SkPathOpsQuad.h revision 07393cab57ce74a4aae89a31fae9aaa9780fc19d 
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    void set(const SkPoint pts[3]) {
23        fPts[0] = pts[0];
24        fPts[1] = pts[1];
25        fPts[2] = pts[2];
26    }
27
28    const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < 3); return fPts[n]; }
29    SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < 3); return fPts[n]; }
30
31    static int AddValidTs(double s[], int realRoots, double* t);
32    SkDQuadPair chopAt(double t) const;
33    SkDVector dxdyAtT(double t) const;
34    static int FindExtrema(double a, double b, double c, double tValue[1]);
35    bool isLinear(int startIndex, int endIndex) const;
36    bool monotonicInY() const;
37    double nearestT(const SkDPoint&) const;
38    bool pointInHull(const SkDPoint&) const;
39    static int RootsReal(double A, double B, double C, double t[2]);
40    static int RootsValidT(const double A, const double B, const double C, double s[2]);
41    static void SetABC(const double* quad, double* a, double* b, double* c);
42    SkDQuad subDivide(double t1, double t2) const;
43    static SkDQuad SubDivide(const SkPoint a[3], double t1, double t2) {
44        SkDQuad quad;
45        quad.set(a);
46        return quad.subDivide(t1, t2);
47    }
48    SkDPoint subDivide(const SkDPoint& a, const SkDPoint& c, double t1, double t2) const;
49    static SkDPoint SubDivide(const SkPoint pts[3], const SkDPoint& a, const SkDPoint& c,
50                              double t1, double t2) {
51        SkDQuad quad;
52        quad.set(pts);
53        return quad.subDivide(a, c, t1, t2);
54    }
55    SkDCubic toCubic() const;
56    SkDPoint top(double startT, double endT) const;
57    SkDPoint xyAtT(double t) const;
58private:
59//  static double Tangent(const double* quadratic, double t);  // uncalled
60};
61
62#endif
63