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/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrAAConvexPathRenderer.h"
#include "GrAAConvexTessellator.h"
#include "GrCaps.h"
#include "GrContext.h"
#include "GrDefaultGeoProcFactory.h"
#include "GrDrawOpTest.h"
#include "GrGeometryProcessor.h"
#include "GrOpFlushState.h"
#include "GrPathUtils.h"
#include "GrProcessor.h"
#include "GrSimpleMeshDrawOpHelper.h"
#include "SkGeometry.h"
#include "SkPathPriv.h"
#include "SkString.h"
#include "SkTraceEvent.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLGeometryProcessor.h"
#include "glsl/GrGLSLProgramDataManager.h"
#include "glsl/GrGLSLUniformHandler.h"
#include "glsl/GrGLSLVarying.h"
#include "glsl/GrGLSLVertexShaderBuilder.h"
#include "ops/GrMeshDrawOp.h"
GrAAConvexPathRenderer::GrAAConvexPathRenderer() {
}
struct Segment {
enum {
// These enum values are assumed in member functions below.
kLine = 0,
kQuad = 1,
} fType;
// line uses one pt, quad uses 2 pts
SkPoint fPts[2];
// normal to edge ending at each pt
SkVector fNorms[2];
// is the corner where the previous segment meets this segment
// sharp. If so, fMid is a normalized bisector facing outward.
SkVector fMid;
int countPoints() {
GR_STATIC_ASSERT(0 == kLine && 1 == kQuad);
return fType + 1;
}
const SkPoint& endPt() const {
GR_STATIC_ASSERT(0 == kLine && 1 == kQuad);
return fPts[fType];
}
const SkPoint& endNorm() const {
GR_STATIC_ASSERT(0 == kLine && 1 == kQuad);
return fNorms[fType];
}
};
typedef SkTArray<Segment, true> SegmentArray;
static void center_of_mass(const SegmentArray& segments, SkPoint* c) {
SkScalar area = 0;
SkPoint center = {0, 0};
int count = segments.count();
SkPoint p0 = {0, 0};
if (count > 2) {
// We translate the polygon so that the first point is at the origin.
// This avoids some precision issues with small area polygons far away
// from the origin.
p0 = segments[0].endPt();
SkPoint pi;
SkPoint pj;
// the first and last iteration of the below loop would compute
// zeros since the starting / ending point is (0,0). So instead we start
// at i=1 and make the last iteration i=count-2.
pj = segments[1].endPt() - p0;
for (int i = 1; i < count - 1; ++i) {
pi = pj;
pj = segments[i + 1].endPt() - p0;
SkScalar t = SkPoint::CrossProduct(pi, pj);
area += t;
center.fX += (pi.fX + pj.fX) * t;
center.fY += (pi.fY + pj.fY) * t;
}
}
// If the poly has no area then we instead return the average of
// its points.
if (SkScalarNearlyZero(area)) {
SkPoint avg;
avg.set(0, 0);
for (int i = 0; i < count; ++i) {
const SkPoint& pt = segments[i].endPt();
avg.fX += pt.fX;
avg.fY += pt.fY;
}
SkScalar denom = SK_Scalar1 / count;
avg.scale(denom);
*c = avg;
} else {
area *= 3;
area = SkScalarInvert(area);
center.scale(area);
// undo the translate of p0 to the origin.
*c = center + p0;
}
SkASSERT(!SkScalarIsNaN(c->fX) && !SkScalarIsNaN(c->fY));
}
static void compute_vectors(SegmentArray* segments,
SkPoint* fanPt,
SkPathPriv::FirstDirection dir,
int* vCount,
int* iCount) {
center_of_mass(*segments, fanPt);
int count = segments->count();
// Make the normals point towards the outside
SkPoint::Side normSide;
if (dir == SkPathPriv::kCCW_FirstDirection) {
normSide = SkPoint::kRight_Side;
} else {
normSide = SkPoint::kLeft_Side;
}
*vCount = 0;
*iCount = 0;
// compute normals at all points
for (int a = 0; a < count; ++a) {
Segment& sega = (*segments)[a];
int b = (a + 1) % count;
Segment& segb = (*segments)[b];
const SkPoint* prevPt = &sega.endPt();
int n = segb.countPoints();
for (int p = 0; p < n; ++p) {
segb.fNorms[p] = segb.fPts[p] - *prevPt;
segb.fNorms[p].normalize();
segb.fNorms[p].setOrthog(segb.fNorms[p], normSide);
prevPt = &segb.fPts[p];
}
if (Segment::kLine == segb.fType) {
*vCount += 5;
*iCount += 9;
} else {
*vCount += 6;
*iCount += 12;
}
}
// compute mid-vectors where segments meet. TODO: Detect shallow corners
// and leave out the wedges and close gaps by stitching segments together.
