blob: 6ffa3c3cacb1bf5a2d02cec32bc3c37b2eb2e99c [file] [log] [blame]
/*
* 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 "GrBitmapTextContext.h"
#include "GrDrawTarget.h"
#include "GrDrawTargetCaps.h"
#include "GrFontScaler.h"
#include "GrGpu.h"
#include "GrIndexBuffer.h"
#include "GrStrokeInfo.h"
#include "GrTexturePriv.h"
#include "GrTextStrike.h"
#include "GrTextStrike_impl.h"
#include "SkAutoKern.h"
#include "SkColorFilter.h"
#include "SkDistanceFieldGen.h"
#include "SkDraw.h"
#include "SkGlyphCache.h"
#include "SkGpuDevice.h"
#include "SkPath.h"
#include "SkRTConf.h"
#include "SkStrokeRec.h"
#include "effects/GrDistanceFieldTextureEffect.h"
SK_CONF_DECLARE(bool, c_DumpFontCache, "gpu.dumpFontCache", false,
"Dump the contents of the font cache before every purge.");
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;
namespace {
// position + texture coord
extern const GrVertexAttrib gTextVertexAttribs[] = {
{kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
{kVec2f_GrVertexAttribType, sizeof(SkPoint) , kGeometryProcessor_GrVertexAttribBinding}
};
static const size_t kTextVASize = 2 * sizeof(SkPoint);
// position + color + texture coord
extern const GrVertexAttrib gTextVertexWithColorAttribs[] = {
{kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
{kVec4ub_GrVertexAttribType, sizeof(SkPoint), kColor_GrVertexAttribBinding},
{kVec2f_GrVertexAttribType, sizeof(SkPoint) + sizeof(GrColor), kGeometryProcessor_GrVertexAttribBinding}
};
static const size_t kTextVAColorSize = 2 * sizeof(SkPoint) + sizeof(GrColor);
static const int kVerticesPerGlyph = 4;
static const int kIndicesPerGlyph = 6;
};
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;
fEffectTextureUniqueID = SK_InvalidUniqueID;
fEffectColor = GrColor_ILLEGAL;
fEffectFlags = kInvalid_DistanceFieldEffectFlag;
fVertices = NULL;
fCurrVertex = 0;
fAllocVertexCount = 0;
fTotalVertexCount = 0;
fCurrTexture = NULL;
fVertexBounds.setLargestInverted();
}
GrDistanceFieldTextContext* GrDistanceFieldTextContext::Create(GrContext* context,
const SkDeviceProperties& props,
bool enable) {
GrDistanceFieldTextContext* textContext = SkNEW_ARGS(GrDistanceFieldTextContext,
(context, props, enable));
textContext->fFallbackTextContext = GrBitmapTextContext::Create(context, props);
return textContext;
}
GrDistanceFieldTextContext::~GrDistanceFieldTextContext() {
this->finish();
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;
}
return true;
}
inline void GrDistanceFieldTextContext::init(const GrPaint& paint, const SkPaint& skPaint) {
GrTextContext::init(paint, skPaint);
fStrike = NULL;
const SkMatrix& ctm = fContext->getMatrix();
// getMaxScale doesn't support perspective, so neither do we at the moment
SkASSERT(!ctm.hasPerspective());
SkScalar maxScale = ctm.getMaxScale();
SkScalar textSize = fSkPaint.getTextSize();
SkScalar scaledTextSize = textSize;
// if we have non-unity scale, we need to choose our base text size
// based on the SkPaint's text size multiplied by the max scale factor
// TODO: do we need to do this if we're scaling down (i.e. maxScale < 1)?
