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 "src/core/SkArenaAlloc.h"
12#include "src/pathops/SkPathOpsTCurve.h"
13
14struct SkOpCurve;
15
16struct SkDQuadPair {
17    const SkDQuad& first() const { return (const SkDQuad&) pts[0]; }
18    const SkDQuad& second() const { return (const SkDQuad&) pts[2]; }
19    SkDPoint pts[5];
20};
21
22struct SkDQuad {
23    static const int kPointCount = 3;
24    static const int kPointLast = kPointCount - 1;
25    static const int kMaxIntersections = 4;
26
27    SkDPoint fPts[kPointCount];
28
29    bool collapsed() const {
30        return fPts[0].approximatelyEqual(fPts[1]) && fPts[0].approximatelyEqual(fPts[2]);
31    }
32
33    bool controlsInside() const {
34        SkDVector v01 = fPts[0] - fPts[1];
35        SkDVector v02 = fPts[0] - fPts[2];
36        SkDVector v12 = fPts[1] - fPts[2];
37        return v02.dot(v01) > 0 && v02.dot(v12) > 0;
38    }
39
40    void debugInit() {
41        sk_bzero(fPts, sizeof(fPts));
42    }
43
44    void debugSet(const SkDPoint* pts);
45
46    SkDQuad flip() const {
47        SkDQuad result = {{fPts[2], fPts[1], fPts[0]}  SkDEBUGPARAMS(fDebugGlobalState) };
48        return result;
49    }
50
51    static bool IsConic() { return false; }
52
53    const SkDQuad& set(const SkPoint pts[kPointCount]
54            SkDEBUGPARAMS(SkOpGlobalState* state = nullptr)) {
55        fPts[0] = pts[0];
56        fPts[1] = pts[1];
57        fPts[2] = pts[2];
58        SkDEBUGCODE(fDebugGlobalState = state);
59        return *this;
60    }
61
62    const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < kPointCount); return fPts[n]; }
63    SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < kPointCount); return fPts[n]; }
64
65    static int AddValidTs(double s[], int realRoots, double* t);
66    void align(int endIndex, SkDPoint* dstPt) const;
67    SkDQuadPair chopAt(double t) const;
68    SkDVector dxdyAtT(double t) const;
69    static int FindExtrema(const double src[], double tValue[1]);
70
71#ifdef SK_DEBUG
72    SkOpGlobalState* globalState() const { return fDebugGlobalState; }
73#endif
74
75    /**
76     *  Return the number of valid roots (0 < root < 1) for this cubic intersecting the
77     *  specified horizontal line.
78     */
79    int horizontalIntersect(double yIntercept, double roots[2]) const;
80
81    bool hullIntersects(const SkDQuad& , bool* isLinear) const;
82    bool hullIntersects(const SkDConic& , bool* isLinear) const;
83    bool hullIntersects(const SkDCubic& , bool* isLinear) const;
84    bool isLinear(int startIndex, int endIndex) const;
85    static int maxIntersections() { return kMaxIntersections; }
86    bool monotonicInX() const;
87    bool monotonicInY() const;
88    void otherPts(int oddMan, const SkDPoint* endPt[2]) const;
89    static int pointCount() { return kPointCount; }
90    static int pointLast() { return kPointLast; }
91    SkDPoint ptAtT(double t) const;
92    static int RootsReal(double A, double B, double C, double t[2]);
93    static int RootsValidT(const double A, const double B, const double C, double s[2]);
94    static void SetABC(const double* quad, double* a, double* b, double* c);
95    SkDQuad subDivide(double t1, double t2) const;
96    void subDivide(double t1, double t2, SkDQuad* quad) const { *quad = this->subDivide(t1, t2); }
97
98    static SkDQuad SubDivide(const SkPoint a[kPointCount], double t1, double t2) {
99        SkDQuad quad;
100        quad.set(a);
101        return quad.subDivide(t1, t2);
102    }
103    SkDPoint subDivide(const SkDPoint& a, const SkDPoint& c, double t1, double t2) const;
104    static SkDPoint SubDivide(const SkPoint pts[kPointCount], const SkDPoint& a, const SkDPoint& c,
105                              double t1, double t2) {
106        SkDQuad quad;
107        quad.set(pts);
108        return quad.subDivide(a, c, t1, t2);
109    }
110
111    /**
112     *  Return the number of valid roots (0 < root < 1) for this cubic intersecting the
113     *  specified vertical line.
114     */
115    int verticalIntersect(double xIntercept, double roots[2]) const;
116
117    SkDCubic debugToCubic() const;
118    // utilities callable by the user from the debugger when the implementation code is linked in
119    void dump() const;
120    void dumpID(int id) const;
121    void dumpInner() const;
122
123    SkDEBUGCODE(SkOpGlobalState* fDebugGlobalState);
124};
125
126
127class SkTQuad : public SkTCurve {
128public:
129    SkDQuad fQuad;
130
131    SkTQuad() {}
132
133    SkTQuad(const SkDQuad& q)
134        : fQuad(q) {
135    }
136
137    ~SkTQuad() override {}
138
139    const SkDPoint& operator[](int n) const override { return fQuad[n]; }
140    SkDPoint& operator[](int n) override { return fQuad[n]; }
141
142    bool collapsed() const override { return fQuad.collapsed(); }
143    bool controlsInside() const override { return fQuad.controlsInside(); }
144    void debugInit() override { return fQuad.debugInit(); }
145#if DEBUG_T_SECT
146    void dumpID(int id) const override { return fQuad.dumpID(id); }
147#endif
148    SkDVector dxdyAtT(double t) const override { return fQuad.dxdyAtT(t); }
149#ifdef SK_DEBUG
150    SkOpGlobalState* globalState() const override { return fQuad.globalState(); }
151#endif
152
153    bool hullIntersects(const SkDQuad& quad, bool* isLinear) const override {
154        return quad.hullIntersects(fQuad, isLinear);
155    }
156
157    bool hullIntersects(const SkDConic& conic, bool* isLinear) const override;
158    bool hullIntersects(const SkDCubic& cubic, bool* isLinear) const override;
159
160    bool hullIntersects(const SkTCurve& curve, bool* isLinear) const override {
161        return curve.hullIntersects(fQuad, isLinear);
162    }
163
164    int intersectRay(SkIntersections* i, const SkDLine& line) const override;
165    bool IsConic() const override { return false; }
166    SkTCurve* make(SkArenaAlloc& heap) const override { return heap.make<SkTQuad>(); }
167
168    int maxIntersections() const override { return SkDQuad::kMaxIntersections; }
169
170    void otherPts(int oddMan, const SkDPoint* endPt[2]) const override {
171        fQuad.otherPts(oddMan, endPt);
172    }
173
174    int pointCount() const override { return SkDQuad::kPointCount; }
175    int pointLast() const override { return SkDQuad::kPointLast; }
176    SkDPoint ptAtT(double t) const override { return fQuad.ptAtT(t); }
177    void setBounds(SkDRect* ) const override;
178
179    void subDivide(double t1, double t2, SkTCurve* curve) const override {
180        ((SkTQuad*) curve)->fQuad = fQuad.subDivide(t1, t2);
181    }
182};
183
184#endif
185