//----------------------------------------------------------------------------
// William Baxter III's Ray Tracer
//
//     Project for Comp 238, Raster Graphics
//     University of North Carolina at Chapel Hill
//     
// $Id:$
//----------------------------------------------------------------------------

#ifndef WB3SAMPLING_H
#define WB3SAMPLING_H

#include <vec3f.hpp>
//----------------------------------------------------------------------------

namespace wb3Sampling
{
  // Construct an orthonormal basis out of L by finding 
  // two vectors U and V that are mutually orthogonal.
  void ComputePerpendiculars(const Vec3f& N, Vec3f& U, Vec3f& V);

  // Perturb pos in the plane defined by either a normal N
  // or orthonormal U and V vectors.  Perturb by a maximum of radius
  // units.
  void PerturbSampleRadially(Vec3f &pos, const Vec3f& N, float radius);
  void PerturbSampleRadially(Vec3f &pos, const Vec3f& U, const Vec3f &V,
                             float radius);
}

#endif