for (int a = 0; a < count; ++a) {
const Segment& sega = (*segments)[a];
int b = (a + 1) % count;
Segment& segb = (*segments)[b];
segb.fMid = segb.fNorms[0] + sega.endNorm();
segb.fMid.normalize();
// corner wedges
*vCount += 4;
*iCount += 6;
}
}
struct DegenerateTestData {
DegenerateTestData() { fStage = kInitial; }
bool isDegenerate() const { return kNonDegenerate != fStage; }
enum {
kInitial,
kPoint,
kLine,
kNonDegenerate
} fStage;
SkPoint fFirstPoint;
SkVector fLineNormal;
SkScalar fLineC;
};
static const SkScalar kClose = (SK_Scalar1 / 16);
static const SkScalar kCloseSqd = kClose * kClose;
static void update_degenerate_test(DegenerateTestData* data, const SkPoint& pt) {
switch (data->fStage) {
case DegenerateTestData::kInitial:
data->fFirstPoint = pt;
data->fStage = DegenerateTestData::kPoint;
break;
case DegenerateTestData::kPoint:
if (pt.distanceToSqd(data->fFirstPoint) > kCloseSqd) {
data->fLineNormal = pt - data->fFirstPoint;
data->fLineNormal.normalize();
data->fLineNormal.setOrthog(data->fLineNormal);
data->fLineC = -data->fLineNormal.dot(data->fFirstPoint);
data->fStage = DegenerateTestData::kLine;
}
break;
case DegenerateTestData::kLine:
if (SkScalarAbs(data->fLineNormal.dot(pt) + data->fLineC) > kClose) {
data->fStage = DegenerateTestData::kNonDegenerate;
}
case DegenerateTestData::kNonDegenerate:
break;
default:
SkFAIL("Unexpected degenerate test stage.");
}
}
static inline bool get_direction(const SkPath& path, const SkMatrix& m,
SkPathPriv::FirstDirection* dir) {
if (!SkPathPriv::CheapComputeFirstDirection(path, dir)) {
return false;
}
// check whether m reverses the orientation
SkASSERT(!m.hasPerspective());
SkScalar det2x2 = m.get(SkMatrix::kMScaleX) * m.get(SkMatrix::kMScaleY) -
m.get(SkMatrix::kMSkewX) * m.get(SkMatrix::kMSkewY);
if (det2x2 < 0) {
*dir = SkPathPriv::OppositeFirstDirection(*dir);
}
return true;
}
static inline void add_line_to_segment(const SkPoint& pt,
SegmentArray* segments) {
segments->push_back();
segments->back().fType = Segment::kLine;
segments->back().fPts[0] = pt;
}
static inline void add_quad_segment(const SkPoint pts[3],
SegmentArray* segments) {
if (pts[0].distanceToSqd(pts[1]) < kCloseSqd || pts[1].distanceToSqd(pts[2]) < kCloseSqd) {
if (pts[0] != pts[2]) {
add_line_to_segment(pts[2], segments);
}
} else {
segments->push_back();
segments->back().fType = Segment::kQuad;
segments->back().fPts[0] = pts[1];
segments->back().fPts[1] = pts[2];
}
}
static inline void add_cubic_segments(const SkPoint pts[4],
SkPathPriv::FirstDirection dir,
SegmentArray* segments) {
SkSTArray<15, SkPoint, true> quads;
GrPathUtils::convertCubicToQuadsConstrainToTangents(pts, SK_Scalar1, dir, &quads);
int count = quads.count();
for (int q = 0; q < count; q += 3) {
add_quad_segment(&quads[q], segments);
}
}
static bool get_segments(const SkPath& path,
const SkMatrix& m,
SegmentArray* segments,
SkPoint* fanPt,
int* vCount,
int* iCount) {
SkPath::Iter iter(path, true);
// This renderer over-emphasizes very thin path regions. We use the distance
// to the path from the sample to compute coverage. Every pixel intersected
// by the path will be hit and the maximum distance is sqrt(2)/2. We don't
// notice that the sample may be close to a very thin area of the path and
// thus should be very light. This is particularly egregious for degenerate
// line paths. We detect paths that are very close to a line (zero area) and
// draw nothing.
