remove prototype pathops code

experimental/Intersection/CubicLineSegments.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 "CubicLineSegments.h"
-#include "QuadraticLineSegments.h"
-
-// http://cagd.cs.byu.edu/~557/text/cagd.pdf 2.7
-// A hodograph is the first derivative curve
-void hodograph(const Cubic& cubic, Quadratic& hodo) {
-    hodo[0].x = 3 * (cubic[1].x - cubic[0].x);
-    hodo[0].y = 3 * (cubic[1].y - cubic[0].y);
-    hodo[1].x = 3 * (cubic[2].x - cubic[1].x);
-    hodo[1].y = 3 * (cubic[2].y - cubic[1].y);
-    hodo[2].x = 3 * (cubic[3].x - cubic[2].x);
-    hodo[2].y = 3 * (cubic[3].y - cubic[2].y);
-}
-
-// A 2nd hodograph is the second derivative curve
-void secondHodograph(const Cubic& cubic, _Line& hodo2) {
-    Quadratic hodo;
-    hodograph(cubic, hodo);
-    hodograph(hodo, hodo2);
-}
-
-// The number of line segments required to approximate the cubic
-// see  http://cagd.cs.byu.edu/~557/text/cagd.pdf 10.6
-double subDivisions(const Cubic& cubic) {
-    _Line hodo2;
-    secondHodograph(cubic, hodo2);
-    double maxX = SkTMax(hodo2[1].x, hodo2[1].x);
-    double maxY = SkTMax(hodo2[1].y, hodo2[1].y);
-    double dist = sqrt(maxX * maxX + maxY * maxY);
-    double segments = sqrt(dist / (8 * FLT_EPSILON));
-    return segments;
-}