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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrDefaultPathRenderer.h"
#include "GrBatch.h"
#include "GrBatchTarget.h"
#include "GrBufferAllocPool.h"
#include "GrContext.h"
#include "GrDefaultGeoProcFactory.h"
#include "GrPathUtils.h"
#include "GrPipelineBuilder.h"
#include "SkGeometry.h"
#include "SkString.h"
#include "SkStrokeRec.h"
#include "SkTLazy.h"
#include "SkTraceEvent.h"
GrDefaultPathRenderer::GrDefaultPathRenderer(bool separateStencilSupport,
bool stencilWrapOpsSupport)
: fSeparateStencil(separateStencilSupport)
, fStencilWrapOps(stencilWrapOpsSupport) {
}
////////////////////////////////////////////////////////////////////////////////
// Stencil rules for paths
////// Even/Odd
GR_STATIC_CONST_SAME_STENCIL(gEOStencilPass,
kInvert_StencilOp,
kKeep_StencilOp,
kAlwaysIfInClip_StencilFunc,
0xffff,
0xffff,
0xffff);
// ok not to check clip b/c stencil pass only wrote inside clip
GR_STATIC_CONST_SAME_STENCIL(gEOColorPass,
kZero_StencilOp,
kZero_StencilOp,
kNotEqual_StencilFunc,
0xffff,
0x0000,
0xffff);
// have to check clip b/c outside clip will always be zero.
GR_STATIC_CONST_SAME_STENCIL(gInvEOColorPass,
kZero_StencilOp,
kZero_StencilOp,
kEqualIfInClip_StencilFunc,
0xffff,
0x0000,
0xffff);
////// Winding
// when we have separate stencil we increment front faces / decrement back faces
// when we don't have wrap incr and decr we use the stencil test to simulate
// them.
GR_STATIC_CONST_STENCIL(gWindStencilSeparateWithWrap,
kIncWrap_StencilOp, kDecWrap_StencilOp,
kKeep_StencilOp, kKeep_StencilOp,
kAlwaysIfInClip_StencilFunc, kAlwaysIfInClip_StencilFunc,
0xffff, 0xffff,
0xffff, 0xffff,
0xffff, 0xffff);
// if inc'ing the max value, invert to make 0
// if dec'ing zero invert to make all ones.
// we can't avoid touching the stencil on both passing and
// failing, so we can't resctrict ourselves to the clip.
GR_STATIC_CONST_STENCIL(gWindStencilSeparateNoWrap,
kInvert_StencilOp, kInvert_StencilOp,
kIncClamp_StencilOp, kDecClamp_StencilOp,
kEqual_StencilFunc, kEqual_StencilFunc,
0xffff, 0xffff,
0xffff, 0x0000,
0xffff, 0xffff);
// When there are no separate faces we do two passes to setup the winding rule
// stencil. First we draw the front faces and inc, then we draw the back faces
// and dec. These are same as the above two split into the incrementing and
// decrementing passes.
GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilWithWrapInc,
kIncWrap_StencilOp,
kKeep_StencilOp,
kAlwaysIfInClip_StencilFunc,
0xffff,
0xffff,
0xffff);
GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilWithWrapDec,
kDecWrap_StencilOp,
kKeep_StencilOp,
kAlwaysIfInClip_StencilFunc,
0xffff,
0xffff,
0xffff);
GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilNoWrapInc,
kInvert_StencilOp,
kIncClamp_StencilOp,
kEqual_StencilFunc,
0xffff,
0xffff,
0xffff);
GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilNoWrapDec,
kInvert_StencilOp,
kDecClamp_StencilOp,
kEqual_StencilFunc,
0xffff,
0x0000,
0xffff);
// Color passes are the same whether we use the two-sided stencil or two passes
GR_STATIC_CONST_SAME_STENCIL(gWindColorPass,
kZero_StencilOp,
kZero_StencilOp,
kNonZeroIfInClip_StencilFunc,
0xffff,
0x0000,
0xffff);
GR_STATIC_CONST_SAME_STENCIL(gInvWindColorPass,
kZero_StencilOp,
kZero_StencilOp,
kEqualIfInClip_StencilFunc,
0xffff,
0x0000,
0xffff);
////// Normal render to stencil
// Sometimes the default path renderer can draw a path directly to the stencil
// buffer without having to first resolve the interior / exterior.
