GLYPH(latin[precacheIndex]));
971        remainingCapacity = getRemainingCacheCapacity();
972        precacheIndex++;
973    }
974}
975
976void FontRenderer::setFont(SkPaint* paint, uint32_t fontId, float fontSize) {
977    uint32_t currentNumFonts = mActiveFonts.size();
978    int flags = 0;
979    if (paint->isFakeBoldText()) {
980        flags |= Font::kFakeBold;
981    }
982
983    const float skewX = paint->getTextSkewX();
984    uint32_t italicStyle = *(uint32_t*) &skewX;
985    const float scaleXFloat = paint->getTextScaleX();
986    uint32_t scaleX = *(uint32_t*) &scaleXFloat;
987    SkPaint::Style style = paint->getStyle();
988    const float strokeWidthFloat = paint->getStrokeWidth();
989    uint32_t strokeWidth = *(uint32_t*) &strokeWidthFloat;
990    mCurrentFont = Font::create(this, fontId, fontSize, flags, italicStyle,
991            scaleX, style, strokeWidth);
992
993    const float maxPrecacheFontSize = 40.0f;
994    bool isNewFont = currentNumFonts != mActiveFonts.size();
995
996    if (isNewFont && fontSize <= maxPrecacheFontSize) {
997        precacheLatin(paint);
998    }
999}
1000
1001FontRenderer::DropShadow FontRenderer::renderDropShadow(SkPaint* paint, const char *text,
1002        uint32_t startIndex, uint32_t len, int numGlyphs, uint32_t radius) {
1003    checkInit();
1004
1005    if (!mCurrentFont) {
1006        DropShadow image;
1007        image.width = 0;
1008        image.height = 0;
1009        image.image = NULL;
1010        image.penX = 0;
1011        image.penY = 0;
1012        return image;
1013    }
1014
1015    mDrawn = false;
1016    mClip = NULL;
1017    mBounds = NULL;
1018
1019    Rect bounds;
1020    mCurrentFont->measure(paint, text, startIndex, len, numGlyphs, &bounds);
1021
1022    uint32_t paddedWidth = (uint32_t) (bounds.right - bounds.left) + 2 * radius;
1023    uint32_t paddedHeight = (uint32_t) (bounds.top - bounds.bottom) + 2 * radius;
1024    uint8_t* dataBuffer = new uint8_t[paddedWidth * paddedHeight];
1025
1026    for (uint32_t i = 0; i < paddedWidth * paddedHeight; i++) {
1027        dataBuffer[i] = 0;
1028    }
1029
1030    int penX = radius - bounds.left;
1031    int penY = radius - bounds.bottom;
1032
1033    mCurrentFont->render(paint, text, startIndex, len, numGlyphs, penX, penY,
1034            dataBuffer, paddedWidth, paddedHeight);
1035    blurImage(dataBuffer, paddedWidth, paddedHeight, radius);
1036
1037    DropShadow image;
1038    image.width = paddedWidth;
1039    image.height = paddedHeight;
1040    image.image = dataBuffer;
1041    image.penX = penX;
1042    image.penY = penY;
1043
1044    return image;
1045}
1046
1047void FontRenderer::initRender(const Rect* clip, Rect* bounds) {
1048    checkInit();
1049
1050    mDrawn = false;
1051    mBounds = bounds;
1052    mClip = clip;
1053}
1054
1055void FontRenderer::finishRender() {
1056    mBounds = NULL;
1057    mClip = NULL;
1058
1059    if (mCurrentQuadIndex != 0) {
1060        issueDrawCommand();
1061        mCurrentQuadIndex = 0;
1062    }
1063}
1064
1065bool FontRenderer::renderText(SkPaint* paint, const Rect* clip, const char *text,
1066        uint32_t startIndex, uint32_t len, int numGlyphs, int x, int y, Rect* bounds) {
1067    if (!mCurrentFont) {
1068        ALOGE("No font set");
1069        return false;
1070    }
1071
1072    initRender(clip, bounds);
1073    mCurrentFont->render(paint, text, startIndex, len, numGlyphs, x, y);
1074    finishRender();
1075
1076    return mDrawn;
1077}
1078
1079bool FontRenderer::renderPosText(SkPaint* paint, const Rect* clip, const char *text,
1080        uint32_t startIndex, uint32_t len, int numGlyphs, int x, int y,
1081        const float* positions, Rect* bounds) {
1082    if (!mCurrentFont) {
1083        ALOGE("No font set");
1084        return false;
1085    }
1086
1087    initRender(clip, bounds);
1088    mCurrentFont->render(paint, text, startIndex, len, numGlyphs, x, y, positions);
1089    finishRender();
1090
1091    return mDrawn;
1092}
1093
1094bool FontRenderer::renderTextOnPath(SkPaint* paint, const Rect* clip, const char *text,
1095        uint32_t startIndex, uint32_t len, int numGlyphs, SkPath* path,
1096        float hOffset, float vOffset, Rect* bounds) {
1097    if (!mCurrentFont) {
1098        ALOGE("No font set");
1099        return false;
1100    }
1101
1102    initRender(clip, bounds);
1103    mCurrentFont->render(paint, text, startIndex, len, numGlyphs, path, hOffset, vOffset);
1104    finishRender();
1105
1106    return mDrawn;
1107}
1108
1109void FontRenderer::computeGaussianWeights(float* weights, int32_t radius) {
1110    // Compute gaussian weights for the blur
1111    // e is the euler's number
1112    float e = 2.718281828459045f;
1113    float pi = 3.1415926535897932f;
1114    // g(x) = ( 1 / sqrt( 2 * pi ) * sigma) * e ^ ( -x^2 / 2 * sigma^2 )
1115    // x is of the form [-radius .. 0 .. radius]
1116    // and sigma varies with radius.
