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skia2/src/gpu/GrOvalRenderer.cpp

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/*
* 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 "GrOvalRenderer.h"
#include "gl/builders/GrGLProgramBuilder.h"
#include "gl/GrGLProcessor.h"
#include "gl/GrGLSL.h"
#include "gl/GrGLGeometryProcessor.h"
#include "GrProcessor.h"
#include "GrTBackendProcessorFactory.h"
#include "GrDrawState.h"
#include "GrDrawTarget.h"
#include "GrGpu.h"
#include "SkRRect.h"
#include "SkStrokeRec.h"
#include "SkTLazy.h"
#include "GrGeometryProcessor.h"
#include "effects/GrRRectEffect.h"
namespace {
// TODO(joshualitt) add per vertex colors
struct CircleVertex {
SkPoint fPos;
SkPoint fOffset;
SkScalar fOuterRadius;
SkScalar fInnerRadius;
};
struct EllipseVertex {
SkPoint fPos;
SkPoint fOffset;
SkPoint fOuterRadii;
SkPoint fInnerRadii;
};
struct DIEllipseVertex {
SkPoint fPos;
SkPoint fOuterOffset;
SkPoint fInnerOffset;
};
inline bool circle_stays_circle(const SkMatrix& m) {
return m.isSimilarity();
}
}
///////////////////////////////////////////////////////////////////////////////
/**
* The output of this effect is a modulation of the input color and coverage for a circle,
* specified as offset_x, offset_y (both from center point), outer radius and inner radius.
*/
class CircleEdgeEffect : public GrGeometryProcessor {
public:
static GrGeometryProcessor* Create(bool stroke) {
GR_CREATE_STATIC_PROCESSOR(gCircleStrokeEdge, CircleEdgeEffect, (true));
GR_CREATE_STATIC_PROCESSOR(gCircleFillEdge, CircleEdgeEffect, (false));
if (stroke) {
gCircleStrokeEdge->ref();
return gCircleStrokeEdge;
} else {
gCircleFillEdge->ref();
return gCircleFillEdge;
}
}
const GrShaderVar& inCircleEdge() const { return fInCircleEdge; }
virtual const GrBackendGeometryProcessorFactory& getFactory() const SK_OVERRIDE {
return GrTBackendGeometryProcessorFactory<CircleEdgeEffect>::getInstance();
}
virtual ~CircleEdgeEffect() {}
static const char* Name() { return "CircleEdge"; }
inline bool isStroked() const { return fStroke; }
class GLProcessor : public GrGLGeometryProcessor {
public:
GLProcessor(const GrBackendProcessorFactory& factory, const GrProcessor&)
: INHERITED (factory) {}
virtual void emitCode(const EmitArgs& args) SK_OVERRIDE {
const CircleEdgeEffect& circleEffect = args.fGP.cast<CircleEdgeEffect>();
GrGLVertToFrag v(kVec4f_GrSLType);
args.fPB->addVarying("CircleEdge", &v);
GrGLVertexBuilder* vsBuilder = args.fPB->getVertexShaderBuilder();;
vsBuilder->codeAppendf("%s = %s;", v.vsOut(), circleEffect.inCircleEdge().c_str());
GrGLGPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
fsBuilder->codeAppendf("float d = length(%s.xy);", v.fsIn());
fsBuilder->codeAppendf("float edgeAlpha = clamp(%s.z - d, 0.0, 1.0);", v.fsIn());
if (circleEffect.isStroked()) {
fsBuilder->codeAppendf("float innerAlpha = clamp(d - %s.w, 0.0, 1.0);",
v.fsIn());
fsBuilder->codeAppend("edgeAlpha *= innerAlpha;");
}
fsBuilder->codeAppendf("%s = %s;\n", args.fOutput,
(GrGLSLExpr4(args.fInput) * GrGLSLExpr1("edgeAlpha")).c_str());
}
static void GenKey(const GrProcessor& processor, const GrGLCaps&,
GrProcessorKeyBuilder* b) {
const CircleEdgeEffect& circleEffect = processor.cast<CircleEdgeEffect>();
b->add32(circleEffect.isStroked());
}
virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE {}
private:
typedef GrGLGeometryProcessor INHERITED;
};
private:
CircleEdgeEffect(bool stroke)
: fInCircleEdge(this->addVertexAttrib(
GrShaderVar("inCircleEdge",
kVec4f_GrSLType,
GrShaderVar::kAttribute_TypeModifier))) {
fStroke = stroke;
}
virtual bool onIsEqual(const GrGeometryProcessor& other) const SK_OVERRIDE {
const CircleEdgeEffect& cee = other.cast<CircleEdgeEffect>();
return cee.fStroke == fStroke;
}
virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
inout->mulByUnknownAlpha();
}
const GrShaderVar& fInCircleEdge;
bool fStroke;
GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
typedef GrGeometryProcessor INHERITED;
};
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(CircleEdgeEffect);
GrGeometryProcessor* CircleEdgeEffect::TestCreate(SkRandom* random,
GrContext* context,
const GrDrawTargetCaps&,
GrTexture* textures[]) {
return CircleEdgeEffect::Create(random->nextBool());
}
///////////////////////////////////////////////////////////////////////////////
/**
* The output of this effect is a modulation of the input color and coverage for an axis-aligned
* ellipse, specified as a 2D offset from center, and the reciprocals of the outer and inner radii,
* in both x and y directions.
*
* We are using an implicit function of x^2/a^2 + y^2/b^2 - 1 = 0.
