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ccpr: Implement conics

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Bug: skia:
Change-Id: I4bae8b059072af987abb7b2d9c57fe08f783d680
Reviewed-on: https://skia-review.googlesource.com/120040
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
This commit is contained in:
Chris Dalton 2018-04-16 13:21:36 -06:00 committed by Skia Commit-Bot
parent 83dc47375f
commit 98b241573e
13 changed files with 436 additions and 64 deletions
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2
gn/gpu.gni
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@ -300,6 +300,8 @@ skia_gpu_sources = [
"$_src/gpu/ccpr/GrCCAtlas.h",
"$_src/gpu/ccpr/GrCCClipProcessor.cpp",
"$_src/gpu/ccpr/GrCCClipProcessor.h",
"$_src/gpu/ccpr/GrCCConicShader.cpp",
"$_src/gpu/ccpr/GrCCConicShader.h",
"$_src/gpu/ccpr/GrCCCoverageProcessor.cpp",
"$_src/gpu/ccpr/GrCCCoverageProcessor_GSImpl.cpp",
"$_src/gpu/ccpr/GrCCCoverageProcessor_VSImpl.cpp",

78
samplecode/SampleCCPRGeometry.cpp
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@ -63,6 +63,8 @@ private:
SkPoint fPoints[4] = {
{100.05f, 100.05f}, {400.75f, 100.05f}, {400.75f, 300.95f}, {100.05f, 300.95f}};
float fConicWeight = .5;
SkTArray<TriPointInstance> fTriPointInstances;
SkTArray<QuadPointInstance> fQuadPointInstances;
@ -148,14 +150,22 @@ void CCPRGeometryView::onDrawContent(SkCanvas* canvas) {
SkPath outline;
outline.moveTo(fPoints[0]);
if (PrimitiveType::kCubics == fPrimitiveType) {
outline.cubicTo(fPoints[1], fPoints[2], fPoints[3]);
} else if (PrimitiveType::kQuadratics == fPrimitiveType) {
outline.quadTo(fPoints[1], fPoints[3]);
} else {
outline.lineTo(fPoints[1]);
outline.lineTo(fPoints[3]);
outline.close();
switch (fPrimitiveType) {
case PrimitiveType::kTriangles:
case PrimitiveType::kWeightedTriangles:
outline.lineTo(fPoints[1]);
outline.lineTo(fPoints[3]);
outline.close();
break;
case PrimitiveType::kQuadratics:
outline.quadTo(fPoints[1], fPoints[3]);
break;
case PrimitiveType::kCubics:
outline.cubicTo(fPoints[1], fPoints[2], fPoints[3]);
break;
case PrimitiveType::kConics:
outline.conicTo(fPoints[1], fPoints[3], fConicWeight);
break;
}
SkPaint outlinePaint;
@ -208,6 +218,8 @@ void CCPRGeometryView::onDrawContent(SkCanvas* canvas) {
GrCCCoverageProcessor::PrimitiveTypeName(fPrimitiveType));
if (PrimitiveType::kCubics == fPrimitiveType) {
caption.appendf(" (%s)", SkCubicTypeName(fCubicType));
} else if (PrimitiveType::kConics == fPrimitiveType) {
caption.appendf(" (w=%f)", fConicWeight);
}
} else {
caption = "Use GPU backend to visualize geometry.";
@ -264,13 +276,18 @@ void CCPRGeometryView::updateGpuData() {
continue;
}
}
} else if (PrimitiveType::kQuadratics == fPrimitiveType) {
} else if (PrimitiveType::kTriangles != fPrimitiveType) {
SkPoint P3[3] = {fPoints[0], fPoints[1], fPoints[3]};
GrCCGeometry geometry;
geometry.beginContour(P3[0]);
geometry.quadraticTo(P3);
if (PrimitiveType::kQuadratics == fPrimitiveType) {
geometry.quadraticTo(P3);
} else {
SkASSERT(PrimitiveType::kConics == fPrimitiveType);
geometry.conicTo(P3, fConicWeight);
}
geometry.endContour();
int ptsIdx = 0;
int ptsIdx = 0, conicWeightIdx = 0;
for (GrCCGeometry::Verb verb : geometry.verbs()) {
if (GrCCGeometry::Verb::kBeginContour == verb ||
GrCCGeometry::Verb::kEndOpenContour == verb ||
@ -281,8 +298,16 @@ void CCPRGeometryView::updateGpuData() {
++ptsIdx;
continue;
}
SkASSERT(GrCCGeometry::Verb::kMonotonicQuadraticTo == verb);
fTriPointInstances.push_back().set(&geometry.points()[ptsIdx], Sk2f(0, 0));
SkASSERT(GrCCGeometry::Verb::kMonotonicQuadraticTo == verb ||
GrCCGeometry::Verb::kMonotonicConicTo == verb);
if (PrimitiveType::kQuadratics == fPrimitiveType &&
GrCCGeometry::Verb::kMonotonicQuadraticTo == verb) {
fTriPointInstances.push_back().set(&geometry.points()[ptsIdx], Sk2f(0, 0));
} else if (PrimitiveType::kConics == fPrimitiveType &&
GrCCGeometry::Verb::kMonotonicConicTo == verb) {
fQuadPointInstances.push_back().setW(&geometry.points()[ptsIdx], Sk2f(0, 0),
geometry.getConicWeight(conicWeightIdx++));
}
ptsIdx += 2;
}
} else {
@ -301,7 +326,8 @@ void CCPRGeometryView::DrawCoverageCountOp::onExecute(GrOpFlushState* state) {
SkDEBUGCODE(proc.enableDebugBloat(kDebugBloat));
SkSTArray<1, GrMesh> mesh;
if (PrimitiveType::kCubics == fView->fPrimitiveType) {
if (PrimitiveType::kCubics == fView->fPrimitiveType ||
PrimitiveType::kConics == fView->fPrimitiveType) {
sk_sp<GrBuffer> instBuff(rp->createBuffer(
fView->fQuadPointInstances.count() * sizeof(QuadPointInstance),
kVertex_GrBufferType, kDynamic_GrAccessPattern,
@ -389,7 +415,7 @@ bool CCPRGeometryView::onQuery(SkEvent* evt) {
}
SkUnichar unichar;
if (SampleCode::CharQ(*evt, &unichar)) {
if (unichar >= '1' && unichar <= '3') {
if (unichar >= '1' && unichar <= '4') {
fPrimitiveType = PrimitiveType(unichar - '1');
if (fPrimitiveType >= PrimitiveType::kWeightedTriangles) {
fPrimitiveType = (PrimitiveType) ((int)fPrimitiveType + 1);
@ -397,6 +423,28 @@ bool CCPRGeometryView::onQuery(SkEvent* evt) {
this->updateAndInval();
return true;
}
if (PrimitiveType::kConics == fPrimitiveType) {
if (unichar == '+') {
fConicWeight *= 2;
this->updateAndInval();
return true;
}
if (unichar == '+' || unichar == '=') {
fConicWeight *= 5/4.f;
this->updateAndInval();
return true;
}
if (unichar == '-') {
fConicWeight *= 4/5.f;
this->updateAndInval();
return true;
}
if (unichar == '_') {
fConicWeight *= .5f;
this->updateAndInval();
return true;
}
}
if (unichar == 'D') {
SkDebugf(" SkPoint fPoints[4] = {\n");
SkDebugf(" {%ff, %ff},\n", fPoints[0].x(), fPoints[0].y());

