1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/pathops/SkOpEdgeBuilder.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,194 @@
1.4 +/*
1.5 + * Copyright 2012 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +#include "SkGeometry.h"
1.11 +#include "SkOpEdgeBuilder.h"
1.12 +#include "SkReduceOrder.h"
1.13 +
1.14 +void SkOpEdgeBuilder::init() {
1.15 + fCurrentContour = NULL;
1.16 + fOperand = false;
1.17 + fXorMask[0] = fXorMask[1] = (fPath->getFillType() & 1) ? kEvenOdd_PathOpsMask
1.18 + : kWinding_PathOpsMask;
1.19 +#ifdef SK_DEBUG
1.20 + SkPathOpsDebug::gContourID = 0;
1.21 + SkPathOpsDebug::gSegmentID = 0;
1.22 +#endif
1.23 + fUnparseable = false;
1.24 + fSecondHalf = preFetch();
1.25 +}
1.26 +
1.27 +void SkOpEdgeBuilder::addOperand(const SkPath& path) {
1.28 + SkASSERT(fPathVerbs.count() > 0 && fPathVerbs.end()[-1] == SkPath::kDone_Verb);
1.29 + fPathVerbs.pop_back();
1.30 + fPath = &path;
1.31 + fXorMask[1] = (fPath->getFillType() & 1) ? kEvenOdd_PathOpsMask
1.32 + : kWinding_PathOpsMask;
1.33 + preFetch();
1.34 +}
1.35 +
1.36 +bool SkOpEdgeBuilder::finish() {
1.37 + if (fUnparseable || !walk()) {
1.38 + return false;
1.39 + }
1.40 + complete();
1.41 + if (fCurrentContour && !fCurrentContour->segments().count()) {
1.42 + fContours.pop_back();
1.43 + }
1.44 + return true;
1.45 +}
1.46 +
1.47 +void SkOpEdgeBuilder::closeContour(const SkPoint& curveEnd, const SkPoint& curveStart) {
1.48 + if (!SkDPoint::ApproximatelyEqual(curveEnd, curveStart)) {
1.49 + fPathVerbs.push_back(SkPath::kLine_Verb);
1.50 + fPathPts.push_back_n(1, &curveStart);
1.51 + } else {
1.52 + fPathPts[fPathPts.count() - 1] = curveStart;
1.53 + }
1.54 + fPathVerbs.push_back(SkPath::kClose_Verb);
1.55 +}
1.56 +
1.57 +int SkOpEdgeBuilder::preFetch() {
1.58 + if (!fPath->isFinite()) {
1.59 + fUnparseable = true;
1.60 + return 0;
1.61 + }
1.62 + SkAutoConicToQuads quadder;
1.63 + const SkScalar quadderTol = SK_Scalar1 / 16;
1.64 + SkPath::RawIter iter(*fPath);
1.65 + SkPoint curveStart;
1.66 + SkPoint curve[4];
1.67 + SkPoint pts[4];
1.68 + SkPath::Verb verb;
1.69 + bool lastCurve = false;
1.70 + do {
1.71 + verb = iter.next(pts);
1.72 + switch (verb) {
1.73 + case SkPath::kMove_Verb:
1.74 + if (!fAllowOpenContours && lastCurve) {
1.75 + closeContour(curve[0], curveStart);
1.76 + }
1.77 + fPathVerbs.push_back(verb);
1.78 + fPathPts.push_back(pts[0]);
1.79 + curveStart = curve[0] = pts[0];
1.80 + lastCurve = false;
1.81 + continue;
1.82 + case SkPath::kLine_Verb:
1.83 + if (SkDPoint::ApproximatelyEqual(curve[0], pts[1])) {
1.84 + uint8_t lastVerb = fPathVerbs.back();
1.85 + if (lastVerb != SkPath::kLine_Verb && lastVerb != SkPath::kMove_Verb) {
1.86 + fPathPts.back() = pts[1];
1.87 + }
1.88 + continue; // skip degenerate points
1.89 + }
1.90 + break;
1.91 + case SkPath::kQuad_Verb:
1.92 + curve[1] = pts[1];
1.93 + curve[2] = pts[2];
1.94 + verb = SkReduceOrder::Quad(curve, pts);
1.95 + if (verb == SkPath::kMove_Verb) {
1.96 + continue; // skip degenerate points
1.97 + }
1.98 + break;