*/
class EllipseEdgeEffect : public GrGeometryProcessor {
public:
static GrGeometryProcessor* Create(bool stroke) {
GR_CREATE_STATIC_PROCESSOR(gEllipseStrokeEdge, EllipseEdgeEffect, (true));
GR_CREATE_STATIC_PROCESSOR(gEllipseFillEdge, EllipseEdgeEffect, (false));
if (stroke) {
gEllipseStrokeEdge->ref();
return gEllipseStrokeEdge;
} else {
gEllipseFillEdge->ref();
return gEllipseFillEdge;
}
}
virtual const GrBackendGeometryProcessorFactory& getFactory() const SK_OVERRIDE {
return GrTBackendGeometryProcessorFactory<EllipseEdgeEffect>::getInstance();
}
virtual ~EllipseEdgeEffect() {}
static const char* Name() { return "EllipseEdge"; }
const GrShaderVar& inEllipseOffset() const { return fInEllipseOffset; }
const GrShaderVar& inEllipseRadii() const { return fInEllipseRadii; }
inline bool isStroked() const { return fStroke; }
class GLProcessor : public GrGLGeometryProcessor {
public:
GLProcessor(const GrBackendProcessorFactory& factory, const GrProcessor&)
: INHERITED (factory) {}
virtual void emitCode(const EmitArgs& args) SK_OVERRIDE {
const EllipseEdgeEffect& ellipseEffect = args.fGP.cast<EllipseEdgeEffect>();
GrGLVertToFrag ellipseOffsets(kVec2f_GrSLType);
args.fPB->addVarying("EllipseOffsets", &ellipseOffsets);
GrGLVertexBuilder* vsBuilder = args.fPB->getVertexShaderBuilder();
vsBuilder->codeAppendf("%s = %s;", ellipseOffsets.vsOut(),
ellipseEffect.inEllipseOffset().c_str());
GrGLVertToFrag ellipseRadii(kVec4f_GrSLType);
args.fPB->addVarying("EllipseRadii", &ellipseRadii);
vsBuilder->codeAppendf("%s = %s;", ellipseRadii.vsOut(),
ellipseEffect.inEllipseRadii().c_str());
// for outer curve
GrGLGPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
fsBuilder->codeAppendf("vec2 scaledOffset = %s*%s.xy;", ellipseOffsets.fsIn(),
ellipseRadii.fsIn());
fsBuilder->codeAppend("float test = dot(scaledOffset, scaledOffset) - 1.0;");
fsBuilder->codeAppendf("vec2 grad = 2.0*scaledOffset*%s.xy;", ellipseRadii.fsIn());
fsBuilder->codeAppend("float grad_dot = dot(grad, grad);");
// avoid calling inversesqrt on zero.
fsBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
fsBuilder->codeAppend("float invlen = inversesqrt(grad_dot);");
fsBuilder->codeAppend("float edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);");
// for inner curve
if (ellipseEffect.isStroked()) {
fsBuilder->codeAppendf("scaledOffset = %s*%s.zw;",
ellipseOffsets.fsIn(), ellipseRadii.fsIn());
fsBuilder->codeAppend("test = dot(scaledOffset, scaledOffset) - 1.0;");
fsBuilder->codeAppendf("grad = 2.0*scaledOffset*%s.zw;",
ellipseRadii.fsIn());
fsBuilder->codeAppend("invlen = inversesqrt(dot(grad, grad));");
fsBuilder->codeAppend("edgeAlpha *= clamp(0.5+test*invlen, 0.0, 1.0);");
}
fsBuilder->codeAppendf("%s = %s;", args.fOutput,
(GrGLSLExpr4(args.fInput) * GrGLSLExpr1("edgeAlpha")).c_str());
}
static void GenKey(const GrProcessor& processor, const GrGLCaps&,
GrProcessorKeyBuilder* b) {
const EllipseEdgeEffect& ellipseEffect = processor.cast<EllipseEdgeEffect>();
b->add32(ellipseEffect.isStroked());
}
virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE {
}
private:
typedef GrGLGeometryProcessor INHERITED;
};
private:
EllipseEdgeEffect(bool stroke)
: fInEllipseOffset(this->addVertexAttrib(
GrShaderVar("inEllipseOffset",
kVec2f_GrSLType,
GrShaderVar::kAttribute_TypeModifier)))
, fInEllipseRadii(this->addVertexAttrib(
GrShaderVar("inEllipseRadii",
kVec4f_GrSLType,
GrShaderVar::kAttribute_TypeModifier))) {
fStroke = stroke;
}
virtual bool onIsEqual(const GrGeometryProcessor& other) const SK_OVERRIDE {
const EllipseEdgeEffect& eee = other.cast<EllipseEdgeEffect>();
return eee.fStroke == fStroke;
}
virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
inout->mulByUnknownAlpha();
}
const GrShaderVar& fInEllipseOffset;
const GrShaderVar& fInEllipseRadii;
bool fStroke;
GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
typedef GrGeometryProcessor INHERITED;
};
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(EllipseEdgeEffect);
GrGeometryProcessor* EllipseEdgeEffect::TestCreate(SkRandom* random,
GrContext* context,
const GrDrawTargetCaps&,
GrTexture* textures[]) {
return EllipseEdgeEffect::Create(random->nextBool());
}
///////////////////////////////////////////////////////////////////////////////
/**
* The output of this effect is a modulation of the input color and coverage for an ellipse,
* specified as a 2D offset from center for both the outer and inner paths (if stroked). The
* implict equation used is for a unit circle (x^2 + y^2 - 1 = 0) and the edge corrected by
* using differentials.
*
* The result is device-independent and can be used with any affine matrix.
