bool GrAADistanceFieldPathRenderer::canDrawPath(const GrDrawTarget* target,
const GrPipelineBuilder* pipelineBuilder,
const SkMatrix& viewMatrix,
const SkPath& path,
const GrStrokeInfo& stroke,
bool antiAlias) const {
// TODO: Support inverse fill
// TODO: Support strokes
if (!target->caps()->shaderCaps()->shaderDerivativeSupport() || !antiAlias
|| path.isInverseFillType() || path.isVolatile() || !stroke.isFillStyle()) {
return false;
}
// currently don't support perspective
if (viewMatrix.hasPerspective()) {
return false;
}
// only support paths smaller than 64x64, scaled to less than 256x256
// the goal is to accelerate rendering of lots of small paths that may be scaling
SkScalar maxScale = viewMatrix.getMaxScale();
const SkRect& bounds = path.getBounds();
SkScalar maxDim = SkMaxScalar(bounds.width(), bounds.height());
return maxDim < 64.f && maxDim * maxScale < 256.f;
}
bool GrDistanceFieldTextContext::canDraw(const SkPaint& paint, const SkMatrix& viewMatrix) {
// TODO: support perspective (need getMaxScale replacement)
if (viewMatrix.hasPerspective()) {
return false;
}
SkScalar maxScale = viewMatrix.getMaxScale();
SkScalar scaledTextSize = maxScale*paint.getTextSize();
// Scaling up beyond 2x yields undesireable artifacts
if (scaledTextSize > 2*kLargeDFFontSize) {
return false;
}
if (!fEnableDFRendering && !paint.isDistanceFieldTextTEMP() &&
scaledTextSize < kLargeDFFontSize) {
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;
}
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);
}
SkScalar scaled_text_size(const SkScalar textSize, const SkMatrix& viewMatrix) {
SkScalar scaledTextSize = textSize;
if (viewMatrix.hasPerspective()) {
// for perspective, we simply force to the medium size
// TODO: compute a size based on approximate screen area
scaledTextSize = kMediumDFFontLimit;
} else {
SkScalar maxScale = viewMatrix.getMaxScale();
// 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;
}
}
return scaledTextSize;
}
// The general idea here is to, conceptually, start with the original polygon and slide
// the vertices along the bisectors until the first intersection. At that
// point two of the edges collapse and the process repeats on the new polygon.
// The polygon state is captured in the Ring class while the GrAAConvexTessellator
// controls the iteration. The CandidateVerts holds the formative points for the
// next ring.
bool GrAAConvexTessellator::tessellate(const SkMatrix& m, const SkPath& path) {
if (!this->extractFromPath(m, path)) {
return false;
}
SkScalar coverage = 1.0f;
SkScalar scaleFactor = 0.0f;
if (fStrokeWidth >= 0.0f) {
SkASSERT(m.isSimilarity());
scaleFactor = m.getMaxScale(); // x and y scale are the same
SkScalar effectiveStrokeWidth = scaleFactor * fStrokeWidth;
Ring outerStrokeRing;
this->createOuterRing(fInitialRing, effectiveStrokeWidth / 2 - kAntialiasingRadius,
coverage, &outerStrokeRing);
outerStrokeRing.init(*this);
Ring outerAARing;
this->createOuterRing(outerStrokeRing, kAntialiasingRadius * 2, 0.0f, &outerAARing);
} else {
Ring outerAARing;
this->createOuterRing(fInitialRing, kAntialiasingRadius, 0.0f, &outerAARing);
}
// the bisectors are only needed for the computation of the outer ring
fBisectors.rewind();
if (fStrokeWidth >= 0.0f && fInitialRing.numPts() > 2) {
SkScalar effectiveStrokeWidth = scaleFactor * fStrokeWidth;
Ring* insetStrokeRing;
SkScalar strokeDepth = effectiveStrokeWidth / 2 - kAntialiasingRadius;
if (this->createInsetRings(fInitialRing, 0.0f, coverage, strokeDepth, coverage,
&insetStrokeRing)) {
Ring* insetAARing;
this->createInsetRings(*insetStrokeRing, strokeDepth, coverage, strokeDepth +
kAntialiasingRadius * 2, 0.0f, &insetAARing);
}
} else {
Ring* insetAARing;
this->createInsetRings(fInitialRing, 0.0f, 0.5f, kAntialiasingRadius, 1.0f, &insetAARing);
}
SkDEBUGCODE(this->validate();)
return true;
SkScalar GrPathUtils::scaleToleranceToSrc(SkScalar devTol,
const SkMatrix& viewM,
const SkRect& pathBounds) {
// In order to tesselate the path we get a bound on how much the matrix can
// scale when mapping to screen coordinates.