GR_STATIC_CONST_SAME_STENCIL(gDirectToStencil,
kZero_StencilOp,
kIncClamp_StencilOp,
kAlwaysIfInClip_StencilFunc,
0xffff,
0x0000,
0xffff);
////////////////////////////////////////////////////////////////////////////////
// Helpers for drawPath
#define STENCIL_OFF 0 // Always disable stencil (even when needed)
static inline bool single_pass_path(const SkPath& path, const SkStrokeRec& stroke) {
#if STENCIL_OFF
return true;
#else
if (!stroke.isHairlineStyle() && !path.isInverseFillType()) {
return path.isConvex();
}
return false;
#endif
}
GrPathRenderer::StencilSupport
GrDefaultPathRenderer::onGetStencilSupport(const GrDrawTarget*,
const GrPipelineBuilder*,
const SkPath& path,
const SkStrokeRec& stroke) const {
if (single_pass_path(path, stroke)) {
return GrPathRenderer::kNoRestriction_StencilSupport;
} else {
return GrPathRenderer::kStencilOnly_StencilSupport;
}
}
static inline void append_countour_edge_indices(bool hairLine,
uint16_t fanCenterIdx,
uint16_t edgeV0Idx,
uint16_t** indices) {
// when drawing lines we're appending line segments along
// the contour. When applying the other fill rules we're
// drawing triangle fans around fanCenterIdx.
if (!hairLine) {
*((*indices)++) = fanCenterIdx;
}
*((*indices)++) = edgeV0Idx;
*((*indices)++) = edgeV0Idx + 1;
}
static inline void add_quad(SkPoint** vert, const SkPoint* base, const SkPoint pts[],
SkScalar srcSpaceTolSqd, SkScalar srcSpaceTol, bool indexed,
bool isHairline, uint16_t subpathIdxStart, int offset, uint16_t** idx) {
// first pt of quad is the pt we ended on in previous step
uint16_t firstQPtIdx = (uint16_t)(*vert - base) - 1 + offset;
uint16_t numPts = (uint16_t)
GrPathUtils::generateQuadraticPoints(
pts[0], pts[1], pts[2],
srcSpaceTolSqd, vert,
GrPathUtils::quadraticPointCount(pts, srcSpaceTol));
if (indexed) {
for (uint16_t i = 0; i < numPts; ++i) {
append_countour_edge_indices(isHairline, subpathIdxStart,
firstQPtIdx + i, idx);
}
}
}
class DefaultPathBatch : public GrBatch {
public:
struct Geometry {
GrColor fColor;
SkPath fPath;
SkScalar fTolerance;
SkDEBUGCODE(SkRect fDevBounds;)
};
static GrBatch* Create(const Geometry& geometry, uint8_t coverage, const SkMatrix& viewMatrix,
bool isHairline) {
return SkNEW_ARGS(DefaultPathBatch, (geometry, coverage, viewMatrix, isHairline));
}
const char* name() const SK_OVERRIDE { return "DefaultPathBatch"; }
void getInvariantOutputColor(GrInitInvariantOutput* out) const SK_OVERRIDE {
// When this is called on a batch, there is only one geometry bundle
out->setKnownFourComponents(fGeoData[0].fColor);
}
void getInvariantOutputCoverage(GrInitInvariantOutput* out) const SK_OVERRIDE {
out->setKnownSingleComponent(this->coverage());
}
void initBatchTracker(const GrPipelineInfo& init) SK_OVERRIDE {
// Handle any color overrides
if (init.fColorIgnored) {
fGeoData[0].fColor = GrColor_ILLEGAL;
} else if (GrColor_ILLEGAL != init.fOverrideColor) {
fGeoData[0].fColor = init.fOverrideColor;
}
// setup batch properties
fBatch.fColorIgnored = init.fColorIgnored;
fBatch.fColor = fGeoData[0].fColor;
fBatch.fUsesLocalCoords = init.fUsesLocalCoords;
fBatch.fCoverageIgnored = init.fCoverageIgnored;
}