1.99 + case SkPath::kConic_Verb: {
1.100 + const SkPoint* quadPts = quadder.computeQuads(pts, iter.conicWeight(),
1.101 + quadderTol);
1.102 + const int nQuads = quadder.countQuads();
1.103 + for (int i = 0; i < nQuads; ++i) {
1.104 + fPathVerbs.push_back(SkPath::kQuad_Verb);
1.105 + }
1.106 + fPathPts.push_back_n(nQuads * 2, quadPts);
1.107 + curve[0] = quadPts[nQuads * 2 - 1];
1.108 + lastCurve = true;
1.109 + }
1.110 + continue;
1.111 + case SkPath::kCubic_Verb:
1.112 + curve[1] = pts[1];
1.113 + curve[2] = pts[2];
1.114 + curve[3] = pts[3];
1.115 + verb = SkReduceOrder::Cubic(curve, pts);
1.116 + if (verb == SkPath::kMove_Verb) {
1.117 + continue; // skip degenerate points
1.118 + }
1.119 + break;
1.120 + case SkPath::kClose_Verb:
1.121 + closeContour(curve[0], curveStart);
1.122 + lastCurve = false;
1.123 + continue;
1.124 + case SkPath::kDone_Verb:
1.125 + continue;
1.126 + }
1.127 + fPathVerbs.push_back(verb);
1.128 + int ptCount = SkPathOpsVerbToPoints(verb);
1.129 + fPathPts.push_back_n(ptCount, &pts[1]);
1.130 + curve[0] = pts[ptCount];
1.131 + lastCurve = true;
1.132 + } while (verb != SkPath::kDone_Verb);
1.133 + if (!fAllowOpenContours && lastCurve) {
1.134 + closeContour(curve[0], curveStart);
1.135 + }
1.136 + fPathVerbs.push_back(SkPath::kDone_Verb);
1.137 + return fPathVerbs.count() - 1;
1.138 +}
1.139 +
1.140 +bool SkOpEdgeBuilder::close() {
1.141 + complete();
1.142 + return true;
1.143 +}
1.144 +
1.145 +bool SkOpEdgeBuilder::walk() {
1.146 + uint8_t* verbPtr = fPathVerbs.begin();
1.147 + uint8_t* endOfFirstHalf = &verbPtr[fSecondHalf];
1.148 + const SkPoint* pointsPtr = fPathPts.begin() - 1;
1.149 + SkPath::Verb verb;
1.150 + while ((verb = (SkPath::Verb) *verbPtr) != SkPath::kDone_Verb) {
1.151 + if (verbPtr == endOfFirstHalf) {
1.152 + fOperand = true;
1.153 + }
1.154 + verbPtr++;
1.155 + switch (verb) {
1.156 + case SkPath::kMove_Verb:
1.157 + if (fCurrentContour) {
1.158 + if (fAllowOpenContours) {
1.159 + complete();
1.160 + } else if (!close()) {
1.161 + return false;
1.162 + }
1.163 + }
1.164 + if (!fCurrentContour) {
1.165 + fCurrentContour = fContours.push_back_n(1);
1.166 + fCurrentContour->setOperand(fOperand);
1.167 + fCurrentContour->setXor(fXorMask[fOperand] == kEvenOdd_PathOpsMask);
1.168 + }
1.169 + pointsPtr += 1;
1.170 + continue;
1.171 + case SkPath::kLine_Verb:
1.172 + fCurrentContour->addLine(pointsPtr);
1.173 + break;
1.174 + case SkPath::kQuad_Verb:
1.175 + fCurrentContour->addQuad(pointsPtr);
1.176 + break;
1.177 + case SkPath::kCubic_Verb:
1.178 + fCurrentContour->addCubic(pointsPtr);
1.179 + break;
1.180 + case SkPath::kClose_Verb:
1.181 + SkASSERT(fCurrentContour);
1.182 + if (!close()) {
1.183 + return false;
1.184 + }
1.185 + continue;
1.186 + default:
1.187 + SkDEBUGFAIL("bad verb");
1.188 + return false;
1.189 + }
1.190 + pointsPtr += SkPathOpsVerbToPoints(verb);
1.191 + SkASSERT(fCurrentContour);
1.192 + }
1.193 + if (fCurrentContour && !fAllowOpenContours && !close()) {
1.194 + return false;
1.195 + }
1.196 + return true;
1.197 +}