SkScalar stretch = viewM.getMaxScale();
SkScalar srcTol = devTol;
if (stretch < 0) {
// take worst case mapRadius amoung four corners.
// (less than perfect)
for (int i = 0; i < 4; ++i) {
SkMatrix mat;
mat.setTranslate((i % 2) ? pathBounds.fLeft : pathBounds.fRight,
(i < 2) ? pathBounds.fTop : pathBounds.fBottom);
mat.postConcat(viewM);
stretch = SkMaxScalar(stretch, mat.mapRadius(SK_Scalar1));
}
}
return srcTol / stretch;
}
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;
}
bool GrTextContext::CanDrawAsDistanceFields(const SkPaint& paint, const SkFont& font,
const SkMatrix& viewMatrix,
const SkSurfaceProps& props,
bool contextSupportsDistanceFieldText,
const Options& options) {
if (!viewMatrix.hasPerspective()) {
SkScalar maxScale = viewMatrix.getMaxScale();
SkScalar scaledTextSize = maxScale * font.getSize();
// Hinted text looks far better at small resolutions
// Scaling up beyond 2x yields undesireable artifacts
if (scaledTextSize < options.fMinDistanceFieldFontSize ||
scaledTextSize > options.fMaxDistanceFieldFontSize) {
return false;
}
bool useDFT = props.isUseDeviceIndependentFonts();
#if SK_FORCE_DISTANCE_FIELD_TEXT
useDFT = true;
#endif
if (!useDFT && scaledTextSize < kLargeDFFontSize) {
return false;
}
}
// mask filters modify alpha, which doesn't translate well to distance
if (paint.getMaskFilter() || !contextSupportsDistanceFieldText) {
return false;
}
// TODO: add some stroking support
if (paint.getStyle() != SkPaint::kFill_Style) {
return false;
}
return true;
}
static void test_matrix_min_max_scale(skiatest::Reporter* reporter) {
SkScalar scales[2];
bool success;
SkMatrix identity;
identity.reset();
REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMinScale());
REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxScale());
success = identity.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, success && SK_Scalar1 == scales[0] && SK_Scalar1 == scales[1]);
SkMatrix scale;
scale.setScale(SK_Scalar1 * 2, SK_Scalar1 * 4);
REPORTER_ASSERT(reporter, SK_Scalar1 * 2 == scale.getMinScale());
REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxScale());
success = scale.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, success && SK_Scalar1 * 2 == scales[0] && SK_Scalar1 * 4 == scales[1]);
SkMatrix rot90Scale;
rot90Scale.setRotate(90 * SK_Scalar1);
rot90Scale.postScale(SK_Scalar1 / 4, SK_Scalar1 / 2);
REPORTER_ASSERT(reporter, SK_Scalar1 / 4 == rot90Scale.getMinScale());
REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxScale());
success = rot90Scale.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, success && SK_Scalar1 / 4 == scales[0] && SK_Scalar1 / 2 == scales[1]);
SkMatrix rotate;
rotate.setRotate(128 * SK_Scalar1);
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMinScale(), SK_ScalarNearlyZero));
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMaxScale(), SK_ScalarNearlyZero));
success = rotate.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, success);
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, scales[0], SK_ScalarNearlyZero));
REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, scales[1], SK_ScalarNearlyZero));
SkMatrix translate;
translate.setTranslate(10 * SK_Scalar1, -5 * SK_Scalar1);
REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMinScale());
REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxScale());
success = translate.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, success && SK_Scalar1 == scales[0] && SK_Scalar1 == scales[1]);
SkMatrix perspX;
perspX.reset();
perspX.setPerspX(SkScalarToPersp(SK_Scalar1 / 1000));
REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMinScale());
REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxScale());
// Verify that getMinMaxScales() doesn't update the scales array on failure.