93
src/gpu/ccpr/GrCCConicShader.cpp Normal file
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@ -0,0 +1,93 @@
/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrCCConicShader.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLVertexGeoBuilder.h"
void GrCCConicShader::emitSetupCode(GrGLSLVertexGeoBuilder* s, const char* pts, const char* wind,
const char** outHull4) const {
// K is distance from the line P2 -> P0. L is distance from the line P0 -> P1, scaled by 2w.
// M is distance from the line P1 -> P2, scaled by 2w. We do this in a space where P1=0.
s->declareGlobal(fKLMMatrix);
s->codeAppendf("float x0 = %s[0].x - %s[1].x, x2 = %s[2].x - %s[1].x;", pts, pts, pts, pts);
s->codeAppendf("float y0 = %s[0].y - %s[1].y, y2 = %s[2].y - %s[1].y;", pts, pts, pts, pts);
s->codeAppendf("float w = %s[3].x;", pts);
s->codeAppendf("%s = float3x3(y2 - y0, x0 - x2, x2*y0 - x0*y2, "
"2*w * float2(+y0, -x0), 0, "
"2*w * float2(-y2, +x2), 0);", fKLMMatrix.c_str());
s->declareGlobal(fControlPoint);
s->codeAppendf("%s = %s[1];", fControlPoint.c_str(), pts);
// Scale KLM by the inverse Manhattan width of K. This allows K to double as the flat opposite
// edge AA. kwidth will not be 0 because we cull degenerate conics on the CPU.
s->codeAppendf("float kwidth = 2*bloat * %s * (abs(%s[0].x) + abs(%s[0].y));",
wind, fKLMMatrix.c_str(), fKLMMatrix.c_str());
s->codeAppendf("%s *= 1/kwidth;", fKLMMatrix.c_str());
if (outHull4) {
// Clip the conic triangle by the tangent line at maximum height. Conics have the nice
// property that maximum height always occurs at T=.5. This is a simple application for
// De Casteljau's algorithm.
s->codeAppendf("float2 p1w = %s[1]*w;", pts);
s->codeAppend ("float r = 1 / (1 + w);");
s->codeAppendf("float2 conic_hull[4] = float2[4](%s[0], "
"(%s[0] + p1w) * r, "
"(p1w + %s[2]) * r, "
"%s[2]);", pts, pts, pts, pts);
*outHull4 = "conic_hull";
}
}
void GrCCConicShader::onEmitVaryings(GrGLSLVaryingHandler* varyingHandler,
GrGLSLVarying::Scope scope, SkString* code,
const char* position, const char* coverage,
const char* cornerCoverage) {
fKLM_fWind.reset(kFloat4_GrSLType, scope);
varyingHandler->addVarying("klm_and_wind", &fKLM_fWind);
code->appendf("float3 klm = float3(%s - %s, 1) * %s;",
position, fControlPoint.c_str(), fKLMMatrix.c_str());
code->appendf("%s.xyz = klm;", OutName(fKLM_fWind));
code->appendf("%s.w = %s;", OutName(fKLM_fWind), coverage); // coverage == wind.
fGrad_fCorner.reset(cornerCoverage ? kFloat4_GrSLType : kFloat2_GrSLType, scope);
varyingHandler->addVarying(cornerCoverage ? "grad_and_corner" : "grad", &fGrad_fCorner);
code->appendf("%s.xy = 2*bloat * (float3x2(%s) * float3(2*klm[0], -klm[2], -klm[1]));",
OutName(fGrad_fCorner), fKLMMatrix.c_str());
if (cornerCoverage) {
code->appendf("half hull_coverage;");
this->calcHullCoverage(code, "klm", OutName(fGrad_fCorner), "hull_coverage");
code->appendf("%s.zw = half2(hull_coverage, 1) * %s;",
OutName(fGrad_fCorner), cornerCoverage);
}
}
void GrCCConicShader::onEmitFragmentCode(GrGLSLFPFragmentBuilder* f,
const char* outputCoverage) const {
this->calcHullCoverage(&AccessCodeString(f), fKLM_fWind.fsIn(), fGrad_fCorner.fsIn(),
outputCoverage);
f->codeAppendf("%s *= %s.w;", outputCoverage, fKLM_fWind.fsIn()); // Wind.
if (kFloat4_GrSLType == fGrad_fCorner.type()) {
f->codeAppendf("%s = %s.z * %s.w + %s;", // Attenuated corner coverage.
outputCoverage, fGrad_fCorner.fsIn(), fGrad_fCorner.fsIn(),
outputCoverage);
}
}
void GrCCConicShader::calcHullCoverage(SkString* code, const char* klm, const char* grad,
const char* outputCoverage) const {
code->appendf("float k = %s.x, l = %s.y, m = %s.z;", klm, klm, klm);
code->append ("float f = k*k - l*m;");
code->appendf("float fwidth = abs(%s.x) + abs(%s.y);", grad, grad);
code->appendf("%s = min(0.5 - f/fwidth, 1);", outputCoverage); // Curve coverage.
code->append ("half d = min(k - 0.5, 0);"); // K doubles as the flat opposite edge's AA.
code->appendf("%s = max(%s + d, 0);", outputCoverage, outputCoverage); // Total hull coverage.
}

