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 SkPathOpsQuad_DEFINED
9#define SkPathOpsQuad_DEFINED
10
11#include "SkPathOpsPoint.h"
12
13struct SkDQuadPair {
14    const SkDQuad& first() const { return (const SkDQuad&) pts[0]; }
15    const SkDQuad& second() const { return (const SkDQuad&) pts[2]; }
16    SkDPoint pts[5];
17};
18
19struct SkDQuad {
20    SkDPoint fPts[3];
21
22    SkDQuad flip() const {
23        SkDQuad result = {{fPts[2], fPts[1], fPts[0]}};
24        return result;
25    }
26
27    void set(const SkPoint pts[3]) {
28        fPts[0] = pts[0];
29        fPts[1] = pts[1];
30        fPts[2] = pts[2];
31    }
32
33    const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < 3); return fPts[n]; }
34    SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < 3); return fPts[n]; }
35
36    static int AddValidTs(double s[], int realRoots, double* t);
37    void align(int endIndex, SkDPoint* dstPt) const;
38    SkDQuadPair chopAt(double t) const;
39    SkDVector dxdyAtT(double t) const;
40    static int FindExtrema(double a, double b, double c, double tValue[1]);
41    bool isLinear(int startIndex, int endIndex) const;
42    bool monotonicInY() const;
43    double nearestT(const SkDPoint&) const;
44    bool pointInHull(const SkDPoint&) const;
45    SkDPoint ptAtT(double t) const;
46    static int RootsReal(double A, double B, double C, double t[2]);
47    static int RootsValidT(const double A, const double B, const double C, double s[2]);
48    static void SetABC(const double* quad, double* a, double* b, double* c);
49    SkDQuad subDivide(double t1, double t2) const;
50    static SkDQuad SubDivide(const SkPoint a[3], double t1, double t2) {
51        SkDQuad quad;
52        quad.set(a);
53        return quad.subDivide(t1, t2);
54    }
55    SkDPoint subDivide(const SkDPoint& a, const SkDPoint& c, double t1, double t2) const;
56    static SkDPoint SubDivide(const SkPoint pts[3], const SkDPoint& a, const SkDPoint& c,
57                              double t1, double t2) {
58        SkDQuad quad;
59        quad.set(pts);
60        return quad.subDivide(a, c, t1, t2);
61    }
62    SkDCubic toCubic() const;
63    SkDPoint top(double startT, double endT) const;
64
65    // utilities callable by the user from the debugger when the implementation code is linked in
66    void dump() const;
67    void dumpComma(const char*) const;
68
69private:
70//  static double Tangent(const double* quadratic, double t);  // uncalled
71};
72
73#endif
74