Font.cpp revision 42ae4cf2ce5ba02c2211813452badc07eab33735 
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#define LOG_TAG "OpenGLRenderer"
18#define ATRACE_TAG ATRACE_TAG_VIEW
19
20#include <cutils/compiler.h>
21
22#include <utils/JenkinsHash.h>
23#include <utils/Trace.h>
24
25#include <SkGlyph.h>
26#include <SkGlyphCache.h>
27#include <SkUtils.h>
28
29#include "FontUtil.h"
30#include "Font.h"
31#include "../Debug.h"
32#include "../FontRenderer.h"
33#include "../PixelBuffer.h"
34#include "../Properties.h"
35
36namespace android {
37namespace uirenderer {
38
39///////////////////////////////////////////////////////////////////////////////
40// Font
41///////////////////////////////////////////////////////////////////////////////
42
43Font::Font(FontRenderer* state, const Font::FontDescription& desc) :
44        mState(state), mDescription(desc) {
45}
46
47Font::FontDescription::FontDescription(const SkPaint* paint, const mat4& matrix) {
48    mFontId = SkTypeface::UniqueID(paint->getTypeface());
49    mFontSize = paint->getTextSize();
50    mFlags = 0;
51    if (paint->isFakeBoldText()) {
52        mFlags |= Font::kFakeBold;
53    }
54    mItalicStyle = paint->getTextSkewX();
55    mScaleX = paint->getTextScaleX();
56    mStyle = paint->getStyle();
57    mStrokeWidth = paint->getStrokeWidth();
58    mAntiAliasing = paint->isAntiAlias();
59    mHinting = paint->getHinting();
60    mLookupTransform.reset();
61    mLookupTransform[SkMatrix::kMScaleX] = roundf(fmaxf(1.0f, matrix[mat4::kScaleX]));
62    mLookupTransform[SkMatrix::kMScaleY] = roundf(fmaxf(1.0f, matrix[mat4::kScaleY]));
63    if (!mLookupTransform.invert(&mInverseLookupTransform)) {
64        ALOGW("Could not query the inverse lookup transform for this font");
65    }
66}
67
68Font::~Font() {
69    mState->removeFont(this);
70
71    for (uint32_t i = 0; i < mCachedGlyphs.size(); i++) {
72        delete mCachedGlyphs.valueAt(i);
73    }
74}
75
76hash_t Font::FontDescription::hash() const {
77    uint32_t hash = JenkinsHashMix(0, mFontId);
78    hash = JenkinsHashMix(hash, android::hash_type(mFontSize));
79    hash = JenkinsHashMix(hash, android::hash_type(mFlags));
80    hash = JenkinsHashMix(hash, android::hash_type(mItalicStyle));
81    hash = JenkinsHashMix(hash, android::hash_type(mScaleX));
82    hash = JenkinsHashMix(hash, android::hash_type(mStyle));
83    hash = JenkinsHashMix(hash, android::hash_type(mStrokeWidth));
84    hash = JenkinsHashMix(hash, int(mAntiAliasing));
85    hash = JenkinsHashMix(hash, android::hash_type(mHinting));
86    hash = JenkinsHashMix(hash, android::hash_type(mLookupTransform[SkMatrix::kMScaleX]));
87    hash = JenkinsHashMix(hash, android::hash_type(mLookupTransform[SkMatrix::kMScaleY]));
88    return JenkinsHashWhiten(hash);
89}
90
91int Font::FontDescription::compare(const Font::FontDescription& lhs,
92        const Font::FontDescription& rhs) {
93    int deltaInt = int(lhs.mFontId) - int(rhs.mFontId);
94    if (deltaInt != 0) return deltaInt;
95
96    if (lhs.mFontSize < rhs.mFontSize) return -1;
97    if (lhs.mFontSize > rhs.mFontSize) return +1;
98
99    if (lhs.mItalicStyle < rhs.mItalicStyle) return -1;
100    if (lhs.mItalicStyle > rhs.mItalicStyle) return +1;
101
102    deltaInt = int(lhs.mFlags) - int(rhs.mFlags);
103    if (deltaInt != 0) return deltaInt;
104
105    if (lhs.mScaleX < rhs.mScaleX) return -1;
106    if (lhs.mScaleX > rhs.mScaleX) return +1;
