| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "GrDistanceFieldTextContext.h" |
| #include "GrAtlas.h" |
| #include "SkColorFilter.h" |
| #include "GrDrawTarget.h" |
| #include "GrDrawTargetCaps.h" |
| #include "GrFontScaler.h" |
| #include "SkGlyphCache.h" |
| #include "GrGpu.h" |
| #include "GrIndexBuffer.h" |
| #include "GrStrokeInfo.h" |
| #include "GrTextStrike.h" |
| #include "GrTextStrike_impl.h" |
| #include "SkDistanceFieldGen.h" |
| #include "SkDraw.h" |
| #include "SkGpuDevice.h" |
| #include "SkPath.h" |
| #include "SkRTConf.h" |
| #include "SkStrokeRec.h" |
| #include "effects/GrDistanceFieldTextureEffect.h" |
| |
| static const int kGlyphCoordsAttributeIndex = 1; |
| |
| static const int kSmallDFFontSize = 32; |
| static const int kSmallDFFontLimit = 32; |
| static const int kMediumDFFontSize = 64; |
| static const int kMediumDFFontLimit = 64; |
| static const int kLargeDFFontSize = 128; |
| |
| SK_CONF_DECLARE(bool, c_DumpFontCache, "gpu.dumpFontCache", false, |
| "Dump the contents of the font cache before every purge."); |
| |
| GrDistanceFieldTextContext::GrDistanceFieldTextContext(GrContext* context, |
| const SkDeviceProperties& properties, |
| bool enable) |
| : GrTextContext(context, properties) { |
| #if SK_FORCE_DISTANCEFIELD_FONTS |
| fEnableDFRendering = true; |
| #else |
| fEnableDFRendering = enable; |
| #endif |
| fStrike = NULL; |
| fGammaTexture = NULL; |
| |
| fCurrTexture = NULL; |
| fCurrVertex = 0; |
| |
| fVertices = NULL; |
| fMaxVertices = 0; |
| } |
| |
| GrDistanceFieldTextContext::~GrDistanceFieldTextContext() { |
| this->flushGlyphs(); |
| SkSafeSetNull(fGammaTexture); |
| } |
| |
| bool GrDistanceFieldTextContext::canDraw(const SkPaint& paint) { |
| if (!fEnableDFRendering && !paint.isDistanceFieldTextTEMP()) { |
| return false; |
| } |
| |
| // rasterizers and mask filters modify alpha, which doesn't |
| // translate well to distance |
| if (paint.getRasterizer() || paint.getMaskFilter() || |
| !fContext->getTextTarget()->caps()->shaderDerivativeSupport()) { |
| return false; |
| } |
| |
| // TODO: add some stroking support |
| if (paint.getStyle() != SkPaint::kFill_Style) { |
| return false; |
| } |
| |
| // TODO: choose an appropriate maximum scale for distance fields and |
| // enable perspective |
| if (SkDraw::ShouldDrawTextAsPaths(paint, fContext->getMatrix())) { |
| return false; |
| } |
| |
| // distance fields cannot represent color fonts |
| SkScalerContext::Rec rec; |
| SkScalerContext::MakeRec(paint, &fDeviceProperties, NULL, &rec); |
| return rec.getFormat() != SkMask::kARGB32_Format; |
| } |
| |
| static inline GrColor skcolor_to_grcolor_nopremultiply(SkColor c) { |
| unsigned r = SkColorGetR(c); |
| unsigned g = SkColorGetG(c); |
| unsigned b = SkColorGetB(c); |
| return GrColorPackRGBA(r, g, b, 0xff); |
| } |
| |
| void GrDistanceFieldTextContext::flushGlyphs() { |
| if (NULL == fDrawTarget) { |
| return; |
| } |
| |
| GrDrawState* drawState = fDrawTarget->drawState(); |
| GrDrawState::AutoRestoreEffects are(drawState); |
