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 SkOpCurve;
14
15struct SkDQuadPair {
16    const SkDQuad& first() const { return (const SkDQuad&) pts[0]; }
17    const SkDQuad& second() const { return (const SkDQuad&) pts[2]; }
18    SkDPoint pts[5];
19};
20
21struct SkDQuad {
22    static const int kPointCount = 3;
23    static const int kPointLast = kPointCount - 1;
24    static const int kMaxIntersections = 4;
25
26    SkDPoint fPts[kPointCount];
27
28    bool collapsed() const {
29        return fPts[0].approximatelyEqual(fPts[1]) && fPts[0].approximatelyEqual(fPts[2]);
30    }
31
32    bool controlsInside() const {
33        SkDVector v01 = fPts[0] - fPts[1];
34        SkDVector v02 = fPts[0] - fPts[2];
35        SkDVector v12 = fPts[1] - fPts[2];
36        return v02.dot(v01) > 0 && v02.dot(v12) > 0;
37    }
38
39    void debugInit() {
40        sk_bzero(fPts, sizeof(fPts));
41    }
42
43    void debugSet(const SkDPoint* pts);
44
45    SkDQuad flip() const {
46        SkDQuad result = {{fPts[2], fPts[1], fPts[0]}  SkDEBUGPARAMS(fDebugGlobalState) };
47        return result;
48    }
49
50    static bool IsConic() { return false; }
51
52    const SkDQuad& set(const SkPoint pts[kPointCount]
53            SkDEBUGPARAMS(SkOpGlobalState* state = nullptr)) {
54        fPts[0] = pts[0];
55        fPts[1] = pts[1];
56        fPts[2] = pts[2];
57        SkDEBUGCODE(fDebugGlobalState = state);
58        return *this;
59    }
60
61    const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < kPointCount); return fPts[n]; }
62    SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < kPointCount); return fPts[n]; }
63
64    static int AddValidTs(double s[], int realRoots, double* t);
65    void align(int endIndex, SkDPoint* dstPt) const;
66    SkDQuadPair chopAt(double t) const;
67    SkDVector dxdyAtT(double t) const;
68    static int FindExtrema(const double src[], double tValue[1]);
69
70#ifdef SK_DEBUG
71    SkOpGlobalState* globalState() const { return fDebugGlobalState; }
72#endif
73
74    /**
75     *  Return the number of valid roots (0 < root < 1) for this cubic intersecting the
76     *  specified horizontal line.
77     */
78    int horizontalIntersect(double yIntercept, double roots[2]) const;
79
80    bool hullIntersects(const SkDQuad& , bool* isLinear) const;
81    bool hullIntersects(const SkDConic& , bool* isLinear) const;
82    bool hullIntersects(const SkDCubic& , bool* isLinear) const;
83    bool isLinear(int startIndex, int endIndex) const;
84    bool monotonicInX() const;
85    bool monotonicInY() const;
86    void otherPts(int oddMan, const SkDPoint* endPt[2]) const;
87    SkDPoint ptAtT(double t) const;
88    static int RootsReal(double A, double B, double C, double t[2]);
89    static int RootsValidT(const double A, const double B, const double C, double s[2]);
90    static void SetABC(const double* quad, double* a, double* b, double* c);
91    SkDQuad subDivide(double t1, double t2) const;
92    static SkDQuad SubDivide(const SkPoint a[kPointCount], double t1, double t2) {
93        SkDQuad quad;
94        quad.set(a);
95        return quad.subDivide(t1, t2);
96    }
97    SkDPoint subDivide(const SkDPoint& a, const SkDPoint& c, double t1, double t2) const;
98    static SkDPoint SubDivide(const SkPoint pts[kPointCount], const SkDPoint& a, const SkDPoint& c,
99                              double t1, double t2) {
100        SkDQuad quad;
101        quad.set(pts);
102        return quad.subDivide(a, c, t1, t2);
103    }
104
105    /**
106     *  Return the number of valid roots (0 < root < 1) for this cubic intersecting the
107     *  specified vertical line.
108     */
109    int verticalIntersect(double xIntercept, double roots[2]) const;
110
111    SkDCubic debugToCubic() const;
112    // utilities callable by the user from the debugger when the implementation code is linked in
113    void dump() const;
114    void dumpID(int id) const;
115    void dumpInner() const;
116
117    SkDEBUGCODE(SkOpGlobalState* fDebugGlobalState);
118};
119
120#endif
121