/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrTextUtils.h"
#include "GrAtlasGlyphCache.h"
#include "GrAtlasTextBlob.h"
#include "GrBlurUtils.h"
#include "GrCaps.h"
#include "GrContext.h"
#include "GrRenderTargetContext.h"
#include "GrSurfaceContextPriv.h"
#include "SkDistanceFieldGen.h"
#include "SkDrawFilter.h"
#include "SkDrawProcs.h"
#include "SkFindAndPlaceGlyph.h"
#include "SkGlyphCache.h"
#include "SkGr.h"
#include "SkPaint.h"
#include "SkRect.h"
#include "SkTextBlobRunIterator.h"
#include "SkTextMapStateProc.h"
#include "SkTextToPathIter.h"
namespace {
static const int kMinDFFontSize = 18;
static const int kSmallDFFontSize = 32;
static const int kSmallDFFontLimit = 32;
static const int kMediumDFFontSize = 72;
static const int kMediumDFFontLimit = 72;
static const int kLargeDFFontSize = 162;
#ifdef SK_BUILD_FOR_ANDROID
static const int kLargeDFFontLimit = 384;
#else
static const int kLargeDFFontLimit = 2 * kLargeDFFontSize;
#endif
};
bool GrTextUtils::Paint::toGrPaint(GrMaskFormat maskFormat, GrRenderTargetContext* rtc,
const SkMatrix& viewMatrix, GrPaint* grPaint) const {
// TODO: this is the last use of GrSurfaceContextPriv
GrContext* context = rtc->surfPriv().getContext();
if (kARGB_GrMaskFormat == maskFormat) {
return SkPaintToGrPaintWithPrimitiveColor(context, rtc, this->skPaint(), grPaint);
} else {
return SkPaintToGrPaint(context, rtc, this->skPaint(), viewMatrix, grPaint);
}
}
bool GrTextUtils::RunPaint::modifyForRun(const SkTextBlobRunIterator& run) {
if (!fModifiedPaint.isValid()) {
fModifiedPaint.init(fOriginalPaint->skPaint());
fPaint = fModifiedPaint.get();
} else if (fFilter) {
// We have to reset before applying the run because the filter could have arbitrary
// changed the paint.
*fModifiedPaint.get() = fOriginalPaint->skPaint();
}
run.applyFontToPaint(fModifiedPaint.get());
if (fFilter) {
if (!fFilter->filter(fModifiedPaint.get(), SkDrawFilter::kText_Type)) {
// A false return from filter() means we should abort the current draw.
return false;
}
// The draw filter could have changed either the paint color or color filter.
this->initFilteredColor();
}
fModifiedPaint.get()->setFlags(FilterTextFlags(fProps, *fModifiedPaint.get()));
return true;
}
void GrTextUtils::DrawBmpText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache* fontCache,
const SkSurfaceProps& props, const GrTextUtils::Paint& paint,
uint32_t scalerContextFlags, const SkMatrix& viewMatrix,
const char text[], size_t byteLength, SkScalar x, SkScalar y) {
SkASSERT(byteLength == 0 || text != nullptr);
// nothing to draw
if (text == nullptr || byteLength == 0) {
return;
}
// Ensure the blob is set for bitmaptext
blob->setHasBitmap();
GrAtlasTextStrike* currStrike = nullptr;
SkGlyphCache* cache = blob->setupCache(runIndex, props, scalerContextFlags, paint, &viewMatrix);
SkFindAndPlaceGlyph::ProcessText(
paint.skPaint().getTextEncoding(), text, byteLength,
{x, y}, viewMatrix, paint.skPaint().getTextAlign(),
cache,
[&](const SkGlyph& glyph, SkPoint position, SkPoint rounding) {
position += rounding;
BmpAppendGlyph(
blob, runIndex, fontCache, &currStrike, glyph,
SkScalarFloorToInt(position.fX), SkScalarFloorToInt(position.fY),
paint.filteredPremulGrColor(), cache);
}
);
SkGlyphCache::AttachCache(cache);
}
void GrTextUtils::DrawBmpPosText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache* fontCache,
const SkSurfaceProps& props, const GrTextUtils::Paint& paint,
uint32_t scalerContextFlags, const SkMatrix& viewMatrix,
const char text[], size_t byteLength, const SkScalar pos[],
int scalarsPerPosition, const SkPoint& offset) {
SkASSERT(byteLength == 0 || text != nullptr);
SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);
// nothing to draw
if (text == nullptr || byteLength == 0) {
return;
}
// Ensure the blob is set for bitmaptext
blob->setHasBitmap();
GrAtlasTextStrike* currStrike = nullptr;
