/*
  Create a gasket for the Radiance rendering program
  (Easily mdified for any other 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;
   
   /* 
      The first argument is the level to create
      The previous level must have already been created
   */
   if (c == 2) {
      n = atoi(v[1]);
      printf("Creating gasket at level %d\n",n);
   }

   /* Open the data file for the last level */
   sprintf(s,"gasket%d",n);
   if ((fin  = fopen(s,"r")) == NULL) {
      printf("Unable to open input file\n");
      return;
   }

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

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

   /* Add some stuff to the top of the Radiance file */
   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");

   /* Read the last level data file and construct the next level */
   while (fscanf(fin,"%f %f %f %f\n",&x,&y,&z,&r) == 4) {

      /* Data file stuff */
      fprintf(fout,"%g %g %g %g\n",x-r/4,y-r/4,z-r/4,r/2);
      fprintf(fout,"%g %g %g %g\n",x-r/4,y+r/4,z-r/4,r/2);
      fprintf(fout,"%g %g %g %g\n",x+r/4,y-r/4,z-r/4,r/2);
      fprintf(fout,"%g %g %g %g\n",x+r/4,y+r/4,z-r/4,r/2);
      fprintf(fout,"%g %g %g %g\n",x    ,y    ,z+r/4,r/2);

      /* Radiance stuff */
      genprism(frad,r/2,x-r/2,y-r/2,z-r/2);
      genprism(frad,r/2,x    ,y-r/2,z-r/2);
      genprism(frad,r/2,x-r/2,y    ,z-r/2);
      genprism(frad,r/2,x    ,y    ,z-r/2);
      genprism(frad,r/2,x-r/4,y-r/4,z    );
   }

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

/* 
  Create the Radiance description for a pyramid
  Don't need the bottom if we always look from above
*/
void genprism(f,r,x,y,z)
FILE *f;
float r,x,y,z;
{
   float r2;

   r2 = r / 2.0;

   fprintf(f,"m polygon p 0 0 9 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g\n",x,y,z,x+r,y,z,x+r2,y+r2,z+r);
   fprintf(f,"m polygon p 0 0 9 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g\n",x+r,y,z,x+r,y+r,z,x+r2,y+r2,z+r);
   fprintf(f,"m polygon p 0 0 9 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g\n",x+r,y+r,z,x,y+r,z,x+r2,y+r2,z+r);
   fprintf(f,"m polygon p 0 0 9 ");
   fprintf(f,"%g %g %g %g %g %g %g %g %g\n",x,y+r,z,x,y,z,x+r2,y+r2,z+r);
}