| drawState->setFromPaint(fPaint, fContext->getMatrix(), fContext->getRenderTarget()); |
| |
| if (fCurrVertex > 0) { |
| // setup our sampler state for our text texture/atlas |
| SkASSERT(SkIsAlign4(fCurrVertex)); |
| SkASSERT(fCurrTexture); |
| GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kBilerp_FilterMode); |
| GrTextureParams gammaParams(SkShader::kClamp_TileMode, GrTextureParams::kNone_FilterMode); |
| |
| // Effects could be stored with one of the cache objects (atlas?) |
| SkColor filteredColor; |
| SkColorFilter* colorFilter = fSkPaint.getColorFilter(); |
| if (NULL != colorFilter) { |
| filteredColor = colorFilter->filterColor(fSkPaint.getColor()); |
| } else { |
| filteredColor = fSkPaint.getColor(); |
| } |
| if (fUseLCDText) { |
| GrColor colorNoPreMul = skcolor_to_grcolor_nopremultiply(filteredColor); |
| bool useBGR = SkDeviceProperties::Geometry::kBGR_Layout == |
| fDeviceProperties.fGeometry.getLayout(); |
| drawState->addCoverageEffect(GrDistanceFieldLCDTextureEffect::Create( |
| fCurrTexture, |
| params, |
| fGammaTexture, |
| gammaParams, |
| colorNoPreMul, |
| fContext->getMatrix().rectStaysRect() && |
| fContext->getMatrix().isSimilarity(), |
| useBGR), |
| kGlyphCoordsAttributeIndex)->unref(); |
| |
| if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() || |
| kISA_GrBlendCoeff != fPaint.getDstBlendCoeff() || |
| fPaint.numColorStages()) { |
| GrPrintf("LCD Text will not draw correctly.\n"); |
| } |
| // We don't use the GrPaint's color in this case because it's been premultiplied by |
| // alpha. Instead we feed in a non-premultiplied color, and multiply its alpha by |
| // the mask texture color. The end result is that we get |
| // mask*paintAlpha*paintColor + (1-mask*paintAlpha)*dstColor |
| int a = SkColorGetA(fSkPaint.getColor()); |
| // paintAlpha |
| drawState->setColor(SkColorSetARGB(a, a, a, a)); |
| // paintColor |
| drawState->setBlendConstant(colorNoPreMul); |
| drawState->setBlendFunc(kConstC_GrBlendCoeff, kISC_GrBlendCoeff); |
| } else { |
| #ifdef SK_GAMMA_APPLY_TO_A8 |
| U8CPU lum = SkColorSpaceLuminance::computeLuminance(fDeviceProperties.fGamma, |
| filteredColor); |
| drawState->addCoverageEffect(GrDistanceFieldTextureEffect::Create( |
| fCurrTexture, params, |
| fGammaTexture, gammaParams, |
| lum/255.f, |
| fContext->getMatrix().isSimilarity()), |
| kGlyphCoordsAttributeIndex)->unref(); |
| #else |
| drawState->addCoverageEffect(GrDistanceFieldTextureEffect::Create( |
| fCurrTexture, params, |
| fContext->getMatrix().isSimilarity()), |
| kGlyphCoordsAttributeIndex)->unref(); |
| #endif |
| // set back to normal in case we took LCD path previously. |
| drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff()); |
| drawState->setColor(fPaint.getColor()); |
| } |
| |
| int nGlyphs = fCurrVertex / 4; |
| fDrawTarget->setIndexSourceToBuffer(fContext->getQuadIndexBuffer()); |
| fDrawTarget->drawIndexedInstances(kTriangles_GrPrimitiveType, |
| nGlyphs, |
| 4, 6); |
| fDrawTarget->resetVertexSource(); |
| fVertices = NULL; |
| fMaxVertices = 0; |
| fCurrVertex = 0; |
