blob: 31a446b32b38fa89a61444c0ca7229cd586dcce4 [file] [log] [blame]
/*
* 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 "SkGeometry.h"
#include "SkOpEdgeBuilder.h"
#include "SkReduceOrder.h"
void SkOpEdgeBuilder::init() {
fCurrentContour = NULL;
fOperand = false;
fXorMask[0] = fXorMask[1] = (fPath->getFillType() & 1) ? kEvenOdd_PathOpsMask
: kWinding_PathOpsMask;
fUnparseable = false;
fSecondHalf = preFetch();
}
void SkOpEdgeBuilder::addOperand(const SkPath& path) {
SkASSERT(fPathVerbs.count() > 0 && fPathVerbs.end()[-1] == SkPath::kDone_Verb);
fPathVerbs.pop_back();
fPath = &path;
fXorMask[1] = (fPath->getFillType() & 1) ? kEvenOdd_PathOpsMask
: kWinding_PathOpsMask;
preFetch();
}
bool SkOpEdgeBuilder::finish() {
if (fUnparseable || !walk()) {
return false;
}
complete();
if (fCurrentContour && !fCurrentContour->segments().count()) {
fContours.pop_back();
}
return true;
}
void SkOpEdgeBuilder::closeContour(const SkPoint& curveEnd, const SkPoint& curveStart) {
if (!SkDPoint::ApproximatelyEqual(curveEnd, curveStart)) {
fPathVerbs.push_back(SkPath::kLine_Verb);
fPathPts.push_back_n(1, &curveStart);
} else {
fPathPts[fPathPts.count() - 1] = curveStart;
}
fPathVerbs.push_back(SkPath::kClose_Verb);
}
int SkOpEdgeBuilder::preFetch() {
if (!fPath->isFinite()) {
fUnparseable = true;
return 0;
}
SkAutoConicToQuads quadder;
const SkScalar quadderTol = SK_Scalar1 / 16;
SkPath::RawIter iter(*fPath);
SkPoint curveStart;
SkPoint curve[4];
SkPoint pts[4];
SkPath::Verb verb;
bool lastCurve = false;
do {
verb = iter.next(pts);
switch (verb) {
case SkPath::kMove_Verb:
if (!fAllowOpenContours && lastCurve) {
closeContour(curve[0], curveStart);
}
fPathVerbs.push_back(verb);
fPathPts.push_back(pts[0]);
curveStart = curve[0] = pts[0];
lastCurve = false;
continue;
case SkPath::kLine_Verb:
if (SkDPoint::ApproximatelyEqual(curve[0], pts[1])) {
uint8_t lastVerb = fPathVerbs.back();
if (lastVerb != SkPath::kLine_Verb && lastVerb != SkPath::kMove_Verb) {
fPathPts.back() = pts[1];
}
continue; // skip degenerate points
}
break;
case SkPath::kQuad_Verb:
curve[1] = pts[1];
curve[2] = pts[2];
verb = SkReduceOrder::Quad(curve, pts);
if (verb == SkPath::kMove_Verb) {
continue; // skip degenerate points
}
break;
case SkPath::kConic_Verb: {
const SkPoint* quadPts = quadder.computeQuads(pts, iter.conicWeight(),
quadderTol);
const int nQuads = quadder.countQuads();
for (int i = 0; i < nQuads; ++i) {
fPathVerbs.push_back(SkPath::kQuad_Verb);
}
fPathPts.push_back_n(nQuads * 2, quadPts);
curve[0] = quadPts[nQuads * 2 - 1];
lastCurve = true;
}
continue;
case SkPath::kCubic_Verb:
curve[1] = pts[1];
curve[2] = pts[2];
curve[3] = pts[3];
verb = SkReduceOrder::Cubic(curve, pts);
if (verb == SkPath::kMove_Verb) {
continue; // skip degenerate points
}
break;
case SkPath::kClose_Verb:
closeContour(curve[0], curveStart);
lastCurve = false;
continue;
case SkPath::kDone_Verb:
continue;
}
fPathVerbs.push_back(verb);
int ptCount = SkPathOpsVerbToPoints(verb);
fPathPts.push_back_n(ptCount, &pts[1]);
curve[0] = pts[ptCount];
lastCurve = true;
} while (verb != SkPath::kDone_Verb);
if (!fAllowOpenContours && lastCurve) {
closeContour(curve[0], curveStart);
}
fPathVerbs.push_back(SkPath::kDone_Verb);
return fPathVerbs.count() - 1;
}
bool SkOpEdgeBuilder::close() {
complete();
return true;
}
bool SkOpEdgeBuilder::walk() {
uint8_t* verbPtr = fPathVerbs.begin();
uint8_t* endOfFirstHalf = &verbPtr[fSecondHalf];
const SkPoint* pointsPtr = fPathPts.begin() - 1;
SkPath::Verb verb;
while ((verb = (SkPath::Verb) *verbPtr) != SkPath::kDone_Verb) {
if (verbPtr == endOfFirstHalf) {
fOperand = true;
}
verbPtr++;
switch (verb) {
case SkPath::kMove_Verb:
if (fCurrentContour) {
if (fAllowOpenContours) {
complete();
} else if (!close()) {
return false;
}
}
if (!fCurrentContour) {
fCurrentContour = fContours.push_back_n(1);
fCurrentContour->setOperand(fOperand);
fCurrentContour->setXor(fXorMask[fOperand] == kEvenOdd_PathOpsMask);
}
pointsPtr += 1;
continue;
case SkPath::kLine_Verb:
fCurrentContour->addLine(pointsPtr);
break;
case SkPath::kQuad_Verb:
fCurrentContour->addQuad(pointsPtr);
break;
case SkPath::kCubic_Verb:
fCurrentContour->addCubic(pointsPtr);
break;
case SkPath::kClose_Verb:
SkASSERT(fCurrentContour);
if (!close()) {
return false;
}
continue;
default:
SkDEBUGFAIL("bad verb");
return false;
}
pointsPtr += SkPathOpsVerbToPoints(verb);
SkASSERT(fCurrentContour);
}
if (fCurrentContour && !fAllowOpenContours && !close()) {
return false;
}
return true;
}