DegenerateTestData degenerateData;
SkPathPriv::FirstDirection dir;
// get_direction can fail for some degenerate paths.
if (!get_direction(path, m, &dir)) {
return false;
}
for (;;) {
SkPoint pts[4];
SkPath::Verb verb = iter.next(pts, true, true);
switch (verb) {
case SkPath::kMove_Verb:
m.mapPoints(pts, 1);
update_degenerate_test(&degenerateData, pts[0]);
break;
case SkPath::kLine_Verb: {
m.mapPoints(&pts[1], 1);
update_degenerate_test(&degenerateData, pts[1]);
add_line_to_segment(pts[1], segments);
break;
}
case SkPath::kQuad_Verb:
m.mapPoints(pts, 3);
update_degenerate_test(&degenerateData, pts[1]);
update_degenerate_test(&degenerateData, pts[2]);
add_quad_segment(pts, segments);
break;
case SkPath::kConic_Verb: {
m.mapPoints(pts, 3);
SkScalar weight = iter.conicWeight();
SkAutoConicToQuads converter;
const SkPoint* quadPts = converter.computeQuads(pts, weight, 0.5f);
for (int i = 0; i < converter.countQuads(); ++i) {
update_degenerate_test(&degenerateData, quadPts[2*i + 1]);
update_degenerate_test(&degenerateData, quadPts[2*i + 2]);
add_quad_segment(quadPts + 2*i, segments);
}
break;
}
case SkPath::kCubic_Verb: {
m.mapPoints(pts, 4);
update_degenerate_test(&degenerateData, pts[1]);
update_degenerate_test(&degenerateData, pts[2]);
update_degenerate_test(&degenerateData, pts[3]);
add_cubic_segments(pts, dir, segments);
break;
};
case SkPath::kDone_Verb:
if (degenerateData.isDegenerate()) {
return false;
} else {
compute_vectors(segments, fanPt, dir, vCount, iCount);
return true;
}
default:
break;
}
}
}
struct QuadVertex {
SkPoint fPos;
GrColor fColor;
SkPoint fUV;
SkScalar fD0;
SkScalar fD1;
};
struct Draw {
Draw() : fVertexCnt(0), fIndexCnt(0) {}
int fVertexCnt;
int fIndexCnt;
};
typedef SkTArray<Draw, true> DrawArray;
static void create_vertices(const SegmentArray& segments,
const SkPoint& fanPt,
GrColor color,
DrawArray* draws,
QuadVertex* verts,
uint16_t* idxs) {
Draw* draw = &draws->push_back();
// alias just to make vert/index assignments easier to read.
int* v = &draw->fVertexCnt;
int* i = &draw->fIndexCnt;
int count = segments.count();
for (int a = 0; a < count; ++a) {
const Segment& sega = segments[a];
int b = (a + 1) % count;
const Segment& segb = segments[b];
// Check whether adding the verts for this segment to the current draw would cause index
// values to overflow.
