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Diffstat (limited to 'extern/bullet2/BulletCollision/Gimpact/btClipPolygon.h')
| -rw-r--r-- | extern/bullet2/BulletCollision/Gimpact/btClipPolygon.h | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/extern/bullet2/BulletCollision/Gimpact/btClipPolygon.h b/extern/bullet2/BulletCollision/Gimpact/btClipPolygon.h new file mode 100644 index 00000000000..5de391a7561 --- /dev/null +++ b/extern/bullet2/BulletCollision/Gimpact/btClipPolygon.h @@ -0,0 +1,182 @@ +#ifndef BT_CLIP_POLYGON_H_INCLUDED +#define BT_CLIP_POLYGON_H_INCLUDED + +/*! \file btClipPolygon.h +\author Francisco Len Nßjera +*/ +/* +This source file is part of GIMPACT Library. + +For the latest info, see http://gimpact.sourceforge.net/ + +Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371. +email: projectileman@yahoo.com + + +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. +*/ + +#include "LinearMath/btTransform.h" +#include "LinearMath/btGeometryUtil.h" + + +SIMD_FORCE_INLINE btScalar bt_distance_point_plane(const btVector4 & plane,const btVector3 &point) +{ + return point.dot(plane) - plane[3]; +} + +/*! Vector blending +Takes two vectors a, b, blends them together*/ +SIMD_FORCE_INLINE void bt_vec_blend(btVector3 &vr, const btVector3 &va,const btVector3 &vb, btScalar blend_factor) +{ + vr = (1-blend_factor)*va + blend_factor*vb; +} + +//! This function calcs the distance from a 3D plane +SIMD_FORCE_INLINE void bt_plane_clip_polygon_collect( + const btVector3 & point0, + const btVector3 & point1, + btScalar dist0, + btScalar dist1, + btVector3 * clipped, + int & clipped_count) +{ + bool _prevclassif = (dist0>SIMD_EPSILON); + bool _classif = (dist1>SIMD_EPSILON); + if(_classif!=_prevclassif) + { + btScalar blendfactor = -dist0/(dist1-dist0); + bt_vec_blend(clipped[clipped_count],point0,point1,blendfactor); + clipped_count++; + } + if(!_classif) + { + clipped[clipped_count] = point1; + clipped_count++; + } +} + + +//! Clips a polygon by a plane +/*! +*\return The count of the clipped counts +*/ +SIMD_FORCE_INLINE int bt_plane_clip_polygon( + const btVector4 & plane, + const btVector3 * polygon_points, + int polygon_point_count, + btVector3 * clipped) +{ + int clipped_count = 0; + + + //clip first point + btScalar firstdist = bt_distance_point_plane(plane,polygon_points[0]);; + if(!(firstdist>SIMD_EPSILON)) + { + clipped[clipped_count] = polygon_points[0]; + clipped_count++; + } + + btScalar olddist = firstdist; + for(int i=1;i<polygon_point_count;i++) + { + btScalar dist = bt_distance_point_plane(plane,polygon_points[i]); + + bt_plane_clip_polygon_collect( + polygon_points[i-1],polygon_points[i], + olddist, + dist, + clipped, + clipped_count); + + + olddist = dist; + } + + //RETURN TO FIRST point + + bt_plane_clip_polygon_collect( + polygon_points[polygon_point_count-1],polygon_points[0], + olddist, + firstdist, + clipped, + clipped_count); + + return clipped_count; +} + +//! Clips a polygon by a plane +/*! +*\param clipped must be an array of 16 points. +*\return The count of the clipped counts +*/ +SIMD_FORCE_INLINE int bt_plane_clip_triangle( + const btVector4 & plane, + const btVector3 & point0, + const btVector3 & point1, + const btVector3& point2, + btVector3 * clipped // an allocated array of 16 points at least + ) +{ + int clipped_count = 0; + + //clip first point0 + btScalar firstdist = bt_distance_point_plane(plane,point0);; + if(!(firstdist>SIMD_EPSILON)) + { + clipped[clipped_count] = point0; + clipped_count++; + } + + // point 1 + btScalar olddist = firstdist; + btScalar dist = bt_distance_point_plane(plane,point1); + + bt_plane_clip_polygon_collect( + point0,point1, + olddist, + dist, + clipped, + clipped_count); + + olddist = dist; + + + // point 2 + dist = bt_distance_point_plane(plane,point2); + + bt_plane_clip_polygon_collect( + point1,point2, + olddist, + dist, + clipped, + clipped_count); + olddist = dist; + + + + //RETURN TO FIRST point0 + bt_plane_clip_polygon_collect( + point2,point0, + olddist, + firstdist, + clipped, + clipped_count); + + return clipped_count; +} + + + + + +#endif // GIM_TRI_COLLISION_H_INCLUDED |