char SegmentTriangleIntersection::SegTriInt( tPointi T, tPointd q, tPointd r, tPointd p )
{
int code = '?';
int m = -1;
code = SegPlaneInt( T, q, r, p, &m );
//printf("SegPlaneInt code=%c, m=%d; p=(%lf,%lf,%lf)\n", code,m,p[X],p[Y],p[Z]);
if ( code == '0')
return '0';
else if ( code == 'q')
return InTri3D( T, m, q );
else if ( code == 'r')
return InTri3D( T, m, r );
else if ( code == 'p' )
return InPlane( T, m, q, r, p );
else if ( code == '1' )
return SegTriCross( T, q, r );
else /* Error */
return code;
}
char SegTriInt( tPointi T, tPointd q, tPointd r, tPointd p )
{
int code = '?';
int m = -1;
code = SegPlaneInt( T, q, r, p, &m );
if ( code == '0')
return '0';
else if ( code == 'q')
return InTri3D( T, m, q );
else if ( code == 'r')
return InTri3D( T, m, r );
else if ( code == 'p' )
return InPlane( T, m, q, r, p );
else if ( code == '1' )
return SegTriCross( T, q, r );
else /* Error */
return code;
}
// return whether the segment intersects a tri edge
// not complete! the c1 == '0' and c2 == '0' case is not handled!
char InPlane( tPointi T, int m, tPointd q, tPointd r, tPointd p)
{
tPointd tmp;
int c1,c2;
c1 = InTri3D(T,m,q);
c2 = InTri3D(T,m,r);
// yes
if(c1 == 'E' && c2 == 'E') return 'f';
if(c1 == 'E' && c2 == 'F') return 'f';
if(c1 == 'F' && c2 == 'E') return 'f';
if(c1 == 'F' && c2 == 'F') return 'f';
if(c1 == '0' && c2 == 'F') return 'f';
if(c1 == 'F' && c2 == '0') return 'f';
// no
if(c1 == 'V' && c2 == 'V') return '0';
// maybe
if(c1 == '0' && (c2 == 'V' || c2 == 'E')) {
tmp[0] = r[0] + 0.001*(p[0]-r[0]);
tmp[1] = r[1] + 0.001*(p[1]-r[1]);
tmp[2] = r[2] + 0.001*(p[2]-r[2]);
if(InTri3D(T,m,tmp) == 'F') return 'f';
else return '0';
}
if((c1 == 'V' || c1 == 'E') && c2 == '0') {
tmp[0] = p[0] + 0.001*(r[0]-p[0]);
tmp[1] = p[1] + 0.001*(r[1]-p[1]);
tmp[2] = p[2] + 0.001*(r[2]-p[2]);
if(InTri3D(T,m,tmp) == 'F') return 'f';
else return '0';
}
return '0';
}