void generateGeometry(GrBatchTarget* batchTarget, const GrPipeline* pipeline) SK_OVERRIDE {
SkAutoTUnref<const GrGeometryProcessor> gp(
GrDefaultGeoProcFactory::Create(GrDefaultGeoProcFactory::kPosition_GPType,
this->color(),
this->viewMatrix(),
SkMatrix::I(),
false,
this->coverage()));
size_t vertexStride = gp->getVertexStride();
SkASSERT(vertexStride == sizeof(SkPoint));
batchTarget->initDraw(gp, pipeline);
// TODO this is hacky, but the only way we have to initialize the GP is to use the
// GrPipelineInfo struct so we can generate the correct shader. Once we have GrBatch
// everywhere we can remove this nastiness
GrPipelineInfo init;
init.fColorIgnored = fBatch.fColorIgnored;
init.fOverrideColor = GrColor_ILLEGAL;
init.fCoverageIgnored = fBatch.fCoverageIgnored;
init.fUsesLocalCoords = this->usesLocalCoords();
gp->initBatchTracker(batchTarget->currentBatchTracker(), init);
int instanceCount = fGeoData.count();
// compute number of vertices
int maxVertices = 0;
// We will use index buffers if we have multiple paths or one path with multiple contours
bool isIndexed = instanceCount > 1;
for (int i = 0; i < instanceCount; i++) {
Geometry& args = fGeoData[i];
int contourCount;
maxVertices += GrPathUtils::worstCasePointCount(args.fPath, &contourCount,
args.fTolerance);
isIndexed = isIndexed || contourCount > 1;
}
if (maxVertices == 0 || maxVertices > ((int)SK_MaxU16 + 1)) {
SkDebugf("Cannot render path (%d)\n", maxVertices);
return;
}
// determine primitiveType
int maxIndices = 0;
GrPrimitiveType primitiveType;
if (this->isHairline()) {
if (isIndexed) {
maxIndices = 2 * maxVertices;
primitiveType = kLines_GrPrimitiveType;
} else {
primitiveType = kLineStrip_GrPrimitiveType;
}
} else {
if (isIndexed) {
maxIndices = 3 * maxVertices;
primitiveType = kTriangles_GrPrimitiveType;
} else {
primitiveType = kTriangleFan_GrPrimitiveType;
}
}
// allocate vertex / index buffers
const GrVertexBuffer* vertexBuffer;
int firstVertex;
void* vertices = batchTarget->vertexPool()->makeSpace(vertexStride,
maxVertices,
&vertexBuffer,
&firstVertex);
const GrIndexBuffer* indexBuffer;
int firstIndex;
void* indices = NULL;
if (isIndexed) {
indices = batchTarget->indexPool()->makeSpace(maxIndices,
&indexBuffer,
&firstIndex);
}
// fill buffers
int vertexOffset = 0;
int indexOffset = 0;
for (int i = 0; i < instanceCount; i++) {
Geometry& args = fGeoData[i];
int vertexCnt = 0;
int indexCnt = 0;
if (!this->createGeom(vertices,
vertexOffset,
indices,
indexOffset,
&vertexCnt,
&indexCnt,
args.fPath,
args.fTolerance,
isIndexed)) {
return;
}
vertexOffset += vertexCnt;
indexOffset += indexCnt;
SkASSERT(vertexOffset <= maxVertices && indexOffset <= maxIndices);
}
GrDrawTarget::DrawInfo drawInfo;
drawInfo.setPrimitiveType(primitiveType);
drawInfo.setVertexBuffer(vertexBuffer);
drawInfo.setStartVertex(firstVertex);
drawInfo.setVertexCount(vertexOffset);
if (isIndexed) {
drawInfo.setIndexBuffer(indexBuffer);
drawInfo.setStartIndex(firstIndex);
drawInfo.setIndexCount(indexOffset);
} else {
drawInfo.setStartIndex(0);
drawInfo.setIndexCount(0);
}
batchTarget->draw(drawInfo);
// put back reserves
batchTarget->putBackIndices((size_t)(maxIndices - indexOffset));
