#ifndef rdo_radiosity_H
#define rdo_radiosity_H
/* The finite element radiosity algorithm. */

#define rdo_radiosity_H_COPYRIGHT "Copyright © 2008 Danillo Pereira and J. Stolfi, UNICAMP"
/* Last edited on 2024-12-21 11:51:52 by stolfi */

#include <stdio.h>

#include <frgb.h>
#include <argparser.h>
#include <dspmat.h>

#include <rdo_geometry.h>
#include <rdo_linear_algebra.h>
#include <rdo_solid.h>
#include <rdo_approx_basis.h>
        
/* THE ITERATIVE RADIOSITY ALGORITHM
 
  The procedures below implement the iterative radiosity algorithm 
  in terms of an arbitrary approximation basis with {n} elements.
  They require:
  
    {E[0..n-1]} approx basis coefficients for the spontaneous radiance
    function (due to emission, or scattering of light that comes from 
    external sources). 
    
    {L[0..n-1]} approx basis coefficients for the total radiance
    function (emission plus scattering).
    
    {*R} the radiance transfer matrix between coefficients of the 
    basis.
    
  Both {E} and {L} are (column) vectors with {n} coefficients relative
  to the approximation basis, and {R} is an {n × n} matrix. */

void rdo_radiosity_initialize_basis_radiance(double E[], double L[], int n);
  /* Copies the emission coefficient vector {E[0..n-1]} into the
    total radiance coefficient vector {L[0..n-1]}. */
    
void rdo_radiosity_basis_transfer_iteration(double E[], dspmat_t *R, double L[], int n);
  /* Executes one iteration of the radiosity algorithm, namely {L = E + R*L}. */

#endif