1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/pathops/SkIntersectionHelper.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,161 @@
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 "SkOpContour.h"
1.11 +#include "SkPath.h"
1.12 +
1.13 +#ifdef SK_DEBUG
1.14 +#include "SkPathOpsPoint.h"
1.15 +#endif
1.16 +
1.17 +class SkIntersectionHelper {
1.18 +public:
1.19 + enum SegmentType {
1.20 + kHorizontalLine_Segment = -1,
1.21 + kVerticalLine_Segment = 0,
1.22 + kLine_Segment = SkPath::kLine_Verb,
1.23 + kQuad_Segment = SkPath::kQuad_Verb,
1.24 + kCubic_Segment = SkPath::kCubic_Verb,
1.25 + };
1.26 +
1.27 + bool addCoincident(SkIntersectionHelper& other, const SkIntersections& ts, bool swap) {
1.28 + return fContour->addCoincident(fIndex, other.fContour, other.fIndex, ts, swap);
1.29 + }
1.30 +
1.31 + // FIXME: does it make sense to write otherIndex now if we're going to
1.32 + // fix it up later?
1.33 + void addOtherT(int index, double otherT, int otherIndex) {
1.34 + fContour->addOtherT(fIndex, index, otherT, otherIndex);
1.35 + }
1.36 +
1.37 + bool addPartialCoincident(SkIntersectionHelper& other, const SkIntersections& ts, int index,
1.38 + bool swap) {
1.39 + return fContour->addPartialCoincident(fIndex, other.fContour, other.fIndex, ts, index,
1.40 + swap);
1.41 + }
1.42 +
1.43 + // Avoid collapsing t values that are close to the same since
1.44 + // we walk ts to describe consecutive intersections. Since a pair of ts can
1.45 + // be nearly equal, any problems caused by this should be taken care
1.46 + // of later.
1.47 + // On the edge or out of range values are negative; add 2 to get end
1.48 + int addT(const SkIntersectionHelper& other, const SkPoint& pt, double newT) {
1.49 + return fContour->addT(fIndex, other.fContour, other.fIndex, pt, newT);
1.50 + }
1.51 +
1.52 + int addSelfT(const SkIntersectionHelper& other, const SkPoint& pt, double newT) {
1.53 + return fContour->addSelfT(fIndex, other.fContour, other.fIndex, pt, newT);
1.54 + }
1.55 +
1.56 + bool advance() {
1.57 + return ++fIndex < fLast;
1.58 + }
1.59 +
1.60 + SkScalar bottom() const {
1.61 + return bounds().fBottom;
1.62 + }
1.63 +
1.64 + const SkPathOpsBounds& bounds() const {
1.65 + return fContour->segments()[fIndex].bounds();
1.66 + }
1.67 +
1.68 + void init(SkOpContour* contour) {
1.69 + fContour = contour;
1.70 + fIndex = 0;
1.71 + fLast = contour->segments().count();
1.72 + }
1.73 +
1.74 + bool isAdjacent(const SkIntersectionHelper& next) {
1.75 + return fContour == next.fContour && fIndex + 1 == next.fIndex;
1.76 + }
1.77 +
1.78 + bool isFirstLast(const SkIntersectionHelper& next) {
1.79 + return fContour == next.fContour && fIndex == 0
1.80 + && next.fIndex == fLast - 1;
1.81 + }
1.82 +
1.83 + bool isPartial(double t1, double t2, const SkDPoint& pt1, const SkDPoint& pt2) const {
1.84 + const SkOpSegment& segment = fContour->segments()[fIndex];
1.85 + double mid = (t1 + t2) / 2;
1.86 + SkDPoint midPtByT = segment.dPtAtT(mid);
1.87 + SkDPoint midPtByAvg = SkDPoint::Mid(pt1, pt2);
1.88 + return midPtByT.approximatelyPEqual(midPtByAvg);
1.89 + }
1.90 +
1.91 + SkScalar left() const {
1.92 + return bounds().fLeft;
1.93 + }
1.94 +
1.95 + const SkPoint* pts() const {
1.96 + return fContour->segments()[fIndex].pts();
1.97 + }
1.98 +
1.99 + SkScalar right() const {
1.100 + return bounds().fRight;
1.101 + }
1.102 +
1.103 + SegmentType segmentType() const {
1.104 + const SkOpSegment& segment = fContour->segments()[fIndex];
1.105 + SegmentType type = (SegmentType) segment.verb();
1.106 + if (type != kLine_Segment) {
1.107 + return type;
1.108 + }
1.109 + if (segment.isHorizontal()) {
1.110 + return kHorizontalLine_Segment;
1.111 + }
1.112 + if (segment.isVertical()) {
1.113 + return kVerticalLine_Segment;
1.114 + }
1.115 + return kLine_Segment;
1.116 + }
1.117 +
1.118 + bool startAfter(const SkIntersectionHelper& after) {
1.119 + fIndex = after.fIndex;
1.120 + return advance();
1.121 + }
1.122 +
1.123 + SkScalar top() const {
1.124 + return bounds().fTop;
1.125 + }
1.126 +
1.127 + SkPath::Verb verb() const {
1.128 + return fContour->segments()[fIndex].verb();
1.129 + }
1.130 +
1.131 + SkScalar x() const {
1.132 + return bounds().fLeft;
1.133 + }
1.134 +
1.135 + bool xFlipped() const {
1.136 + return x() != pts()[0].fX;
1.137 + }
1.138 +
1.139 + SkScalar y() const {
1.140 + return bounds().fTop;
1.141 + }
1.142 +
1.143 + bool yFlipped() const {
1.144 + return y() != pts()[0].fY;
1.145 + }
1.146 +
1.147 +#ifdef SK_DEBUG
1.148 + void dump() {
1.149 + SkDPoint::dump(pts()[0]);
1.150 + SkDPoint::dump(pts()[1]);
1.151 + if (verb() >= SkPath::kQuad_Verb) {
1.152 + SkDPoint::dump(pts()[2]);
1.153 + }
1.154 + if (verb() >= SkPath::kCubic_Verb) {
1.155 + SkDPoint::dump(pts()[3]);
1.156 + }
1.157 + }
1.158 +#endif
1.159 +
1.160 +private:
1.161 + SkOpContour* fContour;
1.162 + int fIndex;
1.163 + int fLast;
1.164 +};