*/
class DIEllipseEdgeEffect : public GrGeometryProcessor {
public:
enum Mode { kStroke = 0, kHairline, kFill };
static GrGeometryProcessor* Create(Mode mode) {
GR_CREATE_STATIC_PROCESSOR(gEllipseStrokeEdge, DIEllipseEdgeEffect, (kStroke));
GR_CREATE_STATIC_PROCESSOR(gEllipseHairlineEdge, DIEllipseEdgeEffect, (kHairline));
GR_CREATE_STATIC_PROCESSOR(gEllipseFillEdge, DIEllipseEdgeEffect, (kFill));
if (kStroke == mode) {
gEllipseStrokeEdge->ref();
return gEllipseStrokeEdge;
} else if (kHairline == mode) {
gEllipseHairlineEdge->ref();
return gEllipseHairlineEdge;
} else {
gEllipseFillEdge->ref();
return gEllipseFillEdge;
}
}
virtual const GrBackendGeometryProcessorFactory& getFactory() const SK_OVERRIDE {
return GrTBackendGeometryProcessorFactory<DIEllipseEdgeEffect>::getInstance();
}
virtual ~DIEllipseEdgeEffect() {}
static const char* Name() { return "DIEllipseEdge"; }
const GrShaderVar& inEllipseOffsets0() const { return fInEllipseOffsets0; }
const GrShaderVar& inEllipseOffsets1() const { return fInEllipseOffsets1; }
inline Mode getMode() const { return fMode; }
class GLProcessor : public GrGLGeometryProcessor {
public:
GLProcessor(const GrBackendProcessorFactory& factory, const GrProcessor&)
: INHERITED (factory) {}
virtual void emitCode(const EmitArgs& args) SK_OVERRIDE {
const DIEllipseEdgeEffect& ellipseEffect = args.fGP.cast<DIEllipseEdgeEffect>();
GrGLVertToFrag offsets0(kVec2f_GrSLType);
args.fPB->addVarying("EllipseOffsets0", &offsets0);
GrGLVertexBuilder* vsBuilder = args.fPB->getVertexShaderBuilder();
vsBuilder->codeAppendf("%s = %s;", offsets0.vsOut(),
ellipseEffect.inEllipseOffsets0().c_str());
GrGLVertToFrag offsets1(kVec2f_GrSLType);
args.fPB->addVarying("EllipseOffsets1", &offsets1);
vsBuilder->codeAppendf("%s = %s;", offsets1.vsOut(),
ellipseEffect.inEllipseOffsets1().c_str());
GrGLGPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
SkAssertResult(fsBuilder->enableFeature(
GrGLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
// for outer curve
fsBuilder->codeAppendf("vec2 scaledOffset = %s.xy;", offsets0.fsIn());
fsBuilder->codeAppend("float test = dot(scaledOffset, scaledOffset) - 1.0;");
fsBuilder->codeAppendf("vec2 duvdx = dFdx(%s);", offsets0.fsIn());
fsBuilder->codeAppendf("vec2 duvdy = dFdy(%s);", offsets0.fsIn());
fsBuilder->codeAppendf("vec2 grad = vec2(2.0*%s.x*duvdx.x + 2.0*%s.y*duvdx.y,"
" 2.0*%s.x*duvdy.x + 2.0*%s.y*duvdy.y);",
offsets0.fsIn(), offsets0.fsIn(), offsets0.fsIn(), offsets0.fsIn());
fsBuilder->codeAppend("float grad_dot = dot(grad, grad);");
// avoid calling inversesqrt on zero.
fsBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
fsBuilder->codeAppend("float invlen = inversesqrt(grad_dot);");
if (kHairline == ellipseEffect.getMode()) {
// can probably do this with one step
fsBuilder->codeAppend("float edgeAlpha = clamp(1.0-test*invlen, 0.0, 1.0);");
fsBuilder->codeAppend("edgeAlpha *= clamp(1.0+test*invlen, 0.0, 1.0);");
} else {
fsBuilder->codeAppend("float edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);");
}
// for inner curve
if (kStroke == ellipseEffect.getMode()) {
fsBuilder->codeAppendf("scaledOffset = %s.xy;", offsets1.fsIn());
fsBuilder->codeAppend("test = dot(scaledOffset, scaledOffset) - 1.0;");
fsBuilder->codeAppendf("duvdx = dFdx(%s);", offsets1.fsIn());
fsBuilder->codeAppendf("duvdy = dFdy(%s);", offsets1.fsIn());
fsBuilder->codeAppendf("grad = vec2(2.0*%s.x*duvdx.x + 2.0*%s.y*duvdx.y,"
" 2.0*%s.x*duvdy.x + 2.0*%s.y*duvdy.y);",
offsets1.fsIn(), offsets1.fsIn(), offsets1.fsIn(),
offsets1.fsIn());
fsBuilder->codeAppend("invlen = inversesqrt(dot(grad, grad));");
fsBuilder->codeAppend("edgeAlpha *= clamp(0.5+test*invlen, 0.0, 1.0);");
}
fsBuilder->codeAppendf("%s = %s;", args.fOutput,
(GrGLSLExpr4(args.fInput) * GrGLSLExpr1("edgeAlpha")).c_str());
}
static void GenKey(const GrProcessor& processor, const GrGLCaps&,
GrProcessorKeyBuilder* b) {
const DIEllipseEdgeEffect& ellipseEffect = processor.cast<DIEllipseEdgeEffect>();
b->add32(ellipseEffect.getMode());
}
virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE {
}
private:
typedef GrGLGeometryProcessor INHERITED;
};
private:
DIEllipseEdgeEffect(Mode mode)
: fInEllipseOffsets0(this->addVertexAttrib(
GrShaderVar("inEllipseOffsets0",
kVec2f_GrSLType,
GrShaderVar::kAttribute_TypeModifier)))
, fInEllipseOffsets1(this->addVertexAttrib(
GrShaderVar("inEllipseOffsets1",
kVec2f_GrSLType,
GrShaderVar::kAttribute_TypeModifier))) {
fMode = mode;
}
virtual bool onIsEqual(const GrGeometryProcessor& other) const SK_OVERRIDE {
const DIEllipseEdgeEffect& eee = other.cast<DIEllipseEdgeEffect>();
return eee.fMode == fMode;
}
virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
inout->mulByUnknownAlpha();
}
const GrShaderVar& fInEllipseOffsets0;
const GrShaderVar& fInEllipseOffsets1;
Mode fMode;
GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
typedef GrGeometryProcessor INHERITED;
};
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(DIEllipseEdgeEffect);
GrGeometryProcessor* DIEllipseEdgeEffect::TestCreate(SkRandom* random,
GrContext* context,
const GrDrawTargetCaps&,
GrTexture* textures[]) {