if (maxScale > 0 && !SkScalarNearlyEqual(maxScale, SK_Scalar1)) {
scaledTextSize *= maxScale;
}
fVertices = NULL;
fCurrVertex = 0;
fAllocVertexCount = 0;
fTotalVertexCount = 0;
if (scaledTextSize <= kSmallDFFontLimit) {
fTextRatio = textSize / kSmallDFFontSize;
fSkPaint.setTextSize(SkIntToScalar(kSmallDFFontSize));
} else if (scaledTextSize <= kMediumDFFontLimit) {
fTextRatio = textSize / kMediumDFFontSize;
fSkPaint.setTextSize(SkIntToScalar(kMediumDFFontSize));
} else {
fTextRatio = textSize / kLargeDFFontSize;
fSkPaint.setTextSize(SkIntToScalar(kLargeDFFontSize));
}
fUseLCDText = fSkPaint.isLCDRenderText();
fSkPaint.setLCDRenderText(false);
fSkPaint.setAutohinted(false);
fSkPaint.setHinting(SkPaint::kNormal_Hinting);
fSkPaint.setSubpixelText(true);
}
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.gamma();
SkScalar deviceGamma = deviceProperties.gamma();
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.
GrSurfaceDesc desc;
desc.fFlags = kNone_GrSurfaceFlags;
desc.fWidth = width;
desc.fHeight = height;
desc.fConfig = kAlpha_8_GrPixelConfig;
*gammaTexture = context->getGpu()->createTexture(desc, NULL, 0);
if (NULL == *gammaTexture) {
return;
}
(*gammaTexture)->writePixels(0, 0, width, height,
(*gammaTexture)->config(), data.get(), 0,
GrContext::kDontFlush_PixelOpsFlag);
}
}
void GrDistanceFieldTextContext::onDrawText(const GrPaint& paint, const SkPaint& skPaint,
const char text[], size_t byteLength,
SkScalar x, SkScalar y) {
SkASSERT(byteLength == 0 || text != NULL);
// nothing to draw
if (text == NULL || byteLength == 0) {
return;
}
SkDrawCacheProc glyphCacheProc = skPaint.getDrawCacheProc();
SkAutoGlyphCache autoCache(skPaint, &fDeviceProperties, NULL);
SkGlyphCache* cache = autoCache.getCache();
SkTArray<SkScalar> positions;
const char* textPtr = text;
SkFixed stopX = 0;
SkFixed stopY = 0;
SkFixed origin;
switch (skPaint.getTextAlign()) {
case SkPaint::kRight_Align: origin = SK_Fixed1; break;
case SkPaint::kCenter_Align: origin = SK_FixedHalf; break;
case SkPaint::kLeft_Align: origin = 0; break;
default: SkFAIL("Invalid paint origin"); return;
}
SkAutoKern autokern;
const char* stop = text + byteLength;
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);
SkFixed width = glyph.fAdvanceX + autokern.adjust(glyph);
positions.push_back(SkFixedToScalar(stopX + SkFixedMul_portable(origin, width)));
SkFixed height = glyph.fAdvanceY;
positions.push_back(SkFixedToScalar(stopY + SkFixedMul_portable(origin, height)));
stopX += width;
stopY += height;
}
SkASSERT(textPtr == stop);
// now adjust starting point depending on alignment
SkScalar alignX = SkFixedToScalar(stopX);
SkScalar alignY = SkFixedToScalar(stopY);
if (skPaint.getTextAlign() == SkPaint::kCenter_Align) {
alignX = SkScalarHalf(alignX);
alignY = SkScalarHalf(alignY);
} else if (skPaint.getTextAlign() == SkPaint::kLeft_Align) {
alignX = 0;
alignY = 0;
}
x -= alignX;
y -= alignY;
SkPoint offset = SkPoint::Make(x, y);
this->drawPosText(paint, skPaint, text, byteLength, positions.begin(), 2, offset);
}
void GrDistanceFieldTextContext::onDrawPosText(const GrPaint& paint, const SkPaint& skPaint,
const char text[], size_t byteLength,
const SkScalar pos[], int scalarsPerPosition,
const SkPoint& offset) {