SkGlyphCache* cache = blob->setupCache(runIndex, props, scalerContextFlags, paint, &viewMatrix);
SkFindAndPlaceGlyph::ProcessPosText(
paint.skPaint().getTextEncoding(), text, byteLength,
offset, viewMatrix, pos, scalarsPerPosition,
paint.skPaint().getTextAlign(), cache,
[&](const SkGlyph& glyph, SkPoint position, SkPoint rounding) {
position += rounding;
BmpAppendGlyph(
blob, runIndex, fontCache, &currStrike, glyph,
SkScalarFloorToInt(position.fX), SkScalarFloorToInt(position.fY),
paint.filteredPremulGrColor(), cache);
}
);
SkGlyphCache::AttachCache(cache);
}
void GrTextUtils::BmpAppendGlyph(GrAtlasTextBlob* blob, int runIndex,
GrAtlasGlyphCache* fontCache,
GrAtlasTextStrike** strike, const SkGlyph& skGlyph,
int vx, int vy, GrColor color, SkGlyphCache* cache) {
if (!*strike) {
*strike = fontCache->getStrike(cache);
}
GrGlyph::PackedID id = GrGlyph::Pack(skGlyph.getGlyphID(),
skGlyph.getSubXFixed(),
skGlyph.getSubYFixed(),
GrGlyph::kCoverage_MaskStyle);
GrGlyph* glyph = (*strike)->getGlyph(skGlyph, id, cache);
if (!glyph) {
return;
}
int x = vx + glyph->fBounds.fLeft;
int y = vy + glyph->fBounds.fTop;
// keep them as ints until we've done the clip-test
int width = glyph->fBounds.width();
int height = glyph->fBounds.height();
SkRect r;
r.fLeft = SkIntToScalar(x);
r.fTop = SkIntToScalar(y);
r.fRight = r.fLeft + SkIntToScalar(width);
r.fBottom = r.fTop + SkIntToScalar(height);
blob->appendGlyph(runIndex, r, color, *strike, glyph, cache, skGlyph,
SkIntToScalar(vx), SkIntToScalar(vy), 1.0f, true);
}
bool GrTextUtils::CanDrawAsDistanceFields(const SkPaint& skPaint, const SkMatrix& viewMatrix,
const SkSurfaceProps& props, const GrShaderCaps& caps) {
// TODO: support perspective (need getMaxScale replacement)
if (viewMatrix.hasPerspective()) {
return false;
}
SkScalar maxScale = viewMatrix.getMaxScale();
SkScalar scaledTextSize = maxScale * skPaint.getTextSize();
// Hinted text looks far better at small resolutions
// Scaling up beyond 2x yields undesireable artifacts
if (scaledTextSize < kMinDFFontSize ||
scaledTextSize > kLargeDFFontLimit) {
return false;
}
bool useDFT = props.isUseDeviceIndependentFonts();
#if SK_FORCE_DISTANCE_FIELD_TEXT
useDFT = true;
#endif
if (!useDFT && scaledTextSize < kLargeDFFontSize) {
return false;
}
// rasterizers and mask filters modify alpha, which doesn't
// translate well to distance
if (skPaint.getRasterizer() || skPaint.getMaskFilter() || !caps.shaderDerivativeSupport()) {
return false;
}
// TODO: add some stroking support
if (skPaint.getStyle() != SkPaint::kFill_Style) {
return false;
}
return true;
}
void GrTextUtils::InitDistanceFieldPaint(GrAtlasTextBlob* blob,
SkPaint* skPaint,
SkScalar* textRatio,
const SkMatrix& viewMatrix) {
// getMaxScale doesn't support perspective, so neither do we at the moment
SkASSERT(!viewMatrix.hasPerspective());
SkScalar maxScale = viewMatrix.getMaxScale();
SkScalar textSize = skPaint->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;
}
// We have three sizes of distance field text, and within each size 'bucket' there is a floor
// and ceiling. A scale outside of this range would require regenerating the distance fields
SkScalar dfMaskScaleFloor;
SkScalar dfMaskScaleCeil;
if (scaledTextSize <= kSmallDFFontLimit) {
dfMaskScaleFloor = kMinDFFontSize;
dfMaskScaleCeil = kSmallDFFontLimit;
*textRatio = textSize / kSmallDFFontSize;
skPaint->setTextSize(SkIntToScalar(kSmallDFFontSize));
} else if (scaledTextSize <= kMediumDFFontLimit) {
dfMaskScaleFloor = kSmallDFFontLimit;
dfMaskScaleCeil = kMediumDFFontLimit;
*textRatio = textSize / kMediumDFFontSize;
skPaint->setTextSize(SkIntToScalar(kMediumDFFontSize));
} else {
dfMaskScaleFloor = kMediumDFFontLimit;
dfMaskScaleCeil = kLargeDFFontLimit;
*textRatio = textSize / kLargeDFFontSize;
skPaint->setTextSize(SkIntToScalar(kLargeDFFontSize));
}
// Because there can be multiple runs in the blob, we want the overall maxMinScale, and
