1 /* 2 * Copyright (C) 2010 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 // Cubic curve classification algorithm from "Rendering Vector Art on 27 // the GPU" by Loop and Blinn, GPU Gems 3, Chapter 25: 28 // http://http.developer.nvidia.com/GPUGems3/gpugems3_ch25.html . 29 30 #ifndef LoopBlinnClassifier_h 31 #define LoopBlinnClassifier_h 32 33 #include <wtf/Noncopyable.h> 34 35 namespace WebCore { 36 37 class FloatPoint; 38 39 // Classifies cubic curves into specific types. 40 class LoopBlinnClassifier { 41 WTF_MAKE_NONCOPYABLE(LoopBlinnClassifier); 42 public: 43 // The types of cubic curves. 44 enum CurveType { 45 kSerpentine, 46 kCusp, 47 kLoop, 48 kQuadratic, 49 kLine, 50 kPoint 51 }; 52 53 // The result of the classifier. 54 struct Result { 55 public: ResultResult56 Result(CurveType inputCurveType, float inputD1, float inputD2, float inputD3) 57 : curveType(inputCurveType) 58 , d1(inputD1) 59 , d2(inputD2) 60 , d3(inputD3) { } 61 62 CurveType curveType; 63 64 // These are coefficients used later in the computation of 65 // texture coordinates per vertex. 66 float d1; 67 float d2; 68 float d3; 69 }; 70 71 // Classifies the given cubic bezier curve starting at c0, ending 72 // at c3, and affected by control points c1 and c2. 73 static Result classify(const FloatPoint& c0, 74 const FloatPoint& c1, 75 const FloatPoint& c2, 76 const FloatPoint& c3); 77 78 private: 79 // This class does not need to be instantiated. LoopBlinnClassifier()80 LoopBlinnClassifier() { } 81 }; 82 83 } // namespace WebCore 84 85 #endif // LoopBlinnClassifier_h 86