| SkSafeSetNull(fCurrTexture); |
| } |
| } |
| |
| namespace { |
| |
| // position + texture coord |
| extern const GrVertexAttrib gTextVertexAttribs[] = { |
| {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding}, |
| {kVec2f_GrVertexAttribType, sizeof(SkPoint), kEffect_GrVertexAttribBinding} |
| }; |
| |
| }; |
| |
| void GrDistanceFieldTextContext::drawPackedGlyph(GrGlyph::PackedID packed, |
| SkFixed vx, SkFixed vy, |
| GrFontScaler* scaler) { |
| if (NULL == fDrawTarget) { |
| return; |
| } |
| if (NULL == fStrike) { |
| fStrike = fContext->getFontCache()->getStrike(scaler, true); |
| } |
| |
| GrGlyph* glyph = fStrike->getGlyph(packed, scaler); |
| if (NULL == glyph || glyph->fBounds.isEmpty()) { |
| return; |
| } |
| |
| SkScalar sx = SkFixedToScalar(vx); |
| SkScalar sy = SkFixedToScalar(vy); |
| /* |
| // not valid, need to find a different solution for this |
| vx += SkIntToFixed(glyph->fBounds.fLeft); |
| vy += SkIntToFixed(glyph->fBounds.fTop); |
| |
| // keep them as ints until we've done the clip-test |
| GrFixed width = glyph->fBounds.width(); |
| GrFixed height = glyph->fBounds.height(); |
| |
| // check if we clipped out |
| if (true || NULL == glyph->fPlot) { |
| int x = vx >> 16; |
| int y = vy >> 16; |
| if (fClipRect.quickReject(x, y, x + width, y + height)) { |
| // SkCLZ(3); // so we can set a break-point in the debugger |
| return; |
| } |
| } |
| */ |
| if (NULL == glyph->fPlot) { |
| if (fStrike->addGlyphToAtlas(glyph, scaler)) { |
| goto HAS_ATLAS; |
| } |
| |
| // try to clear out an unused plot before we flush |
| if (fContext->getFontCache()->freeUnusedPlot(fStrike) && |
| fStrike->addGlyphToAtlas(glyph, scaler)) { |
| goto HAS_ATLAS; |
| } |
| |
| if (c_DumpFontCache) { |
| #ifdef SK_DEVELOPER |
| fContext->getFontCache()->dump(); |
| #endif |
| } |
| |
| // before we purge the cache, we must flush any accumulated draws |
| this->flushGlyphs(); |
| fContext->flush(); |
| |
| // we should have an unused plot now |
| if (fContext->getFontCache()->freeUnusedPlot(fStrike) && |
| fStrike->addGlyphToAtlas(glyph, scaler)) { |
| goto HAS_ATLAS; |
| } |
| |
| if (NULL == glyph->fPath) { |
| SkPath* path = SkNEW(SkPath); |
| if (!scaler->getGlyphPath(glyph->glyphID(), path)) { |
| // flag the glyph as being dead? |
| delete path; |
| return; |
| } |
| glyph->fPath = path; |
| } |
| |
| GrContext::AutoMatrix am; |
| SkMatrix ctm; |
| ctm.setScale(fTextRatio, fTextRatio); |
| ctm.postTranslate(sx, sy); |
| GrPaint tmpPaint(fPaint); |
| am.setPreConcat(fContext, ctm, &tmpPaint); |
| GrStrokeInfo strokeInfo(SkStrokeRec::kFill_InitStyle); |
| fContext->drawPath(tmpPaint, *glyph->fPath, strokeInfo); |
| return; |
| } |
| |
| HAS_ATLAS: |
| SkASSERT(glyph->fPlot); |
| GrDrawTarget::DrawToken drawToken = fDrawTarget->getCurrentDrawToken(); |
| glyph->fPlot->setDrawToken(drawToken); |
| |
| GrTexture* texture = glyph->fPlot->texture(); |
| SkASSERT(texture); |
| |
| if (fCurrTexture != texture || fCurrVertex + 4 > fMaxVertices) { |
| this->flushGlyphs(); |
| fCurrTexture = texture; |
| fCurrTexture->ref(); |
