chromium/third_party/skia/src/pathops/SkOpCubicHull.cpp

/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "src/pathops/SkPathOpsCubic.h"
#include "src/pathops/SkPathOpsPoint.h"
#include "src/pathops/SkPathOpsTypes.h"

#include <algorithm>
#include <cstddef>

static bool rotate(const SkDCubic& cubic, int zero, int index, SkDCubic& rotPath) { … }


// Returns 0 if negative, 1 if zero, 2 if positive
static int side(double x) { … }

/* Given a cubic, find the convex hull described by the end and control points.
   The hull may have 3 or 4 points. Cubics that degenerate into a point or line
   are not considered.

   The hull is computed by assuming that three points, if unique and non-linear,
   form a triangle. The fourth point may replace one of the first three, may be
   discarded if in the triangle or on an edge, or may be inserted between any of
   the three to form a convex quadralateral.

   The indices returned in order describe the convex hull.
*/
int SkDCubic::convexHull(char order[4]) const { … }