#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <math.h>

#define ISIZEX 580
#define ISIZEY 440

#define NUMPIX (ISIZEX * ISIZEY * 3)

#define MAX(x,y) (((x)>(y))?(x):(y))
#define MIN(x,y) (((x)<(y))?(x):(y))

#define pi2 6.2831854

typedef float IMAGE;

int numi; /* number of images */

void do_it(char *argv[]);
void add(IMAGE *A,IMAGE *B,float c);

float *new_image()
{
  float *new_im, *pix;
  int i,j,c;

  new_im = malloc(4 * NUMPIX);
  pix=new_im;

  for (i=0;i<NUMPIX;i++) new_im[i] = 0.0;

  printf("Image created, size is %d bytes.\n",4*NUMPIX);

  return (new_im);
}


void read_image(image,file)
     IMAGE* image;
     char *file;
{
  FILE *fptr1;
  int size,j,i;

  unsigned char *buf;

  unsigned char a;

  buf = malloc(NUMPIX);

  printf("READING IMAGE FROM FILE ...\n");

  fptr1 = fopen(file,"rb");

  size=fread(buf,NUMPIX,1,fptr1);

  fclose(fptr1);

  for (i=0;i<NUMPIX;i++) {
    a = *(buf + i);
    image[i]=(float)((int)a);
  }


  printf("Image read from %s, size is %d bytes.\n",file,NUMPIX);

  free(buf);
}

void write_image(image,file)
     IMAGE *image;
     char *file;
{
  FILE *fptr1;
  int i,j;
  int size;

  unsigned char *buf;
  float a;

  buf = malloc(NUMPIX);

  printf("WRITING IMAGE TO FILE ...\n");

  fptr1 = fopen(file,"wb");

  for (i=0;i<NUMPIX;i++) {
    a = image[i];
    if (a>=256) {
      buf[i] = 255;
    } else {
      buf[i] = (unsigned char)((int)(a));
    }
  }

  size=fwrite(buf,NUMPIX,1,fptr1);

  fclose(fptr1);

  free(buf);

  printf("Image written to %s, size is %d bytes.\n",file,NUMPIX);

}

main(argc,argv)
     int argc;
     char *argv[];
{
  int i;

  if (argc < 3) {
    printf("Specular Compositer\n");
    printf("(C) 1992 Paul E. Debevec\n");
    printf("Usage: %s <diffuse images> <specular images>\n",argv[0]);
    exit(-1);
  }

  numi = (argc-1)/2;

  printf("%d diffuse+specular images to process.\n",numi);

  do_it(argv);

}


void add(IMAGE *A,IMAGE *B,float c)
{
  int i;

  for (i = 0; i < NUMPIX; i++) {
    A[i] += c * B[i];
  }
}

void do_it(char *argv[])
{
  IMAGE *SPEC;
  IMAGE *I;
  IMAGE *DIFF;

  int i;

  SPEC=(IMAGE *)new_image();
  DIFF=(IMAGE *)new_image();
  I=(IMAGE *)new_image();

  for (i=0;i<numi;i++) {
    read_image(SPEC,argv[numi+i+2]);
    read_image(DIFF,argv[i+2]);
    add(DIFF,SPEC,5);
    add(I,DIFF,(3*i*i+i+1)/((float)numi*numi*numi));  /* Scaled sum */
/*    add(I,DIFF,1/((float)numi));             /* Even Sum */
  }

  add(I,DIFF,0.5); /* Add in the last image even extra */

  add(I,I,-0.05);  /* Boost the diffuse image */

/*  scale(I,255.99); */

  write_image(I,argv[1]);

  free(SPEC);free(I);free(DIFF);
}