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);
int numGlyphs = fSkPaint.textToGlyphs(text, byteLength, NULL);
fTotalVertexCount = kVerticesPerGlyph*numGlyphs;
const char* stop = text + byteLength;
SkTArray<char> fallbackTxt;
SkTArray<SkScalar> fallbackPos;
if (SkPaint::kLeft_Align == fSkPaint.getTextAlign()) {
while (text < stop) {
const char* lastText = text;
// the last 2 parameters are ignored
const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
if (glyph.fWidth) {
SkScalar x = offset.x() + pos[0];
SkScalar y = offset.y() + (2 == scalarsPerPosition ? pos[1] : 0);
if (!this->appendGlyph(GrGlyph::Pack(glyph.getGlyphID(),
glyph.getSubXFixed(),
glyph.getSubYFixed()),
x, y, fontScaler)) {
// couldn't append, send to fallback
fallbackTxt.push_back_n(text-lastText, lastText);
fallbackPos.push_back(pos[0]);
if (2 == scalarsPerPosition) {
fallbackPos.push_back(pos[1]);
}
}
}
pos += scalarsPerPosition;
}
} else {
SkScalar alignMul = SkPaint::kCenter_Align == fSkPaint.getTextAlign() ? SK_ScalarHalf
: SK_Scalar1;
while (text < stop) {
const char* lastText = text;
// the last 2 parameters are ignored
const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
if (glyph.fWidth) {
SkScalar x = offset.x() + pos[0];
SkScalar y = offset.y() + (2 == scalarsPerPosition ? pos[1] : 0);
SkScalar advanceX = SkFixedToScalar(glyph.fAdvanceX)*alignMul*fTextRatio;
SkScalar advanceY = SkFixedToScalar(glyph.fAdvanceY)*alignMul*fTextRatio;
if (!this->appendGlyph(GrGlyph::Pack(glyph.getGlyphID(),
glyph.getSubXFixed(),
glyph.getSubYFixed()),
x - advanceX, y - advanceY, fontScaler)) {
// couldn't append, send to fallback
fallbackTxt.push_back_n(text-lastText, lastText);
fallbackPos.push_back(pos[0]);
if (2 == scalarsPerPosition) {
fallbackPos.push_back(pos[1]);
}
}
}
pos += scalarsPerPosition;
}
}
this->finish();
if (fallbackTxt.count() > 0) {
fFallbackTextContext->drawPosText(paint, skPaint, fallbackTxt.begin(), fallbackTxt.count(),
fallbackPos.begin(), scalarsPerPosition, offset);
}
}
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);
}
static void* alloc_vertices(GrDrawTarget* drawTarget, int numVertices, bool useColorVerts) {
if (numVertices <= 0) {
return NULL;
}
// set up attributes
if (useColorVerts) {
drawTarget->drawState()->setVertexAttribs<gTextVertexWithColorAttribs>(
SK_ARRAY_COUNT(gTextVertexWithColorAttribs), kTextVAColorSize);
} else {
drawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
SK_ARRAY_COUNT(gTextVertexAttribs), kTextVASize);
}
void* vertices = NULL;
bool success = drawTarget->reserveVertexAndIndexSpace(numVertices,
0,
&vertices,
NULL);
GrAlwaysAssert(success);
return vertices;
}
void GrDistanceFieldTextContext::setupCoverageEffect(const SkColor& filteredColor) {
GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kBilerp_FilterMode);
GrTextureParams gammaParams(SkShader::kClamp_TileMode, GrTextureParams::kNone_FilterMode);
uint32_t textureUniqueID = fCurrTexture->getUniqueID();
const SkMatrix& ctm = fContext->getMatrix();
// set up any flags
uint32_t flags = 0;
flags |= ctm.isSimilarity() ? kSimilarity_DistanceFieldEffectFlag : 0;
flags |= fUseLCDText ? kUseLCD_DistanceFieldEffectFlag : 0;
flags |= fUseLCDText && ctm.rectStaysRect() ?
