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
37 //! This function calcs the distance from a 3D plane
38 class DISTANCE_PLANE_3D_FUNC
39 {
40 public:
41 template<typename CLASS_POINT,typename CLASS_PLANE>
operator()42 inline GREAL operator()(const CLASS_PLANE & plane, const CLASS_POINT & point)
43 {
44 return DISTANCE_PLANE_POINT(plane, point);
45 }
46 };
47
48
49
50 template<typename CLASS_POINT>
PLANE_CLIP_POLYGON_COLLECT(const CLASS_POINT & point0,const CLASS_POINT & point1,GREAL dist0,GREAL dist1,CLASS_POINT * clipped,GUINT & clipped_count)51 SIMD_FORCE_INLINE void PLANE_CLIP_POLYGON_COLLECT(
52 const CLASS_POINT & point0,
53 const CLASS_POINT & point1,
54 GREAL dist0,
55 GREAL dist1,
56 CLASS_POINT * clipped,
57 GUINT & clipped_count)
58 {
59 GUINT _prevclassif = (dist0>G_EPSILON);
60 GUINT _classif = (dist1>G_EPSILON);
61 if(_classif!=_prevclassif)
62 {
63 GREAL blendfactor = -dist0/(dist1-dist0);
64 VEC_BLEND(clipped[clipped_count],point0,point1,blendfactor);
65 clipped_count++;
66 }
67 if(!_classif)
68 {
69 VEC_COPY(clipped[clipped_count],point1);
70 clipped_count++;
71 }
72 }
73
74
75 //! Clips a polygon by a plane
76 /*!
77 *\return The count of the clipped counts
78 */
79 template<typename CLASS_POINT,typename CLASS_PLANE, typename DISTANCE_PLANE_FUNC>
PLANE_CLIP_POLYGON_GENERIC(const CLASS_PLANE & plane,const CLASS_POINT * polygon_points,GUINT polygon_point_count,CLASS_POINT * clipped,DISTANCE_PLANE_FUNC distance_func)80 SIMD_FORCE_INLINE GUINT PLANE_CLIP_POLYGON_GENERIC(
81 const CLASS_PLANE & plane,
82 const CLASS_POINT * polygon_points,
83 GUINT polygon_point_count,
84 CLASS_POINT * clipped,DISTANCE_PLANE_FUNC distance_func)
85 {
86 GUINT clipped_count = 0;
87
88
89 //clip first point
90 GREAL firstdist = distance_func(plane,polygon_points[0]);;
91 if(!(firstdist>G_EPSILON))
92 {
93 VEC_COPY(clipped[clipped_count],polygon_points[0]);
94 clipped_count++;
95 }
96
97 GREAL olddist = firstdist;
98 for(GUINT _i=1;_i<polygon_point_count;_i++)
99 {
100 GREAL dist = distance_func(plane,polygon_points[_i]);
101
102 PLANE_CLIP_POLYGON_COLLECT(
103 polygon_points[_i-1],polygon_points[_i],
104 olddist,
105 dist,
106 clipped,
107 clipped_count);
108
109
110 olddist = dist;
111 }
112
113 //RETURN TO FIRST point
114
115 PLANE_CLIP_POLYGON_COLLECT(
116 polygon_points[polygon_point_count-1],polygon_points[0],
117 olddist,
118 firstdist,
119 clipped,
120 clipped_count);
121
122 return clipped_count;
123 }
124
125 //! Clips a polygon by a plane
126 /*!
127 *\return The count of the clipped counts
128 */
129 template<typename CLASS_POINT,typename CLASS_PLANE, typename DISTANCE_PLANE_FUNC>
PLANE_CLIP_TRIANGLE_GENERIC(const CLASS_PLANE & plane,const CLASS_POINT & point0,const CLASS_POINT & point1,const CLASS_POINT & point2,CLASS_POINT * clipped,DISTANCE_PLANE_FUNC distance_func)130 SIMD_FORCE_INLINE GUINT PLANE_CLIP_TRIANGLE_GENERIC(
131 const CLASS_PLANE & plane,
132 const CLASS_POINT & point0,
133 const CLASS_POINT & point1,
134 const CLASS_POINT & point2,
135 CLASS_POINT * clipped,DISTANCE_PLANE_FUNC distance_func)
136 {
137 GUINT clipped_count = 0;
138
139 //clip first point
140 GREAL firstdist = distance_func(plane,point0);;
141 if(!(firstdist>G_EPSILON))
142 {
143 VEC_COPY(clipped[clipped_count],point0);
144 clipped_count++;
145 }
146
147 // point 1
148 GREAL olddist = firstdist;
149 GREAL dist = distance_func(plane,point1);
150
151 PLANE_CLIP_POLYGON_COLLECT(
152 point0,point1,
153 olddist,
154 dist,
155 clipped,
156 clipped_count);
157
158 olddist = dist;
159
160
161 // point 2
162 dist = distance_func(plane,point2);
163
164 PLANE_CLIP_POLYGON_COLLECT(
165 point1,point2,
166 olddist,
167 dist,
168 clipped,
169 clipped_count);
170 olddist = dist;
171
172
173
174 //RETURN TO FIRST point
175 PLANE_CLIP_POLYGON_COLLECT(
176 point2,point0,
177 olddist,
178 firstdist,
179 clipped,
180 clipped_count);
181
182 return clipped_count;
183 }
184
185
186 template<typename CLASS_POINT,typename CLASS_PLANE>
PLANE_CLIP_POLYGON3D(const CLASS_PLANE & plane,const CLASS_POINT * polygon_points,GUINT polygon_point_count,CLASS_POINT * clipped)187 SIMD_FORCE_INLINE GUINT PLANE_CLIP_POLYGON3D(
188 const CLASS_PLANE & plane,
189 const CLASS_POINT * polygon_points,
190 GUINT polygon_point_count,
191 CLASS_POINT * clipped)
192 {
193 return PLANE_CLIP_POLYGON_GENERIC<CLASS_POINT,CLASS_PLANE>(plane,polygon_points,polygon_point_count,clipped,DISTANCE_PLANE_3D_FUNC());
194 }
195
196
197 template<typename CLASS_POINT,typename CLASS_PLANE>
PLANE_CLIP_TRIANGLE3D(const CLASS_PLANE & plane,const CLASS_POINT & point0,const CLASS_POINT & point1,const CLASS_POINT & point2,CLASS_POINT * clipped)198 SIMD_FORCE_INLINE GUINT PLANE_CLIP_TRIANGLE3D(
199 const CLASS_PLANE & plane,
200 const CLASS_POINT & point0,
201 const CLASS_POINT & point1,
202 const CLASS_POINT & point2,
203 CLASS_POINT * clipped)
204 {
205 return PLANE_CLIP_TRIANGLE_GENERIC<CLASS_POINT,CLASS_PLANE>(plane,point0,point1,point2,clipped,DISTANCE_PLANE_3D_FUNC());
206 }
207
208
209
210 #endif // GIM_TRI_COLLISION_H_INCLUDED
211