/*
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* Copyright 2012 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkPathOpsCubic_DEFINED
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#define SkPathOpsCubic_DEFINED
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#include "SkArenaAlloc.h"
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#include "SkPath.h"
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#include "SkPathOpsTCurve.h"
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struct SkDCubicPair;
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struct SkDCubic {
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static const int kPointCount = 4;
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static const int kPointLast = kPointCount - 1;
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static const int kMaxIntersections = 9;
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enum SearchAxis {
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kXAxis,
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kYAxis
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};
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bool collapsed() const {
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return fPts[0].approximatelyEqual(fPts[1]) && fPts[0].approximatelyEqual(fPts[2])
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&& fPts[0].approximatelyEqual(fPts[3]);
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}
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bool controlsInside() const {
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SkDVector v01 = fPts[0] - fPts[1];
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SkDVector v02 = fPts[0] - fPts[2];
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SkDVector v03 = fPts[0] - fPts[3];
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SkDVector v13 = fPts[1] - fPts[3];
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SkDVector v23 = fPts[2] - fPts[3];
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return v03.dot(v01) > 0 && v03.dot(v02) > 0 && v03.dot(v13) > 0 && v03.dot(v23) > 0;
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}
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static bool IsConic() { return false; }
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const SkDPoint& operator[](int n) const { SkASSERT(n >= 0 && n < kPointCount); return fPts[n]; }
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SkDPoint& operator[](int n) { SkASSERT(n >= 0 && n < kPointCount); return fPts[n]; }
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void align(int endIndex, int ctrlIndex, SkDPoint* dstPt) const;
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double binarySearch(double min, double max, double axisIntercept, SearchAxis xAxis) const;
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double calcPrecision() const;
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SkDCubicPair chopAt(double t) const;
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static void Coefficients(const double* cubic, double* A, double* B, double* C, double* D);
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static int ComplexBreak(const SkPoint pts[4], SkScalar* t);
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int convexHull(char order[kPointCount]) const;
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void debugInit() {
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sk_bzero(fPts, sizeof(fPts));
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}
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void debugSet(const SkDPoint* pts);
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void dump() const; // callable from the debugger when the implementation code is linked in
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void dumpID(int id) const;
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void dumpInner() const;
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SkDVector dxdyAtT(double t) const;
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bool endsAreExtremaInXOrY() const;
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static int FindExtrema(const double src[], double tValue[2]);
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int findInflections(double tValues[2]) const;
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static int FindInflections(const SkPoint a[kPointCount], double tValues[2]) {
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SkDCubic cubic;
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return cubic.set(a).findInflections(tValues);
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}
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int findMaxCurvature(double tValues[]) const;
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#ifdef SK_DEBUG
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SkOpGlobalState* globalState() const { return fDebugGlobalState; }
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#endif
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bool hullIntersects(const SkDCubic& c2, bool* isLinear) const;
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bool hullIntersects(const SkDConic& c, bool* isLinear) const;
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bool hullIntersects(const SkDQuad& c2, bool* isLinear) const;
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bool hullIntersects(const SkDPoint* pts, int ptCount, bool* isLinear) const;
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bool isLinear(int startIndex, int endIndex) const;
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static int maxIntersections() { return kMaxIntersections; }
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bool monotonicInX() const;
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bool monotonicInY() const;
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void otherPts(int index, const SkDPoint* o1Pts[kPointCount - 1]) const;
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static int pointCount() { return kPointCount; }
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static int pointLast() { return kPointLast; }
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SkDPoint ptAtT(double t) const;
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static int RootsReal(double A, double B, double C, double D, double t[3]);
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static int RootsValidT(const double A, const double B, const double C, double D, double s[3]);
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int searchRoots(double extremes[6], int extrema, double axisIntercept,
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SearchAxis xAxis, double* validRoots) const;
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bool toFloatPoints(SkPoint* ) const;
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/**
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* Return the number of valid roots (0 < root < 1) for this cubic intersecting the
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* specified horizontal line.
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*/
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int horizontalIntersect(double yIntercept, double roots[3]) const;
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/**
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* Return the number of valid roots (0 < root < 1) for this cubic intersecting the
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* specified vertical line.
