/*
* 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 "GrBatchFlushState.h"
#include "GrBatchTest.h"
#include "GrCaps.h"
#include "GrContext.h"
#include "GrDefaultGeoProcFactory.h"
#include "GrGeometryProcessor.h"
#include "GrInvariantOutput.h"
#include "GrPathUtils.h"
#include "GrProcessor.h"
#include "GrPipelineBuilder.h"
#include "GrStrokeInfo.h"
#include "SkGeometry.h"
#include "SkPathPriv.h"
#include "SkString.h"
#include "SkTraceEvent.h"
#include "batches/GrVertexBatch.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"
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 = SkScalarMul(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 = SkScalarMul(m.get(SkMatrix::kMScaleX), m.get(SkMatrix::kMScaleY)) -
SkScalarMul(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);
switch (verb) {
case SkPath::kMove_Verb:
m.mapPoints(pts, 1);
update_degenerate_test(°enerateData, pts[0]);
break;
case SkPath::kLine_Verb: {
m.mapPoints(&pts[1], 1);
update_degenerate_test(°enerateData, pts[1]);
add_line_to_segment(pts[1], segments);
break;
}
case SkPath::kQuad_Verb:
m.mapPoints(pts, 3);
update_degenerate_test(°enerateData, pts[1]);
update_degenerate_test(°enerateData, 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(°enerateData, quadPts[2*i + 1]);
update_degenerate_test(°enerateData, quadPts[2*i + 2]);
add_quad_segment(quadPts + 2*i, segments);
}
break;
}
case SkPath::kCubic_Verb: {
m.mapPoints(pts, 4);
update_degenerate_test(°enerateData, pts[1]);
update_degenerate_test(°enerateData, pts[2]);
update_degenerate_test(°enerateData, 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;
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,
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].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];
// 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;
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), sizeof(SkPoint)>(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 GrGeometryProcessor* Create(GrColor color, const SkMatrix& localMatrix,
bool usesLocalCoords) {
return new QuadEdgeEffect(color, localMatrix, usesLocalCoords);
}
virtual ~QuadEdgeEffect() {}
const char* name() const override { return "QuadEdge"; }
const Attribute* inPosition() const { return fInPosition; }
const Attribute* inQuadEdge() const { return fInQuadEdge; }
GrColor color() const { return fColor; }
bool colorIgnored() const { return GrColor_ILLEGAL == fColor; }
const SkMatrix& localMatrix() const { return fLocalMatrix; }
bool usesLocalCoords() const { return fUsesLocalCoords; }
class GLSLProcessor : public GrGLSLGeometryProcessor {
public:
GLSLProcessor()
: fColor(GrColor_ILLEGAL) {}
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.inQuadEdge()->fName);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
if (!qe.colorIgnored()) {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
// Setup position
this->setupPosition(vertBuilder, gpArgs, qe.inPosition()->fName);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
qe.inPosition()->fName,
qe.localMatrix(),
args.fTransformsIn,
args.fTransformsOut);
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
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 GrGLSLCaps&,
GrProcessorKeyBuilder* b) {
const QuadEdgeEffect& qee = gp.cast<QuadEdgeEffect>();
uint32_t key = 0;
key |= qee.usesLocalCoords() && qee.localMatrix().hasPerspective() ? 0x1 : 0x0;
key |= qee.colorIgnored() ? 0x2 : 0x0;
b->add32(key);
}
void setData(const GrGLSLProgramDataManager& pdman,
const GrPrimitiveProcessor& gp) override {
const QuadEdgeEffect& qe = gp.cast<QuadEdgeEffect>();
if (qe.color() != fColor) {
float c[4];
GrColorToRGBAFloat(qe.color(), c);
pdman.set4fv(fColorUniform, 1, c);
fColor = qe.color();
}
}
void setTransformData(const GrPrimitiveProcessor& primProc,
const GrGLSLProgramDataManager& pdman,
int index,
const SkTArray<const GrCoordTransform*, true>& transforms) override {
this->setTransformDataHelper<QuadEdgeEffect>(primProc, pdman, index, transforms);
}
private:
GrColor fColor;
UniformHandle fColorUniform;
typedef GrGLSLGeometryProcessor INHERITED;
};
void getGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
GLSLProcessor::GenKey(*this, caps, b);
}
GrGLSLPrimitiveProcessor* createGLSLInstance(const GrGLSLCaps&) const override {
return new GLSLProcessor();
}
private:
QuadEdgeEffect(GrColor color, const SkMatrix& localMatrix, bool usesLocalCoords)
: fColor(color)
, fLocalMatrix(localMatrix)
, fUsesLocalCoords(usesLocalCoords) {
this->initClassID<QuadEdgeEffect>();
fInPosition = &this->addVertexAttrib(Attribute("inPosition", kVec2f_GrVertexAttribType));
fInQuadEdge = &this->addVertexAttrib(Attribute("inQuadEdge", kVec4f_GrVertexAttribType));
}
const Attribute* fInPosition;
const Attribute* fInQuadEdge;
GrColor fColor;
SkMatrix fLocalMatrix;
bool fUsesLocalCoords;
GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
typedef GrGeometryProcessor INHERITED;
};
GR_DEFINE_GEOMETRY_PROCESSOR_TEST(QuadEdgeEffect);
const GrGeometryProcessor* QuadEdgeEffect::TestCreate(GrProcessorTestData* d) {
// Doesn't work without derivative instructions.