107
108    deltaInt = int(lhs.mStyle) - int(rhs.mStyle);
109    if (deltaInt != 0) return deltaInt;
110
111    if (lhs.mStrokeWidth < rhs.mStrokeWidth) return -1;
112    if (lhs.mStrokeWidth > rhs.mStrokeWidth) return +1;
113
114    deltaInt = int(lhs.mAntiAliasing) - int(rhs.mAntiAliasing);
115    if (deltaInt != 0) return deltaInt;
116
117    deltaInt = int(lhs.mHinting) - int(rhs.mHinting);
118    if (deltaInt != 0) return deltaInt;
119
120    if (lhs.mLookupTransform[SkMatrix::kMScaleX] <
121            rhs.mLookupTransform[SkMatrix::kMScaleX]) return -1;
122    if (lhs.mLookupTransform[SkMatrix::kMScaleX] >
123            rhs.mLookupTransform[SkMatrix::kMScaleX]) return +1;
124
125    if (lhs.mLookupTransform[SkMatrix::kMScaleY] <
126            rhs.mLookupTransform[SkMatrix::kMScaleY]) return -1;
127    if (lhs.mLookupTransform[SkMatrix::kMScaleY] >
128            rhs.mLookupTransform[SkMatrix::kMScaleY]) return +1;
129
130    return 0;
131}
132
133void Font::invalidateTextureCache(CacheTexture* cacheTexture) {
134    for (uint32_t i = 0; i < mCachedGlyphs.size(); i++) {
135        CachedGlyphInfo* cachedGlyph = mCachedGlyphs.valueAt(i);
136        if (!cacheTexture || cachedGlyph->mCacheTexture == cacheTexture) {
137            cachedGlyph->mIsValid = false;
138        }
139    }
140}
141
142void Font::measureCachedGlyph(CachedGlyphInfo *glyph, int x, int y,
143        uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
144    int nPenX = x + glyph->mBitmapLeft;
145    int nPenY = y + glyph->mBitmapTop;
146
147    int width = (int) glyph->mBitmapWidth;
148    int height = (int) glyph->mBitmapHeight;
149
150    if (bounds->bottom > nPenY) {
151        bounds->bottom = nPenY;
152    }
153    if (bounds->left > nPenX) {
154        bounds->left = nPenX;
155    }
156    if (bounds->right < nPenX + width) {
157        bounds->right = nPenX + width;
158    }
159    if (bounds->top < nPenY + height) {
160        bounds->top = nPenY + height;
161    }
162}
163
164void Font::drawCachedGlyph(CachedGlyphInfo* glyph, int x, int y,
165        uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
166    float nPenX = x + glyph->mBitmapLeft;
167    float nPenY = y + glyph->mBitmapTop + glyph->mBitmapHeight;
168
169    float width = (float) glyph->mBitmapWidth;
170    float height = (float) glyph->mBitmapHeight;
171
172    float u1 = glyph->mBitmapMinU;
173    float u2 = glyph->mBitmapMaxU;
174    float v1 = glyph->mBitmapMinV;
175    float v2 = glyph->mBitmapMaxV;
176
177    mState->appendMeshQuad(nPenX, nPenY, u1, v2,
178            nPenX + width, nPenY, u2, v2,
179            nPenX + width, nPenY - height, u2, v1,
180            nPenX, nPenY - height, u1, v1, glyph->mCacheTexture);
181}
182
183void Font::drawCachedGlyphTransformed(CachedGlyphInfo* glyph, int x, int y,
184        uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
185    SkPoint p[4];
186    p[0].iset(glyph->mBitmapLeft, glyph->mBitmapTop + glyph->mBitmapHeight);
187    p[1].iset(glyph->mBitmapLeft + glyph->mBitmapWidth, glyph->mBitmapTop + glyph->mBitmapHeight);
188    p[2].iset(glyph->mBitmapLeft + glyph->mBitmapWidth, glyph->mBitmapTop);
189    p[3].iset(glyph->mBitmapLeft, glyph->mBitmapTop);
190
191    mDescription.mInverseLookupTransform.mapPoints(p, 4);
192
193    p[0].offset(x, y);
194    p[1].offset(x, y);
195    p[2].offset(x, y);
196    p[3].offset(x, y);
