| /* |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| // Cubic curve classification algorithm from "Rendering Vector Art on |
| // the GPU" by Loop and Blinn, GPU Gems 3, Chapter 25: |
| // http://http.developer.nvidia.com/GPUGems3/gpugems3_ch25.html . |
| |
| #ifndef LoopBlinnClassifier_h |
| #define LoopBlinnClassifier_h |
| |
| #include <wtf/Noncopyable.h> |
| |
| namespace WebCore { |
| |
| class FloatPoint; |
| |
| // Classifies cubic curves into specific types. |
| class LoopBlinnClassifier { |
| WTF_MAKE_NONCOPYABLE(LoopBlinnClassifier); |
| public: |
| // The types of cubic curves. |
| enum CurveType { |
| kSerpentine, |
| kCusp, |
| kLoop, |
| kQuadratic, |
| kLine, |
| kPoint |
| }; |
| |
| // The result of the classifier. |
| struct Result { |
| public: |
| Result(CurveType inputCurveType, float inputD1, float inputD2, float inputD3) |
| : curveType(inputCurveType) |
| , d1(inputD1) |
| , d2(inputD2) |
| , d3(inputD3) { } |
| |
| CurveType curveType; |
| |
| // These are coefficients used later in the computation of |
| // texture coordinates per vertex. |
| float d1; |
| float d2; |
| float d3; |
| }; |
| |
| // Classifies the given cubic bezier curve starting at c0, ending |
| // at c3, and affected by control points c1 and c2. |
| static Result classify(const FloatPoint& c0, |
| const FloatPoint& c1, |
| const FloatPoint& c2, |
| const FloatPoint& c3); |
| |
| private: |
| // This class does not need to be instantiated. |
| LoopBlinnClassifier() { } |
| }; |
| |
| } // namespace WebCore |
| |
| #endif // LoopBlinnClassifier_h |