1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7#ifndef SkOpSegment_DEFINE
8#define SkOpSegment_DEFINE
9
10#include "SkOpAngle.h"
11#include "SkOpSpan.h"
12#include "SkPathOpsBounds.h"
13#include "SkPathOpsCurve.h"
14#include "SkTArray.h"
15#include "SkTDArray.h"
16
17#if defined(SK_DEBUG) || !FORCE_RELEASE
18#include "SkThread.h"
19#endif
20
21struct SkCoincidence;
22class SkPathWriter;
23
24class SkOpSegment {
25public:
26    SkOpSegment() {
27#if defined(SK_DEBUG) || !FORCE_RELEASE
28        fID = sk_atomic_inc(&SkPathOpsDebug::gSegmentID);
29#endif
30    }
31
32    bool operator<(const SkOpSegment& rh) const {
33        return fBounds.fTop < rh.fBounds.fTop;
34    }
35
36    struct AlignedSpan  {
37        double fOldT;
38        double fT;
39        SkPoint fOldPt;
40        SkPoint fPt;
41        const SkOpSegment* fSegment;
42        const SkOpSegment* fOther1;
43        const SkOpSegment* fOther2;
44    };
45
46    const SkPathOpsBounds& bounds() const {
47        return fBounds;
48    }
49
50    // OPTIMIZE
51    // when the edges are initially walked, they don't automatically get the prior and next
52    // edges assigned to positions t=0 and t=1. Doing that would remove the need for this check,
53    // and would additionally remove the need for similar checks in condition edges. It would
54    // also allow intersection code to assume end of segment intersections (maybe?)
55    bool complete() const {
56        int count = fTs.count();
57        return count > 1 && fTs[0].fT == 0 && fTs[--count].fT == 1;
58    }
59
60    int count() const {
61        return fTs.count();
62    }
63
64    bool done() const {
65        SkASSERT(fDoneSpans <= fTs.count());
66        return fDoneSpans == fTs.count();
67    }
68
69    bool done(int min) const {
70        return fTs[min].fDone;
71    }
72
73    bool done(const SkOpAngle* angle) const {
74        return done(SkMin32(angle->start(), angle->end()));
75    }
76
77    SkDPoint dPtAtT(double mid) const {
78        return (*CurveDPointAtT[SkPathOpsVerbToPoints(fVerb)])(fPts, mid);
79    }
80
81    SkVector dxdy(int index) const {
82        return (*CurveSlopeAtT[SkPathOpsVerbToPoints(fVerb)])(fPts, fTs[index].fT);
83    }
84
85    SkScalar dy(int index) const {
86        return dxdy(index).fY;
87    }
88
89    bool hasMultiples() const {
90        return fMultiples;
91    }
92
93    bool hasSmall() const {
94        return fSmall;
95    }
96
97    bool hasTiny() const {
98        return fTiny;
99    }
100
101    bool intersected() const {
102        return fTs.count() > 0;
103    }
104
105    bool isCanceled(int tIndex) const {
106        return fTs[tIndex].fWindValue == 0 && fTs[tIndex].fOppValue == 0;
107    }
108
109    bool isConnected(int startIndex, int endIndex) const {
110        return fTs[startIndex].fWindSum != SK_MinS32 || fTs[endIndex].fWindSum != SK_MinS32;
111    }
112
113    bool isHorizontal() const {
114        return fBounds.fTop == fBounds.fBottom;
115    }
116
117    bool isVertical() const {
118        return fBounds.fLeft == fBounds.fRight;
119    }
120
121    bool isVertical(int start, int end) const {
122        return (*CurveIsVertical[SkPathOpsVerbToPoints(fVerb)])(fPts, start, end);
123    }
124
125    bool operand() const {
126        return fOperand;
127    }
128
129    int oppSign(const SkOpAngle* angle) const {
130        SkASSERT(angle->segment() == this);
131        return oppSign(angle->start(), angle->end());
132    }
133
134    int oppSign(int startIndex, int endIndex) const {
135        int result = startIndex < endIndex ? -fTs[startIndex].fOppValue : fTs[endIndex].fOppValue;
136#if DEBUG_WIND_BUMP
137        SkDebugf("%s oppSign=%d\n", __FUNCTION__, result);
138#endif
139        return result;
140    }
141
142    int oppSum(int tIndex) const {