int vCount = 4;
if (Segment::kLine == segb.fType) {
vCount += 5;
} else {
vCount += 6;
}
if (draw->fVertexCnt + vCount > (1 << 16)) {
verts += *v;
idxs += *i;
draw = &draws->push_back();
v = &draw->fVertexCnt;
i = &draw->fIndexCnt;
}
// FIXME: These tris are inset in the 1 unit arc around the corner
verts[*v + 0].fPos = sega.endPt();
verts[*v + 1].fPos = verts[*v + 0].fPos + sega.endNorm();
verts[*v + 2].fPos = verts[*v + 0].fPos + segb.fMid;
verts[*v + 3].fPos = verts[*v + 0].fPos + segb.fNorms[0];
verts[*v + 0].fColor = color;
verts[*v + 1].fColor = color;
verts[*v + 2].fColor = color;
verts[*v + 3].fColor = color;
verts[*v + 0].fUV.set(0,0);
verts[*v + 1].fUV.set(0,-SK_Scalar1);
verts[*v + 2].fUV.set(0,-SK_Scalar1);
verts[*v + 3].fUV.set(0,-SK_Scalar1);
verts[*v + 0].fD0 = verts[*v + 0].fD1 = -SK_Scalar1;
verts[*v + 1].fD0 = verts[*v + 1].fD1 = -SK_Scalar1;
verts[*v + 2].fD0 = verts[*v + 2].fD1 = -SK_Scalar1;
verts[*v + 3].fD0 = verts[*v + 3].fD1 = -SK_Scalar1;
idxs[*i + 0] = *v + 0;
idxs[*i + 1] = *v + 2;
idxs[*i + 2] = *v + 1;
idxs[*i + 3] = *v + 0;
idxs[*i + 4] = *v + 3;
idxs[*i + 5] = *v + 2;
*v += 4;
*i += 6;
if (Segment::kLine == segb.fType) {
verts[*v + 0].fPos = fanPt;
verts[*v + 1].fPos = sega.endPt();
verts[*v + 2].fPos = segb.fPts[0];
verts[*v + 3].fPos = verts[*v + 1].fPos + segb.fNorms[0];
verts[*v + 4].fPos = verts[*v + 2].fPos + segb.fNorms[0];
verts[*v + 0].fColor = color;
verts[*v + 1].fColor = color;
verts[*v + 2].fColor = color;
verts[*v + 3].fColor = color;
verts[*v + 4].fColor = color;
// we draw the line edge as a degenerate quad (u is 0, v is the
// signed distance to the edge)
SkScalar dist = fanPt.distanceToLineBetween(verts[*v + 1].fPos,
verts[*v + 2].fPos);
verts[*v + 0].fUV.set(0, dist);
verts[*v + 1].fUV.set(0, 0);
verts[*v + 2].fUV.set(0, 0);
verts[*v + 3].fUV.set(0, -SK_Scalar1);
verts[*v + 4].fUV.set(0, -SK_Scalar1);
verts[*v + 0].fD0 = verts[*v + 0].fD1 = -SK_Scalar1;
verts[*v + 1].fD0 = verts[*v + 1].fD1 = -SK_Scalar1;
verts[*v + 2].fD0 = verts[*v + 2].fD1 = -SK_Scalar1;
verts[*v + 3].fD0 = verts[*v + 3].fD1 = -SK_Scalar1;
verts[*v + 4].fD0 = verts[*v + 4].fD1 = -SK_Scalar1;
idxs[*i + 0] = *v + 3;
idxs[*i + 1] = *v + 1;
idxs[*i + 2] = *v + 2;
idxs[*i + 3] = *v + 4;
idxs[*i + 4] = *v + 3;
idxs[*i + 5] = *v + 2;
*i += 6;
// Draw the interior fan if it exists.
// TODO: Detect and combine colinear segments. This will ensure we catch every case
// with no interior, and that the resulting shared edge uses the same endpoints.
if (count >= 3) {
idxs[*i + 0] = *v + 0;
idxs[*i + 1] = *v + 2;
idxs[*i + 2] = *v + 1;
*i += 3;
}
*v += 5;
} else {
SkPoint qpts[] = {sega.endPt(), segb.fPts[0], segb.fPts[1]};
SkVector midVec = segb.fNorms[0] + segb.fNorms[1];
midVec.normalize();
verts[*v + 0].fPos = fanPt;
verts[*v + 1].fPos = qpts[0];
verts[*v + 2].fPos = qpts[2];
verts[*v + 3].fPos = qpts[0] + segb.fNorms[0];
verts[*v + 4].fPos = qpts[2] + segb.fNorms[1];
verts[*v + 5].fPos = qpts[1] + midVec;
verts[*v + 0].fColor = color;
verts[*v + 1].fColor = color;
verts[*v + 2].fColor = color;
verts[*v + 3].fColor = color;
verts[*v + 4].fColor = color;
verts[*v + 5].fColor = color;
SkScalar c = segb.fNorms[0].dot(qpts[0]);
verts[*v + 0].fD0 = -segb.fNorms[0].dot(fanPt) + c;
verts[*v + 1].fD0 = 0.f;
verts[*v + 2].fD0 = -segb.fNorms[0].dot(qpts[2]) + c;
verts[*v + 3].fD0 = -SK_ScalarMax/100;
verts[*v + 4].fD0 = -SK_ScalarMax/100;
verts[*v + 5].fD0 = -SK_ScalarMax/100;
c = segb.fNorms[1].dot(qpts[2]);
verts[*v + 0].fD1 = -segb.fNorms[1].dot(fanPt) + c;
verts[*v + 1].fD1 = -segb.fNorms[1].dot(qpts[0]) + c;
verts[*v + 2].fD1 = 0.f;
verts[*v + 3].fD1 = -SK_ScalarMax/100;
verts[*v + 4].fD1 = -SK_ScalarMax/100;
verts[*v + 5].fD1 = -SK_ScalarMax/100;
GrPathUtils::QuadUVMatrix toUV(qpts);
toUV.apply<6, sizeof(QuadVertex), offsetof(QuadVertex, fUV)>(verts + *v);
idxs[*i + 0] = *v + 3;
idxs[*i + 1] = *v + 1;
idxs[*i + 2] = *v + 2;
idxs[*i + 3] = *v + 4;
idxs[*i + 4] = *v + 3;
idxs[*i + 5] = *v + 2;
idxs[*i + 6] = *v + 5;
idxs[*i + 7] = *v + 3;
idxs[*i + 8] = *v + 4;
*i += 9;
// Draw the interior fan if it exists.