return d->fCaps->shaderCaps()->shaderDerivativeSupport() ?
QuadEdgeEffect::Create(GrRandomColor(d->fRandom),
GrTest::TestMatrix(d->fRandom),
d->fRandom->nextBool()) : nullptr;
}
///////////////////////////////////////////////////////////////////////////////
bool GrAAConvexPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
return (args.fShaderCaps->shaderDerivativeSupport() && args.fAntiAlias &&
args.fStroke->isFillStyle() && !args.fPath->isInverseFillType() &&
args.fPath->isConvex());
}
// extract the result vertices and indices from the GrAAConvexTessellator
static void extract_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 const GrGeometryProcessor* create_fill_gp(bool tweakAlphaForCoverage,
const SkMatrix& viewMatrix,
bool usesLocalCoords,
bool coverageIgnored) {
using namespace GrDefaultGeoProcFactory;
Color color(Color::kAttribute_Type);
Coverage::Type coverageType;
// TODO remove coverage if coverage is ignored
/*if (coverageIgnored) {
coverageType = Coverage::kNone_Type;
} else*/ if (tweakAlphaForCoverage) {
coverageType = Coverage::kSolid_Type;
} else {
coverageType = Coverage::kAttribute_Type;
}
Coverage coverage(coverageType);
LocalCoords localCoords(usesLocalCoords ? LocalCoords::kUsePosition_Type :
LocalCoords::kUnused_Type);
return CreateForDeviceSpace(color, coverage, localCoords, viewMatrix);
}
class AAConvexPathBatch : public GrVertexBatch {
public:
DEFINE_BATCH_CLASS_ID
struct Geometry {
GrColor fColor;
SkMatrix fViewMatrix;
SkPath fPath;
};
static GrDrawBatch* Create(const Geometry& geometry) { return new AAConvexPathBatch(geometry); }
const char* name() const override { return "AAConvexBatch"; }
void computePipelineOptimizations(GrInitInvariantOutput* color,
GrInitInvariantOutput* coverage,
GrBatchToXPOverrides* overrides) const override {
// When this is called on a batch, there is only one geometry bundle
color->setKnownFourComponents(fGeoData[0].fColor);
coverage->setUnknownSingleComponent();
}
private:
void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
// Handle any color overrides
if (!overrides.readsColor()) {
fGeoData[0].fColor = GrColor_ILLEGAL;
}
overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
// setup batch properties
fBatch.fColorIgnored = !overrides.readsColor();
fBatch.fColor = fGeoData[0].fColor;
fBatch.fUsesLocalCoords = overrides.readsLocalCoords();
fBatch.fCoverageIgnored = !overrides.readsCoverage();
fBatch.fLinesOnly = SkPath::kLine_SegmentMask == fGeoData[0].fPath.getSegmentMasks();
fBatch.fCanTweakAlphaForCoverage = overrides.canTweakAlphaForCoverage();
}
void prepareLinesOnlyDraws(Target* target) const {
bool canTweakAlphaForCoverage = this->canTweakAlphaForCoverage();
// Setup GrGeometryProcessor
SkAutoTUnref<const GrGeometryProcessor> gp(create_fill_gp(canTweakAlphaForCoverage,
this->viewMatrix(),
this->usesLocalCoords(),
this->coverageIgnored()));
if (!gp) {
SkDebugf("Could not create GrGeometryProcessor\n");
return;
}
target->initDraw(gp, this->pipeline());
size_t vertexStride = gp->getVertexStride();
SkASSERT(canTweakAlphaForCoverage ?
vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorAttr) :
vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorCoverageAttr));
GrAAConvexTessellator tess;
int instanceCount = fGeoData.count();
for (int i = 0; i < instanceCount; i++) {
tess.rewind();
const Geometry& args = fGeoData[i];
if (!tess.tessellate(args.fViewMatrix, args.fPath)) {
continue;
}
const GrVertexBuffer* vertexBuffer;
int firstVertex;
void* verts = target->makeVertexSpace(vertexStride, tess.numPts(), &vertexBuffer,
&firstVertex);
if (!verts) {
SkDebugf("Could not allocate vertices\n");
return;
}
const GrIndexBuffer* indexBuffer;
int firstIndex;
uint16_t* idxs = target->makeIndexSpace(tess.numIndices(), &indexBuffer, &firstIndex);
if (!idxs) {
SkDebugf("Could not allocate indices\n");
return;
}
extract_verts(tess, verts, vertexStride, args.fColor, idxs, canTweakAlphaForCoverage);
GrVertices info;
info.initIndexed(kTriangles_GrPrimitiveType,
vertexBuffer, indexBuffer,
firstVertex, firstIndex,
tess.numPts(), tess.numIndices());
target->draw(info);
}
}
void onPrepareDraws(Target* target) const override {
#ifndef SK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS
if (this->linesOnly()) {
this->prepareLinesOnlyDraws(target);
return;
}
#endif
int instanceCount = fGeoData.count();
SkMatrix invert;
if (this->usesLocalCoords() && !this->viewMatrix().invert(&invert)) {
SkDebugf("Could not invert viewmatrix\n");
return;
}
// Setup GrGeometryProcessor
SkAutoTUnref<GrGeometryProcessor> quadProcessor(
QuadEdgeEffect::Create(this->color(), invert, this->usesLocalCoords()));
target->initDraw(quadProcessor, this->pipeline());
// TODO generate all segments for all paths and use one vertex buffer
for (int i = 0; i < instanceCount; i++) {
const Geometry& args = fGeoData[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 GrVertexBuffer* 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 GrIndexBuffer* 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, &draws, verts, idxs);
GrVertices vertices;
for (int j = 0; j < draws.count(); ++j) {
const Draw& draw = draws[j];
vertices.initIndexed(kTriangles_GrPrimitiveType, vertexBuffer, indexBuffer,
firstVertex, firstIndex, draw.fVertexCnt, draw.fIndexCnt);
target->draw(vertices);
firstVertex += draw.fVertexCnt;
firstIndex += draw.fIndexCnt;
}
}
}
SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
AAConvexPathBatch(const Geometry& geometry) : INHERITED(ClassID()) {
fGeoData.push_back(geometry);
// compute bounds
fBounds = geometry.fPath.getBounds();
geometry.fViewMatrix.mapRect(&fBounds);
}
bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
AAConvexPathBatch* that = t->cast<AAConvexPathBatch>();
if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
that->bounds(), caps)) {
return false;
}
if (this->color() != that->color()) {
return false;
}
SkASSERT(this->usesLocalCoords() == that->usesLocalCoords());
if (this->usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
return false;
}
if (this->linesOnly() != that->linesOnly()) {
return false;
}
// In the event of two batches, one who can tweak, one who cannot, we just fall back to
// not tweaking
if (this->canTweakAlphaForCoverage() != that->canTweakAlphaForCoverage()) {
fBatch.fCanTweakAlphaForCoverage = false;
}
fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin());
this->joinBounds(that->bounds());
return true;
}
GrColor color() const { return fBatch.fColor; }
bool linesOnly() const { return fBatch.fLinesOnly; }
bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
bool canTweakAlphaForCoverage() const { return fBatch.fCanTweakAlphaForCoverage; }
const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; }
bool coverageIgnored() const { return fBatch.fCoverageIgnored; }
struct BatchTracker {
GrColor fColor;
bool fUsesLocalCoords;
bool fColorIgnored;
bool fCoverageIgnored;
bool fLinesOnly;
bool fCanTweakAlphaForCoverage;
};
BatchTracker fBatch;
SkSTArray<1, Geometry, true> fGeoData;
typedef GrVertexBatch INHERITED;
};
bool GrAAConvexPathRenderer::onDrawPath(const DrawPathArgs& args) {
GR_AUDIT_TRAIL_AUTO_FRAME(args.fTarget->getAuditTrail(), "GrAAConvexPathRenderer::onDrawPath");
if (args.fPath->isEmpty()) {
return true;
}
AAConvexPathBatch::Geometry geometry;
geometry.fColor = args.fColor;
geometry.fViewMatrix = *args.fViewMatrix;
geometry.fPath = *args.fPath;
SkAutoTUnref<GrDrawBatch> batch(AAConvexPathBatch::Create(geometry));
args.fTarget->drawBatch(*args.fPipelineBuilder, batch);
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
#ifdef GR_TEST_UTILS
DRAW_BATCH_TEST_DEFINE(AAConvexPathBatch) {
AAConvexPathBatch::Geometry geometry;
geometry.fColor = GrRandomColor(random);
geometry.fViewMatrix = GrTest::TestMatrixInvertible(random);
geometry.fPath = GrTest::TestPathConvex(random);
return AAConvexPathBatch::Create(geometry);
}
#endif