return DIEllipseEdgeEffect::Create((Mode)(random->nextRangeU(0,2)));
}
///////////////////////////////////////////////////////////////////////////////
void GrOvalRenderer::reset() {
SkSafeSetNull(fRRectIndexBuffer);
SkSafeSetNull(fStrokeRRectIndexBuffer);
}
bool GrOvalRenderer::drawOval(GrDrawTarget* target, const GrContext* context, bool useAA,
const SkRect& oval, const SkStrokeRec& stroke)
{
bool useCoverageAA = useAA &&
!target->getDrawState().getRenderTarget()->isMultisampled() &&
!target->shouldDisableCoverageAAForBlend();
if (!useCoverageAA) {
return false;
}
const SkMatrix& vm = context->getMatrix();
// we can draw circles
if (SkScalarNearlyEqual(oval.width(), oval.height())
&& circle_stays_circle(vm)) {
this->drawCircle(target, context, useCoverageAA, oval, stroke);
// if we have shader derivative support, render as device-independent
} else if (target->caps()->shaderDerivativeSupport()) {
return this->drawDIEllipse(target, context, useCoverageAA, oval, stroke);
// otherwise axis-aligned ellipses only
} else if (vm.rectStaysRect()) {
return this->drawEllipse(target, context, useCoverageAA, oval, stroke);
} else {
return false;
}
return true;
}
///////////////////////////////////////////////////////////////////////////////
// position + edge
extern const GrVertexAttrib gCircleVertexAttribs[] = {
{kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
{kVec4f_GrVertexAttribType, sizeof(SkPoint), kGeometryProcessor_GrVertexAttribBinding}
};
void GrOvalRenderer::drawCircle(GrDrawTarget* target,
const GrContext* context,
bool useCoverageAA,
const SkRect& circle,
const SkStrokeRec& stroke)
{
GrDrawState* drawState = target->drawState();
const SkMatrix& vm = drawState->getViewMatrix();
SkPoint center = SkPoint::Make(circle.centerX(), circle.centerY());
vm.mapPoints(&center, 1);
SkScalar radius = vm.mapRadius(SkScalarHalf(circle.width()));
SkScalar strokeWidth = vm.mapRadius(stroke.getWidth());
GrDrawState::AutoViewMatrixRestore avmr;
if (!avmr.setIdentity(drawState)) {
return;
}
drawState->setVertexAttribs<gCircleVertexAttribs>(SK_ARRAY_COUNT(gCircleVertexAttribs),
sizeof(CircleVertex));
GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
if (!geo.succeeded()) {
GrPrintf("Failed to get space for vertices!\n");
return;
}
CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
SkStrokeRec::Style style = stroke.getStyle();
bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
SkStrokeRec::kHairline_Style == style;
bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;
SkScalar innerRadius = 0.0f;
SkScalar outerRadius = radius;
SkScalar halfWidth = 0;
if (hasStroke) {
if (SkScalarNearlyZero(strokeWidth)) {
halfWidth = SK_ScalarHalf;
} else {
halfWidth = SkScalarHalf(strokeWidth);
}
outerRadius += halfWidth;
if (isStrokeOnly) {
innerRadius = radius - halfWidth;
}
}
GrGeometryProcessor* gp = CircleEdgeEffect::Create(isStrokeOnly && innerRadius > 0);
drawState->setGeometryProcessor(gp)->unref();
// The radii are outset for two reasons. First, it allows the shader to simply perform
// clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the
// verts of the bounding box that is rendered and the outset ensures the box will cover all
// pixels partially covered by the circle.
outerRadius += SK_ScalarHalf;
innerRadius -= SK_ScalarHalf;
SkRect bounds = SkRect::MakeLTRB(
center.fX - outerRadius,
center.fY - outerRadius,
center.fX + outerRadius,
center.fY + outerRadius
);
verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop);
verts[0].fOffset = SkPoint::Make(-outerRadius, -outerRadius);
verts[0].fOuterRadius = outerRadius;
verts[0].fInnerRadius = innerRadius;
verts[1].fPos = SkPoint::Make(bounds.fLeft, bounds.fBottom);
verts[1].fOffset = SkPoint::Make(-outerRadius, outerRadius);
verts[1].fOuterRadius = outerRadius;
verts[1].fInnerRadius = innerRadius;
verts[2].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
verts[2].fOffset = SkPoint::Make(outerRadius, outerRadius);
verts[2].fOuterRadius = outerRadius;
verts[2].fInnerRadius = innerRadius;
verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
verts[3].fOffset = SkPoint::Make(outerRadius, -outerRadius);
verts[3].fOuterRadius = outerRadius;
verts[3].fInnerRadius = innerRadius;
target->setIndexSourceToBuffer(context->getGpu()->getQuadIndexBuffer());
target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1, 4, 6, &bounds);
target->resetIndexSource();
}
///////////////////////////////////////////////////////////////////////////////
// position + offset + 1/radii
extern const GrVertexAttrib gEllipseVertexAttribs[] = {
{kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
{kVec2f_GrVertexAttribType, sizeof(SkPoint), kGeometryProcessor_GrVertexAttribBinding},
{kVec4f_GrVertexAttribType, 2*sizeof(SkPoint), kGeometryProcessor_GrVertexAttribBinding}
};
// position + offsets
extern const GrVertexAttrib gDIEllipseVertexAttribs[] = {
{kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
{kVec2f_GrVertexAttribType, sizeof(SkPoint), kGeometryProcessor_GrVertexAttribBinding},
{kVec2f_GrVertexAttribType, 2*sizeof(SkPoint), kGeometryProcessor_GrVertexAttribBinding},
};