44
src/gpu/ccpr/GrCCConicShader.h Normal file
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@ -0,0 +1,44 @@
/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrCCConicShader_DEFINED
#define GrCCConicShader_DEFINED
#include "ccpr/GrCCCoverageProcessor.h"
/**
* This class renders the coverage of closed conic curves using the techniques outlined in
* "Resolution Independent Curve Rendering using Programmable Graphics Hardware" by Charles Loop and
* Jim Blinn:
*
* https://www.microsoft.com/en-us/research/wp-content/uploads/2005/01/p1000-loop.pdf
*
* The provided curves must be monotonic with respect to the vector of their closing edge [P2 - P0].
* (Use GrCCGeometry::conicTo().)
*/
class GrCCConicShader : public GrCCCoverageProcessor::Shader {
public:
void emitSetupCode(GrGLSLVertexGeoBuilder*, const char* pts, const char* wind,
const char** outHull4) const override;
void onEmitVaryings(GrGLSLVaryingHandler*, GrGLSLVarying::Scope, SkString* code,
const char* position, const char* coverage,
const char* cornerCoverage) override;
void onEmitFragmentCode(GrGLSLFPFragmentBuilder*, const char* outputCoverage) const override;
private:
void calcHullCoverage(SkString* code, const char* klm, const char* grad,
const char* outputCoverage) const;
const GrShaderVar fKLMMatrix{"klm_matrix", kFloat3x3_GrSLType};
const GrShaderVar fControlPoint{"control_point", kFloat2_GrSLType};
GrGLSLVarying fKLM_fWind;
GrGLSLVarying fGrad_fCorner;
};
#endif

4
src/gpu/ccpr/GrCCCoverageProcessor.cpp
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@ -10,6 +10,7 @@
#include "GrGpuCommandBuffer.h"
#include "GrOpFlushState.h"
#include "SkMakeUnique.h"
#include "ccpr/GrCCConicShader.h"
#include "ccpr/GrCCCubicShader.h"
#include "ccpr/GrCCQuadraticShader.h"
#include "glsl/GrGLSLVertexGeoBuilder.h"
@ -174,6 +175,9 @@ GrGLSLPrimitiveProcessor* GrCCCoverageProcessor::createGLSLInstance(const GrShad
case PrimitiveType::kCubics:
shader = skstd::make_unique<GrCCCubicShader>();
break;
case PrimitiveType::kConics:
shader = skstd::make_unique<GrCCConicShader>();
break;
}
return Impl::kGeometryShader == fImpl ? this->createGSImpl(std::move(shader))
: this->createVSImpl(std::move(shader));

