/*
 * CS5600 University of Utah
 * Charles McGarvey
 * mcgarvey@eng.utah.edu
 */

#include "tri.h"

vec_t tri_barycentric(const tri_t* t, vec_t v)
{
    vec_t c = VEC_ZERO;
    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);
    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;
    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;
    c.z = S(1.0) - c.x - c.y;
    return c;
}