include/crbn/basic/trihedron.hpp

#ifndef __trihedron_hpp__
#define __trihedron_hpp__

#include <crbn/basic/vec3.hpp>
#include <crbn/basic/fastmath.h>

// a right hand trihedron

struct trihedron {
  vec3 x;
  vec3 y;
  vec3 z;
};

inline void compute( trihedron& t, vec3& v ) {
  vec3 tmp;
  if( fm_abs( v.x ) < .5f )
    tmp = vec3( 1.f, 0.f, 0.f );
  else
    tmp = vec3( 0.f, 1.f, 0.f );
  vcross( t.x, v, tmp );
  vnormalize( t.x );
  vcross( t.y, t.x, v );
  vnormalize( t.y );
  vnormalize( t.z, v );
}

#endif // __trihedron_hpp__

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