19
src/gpu/ccpr/GrCCCoverageProcessor.h
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@ -40,6 +40,7 @@ public:
kWeightedTriangles, // Triangles (from the tessellator) whose winding magnitude > 1.
kQuadratics,
kCubics,
kConics
};
static const char* PrimitiveTypeName(PrimitiveType);
@ -53,14 +54,15 @@ public:
void set(const SkPoint&, const SkPoint&, const SkPoint&, const Sk2f& trans);
};
// Defines a single primitive shape with 4 input points, or 3 input points plus a W parameter
// duplicated in both 4th components (i.e. Cubics or Triangles with a custom winding number).
// X,Y point values are transposed.
// Defines a single primitive shape with 4 input points, or 3 input points plus a "weight"
// parameter duplicated in both lanes of the 4th input (i.e. Cubics, Conics, and Triangles with
// a weighted winding number). X,Y point values are transposed.
struct QuadPointInstance {
float fX[4];
float fY[4];
void set(const SkPoint[4], float dx, float dy);
void setW(const SkPoint[3], const Sk2f& trans, float w);
void setW(const SkPoint&, const SkPoint&, const SkPoint&, const Sk2f& trans, float w);
};
@ -205,6 +207,11 @@ private:
// Number of bezier points for curves, or 3 for triangles.
int numInputPoints() const { return PrimitiveType::kCubics == fPrimitiveType ? 4 : 3; }
int hasInputWeight() const {
return PrimitiveType::kWeightedTriangles == fPrimitiveType ||
PrimitiveType::kConics == fPrimitiveType;
}
enum class Impl : bool {
kGeometryShader,
kVertexShader
@ -259,6 +266,7 @@ inline const char* GrCCCoverageProcessor::PrimitiveTypeName(PrimitiveType type)
case PrimitiveType::kWeightedTriangles: return "kWeightedTriangles";
case PrimitiveType::kQuadratics: return "kQuadratics";
case PrimitiveType::kCubics: return "kCubics";
case PrimitiveType::kConics: return "kConics";
}
SK_ABORT("Invalid PrimitiveType");
return "";
@ -283,6 +291,11 @@ inline void GrCCCoverageProcessor::QuadPointInstance::set(const SkPoint p[4], fl
(Y + dy).store(&fY);
}
inline void GrCCCoverageProcessor::QuadPointInstance::setW(const SkPoint p[3], const Sk2f& trans,
float w) {
this->setW(p[0], p[1], p[2], trans, w);
}
inline void GrCCCoverageProcessor::QuadPointInstance::setW(const SkPoint& p0, const SkPoint& p1,
const SkPoint& p2, const Sk2f& trans,
float w) {

8
src/gpu/ccpr/GrCCCoverageProcessor_GSImpl.cpp
View File

@ -52,9 +52,10 @@ protected:
int numInputPoints = proc.numInputPoints();
SkASSERT(3 == numInputPoints || 4 == numInputPoints);
const char* posValues = (4 == numInputPoints) ? "sk_Position" : "sk_Position.xyz";
int inputWidth = (4 == numInputPoints || proc.hasInputWeight()) ? 4 : 3;
const char* posValues = (4 == inputWidth) ? "sk_Position" : "sk_Position.xyz";
g->codeAppendf("float%ix2 pts = transpose(float2x%i(sk_in[0].%s, sk_in[1].%s));",
numInputPoints, numInputPoints, posValues, posValues);
inputWidth, inputWidth, posValues, posValues);
GrShaderVar wind("wind", kHalf_GrSLType);
g->declareGlobal(wind);
@ -389,8 +390,7 @@ public:
void GrCCCoverageProcessor::initGS() {
SkASSERT(Impl::kGeometryShader == fImpl);
if (PrimitiveType::kCubics == fPrimitiveType ||
PrimitiveType::kWeightedTriangles == fPrimitiveType) {
if (4 == this->numInputPoints() || this->hasInputWeight()) {
this->addVertexAttrib("x_or_y_values", kFloat4_GrVertexAttribType);
SkASSERT(sizeof(QuadPointInstance) == this->getVertexStride() * 2);
SkASSERT(offsetof(QuadPointInstance, fY) == this->getVertexStride());

12
src/gpu/ccpr/GrCCCoverageProcessor_VSImpl.cpp
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@ -257,9 +257,10 @@ void GrCCCoverageProcessor::VSImpl::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs)
GrGLSLVertexBuilder* v = args.fVertBuilder;
int numInputPoints = proc.numInputPoints();
const char* swizzle = (4 == numInputPoints) ? "xyzw" : "xyz";
int inputWidth = (4 == numInputPoints || proc.hasInputWeight()) ? 4 : 3;
const char* swizzle = (4 == inputWidth) ? "xyzw" : "xyz";
v->codeAppendf("float%ix2 pts = transpose(float2x%i(%s.%s, %s.%s));",
numInputPoints, numInputPoints, proc.getAttrib(kAttribIdx_X).fName, swizzle,
inputWidth, inputWidth, proc.getAttrib(kAttribIdx_X).fName, swizzle,
proc.getAttrib(kAttribIdx_Y).fName, swizzle);
if (PrimitiveType::kWeightedTriangles != proc.fPrimitiveType) {
@ -476,7 +477,8 @@ void GrCCCoverageProcessor::initVS(GrResourceProvider* rp) {
}
case PrimitiveType::kQuadratics:
case PrimitiveType::kCubics: {
case PrimitiveType::kCubics:
case PrimitiveType::kConics: {
GR_DEFINE_STATIC_UNIQUE_KEY(gCurveVertexBufferKey);
fVSVertexBuffer = rp->findOrMakeStaticBuffer(kVertex_GrBufferType,
sizeof(kCurveVertices), kCurveVertices,
@ -499,8 +501,7 @@ void GrCCCoverageProcessor::initVS(GrResourceProvider* rp) {
}
}
if (PrimitiveType::kCubics == fPrimitiveType ||
PrimitiveType::kWeightedTriangles == fPrimitiveType) {
if (4 == this->numInputPoints() || this->hasInputWeight()) {
SkASSERT(kAttribIdx_X == this->numAttribs());
this->addInstanceAttrib("X", kFloat4_GrVertexAttribType);
@ -550,6 +551,7 @@ GrGLSLPrimitiveProcessor* GrCCCoverageProcessor::createVSImpl(std::unique_ptr<Sh
return new VSImpl(std::move(shadr), 3);
case PrimitiveType::kQuadratics:
case PrimitiveType::kCubics:
case PrimitiveType::kConics:
return new VSImpl(std::move(shadr), 4);
}
SK_ABORT("Invalid RenderPass");