143        return fTs[tIndex].fOppSum;
144    }
145
146    int oppSum(const SkOpAngle* angle) const {
147        int lesser = SkMin32(angle->start(), angle->end());
148        return fTs[lesser].fOppSum;
149    }
150
151    int oppValue(int tIndex) const {
152        return fTs[tIndex].fOppValue;
153    }
154
155    int oppValue(const SkOpAngle* angle) const {
156        int lesser = SkMin32(angle->start(), angle->end());
157        return fTs[lesser].fOppValue;
158    }
159
160#if DEBUG_VALIDATE
161    bool oppXor() const {
162        return fOppXor;
163    }
164#endif
165
166    SkPoint ptAtT(double mid) const {
167        return (*CurvePointAtT[SkPathOpsVerbToPoints(fVerb)])(fPts, mid);
168    }
169
170    const SkPoint* pts() const {
171        return fPts;
172    }
173
174    void reset() {
175        init(NULL, (SkPath::Verb) -1, false, false);
176        fBounds.set(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, SK_ScalarMax);
177        fTs.reset();
178    }
179
180    void setOppXor(bool isOppXor) {
181        fOppXor = isOppXor;
182    }
183
184    void setUpWinding(int index, int endIndex, int* maxWinding, int* sumWinding) {
185        int deltaSum = spanSign(index, endIndex);
186        *maxWinding = *sumWinding;
187        *sumWinding -= deltaSum;
188    }
189
190    const SkOpSpan& span(int tIndex) const {
191        return fTs[tIndex];
192    }
193
194    const SkOpAngle* spanToAngle(int tStart, int tEnd) const {
195        SkASSERT(tStart != tEnd);
196        const SkOpSpan& span = fTs[tStart];
197        return tStart < tEnd ? span.fToAngle : span.fFromAngle;
198    }
199
200    // FIXME: create some sort of macro or template that avoids casting
201    SkOpAngle* spanToAngle(int tStart, int tEnd) {
202        const SkOpAngle* cAngle = (const_cast<const SkOpSegment*>(this))->spanToAngle(tStart, tEnd);
203        return const_cast<SkOpAngle*>(cAngle);
204    }
205
206    int spanSign(const SkOpAngle* angle) const {
207        SkASSERT(angle->segment() == this);
208        return spanSign(angle->start(), angle->end());
209    }
210
211    int spanSign(int startIndex, int endIndex) const {
212        int result = startIndex < endIndex ? -fTs[startIndex].fWindValue : fTs[endIndex].fWindValue;
213#if DEBUG_WIND_BUMP
214        SkDebugf("%s spanSign=%d\n", __FUNCTION__, result);
215#endif
216        return result;
217    }
218
219    double t(int tIndex) const {
220        return fTs[tIndex].fT;
221    }
222
223    double tAtMid(int start, int end, double mid) const {
224        return fTs[start].fT * (1 - mid) + fTs[end].fT * mid;
225    }
226
227    void updatePts(const SkPoint pts[]) {
228        fPts = pts;
229    }
230
231    SkPath::Verb verb() const {
232        return fVerb;
233    }
234
235    int windSum(int tIndex) const {
236        return fTs[tIndex].fWindSum;
237    }
238
239    int windValue(int tIndex) const {
240        return fTs[tIndex].fWindValue;
241    }
242
243#if defined(SK_DEBUG) || DEBUG_WINDING
244    SkScalar xAtT(int index) const {
245        return xAtT(&fTs[index]);
246    }
247#endif
248
249#if DEBUG_VALIDATE
250    bool _xor() const {  // FIXME: used only by SkOpAngle::debugValidateLoop()
251        return fXor;
252    }
253#endif
254
255    const SkPoint& xyAtT(const SkOpSpan* span) const {
256        return span->fPt;
257    }
258
259    const SkPoint& xyAtT(int index) const {
260        return xyAtT(&fTs[index]);
261    }
262
263#if defined(SK_DEBUG) || DEBUG_WINDING
264    SkScalar yAtT(int index) const {
265        return yAtT(&fTs[index]);
266    }
267#endif
268
269    const SkOpAngle* activeAngle(int index, int* start, int* end, bool* done,
270                                 bool* sortable) const;
271    SkPoint activeLeftTop(int* firstT) const;
272    bool activeOp(int index, int endIndex, int xorMiMask, int xorSuMask, SkPathOp op);