197
198    float u1 = glyph->mBitmapMinU;
199    float u2 = glyph->mBitmapMaxU;
200    float v1 = glyph->mBitmapMinV;
201    float v2 = glyph->mBitmapMaxV;
202
203    mState->appendRotatedMeshQuad(
204            p[0].x(), p[0].y(), u1, v2,
205            p[1].x(), p[1].y(), u2, v2,
206            p[2].x(), p[2].y(), u2, v1,
207            p[3].x(), p[3].y(), u1, v1, glyph->mCacheTexture);
208}
209
210void Font::drawCachedGlyphBitmap(CachedGlyphInfo* glyph, int x, int y, uint8_t* bitmap,
211        uint32_t bitmapWidth, uint32_t bitmapHeight, Rect* bounds, const float* pos) {
212    int dstX = x + glyph->mBitmapLeft;
213    int dstY = y + glyph->mBitmapTop;
214
215    CacheTexture* cacheTexture = glyph->mCacheTexture;
216
217    uint32_t cacheWidth = cacheTexture->getWidth();
218    uint32_t startY = glyph->mStartY * cacheWidth;
219    uint32_t endY = startY + (glyph->mBitmapHeight * cacheWidth);
220
221    PixelBuffer* pixelBuffer = cacheTexture->getPixelBuffer();
222    const uint8_t* cacheBuffer = pixelBuffer->map();
223
224    for (uint32_t cacheY = startY, bitmapY = dstY * bitmapWidth; cacheY < endY;
225            cacheY += cacheWidth, bitmapY += bitmapWidth) {
226        memcpy(&bitmap[bitmapY + dstX], &cacheBuffer[cacheY + glyph->mStartX], glyph->mBitmapWidth);
227    }
228}
229
230void Font::drawCachedGlyph(CachedGlyphInfo* glyph, float x, float hOffset, float vOffset,
231        SkPathMeasure& measure, SkPoint* position, SkVector* tangent) {
232    const float halfWidth = glyph->mBitmapWidth * 0.5f;
233    const float height = glyph->mBitmapHeight;
234
235    vOffset += glyph->mBitmapTop + height;
236
237    SkPoint destination[4];
238    bool ok = measure.getPosTan(x + hOffset + glyph->mBitmapLeft + halfWidth, position, tangent);
239    if (!ok) {
240        ALOGW("The path for drawTextOnPath is empty or null");
241    }
242
243    // Move along the tangent and offset by the normal
244    destination[0].set(-tangent->fX * halfWidth - tangent->fY * vOffset,
245            -tangent->fY * halfWidth + tangent->fX * vOffset);
246    destination[1].set(tangent->fX * halfWidth - tangent->fY * vOffset,
247            tangent->fY * halfWidth + tangent->fX * vOffset);
248    destination[2].set(destination[1].fX + tangent->fY * height,
249            destination[1].fY - tangent->fX * height);
250    destination[3].set(destination[0].fX + tangent->fY * height,
251            destination[0].fY - tangent->fX * height);
252
253    const float u1 = glyph->mBitmapMinU;
254    const float u2 = glyph->mBitmapMaxU;
255    const float v1 = glyph->mBitmapMinV;
256    const float v2 = glyph->mBitmapMaxV;
257
258    mState->appendRotatedMeshQuad(
259            position->x() + destination[0].x(),
260            position->y() + destination[0].y(), u1, v2,
261            position->x() + destination[1].x(),
262            position->y() + destination[1].y(), u2, v2,
263            position->x() + destination[2].x(),
264            position->y() + destination[2].y(), u2, v1,
265            position->x() + destination[3].x(),
266            position->y() + destination[3].y(), u1, v1,
267            glyph->mCacheTexture);
268}
269
270CachedGlyphInfo* Font::getCachedGlyph(SkPaint* paint, glyph_t textUnit, bool precaching) {
271    CachedGlyphInfo* cachedGlyph = mCachedGlyphs.valueFor(textUnit);
272    if (cachedGlyph) {
273        // Is the glyph still in texture cache?
