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: 
michael@0: #ifndef SkPathOpsCubic_DEFINED
michael@0: #define SkPathOpsCubic_DEFINED
michael@0: 
michael@0: #include "SkPath.h"
michael@0: #include "SkPathOpsPoint.h"
michael@0: #include "SkTArray.h"
michael@0: 
michael@0: struct SkDCubicPair {
michael@0:     const SkDCubic& first() const { return (const SkDCubic&) pts[0]; }
michael@0:     const SkDCubic& second() const { return (const SkDCubic&) pts[3]; }
michael@0:     SkDPoint pts[7];
michael@0: };
michael@0: 
michael@0: struct SkDCubic {
michael@0:     SkDPoint fPts[4];
michael@0: 
michael@0:     void set(const SkPoint pts[4]) {
michael@0:         fPts[0] = pts[0];
michael@0:         fPts[1] = pts[1];
michael@0:         fPts[2] = pts[2];
michael@0:         fPts[3] = pts[3];
michael@0:     }
michael@0: 
michael@0:     static const int gPrecisionUnit;
michael@0: 
michael@0:     const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < 4); return fPts[n]; }
michael@0:     SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < 4); return fPts[n]; }
michael@0: 
michael@0:     void align(int endIndex, int ctrlIndex, SkDPoint* dstPt) const;
michael@0:     double calcPrecision() const;
michael@0:     SkDCubicPair chopAt(double t) const;
michael@0:     bool clockwise() const;
michael@0:     static void Coefficients(const double* cubic, double* A, double* B, double* C, double* D);
michael@0:     bool controlsContainedByEnds() const;
michael@0:     SkDVector dxdyAtT(double t) const;
michael@0:     bool endsAreExtremaInXOrY() const;
michael@0:     static int FindExtrema(double a, double b, double c, double d, double tValue[2]);
michael@0:     int findInflections(double tValues[]) const;
michael@0: 
michael@0:     static int FindInflections(const SkPoint a[4], double tValues[]) {
michael@0:         SkDCubic cubic;
michael@0:         cubic.set(a);
michael@0:         return cubic.findInflections(tValues);
michael@0:     }
michael@0: 
michael@0:     int findMaxCurvature(double tValues[]) const;
michael@0:     bool isLinear(int startIndex, int endIndex) const;
michael@0:     bool monotonicInY() const;
michael@0:     SkDPoint ptAtT(double t) const;
michael@0:     static int RootsReal(double A, double B, double C, double D, double t[3]);
michael@0:     static int RootsValidT(const double A, const double B, const double C, double D, double s[3]);
michael@0:     bool serpentine() const;
michael@0:     SkDCubic subDivide(double t1, double t2) const;
michael@0: 
michael@0:     static SkDCubic SubDivide(const SkPoint a[4], double t1, double t2) {
michael@0:         SkDCubic cubic;
michael@0:         cubic.set(a);
michael@0:         return cubic.subDivide(t1, t2);
michael@0:     }
michael@0: 
michael@0:     void subDivide(const SkDPoint& a, const SkDPoint& d, double t1, double t2, SkDPoint p[2]) const;
michael@0: 
michael@0:     static void SubDivide(const SkPoint pts[4], const SkDPoint& a, const SkDPoint& d, double t1,
michael@0:                           double t2, SkDPoint p[2]) {
michael@0:         SkDCubic cubic;
michael@0:         cubic.set(pts);
michael@0:         cubic.subDivide(a, d, t1, t2, p);
michael@0:     }
michael@0: 
michael@0:     SkDPoint top(double startT, double endT) const;
michael@0:     void toQuadraticTs(double precision, SkTArray<double, true>* ts) const;
michael@0:     SkDQuad toQuad() const;
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0:     void dump();
michael@0: #endif
michael@0: };
michael@0: 
michael@0: #endif