// minMaxScale to make regeneration decisions. Specifically, we want the maximum minimum scale
// we can tolerate before we'd drop to a lower mip size, and the minimum maximum scale we can
// tolerate before we'd have to move to a large mip size. When we actually test these values
// we look at the delta in scale between the new viewmatrix and the old viewmatrix, and test
// against these values to decide if we can reuse or not(ie, will a given scale change our mip
// level)
SkASSERT(dfMaskScaleFloor <= scaledTextSize && scaledTextSize <= dfMaskScaleCeil);
blob->setMinAndMaxScale(dfMaskScaleFloor / scaledTextSize, dfMaskScaleCeil / scaledTextSize);
skPaint->setLCDRenderText(false);
skPaint->setAutohinted(false);
skPaint->setHinting(SkPaint::kNormal_Hinting);
skPaint->setSubpixelText(true);
}
void GrTextUtils::DrawDFText(GrAtlasTextBlob* blob, int runIndex,
GrAtlasGlyphCache* fontCache, const SkSurfaceProps& props,
const GrTextUtils::Paint& paint, uint32_t scalerContextFlags,
const SkMatrix& viewMatrix,
const char text[], size_t byteLength,
SkScalar x, SkScalar y) {
SkASSERT(byteLength == 0 || text != nullptr);
// nothing to draw
if (text == nullptr || byteLength == 0) {
return;
}
const SkPaint& skPaint = paint.skPaint();
SkPaint::GlyphCacheProc glyphCacheProc = SkPaint::GetGlyphCacheProc(skPaint.getTextEncoding(),
skPaint.isDevKernText(),
true);
SkAutoDescriptor desc;
SkScalerContextEffects effects;
// We apply the fake-gamma by altering the distance in the shader, so we ignore the
// passed-in scaler context flags. (It's only used when we fall-back to bitmap text).
skPaint.getScalerContextDescriptor(&effects, &desc, props, SkPaint::kNone_ScalerContextFlags,
nullptr);
SkGlyphCache* origPaintCache = SkGlyphCache::DetachCache(skPaint.getTypeface(), effects,
desc.getDesc());
SkTArray<SkScalar> positions;
const char* textPtr = text;
SkScalar stopX = 0;
SkScalar stopY = 0;
SkScalar origin = 0;
switch (skPaint.getTextAlign()) {
case SkPaint::kRight_Align: origin = SK_Scalar1; break;
case SkPaint::kCenter_Align: origin = SK_ScalarHalf; break;
case SkPaint::kLeft_Align: origin = 0; break;
}
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(origPaintCache, &textPtr);
SkScalar width = SkFloatToScalar(glyph.fAdvanceX) + autokern.adjust(glyph);
positions.push_back(stopX + origin * width);
SkScalar height = SkFloatToScalar(glyph.fAdvanceY);
positions.push_back(stopY + origin * height);
stopX += width;
stopY += height;
}
SkASSERT(textPtr == stop);
SkGlyphCache::AttachCache(origPaintCache);
// now adjust starting point depending on alignment
SkScalar alignX = stopX;
SkScalar alignY = 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);
DrawDFPosText(blob, runIndex, fontCache, props, paint, scalerContextFlags, viewMatrix, text,
byteLength, positions.begin(), 2, offset);
}
void GrTextUtils::DrawDFPosText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache* fontCache,
const SkSurfaceProps& props, const GrTextUtils::Paint& paint,
uint32_t scalerContextFlags, const SkMatrix& viewMatrix,
const char text[], size_t byteLength, const SkScalar pos[],
int scalarsPerPosition, const SkPoint& offset) {
SkASSERT(byteLength == 0 || text != nullptr);
SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);
// nothing to draw
if (text == nullptr || byteLength == 0) {
return;
}
SkTDArray<char> fallbackTxt;
SkTDArray<SkScalar> fallbackPos;
// Setup distance field paint and text ratio
SkScalar textRatio;
SkPaint dfPaint(paint);
GrTextUtils::InitDistanceFieldPaint(blob, &dfPaint, &textRatio, viewMatrix);
blob->setHasDistanceField();
blob->setSubRunHasDistanceFields(runIndex, paint.skPaint().isLCDRenderText());
GrAtlasTextStrike* currStrike = nullptr;
// We apply the fake-gamma by altering the distance in the shader, so we ignore the
// passed-in scaler context flags. (It's only used when we fall-back to bitmap text).