273    bool activeWinding(int index, int endIndex);
274    void addCubic(const SkPoint pts[4], bool operand, bool evenOdd);
275    void addCurveTo(int start, int end, SkPathWriter* path, bool active) const;
276    void addEndSpan(int endIndex);
277    void addLine(const SkPoint pts[2], bool operand, bool evenOdd);
278    void addOtherT(int index, double otherT, int otherIndex);
279    void addQuad(const SkPoint pts[3], bool operand, bool evenOdd);
280    void addSimpleAngle(int endIndex);
281    int addSelfT(const SkPoint& pt, double newT);
282    void addStartSpan(int endIndex);
283    int addT(SkOpSegment* other, const SkPoint& pt, double newT);
284    void addTCancel(const SkPoint& startPt, const SkPoint& endPt, SkOpSegment* other);
285    void addTCoincident(const SkPoint& startPt, const SkPoint& endPt, double endT,
286                        SkOpSegment* other);
287    const SkOpSpan* addTPair(double t, SkOpSegment* other, double otherT, bool borrowWind,
288                             const SkPoint& pt);
289    const SkOpSpan* addTPair(double t, SkOpSegment* other, double otherT, bool borrowWind,
290                             const SkPoint& pt, const SkPoint& oPt);
291    void alignMultiples(SkTDArray<AlignedSpan>* aligned);
292    bool alignSpan(int index, double thisT, const SkPoint& thisPt);
293    void alignSpanState(int start, int end);
294    bool betweenTs(int lesser, double testT, int greater) const;
295    void blindCancel(const SkCoincidence& coincidence, SkOpSegment* other);
296    void blindCoincident(const SkCoincidence& coincidence, SkOpSegment* other);
297    bool calcAngles();
298    double calcMissingTEnd(const SkOpSegment* ref, double loEnd, double min, double max,
299                           double hiEnd, const SkOpSegment* other, int thisEnd);
300    double calcMissingTStart(const SkOpSegment* ref, double loEnd, double min, double max,
301                             double hiEnd, const SkOpSegment* other, int thisEnd);
302    void checkDuplicates();
303    void checkEnds();
304    void checkMultiples();
305    void checkSmall();
306    bool checkSmall(int index) const;
307    void checkTiny();
308    int computeSum(int startIndex, int endIndex, SkOpAngle::IncludeType includeType);
309    bool containsPt(const SkPoint& , int index, int endIndex) const;
310    int crossedSpanY(const SkPoint& basePt, SkScalar* bestY, double* hitT, bool* hitSomething,
311                     double mid, bool opp, bool current) const;
312    bool findCoincidentMatch(const SkOpSpan* span, const SkOpSegment* other, int oStart, int oEnd,
313                             int step, SkPoint* startPt, SkPoint* endPt, double* endT) const;
314    SkOpSegment* findNextOp(SkTDArray<SkOpSpan*>* chase, int* nextStart, int* nextEnd,
315                            bool* unsortable, SkPathOp op, int xorMiMask, int xorSuMask);
316    SkOpSegment* findNextWinding(SkTDArray<SkOpSpan*>* chase, int* nextStart, int* nextEnd,
317                                 bool* unsortable);
318    SkOpSegment* findNextXor(int* nextStart, int* nextEnd, bool* unsortable);
319    int findExactT(double t, const SkOpSegment* ) const;
320    int findOtherT(double t, const SkOpSegment* ) const;
321    int findT(double t, const SkPoint& , const SkOpSegment* ) const;
322    SkOpSegment* findTop(int* tIndex, int* endIndex, bool* unsortable, bool firstPass);
323    void fixOtherTIndex();
324    void initWinding(int start, int end, SkOpAngle::IncludeType angleIncludeType);
325    void initWinding(int start, int end, double tHit, int winding, SkScalar hitDx, int oppWind,
326                     SkScalar hitOppDx);
327    bool isMissing(double startT, const SkPoint& pt) const;
328    bool isTiny(const SkOpAngle* angle) const;
