michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: #include "SkOpContour.h"
michael@0: #include "SkPath.h"
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0: #include "SkPathOpsPoint.h"
michael@0: #endif
michael@0: 
michael@0: class SkIntersectionHelper {
michael@0: public:
michael@0:     enum SegmentType {
michael@0:         kHorizontalLine_Segment = -1,
michael@0:         kVerticalLine_Segment = 0,
michael@0:         kLine_Segment = SkPath::kLine_Verb,
michael@0:         kQuad_Segment = SkPath::kQuad_Verb,
michael@0:         kCubic_Segment = SkPath::kCubic_Verb,
michael@0:     };
michael@0: 
michael@0:     bool addCoincident(SkIntersectionHelper& other, const SkIntersections& ts, bool swap) {
michael@0:         return fContour->addCoincident(fIndex, other.fContour, other.fIndex, ts, swap);
michael@0:     }
michael@0: 
michael@0:     // FIXME: does it make sense to write otherIndex now if we're going to
michael@0:     // fix it up later?
michael@0:     void addOtherT(int index, double otherT, int otherIndex) {
michael@0:         fContour->addOtherT(fIndex, index, otherT, otherIndex);
michael@0:     }
michael@0: 
michael@0:     bool addPartialCoincident(SkIntersectionHelper& other, const SkIntersections& ts, int index,
michael@0:             bool swap) {
michael@0:         return fContour->addPartialCoincident(fIndex, other.fContour, other.fIndex, ts, index,
michael@0:                 swap);
michael@0:     }
michael@0: 
michael@0:     // Avoid collapsing t values that are close to the same since
michael@0:     // we walk ts to describe consecutive intersections. Since a pair of ts can
michael@0:     // be nearly equal, any problems caused by this should be taken care
michael@0:     // of later.
michael@0:     // On the edge or out of range values are negative; add 2 to get end
michael@0:     int addT(const SkIntersectionHelper& other, const SkPoint& pt, double newT) {
michael@0:         return fContour->addT(fIndex, other.fContour, other.fIndex, pt, newT);
michael@0:     }
michael@0: 
michael@0:     int addSelfT(const SkIntersectionHelper& other, const SkPoint& pt, double newT) {
michael@0:         return fContour->addSelfT(fIndex, other.fContour, other.fIndex, pt, newT);
michael@0:     }
michael@0: 
michael@0:     bool advance() {
michael@0:         return ++fIndex < fLast;
michael@0:     }
michael@0: 
michael@0:     SkScalar bottom() const {
michael@0:         return bounds().fBottom;
michael@0:     }
michael@0: 
michael@0:     const SkPathOpsBounds& bounds() const {
michael@0:         return fContour->segments()[fIndex].bounds();
michael@0:     }
michael@0: 
michael@0:     void init(SkOpContour* contour) {
michael@0:         fContour = contour;
michael@0:         fIndex = 0;
michael@0:         fLast = contour->segments().count();
michael@0:     }
michael@0: 
michael@0:     bool isAdjacent(const SkIntersectionHelper& next) {
michael@0:         return fContour == next.fContour && fIndex + 1 == next.fIndex;
michael@0:     }
michael@0: 
michael@0:     bool isFirstLast(const SkIntersectionHelper& next) {
michael@0:         return fContour == next.fContour && fIndex == 0
michael@0:                 && next.fIndex == fLast - 1;
michael@0:     }
michael@0: 
michael@0:     bool isPartial(double t1, double t2, const SkDPoint& pt1, const SkDPoint& pt2) const {
michael@0:         const SkOpSegment& segment = fContour->segments()[fIndex];
michael@0:         double mid = (t1 + t2) / 2;
michael@0:         SkDPoint midPtByT = segment.dPtAtT(mid);
michael@0:         SkDPoint midPtByAvg = SkDPoint::Mid(pt1, pt2);
michael@0:         return midPtByT.approximatelyPEqual(midPtByAvg);
michael@0:     }
michael@0: 
michael@0:     SkScalar left() const {
michael@0:         return bounds().fLeft;
michael@0:     }
michael@0: 
michael@0:     const SkPoint* pts() const {
michael@0:         return fContour->segments()[fIndex].pts();
michael@0:     }
michael@0: 
michael@0:     SkScalar right() const {
michael@0:         return bounds().fRight;
michael@0:     }
michael@0: 
michael@0:     SegmentType segmentType() const {
michael@0:         const SkOpSegment& segment = fContour->segments()[fIndex];
michael@0:         SegmentType type = (SegmentType) segment.verb();
michael@0:         if (type != kLine_Segment) {
michael@0:             return type;
michael@0:         }
michael@0:         if (segment.isHorizontal()) {
michael@0:             return kHorizontalLine_Segment;
michael@0:         }
michael@0:         if (segment.isVertical()) {
michael@0:             return kVerticalLine_Segment;
michael@0:         }
michael@0:         return kLine_Segment;
michael@0:     }
michael@0: 
michael@0:     bool startAfter(const SkIntersectionHelper& after) {
michael@0:         fIndex = after.fIndex;
michael@0:         return advance();
michael@0:     }
michael@0: 
michael@0:     SkScalar top() const {
michael@0:         return bounds().fTop;
michael@0:     }
michael@0: 
michael@0:     SkPath::Verb verb() const {
michael@0:         return fContour->segments()[fIndex].verb();
michael@0:     }
michael@0: 
michael@0:     SkScalar x() const {
michael@0:         return bounds().fLeft;
michael@0:     }
michael@0: 
michael@0:     bool xFlipped() const {
michael@0:         return x() != pts()[0].fX;
michael@0:     }
michael@0: 
michael@0:     SkScalar y() const {
michael@0:         return bounds().fTop;
michael@0:     }
michael@0: 
michael@0:     bool yFlipped() const {
michael@0:         return y() != pts()[0].fY;
michael@0:     }
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0:     void dump() {
michael@0:         SkDPoint::dump(pts()[0]);
michael@0:         SkDPoint::dump(pts()[1]);
michael@0:         if (verb() >= SkPath::kQuad_Verb) {
michael@0:             SkDPoint::dump(pts()[2]);
michael@0:         }
michael@0:         if (verb() >= SkPath::kCubic_Verb) {
michael@0:             SkDPoint::dump(pts()[3]);
michael@0:         }
michael@0:     }
michael@0: #endif
michael@0: 
michael@0: private:
michael@0:     SkOpContour* fContour;
michael@0:     int fIndex;
michael@0:     int fLast;
michael@0: };