161
src/gpu/ccpr/GrCCGeometry.cpp
View File

@ -27,7 +27,7 @@ void GrCCGeometry::beginContour(const SkPoint& pt) {
SkASSERT(!fBuildingContour);
// Store the current verb count in the fTriangles field for now. When we close the contour we
// will use this value to calculate the actual number of triangles in its fan.
fCurrContourTallies = {fVerbs.count(), 0, 0, 0};
fCurrContourTallies = {fVerbs.count(), 0, 0, 0, 0};
fPoints.push_back(pt);
fVerbs.push_back(Verb::kBeginContour);
@ -125,7 +125,8 @@ static inline bool is_convex_curve_monotonic(const Sk2f& startPt, const Sk2f& ta
return dot0 >= tolerance && dot1 >= tolerance;
}
static inline Sk2f lerp(const Sk2f& a, const Sk2f& b, const Sk2f& t) {
template<int N> static inline SkNx<N,float> lerp(const SkNx<N,float>& a, const SkNx<N,float>& b,
const SkNx<N,float>& t) {
return SkNx_fma(t, b - a, a);
}
@ -328,6 +329,54 @@ static inline bool is_cubic_nearly_quadratic(const Sk2f& p0, const Sk2f& p1, con
return ((c1 - c2).abs() <= 1).allTrue();
}
// Given a convex curve segment with the following order-2 tangent function:
//
// |C2x C2y|
// tan = some_scale * |dx/dt dy/dt| = |t^2 t 1| * |C1x C1y|
// |C0x C0y|
//
// This function finds the T value whose tangent angle is halfway between the tangents at T=0 and
// T=1 (tan0 and tan1).
static inline float find_midtangent(const Sk2f& tan0, const Sk2f& tan1,
float scale2, const Sk2f& C2,
float scale1, const Sk2f& C1,
float scale0, const Sk2f& C0) {
// Tangents point in the direction of increasing T, so tan0 and -tan1 both point toward the
// midtangent. 'n' will therefore bisect tan0 and -tan1, giving us the normal to the midtangent.
//
// n dot midtangent = 0
//
Sk2f n = normalize(tan0) - normalize(tan1);
// Find the T value at the midtangent. This is a simple quadratic equation:
//
// midtangent dot n = 0
//
// (|t^2 t 1| * C) dot n = 0
//
// |t^2 t 1| dot C*n = 0
//
// First find coeffs = C*n.
Sk4f C[2];
Sk2f::Store4(C, C2, C1, C0, 0);
Sk4f coeffs = C[0]*n[0] + C[1]*n[1];
if (1 != scale2 || 1 != scale1 || 1 != scale0) {
coeffs *= Sk4f(scale2, scale1, scale0, 0);
}
// Now solve the quadratic.
float a = coeffs[0], b = coeffs[1], c = coeffs[2];
float discr = b*b - 4*a*c;
if (discr < 0) {
return 0; // This will only happen if the curve is a line.
}
// The roots are q/a and c/q. Pick the one closer to T=.5.
float q = -.5f * (b + copysignf(std::sqrt(discr), b));
float r = .5f*q*a;
return std::abs(q*q - r) < std::abs(a*c - r) ? q/a : c/q;
}
void GrCCGeometry::cubicTo(const SkPoint P[4], float inflectPad, float loopIntersectPad) {
SkASSERT(fBuildingContour);
SkASSERT(P[0] == fPoints.back());
@ -486,7 +535,7 @@ void GrCCGeometry::cubicTo(const SkPoint P[4], float inflectPad, float loopInter
this->appendMonotonicCubics(p0, ab2, abc2, abcd2);
} else if (T2 > T1) {
// Section 3 (middle section).
Sk2f midp2 = lerp(abc2, abcd2, T1/T2);
Sk2f midp2 = lerp(abc2, abcd2, Sk2f(T1/T2));
this->appendMonotonicCubics(midp0, midp1, midp2, abcd2);
}
@ -499,25 +548,18 @@ template<GrCCGeometry::AppendCubicFn AppendLeftRight>
inline void GrCCGeometry::chopCubicAtMidTangent(const Sk2f& p0, const Sk2f& p1, const Sk2f& p2,
const Sk2f& p3, const Sk2f& tan0,
const Sk2f& tan1, int maxFutureSubdivisions) {
// Find the T value whose tangent is perpendicular to the vector that bisects tan0 and -tan1.
Sk2f n = normalize(tan0) - normalize(tan1);
float a = 3 * dot(p3 + (p1 - p2)*3 - p0, n);
float b = 6 * dot(p0 - p1*2 + p2, n);
float c = 3 * dot(p1 - p0, n);
float discr = b*b - 4*a*c;
if (discr < 0) {
// If this is the case then the cubic must be nearly flat.
(this->*AppendLeftRight)(p0, p1, p2, p3, maxFutureSubdivisions);
float midT = find_midtangent(tan0, tan1, 3, p3 + (p1 - p2)*3 - p0,
6, p0 - p1*2 + p2,
3, p1 - p0);
// Use positive logic since NaN fails comparisons. (However midT should not be NaN since we cull