batchTarget->putBackVertices((size_t)(maxVertices - vertexOffset), (size_t)vertexStride);
}
SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
private:
DefaultPathBatch(const Geometry& geometry, uint8_t coverage, const SkMatrix& viewMatrix,
bool isHairline) {
this->initClassID<DefaultPathBatch>();
fBatch.fCoverage = coverage;
fBatch.fIsHairline = isHairline;
fBatch.fViewMatrix = viewMatrix;
fGeoData.push_back(geometry);
}
bool onCombineIfPossible(GrBatch* t) SK_OVERRIDE {
DefaultPathBatch* that = t->cast<DefaultPathBatch>();
if (this->color() != that->color()) {
return false;
}
if (this->coverage() != that->coverage()) {
return false;
}
if (!this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
return false;
}
if (this->isHairline() != that->isHairline()) {
return false;
}
fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin());
return true;
}
bool createGeom(void* vertices,
size_t vertexOffset,
void* indices,
size_t indexOffset,
int* vertexCnt,
int* indexCnt,
const SkPath& path,
SkScalar srcSpaceTol,
bool isIndexed) {
{
SkScalar srcSpaceTolSqd = SkScalarMul(srcSpaceTol, srcSpaceTol);
uint16_t indexOffsetU16 = (uint16_t)indexOffset;
uint16_t vertexOffsetU16 = (uint16_t)vertexOffset;
uint16_t* idxBase = reinterpret_cast<uint16_t*>(indices) + indexOffsetU16;
uint16_t* idx = idxBase;
uint16_t subpathIdxStart = vertexOffsetU16;
SkPoint* base = reinterpret_cast<SkPoint*>(vertices) + vertexOffset;
SkPoint* vert = base;
SkPoint pts[4];
bool first = true;
int subpath = 0;
SkPath::Iter iter(path, false);
bool done = false;
while (!done) {
SkPath::Verb verb = iter.next(pts);
switch (verb) {
case SkPath::kMove_Verb:
if (!first) {
uint16_t currIdx = (uint16_t) (vert - base) + vertexOffsetU16;
subpathIdxStart = currIdx;
++subpath;
}
*vert = pts[0];
vert++;
break;
case SkPath::kLine_Verb:
if (isIndexed) {
uint16_t prevIdx = (uint16_t)(vert - base) - 1 + vertexOffsetU16;
append_countour_edge_indices(this->isHairline(), subpathIdxStart,
prevIdx, &idx);
}
*(vert++) = pts[1];
break;
case SkPath::kConic_Verb: {
SkScalar weight = iter.conicWeight();
SkAutoConicToQuads converter;
// Converting in src-space, hance the finer tolerance (0.25)
// TODO: find a way to do this in dev-space so the tolerance means something
const SkPoint* quadPts = converter.computeQuads(pts, weight, 0.25f);
for (int i = 0; i < converter.countQuads(); ++i) {
add_quad(&vert, base, quadPts + i*2, srcSpaceTolSqd, srcSpaceTol,
isIndexed, this->isHairline(), subpathIdxStart,
(int)vertexOffset, &idx);
}
break;
}
case SkPath::kQuad_Verb:
add_quad(&vert, base, pts, srcSpaceTolSqd, srcSpaceTol, isIndexed,
this->isHairline(), subpathIdxStart, (int)vertexOffset, &idx);
break;
case SkPath::kCubic_Verb: {
// first pt of cubic is the pt we ended on in previous step
uint16_t firstCPtIdx = (uint16_t)(vert - base) - 1 + vertexOffsetU16;
uint16_t numPts = (uint16_t) GrPathUtils::generateCubicPoints(
pts[0], pts[1], pts[2], pts[3],
srcSpaceTolSqd, &vert,
GrPathUtils::cubicPointCount(pts, srcSpaceTol));
if (isIndexed) {
for (uint16_t i = 0; i < numPts; ++i) {
append_countour_edge_indices(this->isHairline(), subpathIdxStart,
