/*
  Create a sponge for the Radiance rendering program
  (Can easily be modified for any renderer)

  Paul Bourke
*/
#include "stdio.h"
#include "stdlib.h"
#include "math.h"

main(c,v)
int c;
char **v;
{
   int i,n=0;
   char s[32];
   float x,y,z,r;
   FILE *fin,*fout,*frad;
   
   /* Which level to create */
   if (c == 2) {
      n = atoi(v[1]);
      printf("Creating sponge at level %d\n",n);
   }
   
   /* Open the last level data file */
   sprintf(s,"sponge%d",n);
   if ((fin  = fopen(s,"r")) == NULL) {
      printf("Unable to open input file\n");
      return;
   }

   /* Open the next level data file */
   sprintf(s,"sponge%d",n+1);
   if ((fout = fopen(s,"w")) == NULL) {
      printf("Unavble to open output file\n");
      return;
   }

   /* Open the next level Radiance file */
   sprintf(s,"sponge%d.rad",n+1);
   if ((frad = fopen(s,"w")) == NULL) {
      printf("Unable to open output file\n");
      return;
   }

   /* Write some Radiance header */
   fprintf(frad,"void plastic m 0 0 5 .5 .5 .5 .05 05\n");
   fprintf(frad,"void light light1 0 0 3 100 100 100\n");
   fprintf(frad,"light1 sphere thelight1 0 0 4 100 0 100 10\n");
   fprintf(frad,"light1 sphere thelight2 0 0 4 0 0 0 2\n");
   fprintf(frad,"light1 sphere thelight3 0 0 4 0 -100 0 10\n");

   while (fscanf(fin,"%f %f %f %f\n",&x,&y,&z,&r) == 4) {

      /* Bottom */
      fprintf(fout,"%g %g %g %g\n",x-r/3,y-r/3,z-r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x    ,y-r/3,z-r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y-r/3,z-r/3,r/3);

      fprintf(fout,"%g %g %g %g\n",x-r/3,y+r/3,z-r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x    ,y+r/3,z-r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y+r/3,z-r/3,r/3);

      fprintf(fout,"%g %g %g %g\n",x-r/3,y    ,z-r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y    ,z-r/3,r/3);

      /* Top */
      fprintf(fout,"%g %g %g %g\n",x-r/3,y-r/3,z+r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x    ,y-r/3,z+r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y-r/3,z+r/3,r/3);

      fprintf(fout,"%g %g %g %g\n",x-r/3,y+r/3,z+r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x    ,y+r/3,z+r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y+r/3,z+r/3,r/3);

      fprintf(fout,"%g %g %g %g\n",x-r/3,y    ,z+r/3,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y    ,z+r/3,r/3);

      /* Middle Corners */
      fprintf(fout,"%g %g %g %g\n",x-r/3,y-r/3,z    ,r/3);
      fprintf(fout,"%g %g %g %g\n",x-r/3,y+r/3,z    ,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y-r/3,z    ,r/3);
      fprintf(fout,"%g %g %g %g\n",x+r/3,y+r/3,z    ,r/3);

      /* Create Radiance boxes */

      /* Bottom */
      gencube(frad,x-r/3,y-r/3,z-r/3,r);
      gencube(frad,x    ,y-r/3,z-r/3,r);
      gencube(frad,x+r/3,y-r/3,z-r/3,r);

      gencube(frad,x-r/3,y+r/3,z-r/3,r);
      gencube(frad,x    ,y+r/3,z-r/3,r);
      gencube(frad,x+r/3,y+r/3,z-r/3,r);

      gencube(frad,x-r/3,y    ,z-r/3,r);
      gencube(frad,x+r/3,y    ,z-r/3,r);

      /* Top */
      gencube(frad,x-r/3,y-r/3,z+r/3,r);
      gencube(frad,x    ,y-r/3,z+r/3,r);
      gencube(frad,x+r/3,y-r/3,z+r/3,r);

      gencube(frad,x-r/3,y+r/3,z+r/3,r);
      gencube(frad,x    ,y+r/3,z+r/3,r);
      gencube(frad,x+r/3,y+r/3,z+r/3,r);

      gencube(frad,x-r/3,y    ,z+r/3,r);
      gencube(frad,x+r/3,y    ,z+r/3,r);

      /* Middle Corners */
      gencube(frad,x-r/3,y-r/3,z    ,r);
      gencube(frad,x-r/3,y+r/3,z    ,r);
      gencube(frad,x+r/3,y-r/3,z    ,r);
      gencube(frad,x+r/3,y+r/3,z    ,r);
   }

   /* Finished, close the files */
   fclose(fin);
   fclose(fout);
   fclose(frad);
}

/*
  Create a Radiance descition of a cube
  Only create the three facets if we are propared to 
  view from one quadrant only
*/
void gencube(f,x,y,z,r)
FILE *f;
float r,x,y,z;
{
   float r3;

   r3 = r / 3.0;

   fprintf(f,"m polygon p 0 0 12 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g %g %g %g\n",
      x,y,z,x+r3,y,z,x+r3,y,z+r3,x,y,z+r3);
   fprintf(f,"m polygon p 0 0 12 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g %g %g %g\n",
      x+r3,y,z,x+r3,y+r3,z,x+r3,y+r3,z+r3,x+r3,y,z+r3);
   fprintf(f,"m polygon p 0 0 12 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g %g %g %g\n",
      x,y,z+r3,x+r3,y,z+r3,x+r3,y+r3,z+r3,x,y+r3,z+r3);
}