| } |
| |
| if (NULL == fVertices) { |
| // If we need to reserve vertices allow the draw target to suggest |
| // a number of verts to reserve and whether to perform a flush. |
| fMaxVertices = kMinRequestedVerts; |
| fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>( |
| SK_ARRAY_COUNT(gTextVertexAttribs)); |
| bool flush = fDrawTarget->geometryHints(&fMaxVertices, NULL); |
| if (flush) { |
| this->flushGlyphs(); |
| fContext->flush(); |
| fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>( |
| SK_ARRAY_COUNT(gTextVertexAttribs)); |
| } |
| fMaxVertices = kDefaultRequestedVerts; |
| // ignore return, no point in flushing again. |
| fDrawTarget->geometryHints(&fMaxVertices, NULL); |
| |
| int maxQuadVertices = 4 * fContext->getQuadIndexBuffer()->maxQuads(); |
| if (fMaxVertices < kMinRequestedVerts) { |
| fMaxVertices = kDefaultRequestedVerts; |
| } else if (fMaxVertices > maxQuadVertices) { |
| // don't exceed the limit of the index buffer |
| fMaxVertices = maxQuadVertices; |
| } |
| bool success = fDrawTarget->reserveVertexAndIndexSpace(fMaxVertices, |
| 0, |
| GrTCast<void**>(&fVertices), |
| NULL); |
| GrAlwaysAssert(success); |
| SkASSERT(2*sizeof(SkPoint) == fDrawTarget->getDrawState().getVertexSize()); |
| } |
| |
| SkScalar dx = SkIntToScalar(glyph->fBounds.fLeft + SK_DistanceFieldInset); |
| SkScalar dy = SkIntToScalar(glyph->fBounds.fTop + SK_DistanceFieldInset); |
| SkScalar width = SkIntToScalar(glyph->fBounds.width() - 2*SK_DistanceFieldInset); |
| SkScalar height = SkIntToScalar(glyph->fBounds.height() - 2*SK_DistanceFieldInset); |
| |
| SkScalar scale = fTextRatio; |
| dx *= scale; |
| dy *= scale; |
| sx += dx; |
| sy += dy; |
| width *= scale; |
| height *= scale; |
| |
| SkFixed tx = SkIntToFixed(glyph->fAtlasLocation.fX + SK_DistanceFieldInset); |
| SkFixed ty = SkIntToFixed(glyph->fAtlasLocation.fY + SK_DistanceFieldInset); |
| SkFixed tw = SkIntToFixed(glyph->fBounds.width() - 2*SK_DistanceFieldInset); |
| SkFixed th = SkIntToFixed(glyph->fBounds.height() - 2*SK_DistanceFieldInset); |
| |
| static const size_t kVertexSize = 2 * sizeof(SkPoint); |
| fVertices[2*fCurrVertex].setRectFan(sx, |
| sy, |
| sx + width, |
| sy + height, |
| kVertexSize); |
| fVertices[2*fCurrVertex+1].setRectFan(SkFixedToFloat(texture->normalizeFixedX(tx)), |
| SkFixedToFloat(texture->normalizeFixedY(ty)), |
| SkFixedToFloat(texture->normalizeFixedX(tx + tw)), |
| SkFixedToFloat(texture->normalizeFixedY(ty + th)), |
| kVertexSize); |
| fCurrVertex += 4; |
| } |
| |
| inline void GrDistanceFieldTextContext::init(const GrPaint& paint, const SkPaint& skPaint) { |
| GrTextContext::init(paint, skPaint); |
| |
| fStrike = NULL; |
| |
| fCurrTexture = NULL; |
| fCurrVertex = 0; |
| |
| fVertices = NULL; |
| fMaxVertices = 0; |
| |
| if (fSkPaint.getTextSize() <= kSmallDFFontLimit) { |
| fTextRatio = fSkPaint.getTextSize()/kSmallDFFontSize; |
| fSkPaint.setTextSize(SkIntToScalar(kSmallDFFontSize)); |
| } else if (fSkPaint.getTextSize() <= kMediumDFFontLimit) { |
| fTextRatio = fSkPaint.getTextSize()/kMediumDFFontSize; |