1117    // Based on some experimental radius values and sigma's
1118    // we approximately fit sigma = f(radius) as
1119    // sigma = radius * 0.3  + 0.6
1120    // The larger the radius gets, the more our gaussian blur
1121    // will resemble a box blur since with large sigma
1122    // the gaussian curve begins to lose its shape
1123    float sigma = 0.3f * (float) radius + 0.6f;
1124
1125    // Now compute the coefficints
1126    // We will store some redundant values to save some math during
1127    // the blur calculations
1128    // precompute some values
1129    float coeff1 = 1.0f / (sqrt( 2.0f * pi ) * sigma);
1130    float coeff2 = - 1.0f / (2.0f * sigma * sigma);
1131
1132    float normalizeFactor = 0.0f;
1133    for (int32_t r = -radius; r <= radius; r ++) {
1134        float floatR = (float) r;
1135        weights[r + radius] = coeff1 * pow(e, floatR * floatR * coeff2);
1136        normalizeFactor += weights[r + radius];
1137    }
1138
1139    //Now we need to normalize the weights because all our coefficients need to add up to one
1140    normalizeFactor = 1.0f / normalizeFactor;
1141    for (int32_t r = -radius; r <= radius; r ++) {
1142        weights[r + radius] *= normalizeFactor;
1143    }
1144}
1145
1146void FontRenderer::horizontalBlur(float* weights, int32_t radius,
1147        const uint8_t* source, uint8_t* dest, int32_t width, int32_t height) {
1148    float blurredPixel = 0.0f;
1149    float currentPixel = 0.0f;
1150
1151    for (int32_t y = 0; y < height; y ++) {
1152
1153        const uint8_t* input = source + y * width;
1154        uint8_t* output = dest + y * width;
1155
1156        for (int32_t x = 0; x < width; x ++) {
1157            blurredPixel = 0.0f;
1158            const float* gPtr = weights;
1159            // Optimization for non-border pixels
1160            if (x > radius && x < (width - radius)) {
1161                const uint8_t *i = input + (x - radius);
1162                for (int r = -radius; r <= radius; r ++) {
1163                    currentPixel = (float) (*i);
1164                    blurredPixel += currentPixel * gPtr[0];
1165                    gPtr++;
1166                    i++;
1167                }
1168            } else {
1169                for (int32_t r = -radius; r <= radius; r ++) {
1170                    // Stepping left and right away from the pixel
1171                    int validW = x + r;
1172                    if (validW < 0) {
1173                        validW = 0;
1174                    }
1175                    if (validW > width - 1) {
1176                        validW = width - 1;
1177                    }
1178
1179                    currentPixel = (float) input[validW];
1180                    blurredPixel += currentPixel * gPtr[0];
1181                    gPtr++;
1182                }
1183            }
1184            *output = (uint8_t)blurredPixel;
1185            output ++;
1186        }
1187    }
1188}
1189
1190void FontRenderer::verticalBlur(float* weights, int32_t radius,
1191        const uint8_t* source, uint8_t* dest, int32_t width, int32_t height) {
1192    float blurredPixel = 0.0f;
1193    float currentPixel = 0.0f;
1194
1195    for (int32_t y = 0; y < height; y ++) {
1196
1197        uint8_t* output = dest + y * width;
1198
1199        for (int32_t x = 0; x < width; x ++) {
1200            blurredPixel = 0.0f;
1201            const float* gPtr = weights;
1202            const uint8_t* input = source + x;
1203            // Optimization for non-border pixels
1204            if (y > radius && y < (height - radius)) {
1205                const uint8_t *i = input + ((y - radius) * width);
1206                for (int32_t r = -radius; r <= radius; r ++) {
1207                    currentPixel = (float)(*i);
1208                    blurredPixel += currentPixel * gPtr[0];
1209                    gPtr++;
1210                    i += width;
1211                }
1212            } else {
1213                for (int32_t r = -radius; r <= radius; r ++) {
1214                    int validH = y + r;
1215                    // Clamp to zero and width
1216                    if (validH < 0) {
1217                        validH = 0;
1218                    }
1219                    if (validH > height - 1) {
1220                        validH = height - 1;
1221                    }
1222
1223                    const uint8_t *i = input + validH * width;
1224                    currentPixel = (float) (*i);
1225                    blurredPixel += currentPixel * gPtr[0];
1226                    gPtr++;
1227                }
1228            }
1229            *output = (uint8_t) blurredPixel;
1230            output ++;
1231        }
1232    }
1233}
1234
1235
1236void FontRenderer::blurImage(uint8_t *image, int32_t width, int32_t height, int32_t radius) {
1237    float *gaussian = new float[2 * radius + 1];
1238    computeGaussianWeights(gaussian, radius);
1239
1240    uint8_t* scratch = new uint8_t[width * height];
1241
1242    horizontalBlur(gaussian, radius, image, scratch, width, height);
1243    verticalBlur(gaussian, radius, scratch, image, width, height);
1244
1245    delete[] gaussian;
1246    delete[] scratch;
1247}
1248
1249}; // namespace uirenderer
1250}; // namespace android
1251