// TODO: Detect and combine colinear segments. This will ensure we catch every case
// with no interior, and that the resulting shared edge uses the same endpoints.
if (count >= 3) {
idxs[*i + 0] = *v + 0;
idxs[*i + 1] = *v + 2;
idxs[*i + 2] = *v + 1;
*i += 3;
}
*v += 6;
}
}
}
///////////////////////////////////////////////////////////////////////////////
/*
* Quadratic specified by 0=u^2-v canonical coords. u and v are the first
* two components of the vertex attribute. Coverage is based on signed
* distance with negative being inside, positive outside. The edge is specified in
* window space (y-down). If either the third or fourth component of the interpolated
* vertex coord is > 0 then the pixel is considered outside the edge. This is used to
* attempt to trim to a portion of the infinite quad.
* Requires shader derivative instruction support.
*/
class QuadEdgeEffect : public GrGeometryProcessor {
public:
static sk_sp<GrGeometryProcessor> Make(const SkMatrix& localMatrix, bool usesLocalCoords) {
return sk_sp<GrGeometryProcessor>(new QuadEdgeEffect(localMatrix, usesLocalCoords));
}
~QuadEdgeEffect() override {}
const char* name() const override { return "QuadEdge"; }
class GLSLProcessor : public GrGLSLGeometryProcessor {
public:
GLSLProcessor() {}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const QuadEdgeEffect& qe = args.fGP.cast<QuadEdgeEffect>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(qe);
GrGLSLVertToFrag v(kVec4f_GrSLType);
varyingHandler->addVarying("QuadEdge", &v);
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), qe.fInQuadEdge->fName);
// Setup pass through color
varyingHandler->addPassThroughAttribute(qe.fInColor, args.fOutputColor);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup position
this->setupPosition(vertBuilder, gpArgs, qe.fInPosition->fName);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
qe.fInPosition->fName,
qe.fLocalMatrix,
args.fFPCoordTransformHandler);
fragBuilder->codeAppendf("float edgeAlpha;");
// keep the derivative instructions outside the conditional
fragBuilder->codeAppendf("vec2 duvdx = dFdx(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 duvdy = dFdy(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("if (%s.z > 0.0 && %s.w > 0.0) {", v.fsIn(), v.fsIn());
// today we know z and w are in device space. We could use derivatives
fragBuilder->codeAppendf("edgeAlpha = min(min(%s.z, %s.w) + 0.5, 1.0);", v.fsIn(),
v.fsIn());
fragBuilder->codeAppendf ("} else {");
fragBuilder->codeAppendf("vec2 gF = vec2(2.0*%s.x*duvdx.x - duvdx.y,"
" 2.0*%s.x*duvdy.x - duvdy.y);",
v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("edgeAlpha = (%s.x*%s.x - %s.y);", v.fsIn(), v.fsIn(),
v.fsIn());
fragBuilder->codeAppendf("edgeAlpha = "
"clamp(0.5 - edgeAlpha / length(gF), 0.0, 1.0);}");
fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
}
static inline void GenKey(const GrGeometryProcessor& gp,
const GrShaderCaps&,
GrProcessorKeyBuilder* b) {
const QuadEdgeEffect& qee = gp.cast<QuadEdgeEffect>();
b->add32(SkToBool(qee.fUsesLocalCoords && qee.fLocalMatrix.hasPerspective()));
}
void setData(const GrGLSLProgramDataManager& pdman,
const GrPrimitiveProcessor& gp,
FPCoordTransformIter&& transformIter) override {
const QuadEdgeEffect& qe = gp.cast<QuadEdgeEffect>();
this->setTransformDataHelper(qe.fLocalMatrix, pdman, &transformIter);
}
private:
typedef GrGLSLGeometryProcessor INHERITED;
};
