gl_sphir_tex_coord_gen.C

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#include "gl_sphir_tex_coord_gen.H"




void
GLSphirTexCoordGen ::setup()
{
}

UVpt
GLSphirTexCoordGen ::compute_uv(CBvert *v)
{
  //computes spherical 2d texture coordinates
  //in object coordinates
   Wvec n = v->loc() - Wpt(0,0,0);  
   n = n.normalized(); 

   double alpha = atan2(n[2],n[0]); 
   double theta = acos(n[1]);

   UVpt tex_coord = UVpt((alpha / (TWO_PI) ) + 0.5, (theta / TWO_PI) + 0.5);
   
   return tex_coord;
}


UVpt
GLSphirTexCoordGen ::uv_from_vert(CBvert *v, CBface *f)
{
   //in object coordinates

   UVpt tex_coord = compute_uv(v);

   Bvert* t1 = f->v1();
   Bvert* t2 = f->v2();
   Bvert* t3 = f->v3();

   UVpt ts1;
   UVpt ts2;
   
   //grab the two other UV coordinates for this face
   
   if (t1 == v)
   {
      ts1 = compute_uv(t2);
      ts2 = compute_uv(t3);
   }
   else
   {
      ts1 = compute_uv(t1);
      if (t2 == v)
         ts2 = compute_uv(t3);
      else
         ts2 = compute_uv(t2);
   }

  
   return fix_seems(tex_coord,ts1,ts2);
}

// end of file gl_sphir_tex_coord_gen.C

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