firstCPtIdx + i, &idx);
}
}
break;
}
case SkPath::kClose_Verb:
break;
case SkPath::kDone_Verb:
done = true;
}
first = false;
}
*vertexCnt = static_cast<int>(vert - base);
*indexCnt = static_cast<int>(idx - idxBase);
}
return true;
}
GrColor color() const { return fBatch.fColor; }
uint8_t coverage() const { return fBatch.fCoverage; }
bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
const SkMatrix& viewMatrix() const { return fBatch.fViewMatrix; }
bool isHairline() const { return fBatch.fIsHairline; }
struct BatchTracker {
GrColor fColor;
uint8_t fCoverage;
SkMatrix fViewMatrix;
bool fUsesLocalCoords;
bool fColorIgnored;
bool fCoverageIgnored;
bool fIsHairline;
};
BatchTracker fBatch;
SkSTArray<1, Geometry, true> fGeoData;
};
bool GrDefaultPathRenderer::internalDrawPath(GrDrawTarget* target,
GrPipelineBuilder* pipelineBuilder,
GrColor color,
const SkMatrix& viewMatrix,
const SkPath& path,
const SkStrokeRec& origStroke,
bool stencilOnly) {
SkTCopyOnFirstWrite<SkStrokeRec> stroke(origStroke);
SkScalar hairlineCoverage;
uint8_t newCoverage = 0xff;
if (IsStrokeHairlineOrEquivalent(*stroke, viewMatrix, &hairlineCoverage)) {
newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff);
if (!stroke->isHairlineStyle()) {
stroke.writable()->setHairlineStyle();
}
}
const bool isHairline = stroke->isHairlineStyle();
// Save the current xp on the draw state so we can reset it if needed
SkAutoTUnref<const GrXPFactory> backupXPFactory(SkRef(pipelineBuilder->getXPFactory()));
// face culling doesn't make sense here
SkASSERT(GrPipelineBuilder::kBoth_DrawFace == pipelineBuilder->getDrawFace());
int passCount = 0;
const GrStencilSettings* passes[3];
GrPipelineBuilder::DrawFace drawFace[3];
bool reverse = false;
bool lastPassIsBounds;
if (isHairline) {
passCount = 1;
if (stencilOnly) {
passes[0] = &gDirectToStencil;
} else {
passes[0] = NULL;
}
lastPassIsBounds = false;
drawFace[0] = GrPipelineBuilder::kBoth_DrawFace;
} else {
if (single_pass_path(path, *stroke)) {
passCount = 1;
if (stencilOnly) {
passes[0] = &gDirectToStencil;
} else {
passes[0] = NULL;
}
drawFace[0] = GrPipelineBuilder::kBoth_DrawFace;
lastPassIsBounds = false;
} else {
switch (path.getFillType()) {
case SkPath::kInverseEvenOdd_FillType:
reverse = true;
// fallthrough
case SkPath::kEvenOdd_FillType:
passes[0] = &gEOStencilPass;
if (stencilOnly) {
passCount = 1;
lastPassIsBounds = false;
} else {
passCount = 2;
lastPassIsBounds = true;
if (reverse) {
passes[1] = &gInvEOColorPass;
} else {
passes[1] = &gEOColorPass;
}
}
drawFace[0] = drawFace[1] = GrPipelineBuilder::kBoth_DrawFace;
break;
case SkPath::kInverseWinding_FillType:
reverse = true;
// fallthrough
case SkPath::kWinding_FillType:
if (fSeparateStencil) {
if (fStencilWrapOps) {
passes[0] = &gWindStencilSeparateWithWrap;
} else {
passes[0] = &gWindStencilSeparateNoWrap;
}
passCount = 2;
drawFace[0] = GrPipelineBuilder::kBoth_DrawFace;
} else {
if (fStencilWrapOps) {
passes[0] = &gWindSingleStencilWithWrapInc;
passes[1] = &gWindSingleStencilWithWrapDec;
} else {
passes[0] = &gWindSingleStencilNoWrapInc;
passes[1] = &gWindSingleStencilNoWrapDec;
}
// which is cw and which is ccw is arbitrary.
