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Diffstat (limited to 'thirdparty/bullet/Bullet3Geometry/b3ConvexHullComputer.h')
-rw-r--r-- | thirdparty/bullet/Bullet3Geometry/b3ConvexHullComputer.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/thirdparty/bullet/Bullet3Geometry/b3ConvexHullComputer.h b/thirdparty/bullet/Bullet3Geometry/b3ConvexHullComputer.h new file mode 100644 index 0000000000..6dcc931a78 --- /dev/null +++ b/thirdparty/bullet/Bullet3Geometry/b3ConvexHullComputer.h @@ -0,0 +1,103 @@ +/* +Copyright (c) 2011 Ole Kniemeyer, MAXON, www.maxon.net + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B3_CONVEX_HULL_COMPUTER_H +#define B3_CONVEX_HULL_COMPUTER_H + +#include "Bullet3Common/b3Vector3.h" +#include "Bullet3Common/b3AlignedObjectArray.h" + +/// Convex hull implementation based on Preparata and Hong +/// See http://code.google.com/p/bullet/issues/detail?id=275 +/// Ole Kniemeyer, MAXON Computer GmbH +class b3ConvexHullComputer +{ + private: + b3Scalar compute(const void* coords, bool doubleCoords, int stride, int count, b3Scalar shrink, b3Scalar shrinkClamp); + + public: + + class Edge + { + private: + int next; + int reverse; + int targetVertex; + + friend class b3ConvexHullComputer; + + public: + int getSourceVertex() const + { + return (this + reverse)->targetVertex; + } + + int getTargetVertex() const + { + return targetVertex; + } + + const Edge* getNextEdgeOfVertex() const // clockwise list of all edges of a vertex + { + return this + next; + } + + const Edge* getNextEdgeOfFace() const // counter-clockwise list of all edges of a face + { + return (this + reverse)->getNextEdgeOfVertex(); + } + + const Edge* getReverseEdge() const + { + return this + reverse; + } + }; + + + // Vertices of the output hull + b3AlignedObjectArray<b3Vector3> vertices; + + // Edges of the output hull + b3AlignedObjectArray<Edge> edges; + + // Faces of the convex hull. Each entry is an index into the "edges" array pointing to an edge of the face. Faces are planar n-gons + b3AlignedObjectArray<int> faces; + + /* + Compute convex hull of "count" vertices stored in "coords". "stride" is the difference in bytes + between the addresses of consecutive vertices. If "shrink" is positive, the convex hull is shrunken + by that amount (each face is moved by "shrink" length units towards the center along its normal). + If "shrinkClamp" is positive, "shrink" is clamped to not exceed "shrinkClamp * innerRadius", where "innerRadius" + is the minimum distance of a face to the center of the convex hull. + + The returned value is the amount by which the hull has been shrunken. If it is negative, the amount was so large + that the resulting convex hull is empty. + + The output convex hull can be found in the member variables "vertices", "edges", "faces". + */ + b3Scalar compute(const float* coords, int stride, int count, b3Scalar shrink, b3Scalar shrinkClamp) + { + return compute(coords, false, stride, count, shrink, shrinkClamp); + } + + // same as above, but double precision + b3Scalar compute(const double* coords, int stride, int count, b3Scalar shrink, b3Scalar shrinkClamp) + { + return compute(coords, true, stride, count, shrink, shrinkClamp); + } +}; + + +#endif //B3_CONVEX_HULL_COMPUTER_H + |