329    bool joinCoincidence(SkOpSegment* other, double otherT, const SkPoint& otherPt, int step,
330                         bool cancel);
331    SkOpSpan* markAndChaseDoneBinary(int index, int endIndex);
332    SkOpSpan* markAndChaseDoneUnary(int index, int endIndex);
333    SkOpSpan* markAndChaseWinding(const SkOpAngle* angle, int winding, int oppWinding);
334    SkOpSpan* markAngle(int maxWinding, int sumWinding, int oppMaxWinding, int oppSumWinding,
335                        const SkOpAngle* angle);
336    void markDone(int index, int winding);
337    void markDoneBinary(int index);
338    void markDoneUnary(int index);
339    bool nextCandidate(int* start, int* end) const;
340    int nextSpan(int from, int step) const;
341    void pinT(const SkPoint& pt, double* t);
342    void setUpWindings(int index, int endIndex, int* sumMiWinding, int* sumSuWinding,
343            int* maxWinding, int* sumWinding, int* oppMaxWinding, int* oppSumWinding);
344    void sortAngles();
345    bool subDivide(int start, int end, SkPoint edge[4]) const;
346    bool subDivide(int start, int end, SkDCubic* result) const;
347    void undoneSpan(int* start, int* end);
348    int updateOppWindingReverse(const SkOpAngle* angle) const;
349    int updateWindingReverse(const SkOpAngle* angle) const;
350    static bool UseInnerWinding(int outerWinding, int innerWinding);
351    static bool UseInnerWindingReverse(int outerWinding, int innerWinding);
352    int windingAtT(double tHit, int tIndex, bool crossOpp, SkScalar* dx) const;
353    int windSum(const SkOpAngle* angle) const;
354// available for testing only
355#if defined(SK_DEBUG) || !FORCE_RELEASE
356    int debugID() const {
357        return fID;
358    }
359#else
360    int debugID() const {
361        return -1;
362    }
363#endif
364#if DEBUG_ACTIVE_SPANS || DEBUG_ACTIVE_SPANS_FIRST_ONLY
365    void debugShowActiveSpans() const;
366#endif
367#if DEBUG_CONCIDENT
368    void debugShowTs(const char* prefix) const;
369#endif
370#if DEBUG_SHOW_WINDING
371    int debugShowWindingValues(int slotCount, int ofInterest) const;
372#endif
373    const SkTDArray<SkOpSpan>& debugSpans() const;
374    void debugValidate() const;
375    // available to testing only
376    const SkOpAngle* debugLastAngle() const;
377    void dumpAngles() const;
378    void dumpContour(int firstID, int lastID) const;
379    void dumpPts() const;
380    void dumpSpans() const;
381
382private:
383    struct MissingSpan  {
384        double fT;
385        double fEndT;
386        SkOpSegment* fSegment;
387        SkOpSegment* fOther;
388        double fOtherT;
389        SkPoint fPt;
390    };
391
392    const SkOpAngle* activeAngleInner(int index, int* start, int* end, bool* done,
393                                      bool* sortable) const;
394    const SkOpAngle* activeAngleOther(int index, int* start, int* end, bool* done,
395                                      bool* sortable) const;
396    bool activeOp(int xorMiMask, int xorSuMask, int index, int endIndex, SkPathOp op,
397                  int* sumMiWinding, int* sumSuWinding);
398    bool activeWinding(int index, int endIndex, int* sumWinding);
399    void addCancelOutsides(const SkPoint& startPt, const SkPoint& endPt, SkOpSegment* other);
400    void addCoinOutsides(const SkPoint& startPt, const SkPoint& endPt, SkOpSegment* other);
401    SkOpAngle* addSingletonAngleDown(SkOpSegment** otherPtr, SkOpAngle** );
402    SkOpAngle* addSingletonAngleUp(SkOpSegment** otherPtr, SkOpAngle** );
403    SkOpAngle* addSingletonAngles(int step);
404    void alignSpan(const SkPoint& newPt, double newT, const SkOpSegment* other, double otherT,
405                   const SkOpSegment* other2, SkOpSpan* oSpan, SkTDArray<AlignedSpan>* );
406    bool betweenPoints(double midT, const SkPoint& pt1, const SkPoint& pt2) const;