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*/
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int verticalIntersect(double xIntercept, double roots[3]) const;
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// add debug only global pointer so asserts can be skipped by fuzzers
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const SkDCubic& set(const SkPoint pts[kPointCount]
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SkDEBUGPARAMS(SkOpGlobalState* state = nullptr)) {
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fPts[0] = pts[0];
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fPts[1] = pts[1];
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fPts[2] = pts[2];
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fPts[3] = pts[3];
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SkDEBUGCODE(fDebugGlobalState = state);
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return *this;
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}
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SkDCubic subDivide(double t1, double t2) const;
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void subDivide(double t1, double t2, SkDCubic* c) const { *c = this->subDivide(t1, t2); }
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static SkDCubic SubDivide(const SkPoint a[kPointCount], double t1, double t2) {
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SkDCubic cubic;
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return cubic.set(a).subDivide(t1, t2);
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}
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void subDivide(const SkDPoint& a, const SkDPoint& d, double t1, double t2, SkDPoint p[2]) const;
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static void SubDivide(const SkPoint pts[kPointCount], const SkDPoint& a, const SkDPoint& d, double t1,
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double t2, SkDPoint p[2]) {
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SkDCubic cubic;
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cubic.set(pts).subDivide(a, d, t1, t2, p);
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}
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double top(const SkDCubic& dCurve, double startT, double endT, SkDPoint*topPt) const;
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SkDQuad toQuad() const;
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static const int gPrecisionUnit;
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SkDPoint fPts[kPointCount];
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SkDEBUGCODE(SkOpGlobalState* fDebugGlobalState);
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};
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/* Given the set [0, 1, 2, 3], and two of the four members, compute an XOR mask
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that computes the other two. Note that:
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one ^ two == 3 for (0, 3), (1, 2)
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one ^ two < 3 for (0, 1), (0, 2), (1, 3), (2, 3)
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3 - (one ^ two) is either 0, 1, or 2
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1 >> (3 - (one ^ two)) is either 0 or 1
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thus:
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returned == 2 for (0, 3), (1, 2)
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returned == 3 for (0, 1), (0, 2), (1, 3), (2, 3)
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given that:
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(0, 3) ^ 2 -> (2, 1) (1, 2) ^ 2 -> (3, 0)
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(0, 1) ^ 3 -> (3, 2) (0, 2) ^ 3 -> (3, 1) (1, 3) ^ 3 -> (2, 0) (2, 3) ^ 3 -> (1, 0)
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*/
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inline int other_two(int one, int two) {
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return 1 >> (3 - (one ^ two)) ^ 3;
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}
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struct SkDCubicPair {
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const SkDCubic first() const {
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#ifdef SK_DEBUG
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SkDCubic result;
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result.debugSet(&pts[0]);
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return result;
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#else
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return (const SkDCubic&) pts[0];
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#endif
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}
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const SkDCubic second() const {
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#ifdef SK_DEBUG
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SkDCubic result;
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result.debugSet(&pts[3]);
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return result;
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#else
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return (const SkDCubic&) pts[3];
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#endif
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}
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SkDPoint pts[7];
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};
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class SkTCubic : public SkTCurve {
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public:
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SkDCubic fCubic;
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SkTCubic() {}
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SkTCubic(const SkDCubic& c)
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: fCubic(c) {
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}
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~SkTCubic() override {}
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const SkDPoint& operator[](int n) const override { return fCubic[n]; }
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SkDPoint& operator[](int n) override { return fCubic[n]; }
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bool collapsed() const override { return fCubic.collapsed(); }
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bool controlsInside() const override { return fCubic.controlsInside(); }
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void debugInit() override { return fCubic.debugInit(); }
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#if DEBUG_T_SECT
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void dumpID(int id) const override { return fCubic.dumpID(id); }
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#endif
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SkDVector dxdyAtT(double t) const override { return fCubic.dxdyAtT(t); }
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#ifdef SK_DEBUG
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SkOpGlobalState* globalState() const override { return fCubic.globalState(); }
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#endif
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bool hullIntersects(const SkDQuad& quad, bool* isLinear) const override;
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bool hullIntersects(const SkDConic& conic, bool* isLinear) const override;
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bool hullIntersects(const SkDCubic& cubic, bool* isLinear) const override {
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return cubic.hullIntersects(fCubic, isLinear);
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}
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bool hullIntersects(const SkTCurve& curve, bool* isLinear) const override {
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return curve.hullIntersects(fCubic, isLinear);
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}
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int intersectRay(SkIntersections* i, const SkDLine& line) const override;
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bool IsConic() const override { return false; }
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SkTCurve* make(SkArenaAlloc& heap) const override { return heap.make<SkTCubic>(); }
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int maxIntersections() const override { return SkDCubic::kMaxIntersections; }
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void otherPts(int oddMan, const SkDPoint* endPt[2]) const override {
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fCubic.otherPts(oddMan, endPt);
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}
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int pointCount() const override { return SkDCubic::kPointCount; }
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int pointLast() const override { return SkDCubic::kPointLast; }
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SkDPoint ptAtT(double t) const override { return fCubic.ptAtT(t); }
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void setBounds(SkDRect* ) const override;
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void subDivide(double t1, double t2, SkTCurve* curve) const override {
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((SkTCubic*) curve)->fCubic = fCubic.subDivide(t1, t2);
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}
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};
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#endif
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