bool GrOvalRenderer::drawEllipse(GrDrawTarget* target,
const GrContext* context,
bool useCoverageAA,
const SkRect& ellipse,
const SkStrokeRec& stroke)
{
GrDrawState* drawState = target->drawState();
#ifdef SK_DEBUG
{
// we should have checked for this previously
bool isAxisAlignedEllipse = drawState->getViewMatrix().rectStaysRect();
SkASSERT(useCoverageAA && isAxisAlignedEllipse);
}
#endif
// do any matrix crunching before we reset the draw state for device coords
const SkMatrix& vm = drawState->getViewMatrix();
SkPoint center = SkPoint::Make(ellipse.centerX(), ellipse.centerY());
vm.mapPoints(&center, 1);
SkScalar ellipseXRadius = SkScalarHalf(ellipse.width());
SkScalar ellipseYRadius = SkScalarHalf(ellipse.height());
SkScalar xRadius = SkScalarAbs(vm[SkMatrix::kMScaleX]*ellipseXRadius +
vm[SkMatrix::kMSkewY]*ellipseYRadius);
SkScalar yRadius = SkScalarAbs(vm[SkMatrix::kMSkewX]*ellipseXRadius +
vm[SkMatrix::kMScaleY]*ellipseYRadius);
// do (potentially) anisotropic mapping of stroke
SkVector scaledStroke;
SkScalar strokeWidth = stroke.getWidth();
scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] + vm[SkMatrix::kMSkewY]));
scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] + vm[SkMatrix::kMScaleY]));
SkStrokeRec::Style style = stroke.getStyle();
bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
SkStrokeRec::kHairline_Style == style;
bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;
SkScalar innerXRadius = 0;
SkScalar innerYRadius = 0;
if (hasStroke) {
if (SkScalarNearlyZero(scaledStroke.length())) {
scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
} else {
scaledStroke.scale(SK_ScalarHalf);
}
// we only handle thick strokes for near-circular ellipses
if (scaledStroke.length() > SK_ScalarHalf &&
(SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
return false;
}
// we don't handle it if curvature of the stroke is less than curvature of the ellipse
if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
return false;
}
// this is legit only if scale & translation (which should be the case at the moment)
if (isStrokeOnly) {
innerXRadius = xRadius - scaledStroke.fX;
innerYRadius = yRadius - scaledStroke.fY;
}
xRadius += scaledStroke.fX;
yRadius += scaledStroke.fY;
}
GrDrawState::AutoViewMatrixRestore avmr;
if (!avmr.setIdentity(drawState)) {
return false;
}
drawState->setVertexAttribs<gEllipseVertexAttribs>(SK_ARRAY_COUNT(gEllipseVertexAttribs),
sizeof(EllipseVertex));
GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
if (!geo.succeeded()) {
GrPrintf("Failed to get space for vertices!\n");
return false;
}
EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices());
GrGeometryProcessor* gp = EllipseEdgeEffect::Create(isStrokeOnly &&
innerXRadius > 0 && innerYRadius > 0);
drawState->setGeometryProcessor(gp)->unref();
// Compute the reciprocals of the radii here to save time in the shader
SkScalar xRadRecip = SkScalarInvert(xRadius);
SkScalar yRadRecip = SkScalarInvert(yRadius);
SkScalar xInnerRadRecip = SkScalarInvert(innerXRadius);
SkScalar yInnerRadRecip = SkScalarInvert(innerYRadius);
// We've extended the outer x radius out half a pixel to antialias.
// This will also expand the rect so all the pixels will be captured.
// TODO: Consider if we should use sqrt(2)/2 instead
xRadius += SK_ScalarHalf;
yRadius += SK_ScalarHalf;
SkRect bounds = SkRect::MakeLTRB(
center.fX - xRadius,
center.fY - yRadius,
center.fX + xRadius,
center.fY + yRadius
);
verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop);
verts[0].fOffset = SkPoint::Make(-xRadius, -yRadius);
verts[0].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts[0].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts[1].fPos = SkPoint::Make(bounds.fLeft, bounds.fBottom);
verts[1].fOffset = SkPoint::Make(-xRadius, yRadius);
verts[1].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts[1].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts[2].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
verts[2].fOffset = SkPoint::Make(xRadius, yRadius);
verts[2].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts[2].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
verts[3].fOffset = SkPoint::Make(xRadius, -yRadius);
verts[3].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts[3].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
target->setIndexSourceToBuffer(context->getGpu()->getQuadIndexBuffer());
target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1, 4, 6, &bounds);
target->resetIndexSource();
return true;
}
bool GrOvalRenderer::drawDIEllipse(GrDrawTarget* target,
const GrContext* context,
bool useCoverageAA,
const SkRect& ellipse,
const SkStrokeRec& stroke)
{
GrDrawState* drawState = target->drawState();
const SkMatrix& vm = drawState->getViewMatrix();
SkPoint center = SkPoint::Make(ellipse.centerX(), ellipse.centerY());
SkScalar xRadius = SkScalarHalf(ellipse.width());
SkScalar yRadius = SkScalarHalf(ellipse.height());
SkStrokeRec::Style style = stroke.getStyle();
DIEllipseEdgeEffect::Mode mode = (SkStrokeRec::kStroke_Style == style) ?
DIEllipseEdgeEffect::kStroke :
(SkStrokeRec::kHairline_Style == style) ?