drawFace[0] = GrPipelineBuilder::kCW_DrawFace;
drawFace[1] = GrPipelineBuilder::kCCW_DrawFace;
passCount = 3;
}
if (stencilOnly) {
lastPassIsBounds = false;
--passCount;
} else {
lastPassIsBounds = true;
drawFace[passCount-1] = GrPipelineBuilder::kBoth_DrawFace;
if (reverse) {
passes[passCount-1] = &gInvWindColorPass;
} else {
passes[passCount-1] = &gWindColorPass;
}
}
break;
default:
SkDEBUGFAIL("Unknown path fFill!");
return false;
}
}
}
SkScalar tol = SK_Scalar1;
SkScalar srcSpaceTol = GrPathUtils::scaleToleranceToSrc(tol, viewMatrix, path.getBounds());
SkRect devBounds;
GetPathDevBounds(path, pipelineBuilder->getRenderTarget(), viewMatrix, &devBounds);
for (int p = 0; p < passCount; ++p) {
pipelineBuilder->setDrawFace(drawFace[p]);
if (passes[p]) {
*pipelineBuilder->stencil() = *passes[p];
}
if (lastPassIsBounds && (p == passCount-1)) {
// Reset the XP Factory on pipelineBuilder
pipelineBuilder->setXPFactory(backupXPFactory);
SkRect bounds;
SkMatrix localMatrix = SkMatrix::I();
if (reverse) {
SkASSERT(pipelineBuilder->getRenderTarget());
// draw over the dev bounds (which will be the whole dst surface for inv fill).
bounds = devBounds;
SkMatrix vmi;
// mapRect through persp matrix may not be correct
if (!viewMatrix.hasPerspective() && viewMatrix.invert(&vmi)) {
vmi.mapRect(&bounds);
} else {
if (!viewMatrix.invert(&localMatrix)) {
return false;
}
}
} else {
bounds = path.getBounds();
}
GrDrawTarget::AutoGeometryPush agp(target);
const SkMatrix& viewM = (reverse && viewMatrix.hasPerspective()) ? SkMatrix::I() :
viewMatrix;
target->drawRect(pipelineBuilder, color, viewM, bounds, NULL, &localMatrix);
} else {
if (passCount > 1) {
pipelineBuilder->setDisableColorXPFactory();
}
DefaultPathBatch::Geometry geometry;
geometry.fColor = color;
geometry.fPath = path;
geometry.fTolerance = srcSpaceTol;
SkDEBUGCODE(geometry.fDevBounds = devBounds;)
SkAutoTUnref<GrBatch> batch(DefaultPathBatch::Create(geometry, newCoverage, viewMatrix,
isHairline));
target->drawBatch(pipelineBuilder, batch, &devBounds);
}
}
return true;
}
bool GrDefaultPathRenderer::canDrawPath(const GrDrawTarget* target,
const GrPipelineBuilder* pipelineBuilder,
const SkMatrix& viewMatrix,
const SkPath& path,
const SkStrokeRec& stroke,
bool antiAlias) const {
// this class can draw any path with any fill but doesn't do any anti-aliasing.
return !antiAlias && (stroke.isFillStyle() || IsStrokeHairlineOrEquivalent(stroke,
viewMatrix,
NULL));
}
bool GrDefaultPathRenderer::onDrawPath(GrDrawTarget* target,
GrPipelineBuilder* pipelineBuilder,
GrColor color,
const SkMatrix& viewMatrix,
const SkPath& path,
const SkStrokeRec& stroke,
bool antiAlias) {
return this->internalDrawPath(target,
pipelineBuilder,
color,
viewMatrix,
path,
stroke,
false);
}
void GrDefaultPathRenderer::onStencilPath(GrDrawTarget* target,
GrPipelineBuilder* pipelineBuilder,
const SkMatrix& viewMatrix,
const SkPath& path,
const SkStrokeRec& stroke) {
SkASSERT(SkPath::kInverseEvenOdd_FillType != path.getFillType());
SkASSERT(SkPath::kInverseWinding_FillType != path.getFillType());
this->internalDrawPath(target, pipelineBuilder, GrColor_WHITE, viewMatrix, path, stroke, true);
}