SkGlyphCache* cache = blob->setupCache(runIndex, props, SkPaint::kNone_ScalerContextFlags,
dfPaint, nullptr);
SkPaint::GlyphCacheProc glyphCacheProc = SkPaint::GetGlyphCacheProc(dfPaint.getTextEncoding(),
dfPaint.isDevKernText(),
true);
const char* stop = text + byteLength;
if (SkPaint::kLeft_Align == dfPaint.getTextAlign()) {
while (text < stop) {
const char* lastText = text;
// the last 2 parameters are ignored
const SkGlyph& glyph = glyphCacheProc(cache, &text);
if (glyph.fWidth) {
SkScalar x = offset.x() + pos[0];
SkScalar y = offset.y() + (2 == scalarsPerPosition ? pos[1] : 0);
if (!DfAppendGlyph(blob, runIndex, fontCache, &currStrike, glyph, x, y,
paint.filteredPremulGrColor(), cache, textRatio, viewMatrix)) {
// couldn't append, send to fallback
fallbackTxt.append(SkToInt(text-lastText), lastText);
*fallbackPos.append() = pos[0];
if (2 == scalarsPerPosition) {
*fallbackPos.append() = pos[1];
}
}
}
pos += scalarsPerPosition;
}
} else {
SkScalar alignMul = SkPaint::kCenter_Align == dfPaint.getTextAlign() ? SK_ScalarHalf
: SK_Scalar1;
while (text < stop) {
const char* lastText = text;
// the last 2 parameters are ignored
const SkGlyph& glyph = glyphCacheProc(cache, &text);
if (glyph.fWidth) {
SkScalar x = offset.x() + pos[0];
SkScalar y = offset.y() + (2 == scalarsPerPosition ? pos[1] : 0);
SkScalar advanceX = SkFloatToScalar(glyph.fAdvanceX) * alignMul * textRatio;
SkScalar advanceY = SkFloatToScalar(glyph.fAdvanceY) * alignMul * textRatio;
if (!DfAppendGlyph(blob, runIndex, fontCache, &currStrike, glyph, x - advanceX,
y - advanceY, paint.filteredPremulGrColor(), cache, textRatio,
viewMatrix)) {
// couldn't append, send to fallback
fallbackTxt.append(SkToInt(text-lastText), lastText);
*fallbackPos.append() = pos[0];
if (2 == scalarsPerPosition) {
*fallbackPos.append() = pos[1];
}
}
}
pos += scalarsPerPosition;
}
}
SkGlyphCache::AttachCache(cache);
if (fallbackTxt.count()) {
blob->initOverride(runIndex);
GrTextUtils::DrawBmpPosText(blob, runIndex, fontCache, props, paint, scalerContextFlags,
viewMatrix, fallbackTxt.begin(), fallbackTxt.count(),
fallbackPos.begin(), scalarsPerPosition, offset);
}
}
bool GrTextUtils::DfAppendGlyph(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache* cache,
GrAtlasTextStrike** strike, const SkGlyph& skGlyph,
SkScalar sx, SkScalar sy, GrColor color,
SkGlyphCache* glyphCache,
SkScalar textRatio, const SkMatrix& viewMatrix) {
if (!*strike) {
*strike = cache->getStrike(glyphCache);
}
GrGlyph::PackedID id = GrGlyph::Pack(skGlyph.getGlyphID(),
skGlyph.getSubXFixed(),
skGlyph.getSubYFixed(),
GrGlyph::kDistance_MaskStyle);
GrGlyph* glyph = (*strike)->getGlyph(skGlyph, id, glyphCache);
if (!glyph) {
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 = textRatio;
dx *= scale;
dy *= scale;
width *= scale;
height *= scale;
sx += dx;
sy += dy;
SkRect glyphRect = SkRect::MakeXYWH(sx, sy, width, height);
blob->appendGlyph(runIndex, glyphRect, color, *strike, glyph, glyphCache, skGlyph,
sx - dx, sy - dy, scale, false);
