dali-physics/third-party/bullet3/src/BulletCollision/Gimpact/gim_clip_polygon.h

   1 #ifndef GIM_CLIP_POLYGON_H_INCLUDED
   2 #define GIM_CLIP_POLYGON_H_INCLUDED
   3
   4 /*! \file gim_tri_collision.h
   5 \author Francisco Leon Najera
   6 */
   7 /*
   8 -----------------------------------------------------------------------------
   9 This source file is part of GIMPACT Library.
  10
  11 For the latest info, see http://gimpact.sourceforge.net/
  12
  13 Copyright (c) 2006 Francisco Leon Najera. C.C. 80087371.
  14 email: projectileman@yahoo.com
  15
  16  This library is free software; you can redistribute it and/or
  17  modify it under the terms of EITHER:
  18    (1) The GNU Lesser General Public License as published by the Free
  19        Software Foundation; either version 2.1 of the License, or (at
  20        your option) any later version. The text of the GNU Lesser
  21        General Public License is included with this library in the
  22        file GIMPACT-LICENSE-LGPL.TXT.
  23    (2) The BSD-style license that is included with this library in
  24        the file GIMPACT-LICENSE-BSD.TXT.
  25    (3) The zlib/libpng license that is included with this library in
  26        the file GIMPACT-LICENSE-ZLIB.TXT.
  27
  28  This library is distributed in the hope that it will be useful,
  29  but WITHOUT ANY WARRANTY; without even the implied warranty of
  30  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files
  31  GIMPACT-LICENSE-LGPL.TXT, GIMPACT-LICENSE-ZLIB.TXT and GIMPACT-LICENSE-BSD.TXT for more details.
  32
  33 -----------------------------------------------------------------------------
  34 */
  35
  36 //! This function calcs the distance from a 3D plane
  37 class DISTANCE_PLANE_3D_FUNC
  38 {
  39 public:
  40         template <typename CLASS_POINT, typename CLASS_PLANE>
  41         inline GREAL operator()(const CLASS_PLANE& plane, const CLASS_POINT& point)
  42         {
  43                 return DISTANCE_PLANE_POINT(plane, point);
  44         }
  45 };
  46
  47 template <typename CLASS_POINT>
  48 SIMD_FORCE_INLINE void PLANE_CLIP_POLYGON_COLLECT(
  49         const CLASS_POINT& point0,
  50         const CLASS_POINT& point1,
  51         GREAL dist0,
  52         GREAL dist1,
  53         CLASS_POINT* clipped,
  54         GUINT& clipped_count)
  55 {
  56         GUINT _prevclassif = (dist0 > G_EPSILON);
  57         GUINT _classif = (dist1 > G_EPSILON);
  58         if (_classif != _prevclassif)
  59         {
  60                 GREAL blendfactor = -dist0 / (dist1 - dist0);
  61                 VEC_BLEND(clipped[clipped_count], point0, point1, blendfactor);
  62                 clipped_count++;
  63         }
  64         if (!_classif)
  65         {
  66                 VEC_COPY(clipped[clipped_count], point1);
  67                 clipped_count++;
  68         }
  69 }
  70
  71 //! Clips a polygon by a plane
  72 /*!