| fSkPaint.setTextSize(SkIntToScalar(kMediumDFFontSize)); |
| } else { |
| fTextRatio = fSkPaint.getTextSize()/kLargeDFFontSize; |
| fSkPaint.setTextSize(SkIntToScalar(kLargeDFFontSize)); |
| } |
| |
| fUseLCDText = fSkPaint.isLCDRenderText(); |
| |
| fSkPaint.setLCDRenderText(false); |
| fSkPaint.setAutohinted(false); |
| fSkPaint.setHinting(SkPaint::kNormal_Hinting); |
| fSkPaint.setSubpixelText(true); |
| |
| } |
| |
| inline void GrDistanceFieldTextContext::finish() { |
| flushGlyphs(); |
| |
| GrTextContext::finish(); |
| } |
| |
| static void setup_gamma_texture(GrContext* context, const SkGlyphCache* cache, |
| const SkDeviceProperties& deviceProperties, |
| GrTexture** gammaTexture) { |
| if (NULL == *gammaTexture) { |
| int width, height; |
| size_t size; |
| |
| #ifdef SK_GAMMA_CONTRAST |
| SkScalar contrast = SK_GAMMA_CONTRAST; |
| #else |
| SkScalar contrast = 0.5f; |
| #endif |
| SkScalar paintGamma = deviceProperties.fGamma; |
| SkScalar deviceGamma = deviceProperties.fGamma; |
| |
| size = SkScalerContext::GetGammaLUTSize(contrast, paintGamma, deviceGamma, |
| &width, &height); |
| |
| SkAutoTArray<uint8_t> data((int)size); |
| SkScalerContext::GetGammaLUTData(contrast, paintGamma, deviceGamma, data.get()); |
| |
| // TODO: Update this to use the cache rather than directly creating a texture. |
| GrTextureDesc desc; |
| desc.fFlags = kDynamicUpdate_GrTextureFlagBit; |
| desc.fWidth = width; |
| desc.fHeight = height; |
| desc.fConfig = kAlpha_8_GrPixelConfig; |
| |
| *gammaTexture = context->getGpu()->createTexture(desc, NULL, 0); |
| if (NULL == *gammaTexture) { |
| return; |
| } |
| |
| context->writeTexturePixels(*gammaTexture, |
| 0, 0, width, height, |
| (*gammaTexture)->config(), data.get(), 0, |
| GrContext::kDontFlush_PixelOpsFlag); |
| } |
| } |
| |
| void GrDistanceFieldTextContext::drawText(const GrPaint& paint, const SkPaint& skPaint, |
| const char text[], size_t byteLength, |
| SkScalar x, SkScalar y) { |
| SkASSERT(byteLength == 0 || text != NULL); |
| |
| // nothing to draw or can't draw |
| if (text == NULL || byteLength == 0 /* no raster clip? || fRC->isEmpty()*/ |
| || fSkPaint.getRasterizer()) { |
| return; |
| } |
| |
| this->init(paint, skPaint); |
| |
| SkScalar sizeRatio = fTextRatio; |
| |
| SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc(); |
| |
| SkAutoGlyphCacheNoGamma autoCache(fSkPaint, &fDeviceProperties, NULL); |
| SkGlyphCache* cache = autoCache.getCache(); |
| GrFontScaler* fontScaler = GetGrFontScaler(cache); |
| |
| setup_gamma_texture(fContext, cache, fDeviceProperties, &fGammaTexture); |
| |
| // need to measure first |
| // TODO - generate positions and pre-load cache as well? |
| const char* stop = text + byteLength; |
| if (fSkPaint.getTextAlign() != SkPaint::kLeft_Align) { |
| SkFixed stopX = 0; |
| SkFixed stopY = 0; |
| |
| const char* textPtr = text; |
| while (textPtr < stop) { |
| // don't need x, y here, since all subpixel variants will have the |
| // same advance |
| const SkGlyph& glyph = glyphCacheProc(cache, &textPtr, 0, 0); |