kRectToRect_DistanceFieldEffectFlag : 0;
bool useBGR = SkPixelGeometryIsBGR(fDeviceProperties.pixelGeometry());
flags |= fUseLCDText && useBGR ? kBGR_DistanceFieldEffectFlag : 0;
// see if we need to create a new effect
if (textureUniqueID != fEffectTextureUniqueID ||
filteredColor != fEffectColor ||
flags != fEffectFlags) {
if (fUseLCDText) {
GrColor colorNoPreMul = skcolor_to_grcolor_nopremultiply(filteredColor);
fCachedGeometryProcessor.reset(GrDistanceFieldLCDTextureEffect::Create(fCurrTexture,
params,
fGammaTexture,
gammaParams,
colorNoPreMul,
flags));
} else {
#ifdef SK_GAMMA_APPLY_TO_A8
U8CPU lum = SkColorSpaceLuminance::computeLuminance(fDeviceProperties.gamma(),
filteredColor);
fCachedGeometryProcessor.reset(GrDistanceFieldTextureEffect::Create(fCurrTexture,
params,
fGammaTexture,
gammaParams,
lum/255.f,
flags));
#else
fCachedGeometryProcessor.reset(GrDistanceFieldNoGammaTextureEffect::Create(fCurrTexture,
params, flags));
#endif
}
fEffectTextureUniqueID = textureUniqueID;
fEffectColor = filteredColor;
fEffectFlags = flags;
}
}
// Returns true if this method handled the glyph, false if needs to be passed to fallback
//
bool GrDistanceFieldTextContext::appendGlyph(GrGlyph::PackedID packed,
SkScalar sx, SkScalar sy,
GrFontScaler* scaler) {
if (NULL == fDrawTarget) {
return true;
}
if (NULL == fStrike) {
fStrike = fContext->getFontCache()->getStrike(scaler, true);
}
GrGlyph* glyph = fStrike->getGlyph(packed, scaler);
if (NULL == glyph || glyph->fBounds.isEmpty()) {
return true;
}
// fallback to color glyph support
if (kA8_GrMaskFormat != glyph->fMaskFormat) {
return false;
}
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;
SkRect glyphRect = SkRect::MakeXYWH(sx, sy, width, height);
// check if we clipped out
SkRect dstRect;
const SkMatrix& ctm = fContext->getMatrix();
(void) ctm.mapRect(&dstRect, glyphRect);
if (fClipRect.quickReject(SkScalarTruncToInt(dstRect.left()),
SkScalarTruncToInt(dstRect.top()),
SkScalarTruncToInt(dstRect.right()),
SkScalarTruncToInt(dstRect.bottom()))) {
// SkCLZ(3); // so we can set a break-point in the debugger
return true;
}
if (NULL == glyph->fPlot) {
if (!fStrike->glyphTooLargeForAtlas(glyph)) {
if (fStrike->addGlyphToAtlas(glyph, scaler)) {
goto HAS_ATLAS;
}
// try to clear out an unused plot before we flush
if (fContext->getFontCache()->freeUnusedPlot(fStrike, glyph) &&
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->flush();
fContext->flush();
// we should have an unused plot now
if (fContext->getFontCache()->freeUnusedPlot(fStrike, glyph) &&
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 true;
}
glyph->fPath = path;
}
// flush any accumulated draws before drawing this glyph as a path.