scales[0] = -5;
scales[1] = -5;
success = perspX.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, !success && -5 * SK_Scalar1 == scales[0] && -5 * SK_Scalar1 == scales[1]);
SkMatrix perspY;
perspY.reset();
perspY.setPerspY(SkScalarToPersp(-SK_Scalar1 / 500));
REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMinScale());
REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxScale());
scales[0] = -5;
scales[1] = -5;
success = perspY.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, !success && -5 * SK_Scalar1 == scales[0] && -5 * SK_Scalar1 == scales[1]);
SkMatrix baseMats[] = {scale, rot90Scale, rotate,
translate, perspX, perspY};
SkMatrix mats[2*SK_ARRAY_COUNT(baseMats)];
for (size_t i = 0; i < SK_ARRAY_COUNT(baseMats); ++i) {
mats[i] = baseMats[i];
bool invertable = mats[i].invert(&mats[i + SK_ARRAY_COUNT(baseMats)]);
REPORTER_ASSERT(reporter, invertable);
}
SkRandom rand;
for (int m = 0; m < 1000; ++m) {
SkMatrix mat;
mat.reset();
for (int i = 0; i < 4; ++i) {
int x = rand.nextU() % SK_ARRAY_COUNT(mats);
mat.postConcat(mats[x]);
}
SkScalar minScale = mat.getMinScale();
SkScalar maxScale = mat.getMaxScale();
REPORTER_ASSERT(reporter, (minScale < 0) == (maxScale < 0));
REPORTER_ASSERT(reporter, (maxScale < 0) == mat.hasPerspective());
SkScalar scales[2];
bool success = mat.getMinMaxScales(scales);
REPORTER_ASSERT(reporter, success == !mat.hasPerspective());
REPORTER_ASSERT(reporter, !success || (scales[0] == minScale && scales[1] == maxScale));
if (mat.hasPerspective()) {
m -= 1; // try another non-persp matrix
continue;
}
// test a bunch of vectors. All should be scaled by between minScale and maxScale
// (modulo some error) and we should find a vector that is scaled by almost each.
static const SkScalar gVectorScaleTol = (105 * SK_Scalar1) / 100;
static const SkScalar gCloseScaleTol = (97 * SK_Scalar1) / 100;
SkScalar max = 0, min = SK_ScalarMax;
SkVector vectors[1000];
for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
vectors[i].fX = rand.nextSScalar1();
vectors[i].fY = rand.nextSScalar1();
if (!vectors[i].normalize()) {
i -= 1;
continue;
}
}
mat.mapVectors(vectors, SK_ARRAY_COUNT(vectors));
for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
SkScalar d = vectors[i].length();
REPORTER_ASSERT(reporter, SkScalarDiv(d, maxScale) < gVectorScaleTol);
REPORTER_ASSERT(reporter, SkScalarDiv(minScale, d) < gVectorScaleTol);
if (max < d) {
max = d;
}
if (min > d) {
min = d;
}
}
REPORTER_ASSERT(reporter, SkScalarDiv(max, maxScale) >= gCloseScaleTol);
REPORTER_ASSERT(reporter, SkScalarDiv(minScale, min) >= gCloseScaleTol);
}
}
bool GrStencilAndCoverPathRenderer::onDrawPath(GrDrawTarget* target,
GrPipelineBuilder* pipelineBuilder,
GrColor color,
const SkMatrix& viewMatrix,
const SkPath& path,
const GrStrokeInfo& stroke,
bool antiAlias) {
SkASSERT(!antiAlias);
SkASSERT(!stroke.getStrokeRec().isHairlineStyle());
SkASSERT(!stroke.isDashed());
SkASSERT(pipelineBuilder->getStencil().isDisabled());
SkAutoTUnref<GrPath> p(get_gr_path(fGpu, path, stroke.getStrokeRec()));
if (path.isInverseFillType()) {
GR_STATIC_CONST_SAME_STENCIL(kInvertedStencilPass,
kZero_StencilOp,
kZero_StencilOp,
// We know our rect will hit pixels outside the clip and the user bits will be 0
// outside the clip. So we can't just fill where the user bits are 0. We also need to
// check that the clip bit is set.
kEqualIfInClip_StencilFunc,
0xffff,
0x0000,
0xffff);
pipelineBuilder->setStencil(kInvertedStencilPass);
// fake inverse with a stencil and cover
SkAutoTUnref<GrPathProcessor> pp(GrPathProcessor::Create(GrColor_WHITE, viewMatrix));
target->stencilPath(pipelineBuilder, pp, p, convert_skpath_filltype(path.getFillType()));
SkMatrix invert = SkMatrix::I();
SkRect bounds =
SkRect::MakeLTRB(0, 0, SkIntToScalar(pipelineBuilder->getRenderTarget()->width()),
SkIntToScalar(pipelineBuilder->getRenderTarget()->height()));
SkMatrix vmi;
// mapRect through persp matrix may not be correct
if (!viewMatrix.hasPerspective() && viewMatrix.invert(&vmi)) {
vmi.mapRect(&bounds);
// theoretically could set bloat = 0, instead leave it because of matrix inversion
// precision.