407    void bumpCoincidentBlind(bool binary, int index, int last);
408    void bumpCoincidentThis(const SkOpSpan& oTest, bool binary, int* index,
409                           SkTArray<SkPoint, true>* outsideTs);
410    void bumpCoincidentOBlind(int index, int last);
411    void bumpCoincidentOther(const SkOpSpan& oTest, int* index,
412                           SkTArray<SkPoint, true>* outsideTs);
413    bool bumpSpan(SkOpSpan* span, int windDelta, int oppDelta);
414    bool calcLoopSpanCount(const SkOpSpan& thisSpan, int* smallCounts);
415    bool checkForSmall(const SkOpSpan* span, const SkPoint& pt, double newT,
416                       int* less, int* more) const;
417    void checkLinks(const SkOpSpan* ,
418                    SkTArray<MissingSpan, true>* missingSpans) const;
419    static void CheckOneLink(const SkOpSpan* test, const SkOpSpan* oSpan,
420                             const SkOpSpan* oFirst, const SkOpSpan* oLast,
421                             const SkOpSpan** missingPtr,
422                             SkTArray<MissingSpan, true>* missingSpans);
423    int checkSetAngle(int tIndex) const;
424    void checkSmallCoincidence(const SkOpSpan& span, SkTArray<MissingSpan, true>* );
425    bool coincidentSmall(const SkPoint& pt, double t, const SkOpSegment* other) const;
426    bool clockwise(int tStart, int tEnd, bool* swap) const;
427    static void ComputeOneSum(const SkOpAngle* baseAngle, SkOpAngle* nextAngle,
428                              SkOpAngle::IncludeType );
429    static void ComputeOneSumReverse(const SkOpAngle* baseAngle, SkOpAngle* nextAngle,
430                                     SkOpAngle::IncludeType );
431    bool containsT(double t, const SkOpSegment* other, double otherT) const;
432    bool decrementSpan(SkOpSpan* span);
433    int findEndSpan(int endIndex) const;
434    int findStartSpan(int startIndex) const;
435    int firstActive(int tIndex) const;
436    const SkOpSpan& firstSpan(const SkOpSpan& thisSpan) const;
437    void init(const SkPoint pts[], SkPath::Verb verb, bool operand, bool evenOdd);
438    bool inCoincidentSpan(double t, const SkOpSegment* other) const;
439    bool inLoop(const SkOpAngle* baseAngle, int spanCount, int* indexPtr) const;
440#if OLD_CHASE
441    bool isSimple(int end) const;
442#else
443    SkOpSegment* isSimple(int* end, int* step);
444#endif
445    bool isTiny(int index) const;
446    const SkOpSpan& lastSpan(const SkOpSpan& thisSpan) const;
447    void matchWindingValue(int tIndex, double t, bool borrowWind);
448    SkOpSpan* markAndChaseDone(int index, int endIndex, int winding);
449    SkOpSpan* markAndChaseDoneBinary(const SkOpAngle* angle, int winding, int oppWinding);
450    SkOpSpan* markAndChaseWinding(const SkOpAngle* angle, int winding);
451    SkOpSpan* markAndChaseWinding(int index, int endIndex, int winding);
452    SkOpSpan* markAndChaseWinding(int index, int endIndex, int winding, int oppWinding);
453    SkOpSpan* markAngle(int maxWinding, int sumWinding, const SkOpAngle* angle);
454    void markDoneBinary(int index, int winding, int oppWinding);
455    SkOpSpan* markAndChaseDoneUnary(const SkOpAngle* angle, int winding);
456    void markOneDone(const char* funName, int tIndex, int winding);
457    void markOneDoneBinary(const char* funName, int tIndex);
458    void markOneDoneBinary(const char* funName, int tIndex, int winding, int oppWinding);
459    void markOneDoneUnary(const char* funName, int tIndex);
460    SkOpSpan* markOneWinding(const char* funName, int tIndex, int winding);
461    SkOpSpan* markOneWinding(const char* funName, int tIndex, int winding, int oppWinding);
462    void markWinding(int index, int winding);
463    void markWinding(int index, int winding, int oppWinding);
464    bool monotonicInY(int tStart, int tEnd) const;
465
466    bool multipleEnds() const { return fTs[count() - 2].fT == 1; }