274        if (!cachedGlyph->mIsValid) {
275            SkAutoGlyphCache autoCache(*paint, NULL, &mDescription.mLookupTransform);
276            const SkGlyph& skiaGlyph = GET_METRICS(autoCache.getCache(), textUnit);
277            updateGlyphCache(paint, skiaGlyph, autoCache.getCache(), cachedGlyph, precaching);
278        }
279    } else {
280        cachedGlyph = cacheGlyph(paint, textUnit, precaching);
281    }
282
283    return cachedGlyph;
284}
285
286void Font::render(SkPaint* paint, const char *text, uint32_t start, uint32_t len,
287            int numGlyphs, int x, int y, const float* positions) {
288    render(paint, text, start, len, numGlyphs, x, y, FRAMEBUFFER, NULL,
289            0, 0, NULL, positions);
290}
291
292void Font::render(SkPaint* paint, const char *text, uint32_t start, uint32_t len,
293        int numGlyphs, SkPath* path, float hOffset, float vOffset) {
294    if (numGlyphs == 0 || text == NULL || len == 0) {
295        return;
296    }
297
298    text += start;
299
300    int glyphsCount = 0;
301    SkFixed prevRsbDelta = 0;
302
303    float penX = 0.0f;
304
305    SkPoint position;
306    SkVector tangent;
307
308    SkPathMeasure measure(*path, false);
309    float pathLength = SkScalarToFloat(measure.getLength());
310
311    if (paint->getTextAlign() != SkPaint::kLeft_Align) {
312        float textWidth = SkScalarToFloat(paint->measureText(text, len));
313        float pathOffset = pathLength;
314        if (paint->getTextAlign() == SkPaint::kCenter_Align) {
315            textWidth *= 0.5f;
316            pathOffset *= 0.5f;
317        }
318        penX += pathOffset - textWidth;
319    }
320
321    while (glyphsCount < numGlyphs && penX < pathLength) {
322        glyph_t glyph = GET_GLYPH(text);
323
324        if (IS_END_OF_STRING(glyph)) {
325            break;
326        }
327
328        CachedGlyphInfo* cachedGlyph = getCachedGlyph(paint, glyph);
329        penX += SkFixedToFloat(AUTO_KERN(prevRsbDelta, cachedGlyph->mLsbDelta));
330        prevRsbDelta = cachedGlyph->mRsbDelta;
331
332        if (cachedGlyph->mIsValid && cachedGlyph->mCacheTexture) {
333            drawCachedGlyph(cachedGlyph, penX, hOffset, vOffset, measure, &position, &tangent);
334        }
335
336        penX += SkFixedToFloat(cachedGlyph->mAdvanceX);
337
338        glyphsCount++;
339    }
340}
341
342void Font::measure(SkPaint* paint, const char* text, uint32_t start, uint32_t len,
343        int numGlyphs, Rect *bounds, const float* positions) {
344    if (bounds == NULL) {
345        ALOGE("No return rectangle provided to measure text");
346        return;
347    }
348    bounds->set(1e6, -1e6, -1e6, 1e6);
349    render(paint, text, start, len, numGlyphs, 0, 0, MEASURE, NULL, 0, 0, bounds, positions);
350}
351
352void Font::precache(SkPaint* paint, const char* text, int numGlyphs) {
353    ATRACE_NAME("precacheText");
354
355    if (numGlyphs == 0 || text == NULL) {
356        return;
357    }
358
359    int glyphsCount = 0;
360    while (glyphsCount < numGlyphs) {
361        glyph_t glyph = GET_GLYPH(text);
362
363        // Reached the end of the string
364        if (IS_END_OF_STRING(glyph)) {
365            break;
366        }
367
368        CachedGlyphInfo* cachedGlyph = getCachedGlyph(paint, glyph, true);
369        glyphsCount++;
370    }
371}
372
373void Font::render(SkPaint* paint, const char* text, uint32_t start, uint32_t len,
374        int numGlyphs, int x, int y, RenderMode mode, uint8_t *bitmap,
375        uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* positions) {
376    if (numGlyphs == 0 || text == NULL || len == 0) {
377        return;
378    }
379
380    static RenderGlyph gRenderGlyph[] = {
381            &android::uirenderer::Font::drawCachedGlyph,
382            &android::uirenderer::Font::drawCachedGlyphTransformed,
383            &android::uirenderer::Font::drawCachedGlyphBitmap,