SkScalar bloat = viewMatrix.getMaxScale() * SK_ScalarHalf;
bounds.outset(bloat, bloat);
} else {
if (!viewMatrix.invert(&invert)) {
return false;
}
}
const SkMatrix& viewM = viewMatrix.hasPerspective() ? SkMatrix::I() : viewMatrix;
target->drawRect(pipelineBuilder, color, viewM, bounds, NULL, &invert);
} else {
GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
kZero_StencilOp,
kZero_StencilOp,
kNotEqual_StencilFunc,
0xffff,
0x0000,
0xffff);
pipelineBuilder->setStencil(kStencilPass);
SkAutoTUnref<GrPathProcessor> pp(GrPathProcessor::Create(color, viewMatrix));
target->drawPath(pipelineBuilder, pp, p, convert_skpath_filltype(path.getFillType()));
}
pipelineBuilder->stencil()->setDisabled();
return true;
}
bool GrAtlasTextBlob::mustRegenerate(const SkPaint& paint,
GrColor color, const SkMaskFilter::BlurRec& blurRec,
const SkMatrix& viewMatrix, SkScalar x, SkScalar y) {
// If we have LCD text then our canonical color will be set to transparent, in this case we have
// to regenerate the blob on any color change
// We use the grPaint to get any color filter effects
if (fKey.fCanonicalColor == SK_ColorTRANSPARENT &&
fPaintColor != color) {
return true;
}
if (fInitialViewMatrix.hasPerspective() != viewMatrix.hasPerspective()) {
return true;
}
if (fInitialViewMatrix.hasPerspective() && !fInitialViewMatrix.cheapEqualTo(viewMatrix)) {
return true;
}
// We only cache one masked version
if (fKey.fHasBlur &&
(fBlurRec.fSigma != blurRec.fSigma ||
fBlurRec.fStyle != blurRec.fStyle ||
fBlurRec.fQuality != blurRec.fQuality)) {
return true;
}
// Similarly, we only cache one version for each style
if (fKey.fStyle != SkPaint::kFill_Style &&
(fStrokeInfo.fFrameWidth != paint.getStrokeWidth() ||
fStrokeInfo.fMiterLimit != paint.getStrokeMiter() ||
fStrokeInfo.fJoin != paint.getStrokeJoin())) {
return true;
}
// Mixed blobs must be regenerated. We could probably figure out a way to do integer scrolls
// for mixed blobs if this becomes an issue.
if (this->hasBitmap() && this->hasDistanceField()) {
// Identical viewmatrices and we can reuse in all cases
if (fInitialViewMatrix.cheapEqualTo(viewMatrix) && x == fInitialX && y == fInitialY) {
return false;
}
return true;
}
if (this->hasBitmap()) {
if (fInitialViewMatrix.getScaleX() != viewMatrix.getScaleX() ||
fInitialViewMatrix.getScaleY() != viewMatrix.getScaleY() ||
fInitialViewMatrix.getSkewX() != viewMatrix.getSkewX() ||
fInitialViewMatrix.getSkewY() != viewMatrix.getSkewY()) {
return true;
}
// We can update the positions in the cachedtextblobs without regenerating the whole blob,
// but only for integer translations.
// This cool bit of math will determine the necessary translation to apply to the already
// generated vertex coordinates to move them to the correct position
SkScalar transX = viewMatrix.getTranslateX() +
viewMatrix.getScaleX() * (x - fInitialX) +
viewMatrix.getSkewX() * (y - fInitialY) -
fInitialViewMatrix.getTranslateX();
SkScalar transY = viewMatrix.getTranslateY() +
viewMatrix.getSkewY() * (x - fInitialX) +
viewMatrix.getScaleY() * (y - fInitialY) -
fInitialViewMatrix.getTranslateY();
if (!SkScalarIsInt(transX) || !SkScalarIsInt(transY)) {
return true;
}
} else if (this->hasDistanceField()) {
// A scale outside of [blob.fMaxMinScale, blob.fMinMaxScale] would result in a different
// distance field being generated, so we have to regenerate in those cases
SkScalar newMaxScale = viewMatrix.getMaxScale();
SkScalar oldMaxScale = fInitialViewMatrix.getMaxScale();
SkScalar scaleAdjust = newMaxScale / oldMaxScale;
if (scaleAdjust < fMaxMinScale || scaleAdjust > fMinMaxScale) {
return true;
}
}
// It is possible that a blob has neither distanceField nor bitmaptext. This is in the case
// when all of the runs inside the blob are drawn as paths. In this case, we always regenerate
// the blob anyways at flush time, so no need to regenerate explicitly
return false;
}