  73 *\return The count of the clipped counts
  74 */
  75 template <typename CLASS_POINT, typename CLASS_PLANE, typename DISTANCE_PLANE_FUNC>
  76 SIMD_FORCE_INLINE GUINT PLANE_CLIP_POLYGON_GENERIC(
  77         const CLASS_PLANE& plane,
  78         const CLASS_POINT* polygon_points,
  79         GUINT polygon_point_count,
  80         CLASS_POINT* clipped, DISTANCE_PLANE_FUNC distance_func)
  81 {
  82         GUINT clipped_count = 0;
  83
  84         //clip first point
  85         GREAL firstdist = distance_func(plane, polygon_points[0]);
  86         ;
  87         if (!(firstdist > G_EPSILON))
  88         {
  89                 VEC_COPY(clipped[clipped_count], polygon_points[0]);
  90                 clipped_count++;
  91         }
  92
  93         GREAL olddist = firstdist;
  94         for (GUINT _i = 1; _i < polygon_point_count; _i++)
  95         {
  96                 GREAL dist = distance_func(plane, polygon_points[_i]);
  97
  98                 PLANE_CLIP_POLYGON_COLLECT(
  99                         polygon_points[_i - 1], polygon_points[_i],
 100                         olddist,
 101                         dist,
 102                         clipped,
 103                         clipped_count);
 104
 105                 olddist = dist;
 106         }
 107
 108         //RETURN TO FIRST  point
 109
 110         PLANE_CLIP_POLYGON_COLLECT(
 111                 polygon_points[polygon_point_count - 1], polygon_points[0],
 112                 olddist,
 113                 firstdist,
 114                 clipped,
 115                 clipped_count);
 116
 117         return clipped_count;
 118 }
 119
 120 //! Clips a polygon by a plane
 121 /*!
 122 *\return The count of the clipped counts
 123 */
 124 template <typename CLASS_POINT, typename CLASS_PLANE, typename DISTANCE_PLANE_FUNC>
 125 SIMD_FORCE_INLINE GUINT PLANE_CLIP_TRIANGLE_GENERIC(
 126         const CLASS_PLANE& plane,
 127         const CLASS_POINT& point0,
 128         const CLASS_POINT& point1,
 129         const CLASS_POINT& point2,
 130         CLASS_POINT* clipped, DISTANCE_PLANE_FUNC distance_func)
 131 {
 132         GUINT clipped_count = 0;
 133
 134         //clip first point
 135         GREAL firstdist = distance_func(plane, point0);
 136         ;
 137         if (!(firstdist > G_EPSILON))
 138         {
 139                 VEC_COPY(clipped[clipped_count], point0);
 140                 clipped_count++;
 141         }
 142
 143         // point 1
 144         GREAL olddist = firstdist;
 145         GREAL dist = distance_func(plane, point1);
 146
 147         PLANE_CLIP_POLYGON_COLLECT(
 148                 point0, point1,
 149                 olddist,
 150                 dist,
 151                 clipped,
 152                 clipped_count);
 153
 154         olddist = dist;
 155
 156         // point 2
 157         dist = distance_func(plane, point2);
 158
 159         PLANE_CLIP_POLYGON_COLLECT(
 160                 point1, point2,
 161                 olddist,
 162                 dist,
 163                 clipped,
 164                 clipped_count);
 165         olddist = dist;
 166
 167         //RETURN TO FIRST  point
 168         PLANE_CLIP_POLYGON_COLLECT(
 169                 point2, point0,
 170                 olddist,
 171                 firstdist,
 172                 clipped,
 173                 clipped_count);
 174
 175         return clipped_count;
 176 }
 177
 178 template <typename CLASS_POINT, typename CLASS_PLANE>
 179 SIMD_FORCE_INLINE GUINT PLANE_CLIP_POLYGON3D(
 180         const CLASS_PLANE& plane,
 181         const CLASS_POINT* polygon_points,
 182         GUINT polygon_point_count,
 183         CLASS_POINT* clipped)
 184 {
 185         return PLANE_CLIP_POLYGON_GENERIC<CLASS_POINT, CLASS_PLANE>(plane, polygon_points, polygon_point_count, clipped, DISTANCE_PLANE_3D_FUNC());
 186 }
 187
 188 template <typename CLASS_POINT, typename CLASS_PLANE>
 189 SIMD_FORCE_INLINE GUINT PLANE_CLIP_TRIANGLE3D(
 190         const CLASS_PLANE& plane,
 191         const CLASS_POINT& point0,
 192         const CLASS_POINT& point1,
 193         const CLASS_POINT& point2,
 194         CLASS_POINT* clipped)
 195 {
 196         return PLANE_CLIP_TRIANGLE_GENERIC<CLASS_POINT, CLASS_PLANE>(plane, point0, point1, point2, clipped, DISTANCE_PLANE_3D_FUNC());
 197 }
 198
 199 #endif  // GIM_TRI_COLLISION_H_INCLUDED