// near-flat cubics in cubicTo().)
if (!(midT > 0 && midT < 1)) {
// The cubic is flat. Otherwise there would be a real midtangent inside T=0..1.
this->appendLine(p3);
return;
}
float q = -.5f * (b + copysignf(std::sqrt(discr), b));
float m = .5f*q*a;
float T = std::abs(q*q - m) < std::abs(a*c - m) ? q/a : c/q;
this->chopCubic<AppendLeftRight, AppendLeftRight>(p0, p1, p2, p3, T, maxFutureSubdivisions);
this->chopCubic<AppendLeftRight, AppendLeftRight>(p0, p1, p2, p3, midT, maxFutureSubdivisions);
}
template<GrCCGeometry::AppendCubicFn AppendLeft, GrCCGeometry::AppendCubicFn AppendRight>
@ -610,6 +652,87 @@ void GrCCGeometry::appendCubicApproximation(const Sk2f& p0, const Sk2f& p1, cons
}
}
void GrCCGeometry::conicTo(const SkPoint P[3], float w) {
SkASSERT(fBuildingContour);
SkASSERT(P[0] == fPoints.back());
Sk2f p0 = Sk2f::Load(P);
Sk2f p1 = Sk2f::Load(P+1);
Sk2f p2 = Sk2f::Load(P+2);
// Don't crunch on the curve if it is nearly flat (or just very small). Collinear control points
// can break the midtangent-finding math below.
if (are_collinear(p0, p1, p2)) {
this->appendLine(p2);
return;
}
Sk2f tan0 = p1 - p0;
Sk2f tan1 = p2 - p1;
// The derivative of a conic has a cumbersome order-4 denominator. However, this isn't necessary
// if we are only interested in a vector in the same *direction* as a given tangent line. Since
// the denominator scales dx and dy uniformly, we can throw it out completely after evaluating
// the derivative with the standard quotient rule. This leaves us with a simpler quadratic
// function that we use to find the midtangent.
float midT = find_midtangent(tan0, tan1, 1, (w - 1) * (p2 - p0),
1, (p2 - p0) - 2*w*(p1 - p0),
1, w*(p1 - p0));
// Use positive logic since NaN fails comparisons. (However midT should not be NaN since we cull
// near-linear conics above. And while w=0 is flat, it's not a line and has valid midtangents.)
if (!(midT > 0 && midT < 1)) {
// The conic is flat. Otherwise there would be a real midtangent inside T=0..1.
this->appendLine(p2);
return;
}
// Evaluate the conic at midT.
Sk4f p3d0 = Sk4f(p0[0], p0[1], 1, 0);
Sk4f p3d1 = Sk4f(p1[0], p1[1], 1, 0) * w;
Sk4f p3d2 = Sk4f(p2[0], p2[1], 1, 0);
Sk4f midT4 = midT;
Sk4f p3d01 = lerp(p3d0, p3d1, midT4);
Sk4f p3d12 = lerp(p3d1, p3d2, midT4);
Sk4f p3d012 = lerp(p3d01, p3d12, midT4);
Sk2f midpoint = Sk2f(p3d012[0], p3d012[1]) / p3d012[2];
if (are_collinear(p0, midpoint, p2, 1) || // Check if the curve is within one pixel of flat.
((midpoint - p1).abs() < 1).allTrue()) { // Check if the curve is almost a triangle.
// Draw the conic as a triangle instead. Our AA approximation won't do well if the curve
// gets wrapped too tightly, and if we get too close to p1 we will pick up artifacts from
// the implicit function's reflection.
this->appendLine(midpoint);
this->appendLine(p2);
return;
}
if (!is_convex_curve_monotonic(p0, tan0, p2, tan1)) {
// Chop the conic at midtangent to produce two monotonic segments.
Sk2f ww = Sk2f(p3d01[2], p3d12[2]) * Sk2f(p3d012[2]).rsqrt();
this->appendMonotonicConic(p0, Sk2f(p3d01[0], p3d01[1]) / p3d01[2], midpoint, ww[0]);
this->appendMonotonicConic(midpoint, Sk2f(p3d12[0], p3d12[1]) / p3d12[2], p2, ww[1]);
return;
}
this->appendMonotonicConic(p0, p1, p2, w);
}
void GrCCGeometry::appendMonotonicConic(const Sk2f& p0, const Sk2f& p1, const Sk2f& p2, float w) {
SkASSERT(fPoints.back() == SkPoint::Make(p0[0], p0[1]));
// Don't send curves to the GPU if we know they are nearly flat (or just very small).
if (are_collinear(p0, p1, p2)) {
this->appendLine(p2);
return;
}
p1.store(&fPoints.push_back());
p2.store(&fPoints.push_back());
fConicWeights.push_back(w);
fVerbs.push_back(Verb::kMonotonicConicTo);
++fCurrContourTallies.fConics;
}
GrCCGeometry::PrimitiveTallies GrCCGeometry::endContour() {
SkASSERT(fBuildingContour);
SkASSERT(fVerbs.count() >= fCurrContourTallies.fTriangles);

