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 8 #ifndef SkPathOpsCubic_DEFINED 9 #define SkPathOpsCubic_DEFINED 10 11 #include "SkPath.h" 12 #include "SkPathOpsPoint.h" 13 #include "SkTArray.h" 14 15 struct SkDCubicPair { firstSkDCubicPair16 const SkDCubic& first() const { return (const SkDCubic&) pts[0]; } secondSkDCubicPair17 const SkDCubic& second() const { return (const SkDCubic&) pts[3]; } 18 SkDPoint pts[7]; 19 }; 20 21 struct SkDCubic { 22 enum SearchAxis { 23 kXAxis, 24 kYAxis 25 }; 26 27 const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < 4); return fPts[n]; } 28 SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < 4); return fPts[n]; } 29 30 void align(int endIndex, int ctrlIndex, SkDPoint* dstPt) const; 31 double binarySearch(double min, double max, double axisIntercept, SearchAxis xAxis) const; 32 double calcPrecision() const; 33 SkDCubicPair chopAt(double t) const; 34 bool clockwise() const; 35 static void Coefficients(const double* cubic, double* A, double* B, double* C, double* D); 36 bool controlsContainedByEnds() const; 37 SkDVector dxdyAtT(double t) const; 38 bool endsAreExtremaInXOrY() const; 39 static int FindExtrema(double a, double b, double c, double d, double tValue[2]); 40 int findInflections(double tValues[2]) const; 41 FindInflectionsSkDCubic42 static int FindInflections(const SkPoint a[4], double tValues[2]) { 43 SkDCubic cubic; 44 cubic.set(a); 45 return cubic.findInflections(tValues); 46 } 47 48 int findMaxCurvature(double tValues[]) const; 49 bool isLinear(int startIndex, int endIndex) const; 50 bool monotonicInY() const; 51 SkDPoint ptAtT(double t) const; 52 static int RootsReal(double A, double B, double C, double D, double t[3]); 53 static int RootsValidT(const double A, const double B, const double C, double D, double s[3]); 54 55 int searchRoots(double extremes[6], int extrema, double axisIntercept, 56 SearchAxis xAxis, double* validRoots) const; 57 bool serpentine() const; 58 setSkDCubic59 void set(const SkPoint pts[4]) { 60 fPts[0] = pts[0]; 61 fPts[1] = pts[1]; 62 fPts[2] = pts[2]; 63 fPts[3] = pts[3]; 64 } 65 66 SkDCubic subDivide(double t1, double t2) const; 67 SubDivideSkDCubic68 static SkDCubic SubDivide(const SkPoint a[4], double t1, double t2) { 69 SkDCubic cubic; 70 cubic.set(a); 71 return cubic.subDivide(t1, t2); 72 } 73 74 void subDivide(const SkDPoint& a, const SkDPoint& d, double t1, double t2, SkDPoint p[2]) const; 75 SubDivideSkDCubic76 static void SubDivide(const SkPoint pts[4], const SkDPoint& a, const SkDPoint& d, double t1, 77 double t2, SkDPoint p[2]) { 78 SkDCubic cubic; 79 cubic.set(pts); 80 cubic.subDivide(a, d, t1, t2, p); 81 } 82 83 SkDPoint top(double startT, double endT) const; 84 void toQuadraticTs(double precision, SkTArray<double, true>* ts) const; 85 SkDQuad toQuad() const; 86 87 // utilities callable by the user from the debugger when the implementation code is linked in 88 void dump() const; 89 void dumpNumber() const; 90 91 static const int gPrecisionUnit; 92 93 SkDPoint fPts[4]; 94 }; 95 96 #endif 97