467    bool multipleStarts() const { return fTs[1].fT == 0; }
468
469    SkOpSegment* nextChase(int* index, int* step, int* min, SkOpSpan** last);
470    int nextExactSpan(int from, int step) const;
471    bool serpentine(int tStart, int tEnd) const;
472    void setCoincidentRange(const SkPoint& startPt, const SkPoint& endPt,  SkOpSegment* other);
473    void setFromAngle(int endIndex, SkOpAngle* );
474    void setToAngle(int endIndex, SkOpAngle* );
475    void setUpWindings(int index, int endIndex, int* sumMiWinding,
476            int* maxWinding, int* sumWinding);
477    void subDivideBounds(int start, int end, SkPathOpsBounds* bounds) const;
478    static void TrackOutsidePair(SkTArray<SkPoint, true>* outsideTs, const SkPoint& endPt,
479            const SkPoint& startPt);
480    static void TrackOutside(SkTArray<SkPoint, true>* outsideTs, const SkPoint& startPt);
481    int updateOppWinding(int index, int endIndex) const;
482    int updateOppWinding(const SkOpAngle* angle) const;
483    int updateWinding(int index, int endIndex) const;
484    int updateWinding(const SkOpAngle* angle) const;
485    int updateWindingReverse(int index, int endIndex) const;
486    SkOpSpan* verifyOneWinding(const char* funName, int tIndex);
487    SkOpSpan* verifyOneWindingU(const char* funName, int tIndex);
488
489    SkScalar xAtT(const SkOpSpan* span) const {
490        return xyAtT(span).fX;
491    }
492
493    SkScalar yAtT(const SkOpSpan* span) const {
494        return xyAtT(span).fY;
495    }
496
497    void zeroSpan(SkOpSpan* span);
498
499#if DEBUG_SWAP_TOP
500    bool controlsContainedByEnds(int tStart, int tEnd) const;
501#endif
502    void debugAddAngle(int start, int end);
503#if DEBUG_CONCIDENT
504    void debugAddTPair(double t, const SkOpSegment& other, double otherT) const;
505#endif
506#if DEBUG_ANGLE
507    void debugCheckPointsEqualish(int tStart, int tEnd) const;
508#endif
509#if DEBUG_SWAP_TOP
510    int debugInflections(int index, int endIndex) const;
511#endif
512#if DEBUG_MARK_DONE || DEBUG_UNSORTABLE
513    void debugShowNewWinding(const char* fun, const SkOpSpan& span, int winding);
514    void debugShowNewWinding(const char* fun, const SkOpSpan& span, int winding, int oppWinding);
515#endif
516#if DEBUG_WINDING
517    static char as_digit(int value) {
518        return value < 0 ? '?' : value <= 9 ? '0' + value : '+';
519    }
520#endif
521    // available to testing only
522    void debugConstruct();
523    void debugConstructCubic(SkPoint shortQuad[4]);
524    void debugConstructLine(SkPoint shortQuad[2]);
525    void debugConstructQuad(SkPoint shortQuad[3]);
526    void debugReset();
527    void dumpDPts() const;
528    void dumpSpan(int index) const;
529
530    const SkPoint* fPts;
531    SkPathOpsBounds fBounds;
532    // FIXME: can't convert to SkTArray because it uses insert
533    SkTDArray<SkOpSpan> fTs;  // 2+ (always includes t=0 t=1) -- at least (number of spans) + 1
534    SkOpAngleSet fAngles;  // empty or 2+ -- (number of non-zero spans) * 2
535    // OPTIMIZATION: could pack donespans, verb, operand, xor into 1 int-sized value
536    int fDoneSpans;  // quick check that segment is finished
537    // OPTIMIZATION: force the following to be byte-sized
538    SkPath::Verb fVerb;
539    bool fLoop;   // set if cubic intersects itself
540    bool fMultiples;  // set if curve intersects multiple other curves at one interior point
541    bool fOperand;
542    bool fXor;  // set if original contour had even-odd fill
543    bool fOppXor;  // set if opposite operand had even-odd fill
544    bool fSmall;  // set if some span is small
545    bool fTiny;  // set if some span is tiny
546#if defined(SK_DEBUG) || !FORCE_RELEASE
547    int fID;
548#endif
549
550    friend class PathOpsSegmentTester;
551};
552
553#endif
554