19
src/gpu/ccpr/GrCCGeometry.h
View File

@ -31,6 +31,7 @@ public:
kLineTo,
kMonotonicQuadraticTo, // Monotonic relative to the vector between its endpoints [P2 - P0].
kMonotonicCubicTo,
kMonotonicConicTo,
kEndClosedContour, // endPt == startPt.
kEndOpenContour // endPt != startPt.
};
@ -41,6 +42,7 @@ public:
int fWeightedTriangles; // Triangles (from the tessellator) whose winding magnitude > 1.
int fQuadratics;
int fCubics;
int fConics;
void operator+=(const PrimitiveTallies&);
PrimitiveTallies operator-(const PrimitiveTallies&) const;
@ -53,6 +55,7 @@ public:
const SkTArray<SkPoint, true>& points() const { SkASSERT(!fBuildingContour); return fPoints; }
const SkTArray<Verb, true>& verbs() const { SkASSERT(!fBuildingContour); return fVerbs; }
float getConicWeight(int idx) const { SkASSERT(!fBuildingContour); return fConicWeights[idx]; }
void reset() {
SkASSERT(!fBuildingContour);
@ -89,6 +92,8 @@ public:
// intersection vs. 1.489 on the tiger).
void cubicTo(const SkPoint[4], float inflectPad = 0.55f, float loopIntersectPad = 2);
void conicTo(const SkPoint[3], float w);
PrimitiveTallies endContour(); // Returns the numbers of primitives needed to draw the contour.
private:
@ -116,15 +121,17 @@ private:
void appendCubicApproximation(const Sk2f& p0, const Sk2f& p1, const Sk2f& p2, const Sk2f& p3,
int maxSubdivisions = kMaxSubdivionsPerCubicSection);
void appendMonotonicConic(const Sk2f& p0, const Sk2f& p1, const Sk2f& p2, float w);
// Transient state used while building a contour.
SkPoint fCurrAnchorPoint;
PrimitiveTallies fCurrContourTallies;
SkCubicType fCurrCubicType;
SkDEBUGCODE(bool fBuildingContour = false);
// TODO: These points could eventually be written directly to block-allocated GPU buffers.
SkSTArray<128, SkPoint, true> fPoints;
SkSTArray<128, Verb, true> fVerbs;
SkSTArray<128, SkPoint, true> fPoints;
SkSTArray<32, float, true> fConicWeights;
SkSTArray<128, Verb, true> fVerbs;
};
inline void GrCCGeometry::PrimitiveTallies::operator+=(const PrimitiveTallies& b) {
@ -132,6 +139,7 @@ inline void GrCCGeometry::PrimitiveTallies::operator+=(const PrimitiveTallies& b
fWeightedTriangles += b.fWeightedTriangles;
fQuadratics += b.fQuadratics;
fCubics += b.fCubics;
fConics += b.fConics;
}
GrCCGeometry::PrimitiveTallies
@ -139,12 +147,13 @@ inline GrCCGeometry::PrimitiveTallies::operator-(const PrimitiveTallies& b) cons
return {fTriangles - b.fTriangles,
fWeightedTriangles - b.fWeightedTriangles,
fQuadratics - b.fQuadratics,
fCubics - b.fCubics};
fCubics - b.fCubics,
fConics - b.fConics};
}
inline bool GrCCGeometry::PrimitiveTallies::operator==(const PrimitiveTallies& b) {
return fTriangles == b.fTriangles && fWeightedTriangles == b.fWeightedTriangles &&
fQuadratics == b.fQuadratics && fCubics == b.fCubics;
fQuadratics == b.fQuadratics && fCubics == b.fCubics && fConics == b.fConics;
}
#endif