DIEllipseEdgeEffect::kHairline : DIEllipseEdgeEffect::kFill;
SkScalar innerXRadius = 0;
SkScalar innerYRadius = 0;
if (SkStrokeRec::kFill_Style != style && SkStrokeRec::kHairline_Style != style) {
SkScalar strokeWidth = stroke.getWidth();
if (SkScalarNearlyZero(strokeWidth)) {
strokeWidth = SK_ScalarHalf;
} else {
strokeWidth *= SK_ScalarHalf;
}
// we only handle thick strokes for near-circular ellipses
if (strokeWidth > SK_ScalarHalf &&
(SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
return false;
}
// we don't handle it if curvature of the stroke is less than curvature of the ellipse
if (strokeWidth*(yRadius*yRadius) < (strokeWidth*strokeWidth)*xRadius ||
strokeWidth*(xRadius*xRadius) < (strokeWidth*strokeWidth)*yRadius) {
return false;
}
// set inner radius (if needed)
if (SkStrokeRec::kStroke_Style == style) {
innerXRadius = xRadius - strokeWidth;
innerYRadius = yRadius - strokeWidth;
}
xRadius += strokeWidth;
yRadius += strokeWidth;
}
if (DIEllipseEdgeEffect::kStroke == mode) {
mode = (innerXRadius > 0 && innerYRadius > 0) ? DIEllipseEdgeEffect::kStroke :
DIEllipseEdgeEffect::kFill;
}
SkScalar innerRatioX = SkScalarDiv(xRadius, innerXRadius);
SkScalar innerRatioY = SkScalarDiv(yRadius, innerYRadius);
drawState->setVertexAttribs<gDIEllipseVertexAttribs>(SK_ARRAY_COUNT(gDIEllipseVertexAttribs),
sizeof(DIEllipseVertex));
GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
if (!geo.succeeded()) {
GrPrintf("Failed to get space for vertices!\n");
return false;
}
DIEllipseVertex* verts = reinterpret_cast<DIEllipseVertex*>(geo.vertices());
GrGeometryProcessor* gp = DIEllipseEdgeEffect::Create(mode);
drawState->setGeometryProcessor(gp)->unref();
// This expands the outer rect so that after CTM we end up with a half-pixel border
SkScalar a = vm[SkMatrix::kMScaleX];
SkScalar b = vm[SkMatrix::kMSkewX];
SkScalar c = vm[SkMatrix::kMSkewY];
SkScalar d = vm[SkMatrix::kMScaleY];
SkScalar geoDx = SkScalarDiv(SK_ScalarHalf, SkScalarSqrt(a*a + c*c));
SkScalar geoDy = SkScalarDiv(SK_ScalarHalf, SkScalarSqrt(b*b + d*d));
// This adjusts the "radius" to include the half-pixel border
SkScalar offsetDx = SkScalarDiv(geoDx, xRadius);
SkScalar offsetDy = SkScalarDiv(geoDy, yRadius);
SkRect bounds = SkRect::MakeLTRB(
center.fX - xRadius - geoDx,
center.fY - yRadius - geoDy,
center.fX + xRadius + geoDx,
center.fY + yRadius + geoDy
);
verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop);
verts[0].fOuterOffset = SkPoint::Make(-1.0f - offsetDx, -1.0f - offsetDy);
verts[0].fInnerOffset = SkPoint::Make(-innerRatioX - offsetDx, -innerRatioY - offsetDy);
verts[1].fPos = SkPoint::Make(bounds.fLeft, bounds.fBottom);
verts[1].fOuterOffset = SkPoint::Make(-1.0f - offsetDx, 1.0f + offsetDy);
verts[1].fInnerOffset = SkPoint::Make(-innerRatioX - offsetDx, innerRatioY + offsetDy);
verts[2].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
verts[2].fOuterOffset = SkPoint::Make(1.0f + offsetDx, 1.0f + offsetDy);
verts[2].fInnerOffset = SkPoint::Make(innerRatioX + offsetDx, innerRatioY + offsetDy);
verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
verts[3].fOuterOffset = SkPoint::Make(1.0f + offsetDx, -1.0f - offsetDy);
verts[3].fInnerOffset = SkPoint::Make(innerRatioX + offsetDx, -innerRatioY - offsetDy);
target->setIndexSourceToBuffer(context->getGpu()->getQuadIndexBuffer());
target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1, 4, 6, &bounds);
target->resetIndexSource();
return true;
}
///////////////////////////////////////////////////////////////////////////////
static const uint16_t gRRectIndices[] = {
// corners
0, 1, 5, 0, 5, 4,
2, 3, 7, 2, 7, 6,
8, 9, 13, 8, 13, 12,
10, 11, 15, 10, 15, 14,
// edges
1, 2, 6, 1, 6, 5,
4, 5, 9, 4, 9, 8,
6, 7, 11, 6, 11, 10,
9, 10, 14, 9, 14, 13,
// center
// we place this at the end so that we can ignore these indices when rendering stroke-only
5, 6, 10, 5, 10, 9
};
static const int kIndicesPerStrokeRRect = SK_ARRAY_COUNT(gRRectIndices) - 6;
static const int kIndicesPerRRect = SK_ARRAY_COUNT(gRRectIndices);
static const int kVertsPerRRect = 16;
static const int kNumRRectsInIndexBuffer = 256;
GrIndexBuffer* GrOvalRenderer::rRectIndexBuffer(bool isStrokeOnly, GrGpu* gpu) {
if (isStrokeOnly) {
if (NULL == fStrokeRRectIndexBuffer) {
fStrokeRRectIndexBuffer = gpu->createInstancedIndexBuffer(gRRectIndices,
kIndicesPerStrokeRRect,
kNumRRectsInIndexBuffer,
kVertsPerRRect);
}
return fStrokeRRectIndexBuffer;
} else {
if (NULL == fRRectIndexBuffer) {
fRRectIndexBuffer = gpu->createInstancedIndexBuffer(gRRectIndices,
kIndicesPerRRect,
kNumRRectsInIndexBuffer,
kVertsPerRRect);
}
return fRRectIndexBuffer;
}
}
bool GrOvalRenderer::drawDRRect(GrDrawTarget* target, GrContext* context, bool useAA,
const SkRRect& origOuter, const SkRRect& origInner) {
bool applyAA = useAA &&
!target->getDrawState().getRenderTarget()->isMultisampled() &&
!target->shouldDisableCoverageAAForBlend();
GrDrawState::AutoRestoreEffects are;
if (!origInner.isEmpty()) {
SkTCopyOnFirstWrite<SkRRect> inner(origInner);
if (!context->getMatrix().isIdentity()) {
if (!origInner.transform(context->getMatrix(), inner.writable())) {
return false;
}
}
GrPrimitiveEdgeType edgeType = applyAA ?