this->flush();
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);
// remove this glyph from the vertices we need to allocate
fTotalVertexCount -= kVerticesPerGlyph;
return true;
}
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 + kVerticesPerGlyph > fTotalVertexCount) {
this->flush();
fCurrTexture = texture;
fCurrTexture->ref();
}
bool useColorVerts = !fUseLCDText;
if (NULL == fVertices) {
int maxQuadVertices = kVerticesPerGlyph * fContext->getQuadIndexBuffer()->maxQuads();
fAllocVertexCount = SkMin32(fTotalVertexCount, maxQuadVertices);
fVertices = alloc_vertices(fDrawTarget, fAllocVertexCount, useColorVerts);
}
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);
fVertexBounds.joinNonEmptyArg(glyphRect);
size_t vertSize = fUseLCDText ? (2 * sizeof(SkPoint))
: (2 * sizeof(SkPoint) + sizeof(GrColor));
SkASSERT(vertSize == fDrawTarget->getDrawState().getVertexStride());
SkPoint* positions = reinterpret_cast<SkPoint*>(
reinterpret_cast<intptr_t>(fVertices) + vertSize * fCurrVertex);
positions->setRectFan(glyphRect.fLeft, glyphRect.fTop, glyphRect.fRight, glyphRect.fBottom,
vertSize);
// The texture coords are last in both the with and without color vertex layouts.
SkPoint* textureCoords = reinterpret_cast<SkPoint*>(
reinterpret_cast<intptr_t>(positions) + vertSize - sizeof(SkPoint));
textureCoords->setRectFan(SkFixedToFloat(texture->texturePriv().normalizeFixedX(tx)),
SkFixedToFloat(texture->texturePriv().normalizeFixedY(ty)),
SkFixedToFloat(texture->texturePriv().normalizeFixedX(tx + tw)),
SkFixedToFloat(texture->texturePriv().normalizeFixedY(ty + th)),
vertSize);
if (useColorVerts) {
if (0xFF == GrColorUnpackA(fPaint.getColor())) {
fDrawTarget->drawState()->setHint(GrDrawState::kVertexColorsAreOpaque_Hint, true);
}
// color comes after position.
GrColor* colors = reinterpret_cast<GrColor*>(positions + 1);
for (int i = 0; i < 4; ++i) {
*colors = fPaint.getColor();
colors = reinterpret_cast<GrColor*>(reinterpret_cast<intptr_t>(colors) + vertSize);
}
}
fCurrVertex += 4;
return true;
}
void GrDistanceFieldTextContext::flush() {
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));
// get our current color
SkColor filteredColor;
SkColorFilter* colorFilter = fSkPaint.getColorFilter();
if (colorFilter) {
filteredColor = colorFilter->filterColor(fSkPaint.getColor());
} else {
filteredColor = fSkPaint.getColor();
}
this->setupCoverageEffect(filteredColor);
// Effects could be stored with one of the cache objects (atlas?)
drawState->setGeometryProcessor(fCachedGeometryProcessor.get());
// Set draw state
if (fUseLCDText) {
GrColor colorNoPreMul = skcolor_to_grcolor_nopremultiply(filteredColor);
if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() ||
kISA_GrBlendCoeff != fPaint.getDstBlendCoeff() ||
fPaint.numColorStages()) {
SkDebugf("LCD Text will not draw correctly.\n");
}
SkASSERT(!drawState->hasColorVertexAttribute());
// 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 {
// set back to normal in case we took LCD path previously.
drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff());
// We're using per-vertex color.
SkASSERT(drawState->hasColorVertexAttribute());
}
int nGlyphs = fCurrVertex / kVerticesPerGlyph;
fDrawTarget->setIndexSourceToBuffer(fContext->getQuadIndexBuffer());
fDrawTarget->drawIndexedInstances(kTriangles_GrPrimitiveType,
nGlyphs,
kVerticesPerGlyph, kIndicesPerGlyph, &fVertexBounds);
fDrawTarget->resetVertexSource();
fVertices = NULL;
fTotalVertexCount -= fCurrVertex;
fCurrVertex = 0;
SkSafeSetNull(fCurrTexture);
fVertexBounds.setLargestInverted();
}
}
inline void GrDistanceFieldTextContext::finish() {
this->flush();
fTotalVertexCount = 0;
GrTextContext::finish();
}