Dogcows Code - chaz/rasterize/blob - tri.c

   1
   2 /*
   3  * CS5600 University of Utah
   4  * Charles McGarvey
   5  * mcgarvey@eng.utah.edu
   6  */
   7
   8 #include "tri.h"
   9
  10 vec_t tri_barycentric(const tri_t* t, vec_t v)
  11 {
  12     vec_t c = VEC_ZERO;
  13     scal_t denom = (t->b.v.y - t->c.v.y) * (t->a.v.x - t->c.v.x) + (t->c.v.x - t->b.v.x) * (t->a.v.y - t->c.v.y);
  14     c.x = ((t->b.v.y - t->c.v.y) * (v.x - t->c.v.x) + (t->c.v.x - t->b.v.x) * (v.y - t->c.v.y)) / denom;
  15     c.y = ((t->c.v.y - t->a.v.y) * (v.x - t->c.v.x) + (t->a.v.x - t->c.v.x) * (v.y - t->c.v.y)) / denom;
  16     c.z = S(1.0) - c.x - c.y;
  17     return c;
  18 }
  19