kInverseFillAA_GrProcessorEdgeType :
kInverseFillBW_GrProcessorEdgeType;
GrFragmentProcessor* fp = GrRRectEffect::Create(edgeType, *inner);
if (NULL == fp) {
return false;
}
are.set(target->drawState());
target->drawState()->addCoverageProcessor(fp)->unref();
}
SkStrokeRec fillRec(SkStrokeRec::kFill_InitStyle);
if (this->drawRRect(target, context, useAA, origOuter, fillRec)) {
return true;
}
SkASSERT(!origOuter.isEmpty());
SkTCopyOnFirstWrite<SkRRect> outer(origOuter);
if (!context->getMatrix().isIdentity()) {
if (!origOuter.transform(context->getMatrix(), outer.writable())) {
return false;
}
}
GrPrimitiveEdgeType edgeType = applyAA ? kFillAA_GrProcessorEdgeType :
kFillBW_GrProcessorEdgeType;
GrFragmentProcessor* effect = GrRRectEffect::Create(edgeType, *outer);
if (NULL == effect) {
return false;
}
if (!are.isSet()) {
are.set(target->drawState());
}
GrDrawState::AutoViewMatrixRestore avmr;
if (!avmr.setIdentity(target->drawState())) {
return false;
}
target->drawState()->addCoverageProcessor(effect)->unref();
SkRect bounds = outer->getBounds();
if (applyAA) {
bounds.outset(SK_ScalarHalf, SK_ScalarHalf);
}
target->drawRect(bounds, NULL, NULL);
return true;
}
bool GrOvalRenderer::drawRRect(GrDrawTarget* target, GrContext* context, bool useAA,
const SkRRect& rrect, const SkStrokeRec& stroke) {
if (rrect.isOval()) {
return this->drawOval(target, context, useAA, rrect.getBounds(), stroke);
}
bool useCoverageAA = useAA &&
!target->getDrawState().getRenderTarget()->isMultisampled() &&
!target->shouldDisableCoverageAAForBlend();
// only anti-aliased rrects for now
if (!useCoverageAA) {
return false;
}
const SkMatrix& vm = context->getMatrix();
if (!vm.rectStaysRect() || !rrect.isSimple()) {
return false;
}
// do any matrix crunching before we reset the draw state for device coords
const SkRect& rrectBounds = rrect.getBounds();
SkRect bounds;
vm.mapRect(&bounds, rrectBounds);
SkVector radii = rrect.getSimpleRadii();
SkScalar xRadius = SkScalarAbs(vm[SkMatrix::kMScaleX]*radii.fX +
vm[SkMatrix::kMSkewY]*radii.fY);
SkScalar yRadius = SkScalarAbs(vm[SkMatrix::kMSkewX]*radii.fX +
vm[SkMatrix::kMScaleY]*radii.fY);
SkStrokeRec::Style style = stroke.getStyle();
// do (potentially) anisotropic mapping of stroke
SkVector scaledStroke;
SkScalar strokeWidth = stroke.getWidth();
bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
SkStrokeRec::kHairline_Style == style;
bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;
if (hasStroke) {
if (SkStrokeRec::kHairline_Style == style) {
scaledStroke.set(1, 1);
} else {
scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] +
vm[SkMatrix::kMSkewY]));
scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] +
vm[SkMatrix::kMScaleY]));
}
// if half of strokewidth is greater than radius, we don't handle that right now
if (SK_ScalarHalf*scaledStroke.fX > xRadius || SK_ScalarHalf*scaledStroke.fY > yRadius) {
return false;
}
}
// The way the effect interpolates the offset-to-ellipse/circle-center attribute only works on
// the interior of the rrect if the radii are >= 0.5. Otherwise, the inner rect of the nine-
// patch will have fractional coverage. This only matters when the interior is actually filled.
// We could consider falling back to rect rendering here, since a tiny radius is
// indistinguishable from a square corner.
if (!isStrokeOnly && (SK_ScalarHalf > xRadius || SK_ScalarHalf > yRadius)) {
return false;
}
// reset to device coordinates
GrDrawState* drawState = target->drawState();
GrDrawState::AutoViewMatrixRestore avmr;
if (!avmr.setIdentity(drawState)) {
return false;
}
GrIndexBuffer* indexBuffer = this->rRectIndexBuffer(isStrokeOnly, context->getGpu());
if (NULL == indexBuffer) {
GrPrintf("Failed to create index buffer!\n");
return false;
}
// if the corners are circles, use the circle renderer
if ((!hasStroke || scaledStroke.fX == scaledStroke.fY) && xRadius == yRadius) {
drawState->setVertexAttribs<gCircleVertexAttribs>(SK_ARRAY_COUNT(gCircleVertexAttribs),
sizeof(CircleVertex));
GrDrawTarget::AutoReleaseGeometry geo(target, 16, 0);
if (!geo.succeeded()) {
GrPrintf("Failed to get space for vertices!\n");
return false;
}
CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
SkScalar innerRadius = 0.0f;
SkScalar outerRadius = xRadius;
SkScalar halfWidth = 0;
if (hasStroke) {
if (SkScalarNearlyZero(scaledStroke.fX)) {
halfWidth = SK_ScalarHalf;
} else {
halfWidth = SkScalarHalf(scaledStroke.fX);
}
if (isStrokeOnly) {
innerRadius = xRadius - halfWidth;
}
outerRadius += halfWidth;
bounds.outset(halfWidth, halfWidth);
}
isStrokeOnly = (isStrokeOnly && innerRadius >= 0);
GrGeometryProcessor* effect = CircleEdgeEffect::Create(isStrokeOnly);
drawState->setGeometryProcessor(effect)->unref();
// The radii are outset for two reasons. First, it allows the shader to simply perform
// clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the
// verts of the bounding box that is rendered and the outset ensures the box will cover all
// pixels partially covered by the circle.