void getGLSLProcessorKey(const GrShaderCaps& caps, GrProcessorKeyBuilder* b) const override {
GLSLProcessor::GenKey(*this, caps, b);
}
GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const override {
return new GLSLProcessor();
}
private:
QuadEdgeEffect(const SkMatrix& localMatrix, bool usesLocalCoords)
: fLocalMatrix(localMatrix), fUsesLocalCoords(usesLocalCoords) {
this->initClassID<QuadEdgeEffect>();
fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType);
fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
fInQuadEdge = &this->addVertexAttrib("inQuadEdge", kVec4f_GrVertexAttribType);
}
const Attribute* fInPosition;
const Attribute* fInQuadEdge;
const Attribute* fInColor;
SkMatrix fLocalMatrix;
bool fUsesLocalCoords;
GR_DECLARE_GEOMETRY_PROCESSOR_TEST
typedef GrGeometryProcessor INHERITED;
};
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(QuadEdgeEffect);
#if GR_TEST_UTILS
sk_sp<GrGeometryProcessor> QuadEdgeEffect::TestCreate(GrProcessorTestData* d) {
// Doesn't work without derivative instructions.
return d->caps()->shaderCaps()->shaderDerivativeSupport()
? QuadEdgeEffect::Make(GrTest::TestMatrix(d->fRandom), d->fRandom->nextBool())
: nullptr;
}
#endif
///////////////////////////////////////////////////////////////////////////////
bool GrAAConvexPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
return (args.fCaps->shaderCaps()->shaderDerivativeSupport() &&
(GrAAType::kCoverage == args.fAAType) && args.fShape->style().isSimpleFill() &&
!args.fShape->inverseFilled() && args.fShape->knownToBeConvex());
}
// extract the result vertices and indices from the GrAAConvexTessellator
static void extract_lines_only_verts(const GrAAConvexTessellator& tess,
void* vertices,
size_t vertexStride,
GrColor color,
uint16_t* idxs,
bool tweakAlphaForCoverage) {
intptr_t verts = reinterpret_cast<intptr_t>(vertices);
for (int i = 0; i < tess.numPts(); ++i) {
*((SkPoint*)((intptr_t)verts + i * vertexStride)) = tess.point(i);
}
// Make 'verts' point to the colors
verts += sizeof(SkPoint);
for (int i = 0; i < tess.numPts(); ++i) {
if (tweakAlphaForCoverage) {
SkASSERT(SkScalarRoundToInt(255.0f * tess.coverage(i)) <= 255);
unsigned scale = SkScalarRoundToInt(255.0f * tess.coverage(i));
GrColor scaledColor = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
} else {
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = color;
*reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) =
tess.coverage(i);
}
}
for (int i = 0; i < tess.numIndices(); ++i) {
idxs[i] = tess.index(i);
}
}
static sk_sp<GrGeometryProcessor> make_lines_only_gp(bool tweakAlphaForCoverage,
const SkMatrix& viewMatrix,
bool usesLocalCoords) {
using namespace GrDefaultGeoProcFactory;
Coverage::Type coverageType;
if (tweakAlphaForCoverage) {
coverageType = Coverage::kSolid_Type;
} else {
coverageType = Coverage::kAttribute_Type;
}
LocalCoords::Type localCoordsType =
usesLocalCoords ? LocalCoords::kUsePosition_Type : LocalCoords::kUnused_Type;
return MakeForDeviceSpace(Color::kPremulGrColorAttribute_Type, coverageType, localCoordsType,
viewMatrix);
}
namespace {
class AAConvexPathOp final : public GrMeshDrawOp {
private:
using Helper = GrSimpleMeshDrawOpHelperWithStencil;
public:
DEFINE_OP_CLASS_ID
static std::unique_ptr<GrDrawOp> Make(GrPaint&& paint, const SkMatrix& viewMatrix,
const SkPath& path,
const GrUserStencilSettings* stencilSettings) {
return Helper::FactoryHelper<AAConvexPathOp>(std::move(paint), viewMatrix, path,