35
src/gpu/ccpr/GrCCPathParser.cpp
View File

@ -114,7 +114,9 @@ void GrCCPathParser::parsePath(const SkPath& path, const SkPoint* deviceSpacePts
return;
}
const float* conicWeights = SkPathPriv::ConicWeightData(path);
int ptsIdx = 0;
int conicWeightsIdx = 0;
bool insideContour = false;
for (SkPath::Verb verb : SkPathPriv::Verbs(path)) {
@ -142,11 +144,16 @@ void GrCCPathParser::parsePath(const SkPath& path, const SkPoint* deviceSpacePts
ptsIdx += 3;
continue;
case SkPath::kConic_Verb:
SK_ABORT("Conics are not supported.");
fGeometry.conicTo(&deviceSpacePts[ptsIdx - 1], conicWeights[conicWeightsIdx]);
ptsIdx += 2;
++conicWeightsIdx;
continue;
default:
SK_ABORT("Unexpected path verb.");
}
}
SkASSERT(ptsIdx == path.countPoints());
SkASSERT(conicWeightsIdx == SkPathPriv::ConicWeightCnt(path));
this->endContourIfNeeded(insideContour);
}
@ -196,6 +203,7 @@ void GrCCPathParser::saveParsedPath(ScissorMode scissorMode, const SkIRect& clip
continue;
case GrCCGeometry::Verb::kMonotonicQuadraticTo:
case GrCCGeometry::Verb::kMonotonicConicTo:
fan.lineTo(pts[ptsIdx + 1]);
ptsIdx += 2;
continue;
@ -377,7 +385,9 @@ bool GrCCPathParser::finalize(GrOnFlushResourceProvider* onFlushRP) {
fBaseInstances[0].fCubics = fBaseInstances[1].fWeightedTriangles +
fTotalPrimitiveCounts[1].fWeightedTriangles;
fBaseInstances[1].fCubics = fBaseInstances[0].fCubics + fTotalPrimitiveCounts[0].fCubics;
int quadEndIdx = fBaseInstances[1].fCubics + fTotalPrimitiveCounts[1].fCubics;
fBaseInstances[0].fConics = fBaseInstances[1].fCubics + fTotalPrimitiveCounts[1].fCubics;
fBaseInstances[1].fConics = fBaseInstances[0].fConics + fTotalPrimitiveCounts[0].fConics;
int quadEndIdx = fBaseInstances[1].fConics + fTotalPrimitiveCounts[1].fConics;
fInstanceBuffer = onFlushRP->makeBuffer(kVertex_GrBufferType,
quadEndIdx * sizeof(QuadPointInstance));
@ -400,6 +410,7 @@ bool GrCCPathParser::finalize(GrOnFlushResourceProvider* onFlushRP) {
const SkTArray<SkPoint, true>& pts = fGeometry.points();
int ptsIdx = -1;
int nextConicWeightIdx = 0;
// Expand the ccpr verbs into GPU instance buffers.
for (GrCCGeometry::Verb verb : fGeometry.verbs()) {
@ -454,6 +465,17 @@ bool GrCCPathParser::finalize(GrOnFlushResourceProvider* onFlushRP) {
}
continue;
case GrCCGeometry::Verb::kMonotonicConicTo:
quadPointInstanceData[currIndices->fConics++].setW(
&pts[ptsIdx], atlasOffset, fGeometry.getConicWeight(nextConicWeightIdx));
ptsIdx += 2;
++nextConicWeightIdx;
if (!currFanIsTessellated) {
SkASSERT(!currFan.empty());
currFan.push_back(ptsIdx);
}
continue;
case GrCCGeometry::Verb::kEndClosedContour: // endPt == startPt.
if (!currFanIsTessellated) {
SkASSERT(!currFan.empty());
@ -489,7 +511,9 @@ bool GrCCPathParser::finalize(GrOnFlushResourceProvider* onFlushRP) {
SkASSERT(instanceIndices[0].fWeightedTriangles == fBaseInstances[1].fWeightedTriangles);
SkASSERT(instanceIndices[1].fWeightedTriangles == fBaseInstances[0].fCubics);
SkASSERT(instanceIndices[0].fCubics == fBaseInstances[1].fCubics);
SkASSERT(instanceIndices[1].fCubics == quadEndIdx);
SkASSERT(instanceIndices[1].fCubics == fBaseInstances[0].fConics);
SkASSERT(instanceIndices[0].fConics == fBaseInstances[1].fConics);
SkASSERT(instanceIndices[1].fConics == quadEndIdx);
fMeshesScratchBuffer.reserve(fMaxMeshesPerDraw);
fDynamicStatesScratchBuffer.reserve(fMaxMeshesPerDraw);
@ -527,6 +551,11 @@ void GrCCPathParser::drawCoverageCount(GrOpFlushState* flushState, CoverageCount
this->drawPrimitives(flushState, pipeline, batchID, PrimitiveType::kCubics,
&PrimitiveTallies::fCubics, drawBounds);
}
if (batchTotalCounts.fConics) {
this->drawPrimitives(flushState, pipeline, batchID, PrimitiveType::kConics,
&PrimitiveTallies::fConics, drawBounds);
}
}
void GrCCPathParser::drawPrimitives(GrOpFlushState* flushState, const GrPipeline& pipeline,

9
src/gpu/ccpr/GrCoverageCountingPathRenderer.cpp
View File

@ -65,10 +65,6 @@ GrPathRenderer::CanDrawPath GrCoverageCountingPathRenderer::onCanDrawPath(
SkPath path;
args.fShape->asPath(&path);
if (SkPathPriv::ConicWeightCnt(path)) {
return CanDrawPath::kNo;
}
SkRect devBounds;
SkIRect devIBounds;
args.fViewMatrix->mapRect(&devBounds, path.getBounds());
@ -193,11 +189,6 @@ bool GrCoverageCountingPathRenderer::canMakeClipProcessor(const SkPath& deviceSp
if (!fDrawCachablePaths && !deviceSpacePath.isVolatile()) {
return false;
}
if (SkPathPriv::ConicWeightCnt(deviceSpacePath)) {
return false;
}
return true;
}

16
tests/SkNxTest.cpp
View File

@ -467,7 +467,8 @@ DEF_TEST(Sk2f_Store4, r) {
Sk2f p1{1, 5};
Sk2f p2{2, 6};
Sk2f p3{3, 7};
float dst[8];
float dst[8] = {-1, -1, -1, -1, -1, -1, -1, -1};
Sk2f::Store4(dst, p0, p1, p2, p3);
REPORTER_ASSERT(r, dst[0] == 0);
REPORTER_ASSERT(r, dst[1] == 1);
@ -477,6 +478,19 @@ DEF_TEST(Sk2f_Store4, r) {
REPORTER_ASSERT(r, dst[5] == 5);
REPORTER_ASSERT(r, dst[6] == 6);
REPORTER_ASSERT(r, dst[7] == 7);
// Ensure transposing to Sk4f works.
Sk4f dst4f[2] = {{-1, -1, -1, -1}, {-1, -1, -1, -1}};
Sk2f::Store4(dst4f, p0, p1, p2, p3);
REPORTER_ASSERT(r, dst4f[0][0] == 0);
REPORTER_ASSERT(r, dst4f[0][1] == 1);
REPORTER_ASSERT(r, dst4f[0][2] == 2);
REPORTER_ASSERT(r, dst4f[0][3] == 3);
REPORTER_ASSERT(r, dst4f[1][0] == 4);
REPORTER_ASSERT(r, dst4f[1][1] == 5);
REPORTER_ASSERT(r, dst4f[1][2] == 6);
REPORTER_ASSERT(r, dst4f[1][3] == 7);
}
DEF_TEST(Sk4f_minmax, r) {