outerRadius += SK_ScalarHalf;
innerRadius -= SK_ScalarHalf;
// Expand the rect so all the pixels will be captured.
bounds.outset(SK_ScalarHalf, SK_ScalarHalf);
SkScalar yCoords[4] = {
bounds.fTop,
bounds.fTop + outerRadius,
bounds.fBottom - outerRadius,
bounds.fBottom
};
SkScalar yOuterRadii[4] = {
-outerRadius,
0,
0,
outerRadius
};
for (int i = 0; i < 4; ++i) {
verts->fPos = SkPoint::Make(bounds.fLeft, yCoords[i]);
verts->fOffset = SkPoint::Make(-outerRadius, yOuterRadii[i]);
verts->fOuterRadius = outerRadius;
verts->fInnerRadius = innerRadius;
verts++;
verts->fPos = SkPoint::Make(bounds.fLeft + outerRadius, yCoords[i]);
verts->fOffset = SkPoint::Make(0, yOuterRadii[i]);
verts->fOuterRadius = outerRadius;
verts->fInnerRadius = innerRadius;
verts++;
verts->fPos = SkPoint::Make(bounds.fRight - outerRadius, yCoords[i]);
verts->fOffset = SkPoint::Make(0, yOuterRadii[i]);
verts->fOuterRadius = outerRadius;
verts->fInnerRadius = innerRadius;
verts++;
verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
verts->fOffset = SkPoint::Make(outerRadius, yOuterRadii[i]);
verts->fOuterRadius = outerRadius;
verts->fInnerRadius = innerRadius;
verts++;
}
// drop out the middle quad if we're stroked
int indexCnt = isStrokeOnly ? SK_ARRAY_COUNT(gRRectIndices) - 6 :
SK_ARRAY_COUNT(gRRectIndices);
target->setIndexSourceToBuffer(indexBuffer);
target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1, 16, indexCnt, &bounds);
// otherwise we use the ellipse renderer
} else {
drawState->setVertexAttribs<gEllipseVertexAttribs>(SK_ARRAY_COUNT(gEllipseVertexAttribs),
sizeof(EllipseVertex));
SkScalar innerXRadius = 0.0f;
SkScalar innerYRadius = 0.0f;
if (hasStroke) {
if (SkScalarNearlyZero(scaledStroke.length())) {
scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
} else {
scaledStroke.scale(SK_ScalarHalf);
}
// we only handle thick strokes for near-circular ellipses
if (scaledStroke.length() > SK_ScalarHalf &&
(SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
return false;
}
// we don't handle it if curvature of the stroke is less than curvature of the ellipse
if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
return false;
}
// this is legit only if scale & translation (which should be the case at the moment)
if (isStrokeOnly) {
innerXRadius = xRadius - scaledStroke.fX;
innerYRadius = yRadius - scaledStroke.fY;
}
xRadius += scaledStroke.fX;
yRadius += scaledStroke.fY;
bounds.outset(scaledStroke.fX, scaledStroke.fY);
}
isStrokeOnly = (isStrokeOnly && innerXRadius >= 0 && innerYRadius >= 0);
GrDrawTarget::AutoReleaseGeometry geo(target, 16, 0);
if (!geo.succeeded()) {
GrPrintf("Failed to get space for vertices!\n");
return false;
}
EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices());
GrGeometryProcessor* effect = EllipseEdgeEffect::Create(isStrokeOnly);
drawState->setGeometryProcessor(effect)->unref();
// Compute the reciprocals of the radii here to save time in the shader
SkScalar xRadRecip = SkScalarInvert(xRadius);
SkScalar yRadRecip = SkScalarInvert(yRadius);
SkScalar xInnerRadRecip = SkScalarInvert(innerXRadius);
SkScalar yInnerRadRecip = SkScalarInvert(innerYRadius);
// Extend the radii out half a pixel to antialias.
SkScalar xOuterRadius = xRadius + SK_ScalarHalf;
SkScalar yOuterRadius = yRadius + SK_ScalarHalf;
// Expand the rect so all the pixels will be captured.
bounds.outset(SK_ScalarHalf, SK_ScalarHalf);
SkScalar yCoords[4] = {
bounds.fTop,
bounds.fTop + yOuterRadius,
bounds.fBottom - yOuterRadius,
bounds.fBottom
};
SkScalar yOuterOffsets[4] = {
yOuterRadius,
SK_ScalarNearlyZero, // we're using inversesqrt() in the shader, so can't be exactly 0
SK_ScalarNearlyZero,
yOuterRadius
};
for (int i = 0; i < 4; ++i) {
verts->fPos = SkPoint::Make(bounds.fLeft, yCoords[i]);
verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts++;
verts->fPos = SkPoint::Make(bounds.fLeft + xOuterRadius, yCoords[i]);
verts->fOffset = SkPoint::Make(SK_ScalarNearlyZero, yOuterOffsets[i]);
verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts++;
verts->fPos = SkPoint::Make(bounds.fRight - xOuterRadius, yCoords[i]);
verts->fOffset = SkPoint::Make(SK_ScalarNearlyZero, yOuterOffsets[i]);
verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts++;
verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
verts++;
}
// drop out the middle quad if we're stroked
int indexCnt = isStrokeOnly ? SK_ARRAY_COUNT(gRRectIndices) - 6 :
SK_ARRAY_COUNT(gRRectIndices);
target->setIndexSourceToBuffer(indexBuffer);
target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1, 16, indexCnt, &bounds);
}
target->resetIndexSource();
return true;
}
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