stencilSettings);
}
AAConvexPathOp(const Helper::MakeArgs& helperArgs, GrColor color, const SkMatrix& viewMatrix,
const SkPath& path, const GrUserStencilSettings* stencilSettings)
: INHERITED(ClassID()), fHelper(helperArgs, GrAAType::kCoverage, stencilSettings) {
fPaths.emplace_back(PathData{viewMatrix, path, color});
this->setTransformedBounds(path.getBounds(), viewMatrix, HasAABloat::kYes, IsZeroArea::kNo);
fLinesOnly = SkPath::kLine_SegmentMask == path.getSegmentMasks();
}
const char* name() const override { return "AAConvexPathOp"; }
SkString dumpInfo() const override {
SkString string;
string.appendf("Count: %d\n", fPaths.count());
string += fHelper.dumpInfo();
string += INHERITED::dumpInfo();
return string;
}
FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
RequiresDstTexture finalize(const GrCaps& caps, const GrAppliedClip* clip) override {
return fHelper.xpRequiresDstTexture(caps, clip, GrProcessorAnalysisCoverage::kSingleChannel,
&fPaths.back().fColor);
}
private:
void prepareLinesOnlyDraws(Target* target) const {
// Setup GrGeometryProcessor
sk_sp<GrGeometryProcessor> gp(make_lines_only_gp(fHelper.compatibleWithAlphaAsCoverage(),
fPaths.back().fViewMatrix,
fHelper.usesLocalCoords()));
if (!gp) {
SkDebugf("Could not create GrGeometryProcessor\n");
return;
}
size_t vertexStride = gp->getVertexStride();
SkASSERT(fHelper.compatibleWithAlphaAsCoverage()
? vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorAttr)
: vertexStride ==
sizeof(GrDefaultGeoProcFactory::PositionColorCoverageAttr));
GrAAConvexTessellator tess;
int instanceCount = fPaths.count();
const GrPipeline* pipeline = fHelper.makePipeline(target);
for (int i = 0; i < instanceCount; i++) {
tess.rewind();
const PathData& args = fPaths[i];
if (!tess.tessellate(args.fViewMatrix, args.fPath)) {
continue;
}
const GrBuffer* vertexBuffer;
int firstVertex;
void* verts = target->makeVertexSpace(vertexStride, tess.numPts(), &vertexBuffer,
&firstVertex);
if (!verts) {
SkDebugf("Could not allocate vertices\n");
return;
}
const GrBuffer* indexBuffer;
int firstIndex;
uint16_t* idxs = target->makeIndexSpace(tess.numIndices(), &indexBuffer, &firstIndex);
if (!idxs) {
SkDebugf("Could not allocate indices\n");
return;
}
extract_lines_only_verts(tess, verts, vertexStride, args.fColor, idxs,
fHelper.compatibleWithAlphaAsCoverage());
GrMesh mesh(GrPrimitiveType::kTriangles);
mesh.setIndexed(indexBuffer, tess.numIndices(), firstIndex, 0, tess.numPts() - 1);
mesh.setVertexData(vertexBuffer, firstVertex);
target->draw(gp.get(), pipeline, mesh);
}
}
void onPrepareDraws(Target* target) const override {
#ifndef SK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS
if (fLinesOnly) {
this->prepareLinesOnlyDraws(target);
return;
}
#endif
const GrPipeline* pipeline = fHelper.makePipeline(target);
int instanceCount = fPaths.count();
SkMatrix invert;
if (fHelper.usesLocalCoords() && !fPaths.back().fViewMatrix.invert(&invert)) {
SkDebugf("Could not invert viewmatrix\n");
return;
}
// Setup GrGeometryProcessor
sk_sp<GrGeometryProcessor> quadProcessor(
QuadEdgeEffect::Make(invert, fHelper.usesLocalCoords()));
// TODO generate all segments for all paths and use one vertex buffer
for (int i = 0; i < instanceCount; i++) {
const PathData& args = fPaths[i];
// We use the fact that SkPath::transform path does subdivision based on
// perspective. Otherwise, we apply the view matrix when copying to the
// segment representation.