return true;
}
void GrTextUtils::DrawTextAsPath(GrContext* context, GrRenderTargetContext* rtc, const GrClip& clip,
const SkPaint& paint, const SkMatrix& viewMatrix,
const char text[], size_t byteLength, SkScalar x, SkScalar y,
const SkIRect& clipBounds) {
SkTextToPathIter iter(text, byteLength, paint, true);
SkMatrix matrix;
matrix.setScale(iter.getPathScale(), iter.getPathScale());
matrix.postTranslate(x, y);
const SkPath* iterPath;
SkScalar xpos, prevXPos = 0;
while (iter.next(&iterPath, &xpos)) {
matrix.postTranslate(xpos - prevXPos, 0);
if (iterPath) {
const SkPaint& pnt = iter.getPaint();
GrBlurUtils::drawPathWithMaskFilter(context, rtc, clip, *iterPath,
pnt, viewMatrix, &matrix, clipBounds, false);
}
prevXPos = xpos;
}
}
void GrTextUtils::DrawPosTextAsPath(GrContext* context,
GrRenderTargetContext* rtc,
const SkSurfaceProps& props,
const GrClip& clip,
const SkPaint& origPaint, const SkMatrix& viewMatrix,
const char text[], size_t byteLength,
const SkScalar pos[], int scalarsPerPosition,
const SkPoint& offset, const SkIRect& clipBounds) {
// setup our std paint, in hopes of getting hits in the cache
SkPaint paint(origPaint);
SkScalar matrixScale = paint.setupForAsPaths();
SkMatrix matrix;
matrix.setScale(matrixScale, matrixScale);
// Temporarily jam in kFill, so we only ever ask for the raw outline from the cache.
paint.setStyle(SkPaint::kFill_Style);
paint.setPathEffect(nullptr);
SkPaint::GlyphCacheProc glyphCacheProc = SkPaint::GetGlyphCacheProc(paint.getTextEncoding(),
paint.isDevKernText(),
true);
SkAutoGlyphCache autoCache(paint, &props, nullptr);
SkGlyphCache* cache = autoCache.getCache();
const char* stop = text + byteLength;
SkTextAlignProc alignProc(paint.getTextAlign());
SkTextMapStateProc tmsProc(SkMatrix::I(), offset, scalarsPerPosition);
// Now restore the original settings, so we "draw" with whatever style/stroking.
paint.setStyle(origPaint.getStyle());
paint.setPathEffect(origPaint.refPathEffect());
while (text < stop) {
const SkGlyph& glyph = glyphCacheProc(cache, &text);
if (glyph.fWidth) {
const SkPath* path = cache->findPath(glyph);
if (path) {
SkPoint tmsLoc;
tmsProc(pos, &tmsLoc);
SkPoint loc;
alignProc(tmsLoc, glyph, &loc);
matrix[SkMatrix::kMTransX] = loc.fX;
matrix[SkMatrix::kMTransY] = loc.fY;
GrBlurUtils::drawPathWithMaskFilter(context, rtc, clip, *path, paint,
viewMatrix, &matrix, clipBounds, false);
}
}
pos += scalarsPerPosition;
}
}
bool GrTextUtils::ShouldDisableLCD(const SkPaint& paint) {
return paint.getMaskFilter() ||
paint.getRasterizer() ||
paint.getPathEffect() ||
paint.isFakeBoldText() ||
paint.getStyle() != SkPaint::kFill_Style;
}
uint32_t GrTextUtils::FilterTextFlags(const SkSurfaceProps& surfaceProps, const SkPaint& paint) {
uint32_t flags = paint.getFlags();
if (!paint.isLCDRenderText() || !paint.isAntiAlias()) {
return flags;
}
if (kUnknown_SkPixelGeometry == surfaceProps.pixelGeometry() || ShouldDisableLCD(paint)) {
flags &= ~SkPaint::kLCDRenderText_Flag;
flags |= SkPaint::kGenA8FromLCD_Flag;
}
return flags;
}