Model::Model(char *tris_file)
{
FILE *fp = fopen(tris_file,"r");
if (fp == NULL)
{
fprintf(stderr,"Model Constructor: Couldn't open %s\n",tris_file);
exit(-1);
}
fscanf(fp,"%d",&ntris);
tri = new ModelTri[ntris];
int i;
for (i = 0; i < ntris; i++)
{
// read the tri verts
fscanf(fp,"%lf %lf %lf %lf %lf %lf %lf %lf %lf",
&tri[i].p0[0], &tri[i].p0[1], &tri[i].p0[2],
&tri[i].p1[0], &tri[i].p1[1], &tri[i].p1[2],
&tri[i].p2[0], &tri[i].p2[1], &tri[i].p2[2]);
// set the normal
double a[3],b[3];
VmV(a,tri[i].p1,tri[i].p0);
VmV(b,tri[i].p2,tri[i].p0);
VcrossV(tri[i].n,a,b);
Vnormalize(tri[i].n);
}
fclose(fp);
// generate display list
display_list = glGenLists(1);
glNewList(display_list,GL_COMPILE);
glBegin(GL_TRIANGLES);
for (i = 0; i < ntris; i++)
{
glNormal3dv(tri[i].n);
glVertex3dv(tri[i].p0);
glVertex3dv(tri[i].p1);
glVertex3dv(tri[i].p2);
}
glEnd();
glEndList();
}
//sets all the members of Tri3B given the values of the vertices
void Tri3B::Set( const PQP_REAL *pt1, const PQP_REAL *pt2,
const PQP_REAL *pt3, int iden )
{
id = iden;
//vertices of triangle in model's coord. frame
p1[0] = pt1[0];
p1[1] = pt1[1];
p1[2] = pt1[2];
p2[0] = pt2[0];
p2[1] = pt2[1];
p2[2] = pt2[2];
p3[0] = pt3[0];
p3[1] = pt3[1];
p3[2] = pt3[2];
//normalized vectors along side of triangle
VmV( s12, p2, p1 );
Vnormalize( s12 );
VmV( s23, p3, p2 );
Vnormalize( s23 );
VmV( s31, p1, p3 );
Vnormalize( s31 );
//normal vector to plane of triangle
VcrossV( n, s31, s12 );
Vnormalize( n );
//normal vectors to each side in the plane of the triangle
//from cross product of side-vector and normal
VcrossV( ns12, s12, n );
Vnormalize( ns12 );
VcrossV( ns23, s23, n );
Vnormalize( ns23 );
VcrossV( ns31, s31, n );
Vnormalize( ns31 );
}