const SkMatrix* viewMatrix = &args.fViewMatrix;
// We avoid initializing the path unless we have to
const SkPath* pathPtr = &args.fPath;
SkTLazy<SkPath> tmpPath;
if (viewMatrix->hasPerspective()) {
SkPath* tmpPathPtr = tmpPath.init(*pathPtr);
tmpPathPtr->setIsVolatile(true);
tmpPathPtr->transform(*viewMatrix);
viewMatrix = &SkMatrix::I();
pathPtr = tmpPathPtr;
}
int vertexCount;
int indexCount;
enum {
kPreallocSegmentCnt = 512 / sizeof(Segment),
kPreallocDrawCnt = 4,
};
SkSTArray<kPreallocSegmentCnt, Segment, true> segments;
SkPoint fanPt;
if (!get_segments(*pathPtr, *viewMatrix, &segments, &fanPt, &vertexCount,
&indexCount)) {
continue;
}
const GrBuffer* vertexBuffer;
int firstVertex;
size_t vertexStride = quadProcessor->getVertexStride();
QuadVertex* verts = reinterpret_cast<QuadVertex*>(target->makeVertexSpace(
vertexStride, vertexCount, &vertexBuffer, &firstVertex));
if (!verts) {
SkDebugf("Could not allocate vertices\n");
return;
}
const GrBuffer* indexBuffer;
int firstIndex;
uint16_t *idxs = target->makeIndexSpace(indexCount, &indexBuffer, &firstIndex);
if (!idxs) {
SkDebugf("Could not allocate indices\n");
return;
}
SkSTArray<kPreallocDrawCnt, Draw, true> draws;
create_vertices(segments, fanPt, args.fColor, &draws, verts, idxs);
GrMesh mesh(GrPrimitiveType::kTriangles);
for (int j = 0; j < draws.count(); ++j) {
const Draw& draw = draws[j];
mesh.setIndexed(indexBuffer, draw.fIndexCnt, firstIndex, 0, draw.fVertexCnt - 1);
mesh.setVertexData(vertexBuffer, firstVertex);
target->draw(quadProcessor.get(), pipeline, mesh);
firstIndex += draw.fIndexCnt;
firstVertex += draw.fVertexCnt;
}
}
}
bool onCombineIfPossible(GrOp* t, const GrCaps& caps) override {
AAConvexPathOp* that = t->cast<AAConvexPathOp>();
if (!fHelper.isCompatible(that->fHelper, caps, this->bounds(), that->bounds())) {
return false;
}
if (fHelper.usesLocalCoords() &&
!fPaths[0].fViewMatrix.cheapEqualTo(that->fPaths[0].fViewMatrix)) {
return false;
}
if (fLinesOnly != that->fLinesOnly) {
return false;
}
fPaths.push_back_n(that->fPaths.count(), that->fPaths.begin());
this->joinBounds(*that);
return true;
}
struct PathData {
SkMatrix fViewMatrix;
SkPath fPath;
GrColor fColor;
};
Helper fHelper;
SkSTArray<1, PathData, true> fPaths;
bool fLinesOnly;
typedef GrMeshDrawOp INHERITED;
};
} // anonymous namespace
bool GrAAConvexPathRenderer::onDrawPath(const DrawPathArgs& args) {
GR_AUDIT_TRAIL_AUTO_FRAME(args.fRenderTargetContext->auditTrail(),
"GrAAConvexPathRenderer::onDrawPath");
SkASSERT(GrFSAAType::kUnifiedMSAA != args.fRenderTargetContext->fsaaType());
SkASSERT(!args.fShape->isEmpty());
SkPath path;
args.fShape->asPath(&path);
std::unique_ptr<GrDrawOp> op = AAConvexPathOp::Make(std::move(args.fPaint), *args.fViewMatrix,
path, args.fUserStencilSettings);
args.fRenderTargetContext->addDrawOp(*args.fClip, std::move(op));
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
#if GR_TEST_UTILS
GR_DRAW_OP_TEST_DEFINE(AAConvexPathOp) {
SkMatrix viewMatrix = GrTest::TestMatrixInvertible(random);
SkPath path = GrTest::TestPathConvex(random);
const GrUserStencilSettings* stencilSettings = GrGetRandomStencil(random, context);
return AAConvexPathOp::Make(std::move(paint), viewMatrix, path, stencilSettings);
}
#endif