384            &android::uirenderer::Font::drawCachedGlyphBitmap,
385            &android::uirenderer::Font::measureCachedGlyph,
386            &android::uirenderer::Font::measureCachedGlyph
387    };
388    RenderGlyph render = gRenderGlyph[(mode << 1) + !mIdentityTransform];
389
390    text += start;
391    int glyphsCount = 0;
392
393    const SkPaint::Align align = paint->getTextAlign();
394
395    while (glyphsCount < numGlyphs) {
396        glyph_t glyph = GET_GLYPH(text);
397
398        // Reached the end of the string
399        if (IS_END_OF_STRING(glyph)) {
400            break;
401        }
402
403        CachedGlyphInfo* cachedGlyph = getCachedGlyph(paint, glyph);
404
405        // If it's still not valid, we couldn't cache it, so we shouldn't
406        // draw garbage; also skip empty glyphs (spaces)
407        if (cachedGlyph->mIsValid && cachedGlyph->mCacheTexture) {
408            int penX = x + (int) roundf(positions[(glyphsCount << 1)]);
409            int penY = y + (int) roundf(positions[(glyphsCount << 1) + 1]);
410
411            (*this.*render)(cachedGlyph, penX, penY,
412                    bitmap, bitmapW, bitmapH, bounds, positions);
413        }
414
415        glyphsCount++;
416    }
417}
418
419void Font::updateGlyphCache(SkPaint* paint, const SkGlyph& skiaGlyph, SkGlyphCache* skiaGlyphCache,
420        CachedGlyphInfo* glyph, bool precaching) {
421    glyph->mAdvanceX = skiaGlyph.fAdvanceX;
422    glyph->mAdvanceY = skiaGlyph.fAdvanceY;
423    glyph->mBitmapLeft = skiaGlyph.fLeft;
424    glyph->mBitmapTop = skiaGlyph.fTop;
425    glyph->mLsbDelta = skiaGlyph.fLsbDelta;
426    glyph->mRsbDelta = skiaGlyph.fRsbDelta;
427
428    uint32_t startX = 0;
429    uint32_t startY = 0;
430
431    // Get the bitmap for the glyph
432    if (!skiaGlyph.fImage) {
433        skiaGlyphCache->findImage(skiaGlyph);
434    }
435    mState->cacheBitmap(skiaGlyph, glyph, &startX, &startY, precaching);
436
437    if (!glyph->mIsValid) {
438        return;
439    }
440
441    uint32_t endX = startX + skiaGlyph.fWidth;
442    uint32_t endY = startY + skiaGlyph.fHeight;
443
444    glyph->mStartX = startX;
445    glyph->mStartY = startY;
446    glyph->mBitmapWidth = skiaGlyph.fWidth;
447    glyph->mBitmapHeight = skiaGlyph.fHeight;
448
449    bool empty = skiaGlyph.fWidth == 0 || skiaGlyph.fHeight == 0;
450    if (!empty) {
451        uint32_t cacheWidth = glyph->mCacheTexture->getWidth();
452        uint32_t cacheHeight = glyph->mCacheTexture->getHeight();
453
454        glyph->mBitmapMinU = startX / (float) cacheWidth;
455        glyph->mBitmapMinV = startY / (float) cacheHeight;
456        glyph->mBitmapMaxU = endX / (float) cacheWidth;
457        glyph->mBitmapMaxV = endY / (float) cacheHeight;
458
459        mState->setTextureDirty();
460    }
461}
462
463CachedGlyphInfo* Font::cacheGlyph(SkPaint* paint, glyph_t glyph, bool precaching) {
464    CachedGlyphInfo* newGlyph = new CachedGlyphInfo();
465    mCachedGlyphs.add(glyph, newGlyph);
466
467    SkAutoGlyphCache autoCache(*paint, NULL, &mDescription.mLookupTransform);
468    const SkGlyph& skiaGlyph = GET_METRICS(autoCache.getCache(), glyph);
469    newGlyph->mIsValid = false;
470    newGlyph->mGlyphIndex = skiaGlyph.fID;
471
472    updateGlyphCache(paint, skiaGlyph, autoCache.getCache(), newGlyph, precaching);
473
474    return newGlyph;
475}
476
477Font* Font::create(FontRenderer* state, const SkPaint* paint, const mat4& matrix) {
478    FontDescription description(paint, matrix);
479    Font* font = state->mActiveFonts.get(description);
480
481    if (!font) {
482        font = new Font(state, description);
483        state->mActiveFonts.put(description, font);
484    }
485    font->mIdentityTransform = matrix.isIdentity();
486
487    return font;
488}
489
490}; // namespace uirenderer
491}; // namespace android
492