| |
| stopX += glyph.fAdvanceX; |
| stopY += glyph.fAdvanceY; |
| } |
| SkASSERT(textPtr == stop); |
| |
| SkScalar alignX = SkFixedToScalar(stopX)*sizeRatio; |
| SkScalar alignY = SkFixedToScalar(stopY)*sizeRatio; |
| |
| if (fSkPaint.getTextAlign() == SkPaint::kCenter_Align) { |
| alignX = SkScalarHalf(alignX); |
| alignY = SkScalarHalf(alignY); |
| } |
| |
| x -= alignX; |
| y -= alignY; |
| } |
| |
| SkFixed fx = SkScalarToFixed(x); |
| SkFixed fy = SkScalarToFixed(y); |
| SkFixed fixedScale = SkScalarToFixed(sizeRatio); |
| while (text < stop) { |
| const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0); |
| |
| if (glyph.fWidth) { |
| this->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(), |
| glyph.getSubXFixed(), |
| glyph.getSubYFixed()), |
| fx, |
| fy, |
| fontScaler); |
| } |
| |
| fx += SkFixedMul_portable(glyph.fAdvanceX, fixedScale); |
| fy += SkFixedMul_portable(glyph.fAdvanceY, fixedScale); |
| } |
| |
| this->finish(); |
| } |
| |
| void GrDistanceFieldTextContext::drawPosText(const GrPaint& paint, const SkPaint& skPaint, |
| const char text[], size_t byteLength, |
| const SkScalar pos[], SkScalar constY, |
| int scalarsPerPosition) { |
| |
| SkASSERT(byteLength == 0 || text != NULL); |
| SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition); |
| |
| // nothing to draw |
| if (text == NULL || byteLength == 0 /* no raster clip? || fRC->isEmpty()*/) { |
| return; |
| } |
| |
| this->init(paint, skPaint); |
| |
| SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc(); |
| |
| SkAutoGlyphCacheNoGamma autoCache(fSkPaint, &fDeviceProperties, NULL); |
| SkGlyphCache* cache = autoCache.getCache(); |
| GrFontScaler* fontScaler = GetGrFontScaler(cache); |
| |
| setup_gamma_texture(fContext, cache, fDeviceProperties, &fGammaTexture); |
| |
| const char* stop = text + byteLength; |
| |
| if (SkPaint::kLeft_Align == fSkPaint.getTextAlign()) { |
| while (text < stop) { |
| // the last 2 parameters are ignored |
| const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0); |
| |
| if (glyph.fWidth) { |
| SkScalar x = pos[0]; |
| SkScalar y = scalarsPerPosition == 1 ? constY : pos[1]; |
| |
| this->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(), |
| glyph.getSubXFixed(), |
| glyph.getSubYFixed()), |
| SkScalarToFixed(x), |
| SkScalarToFixed(y), |
| fontScaler); |
| } |
| pos += scalarsPerPosition; |
| } |
| } else { |
| int alignShift = SkPaint::kCenter_Align == fSkPaint.getTextAlign() ? 1 : 0; |
| while (text < stop) { |
| // the last 2 parameters are ignored |
| const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0); |
| |
| if (glyph.fWidth) { |
| SkScalar x = pos[0]; |
| SkScalar y = scalarsPerPosition == 1 ? constY : pos[1]; |
| |
| this->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(), |
| glyph.getSubXFixed(), |
| glyph.getSubYFixed()), |
| SkScalarToFixed(x) - (glyph.fAdvanceX >> alignShift), |
| SkScalarToFixed(y) - (glyph.fAdvanceY >> alignShift), |
| fontScaler); |
| } |
| pos += scalarsPerPosition; |
| } |
| } |
| |
| this->finish(); |
| } |
