Go to the documentation of this file.00001 #include <stdio.h>
00002 #include <stdlib.h>
00003 #include <string.h>
00004 #include <assert.h>
00005 #include <math.h>
00006
00063 #include "raytri.h"
00064
00065 namespace ConvexDecomposition
00066 {
00067
00068
00069
00070 #define vector(a,b,c) \
00071 (a)[0] = (b)[0] - (c)[0]; \
00072 (a)[1] = (b)[1] - (c)[1]; \
00073 (a)[2] = (b)[2] - (c)[2];
00074
00075
00076
00077 #define innerProduct(v,q) \
00078 ((v)[0] * (q)[0] + \
00079 (v)[1] * (q)[1] + \
00080 (v)[2] * (q)[2])
00081
00082 #define crossProduct(a,b,c) \
00083 (a)[0] = (b)[1] * (c)[2] - (c)[1] * (b)[2]; \
00084 (a)[1] = (b)[2] * (c)[0] - (c)[2] * (b)[0]; \
00085 (a)[2] = (b)[0] * (c)[1] - (c)[0] * (b)[1];
00086
00087 bool rayIntersectsTriangle(const double *p,const double *d,const double *v0,const double *v1,const double *v2,double &t)
00088 {
00089
00090 double e1[3],e2[3],h[3],s[3],q[3];
00091 double a,f,u,v;
00092
00093 vector(e1,v1,v0);
00094 vector(e2,v2,v0);
00095 crossProduct(h,d,e2);
00096 a = innerProduct(e1,h);
00097
00098 if (a > -0.00001 && a < 0.00001)
00099 return(false);
00100
00101 f = 1/a;
00102 vector(s,p,v0);
00103 u = f * (innerProduct(s,h));
00104
00105 if (u < 0.0 || u > 1.0)
00106 return(false);
00107
00108 crossProduct(q,s,e1);
00109 v = f * innerProduct(d,q);
00110 if (v < 0.0 || u + v > 1.0)
00111 return(false);
00112
00113
00114 t = f * innerProduct(e2,q);
00115 if (t > 0)
00116 return(true);
00117 else
00118
00119 return (false);
00120 }
00121
00122
00123 bool lineIntersectsTriangle(const double *rayStart,const double *rayEnd,const double *p1,const double *p2,const double *p3,double *sect)
00124 {
00125 double dir[3];
00126
00127 dir[0] = rayEnd[0] - rayStart[0];
00128 dir[1] = rayEnd[1] - rayStart[1];
00129 dir[2] = rayEnd[2] - rayStart[2];
00130
00131 double d = sqrt(dir[0]*dir[0] + dir[1]*dir[1] + dir[2]*dir[2]);
00132 double r = 1.0f / d;
00133
00134 dir[0]*=r;
00135 dir[1]*=r;
00136 dir[2]*=r;
00137
00138
00139 double t;
00140
00141 bool ret = rayIntersectsTriangle(rayStart, dir, p1, p2, p3, t );
00142
00143 if ( ret )
00144 {
00145 if ( t > d )
00146 {
00147 sect[0] = rayStart[0] + dir[0]*t;
00148 sect[1] = rayStart[1] + dir[1]*t;
00149 sect[2] = rayStart[2] + dir[2]*t;
00150 }
00151 else
00152 {
00153 ret = false;
00154 }
00155 }
00156
00157 return ret;
00158 }
00159
00160 };