/* demoras.c:
	This demo demonstrates how to read/save sun rasterfiles using
	sunras.c routines.
	The routines "readsunras" and "savesunras" are interface
	routines into sunras.c.  The are included in this file
	so that you may use your own error handlers.
	
	Created by: Hai Pham and Don Quon
*/


#include <malloc.h>
#include <stdio.h>
#include "sunras.h"



void readsunras(char *,long **,int *,int *);
void savesunras(char *,long *,int ,int );

int main(void){
long i,j; 
long *finalimage;
long *image;
long *image2;
int dx,dy; 
int dx2,dy2;
char infilename[60];
char outfilename[60];

   printf("enter input filename: ");
   scanf("%s",infilename);
   printf("enter output filename: ");
   scanf("%s",outfilename);

   /* read in the image */ 
   readsunras(infilename,&image,&dx,&dy);

   /*allocate memory for new image*/
   finalimage=(long *)malloc(dx*dy*sizeof(long));
   if (finalimage==NULL){
	printf("error allocating memory\n");
        return 0;
   }/* end if*/

    /* copy old image into new image */
    for (i=0;i<dy*dx;i++)
		finalimage[i]=image[i];

   /*save the final image*/
   savesunras(outfilename,finalimage,dx,dy);
   return;
}


void readsunras(char *fname,long **image,int *dx, int *dy){
FILE *fp;
PICINFO picptr;
long count;
long w,h;
   fp=fopen(fname,"r");
   if (fp==NULL) {
	/* place error handler for fopen error here*/
	printf ("error opening input file\n");
	exit (0);
   }
   LoadSunRas(fp,&picptr);
   fclose(fp);
   *dx=picptr.w;
   *dy=picptr.h;
   w=*dx;
   h=*dy;
   *image=(long *)malloc(w*h*sizeof(long));
   if (*image==NULL) {
	/* place error handler for memory allocation here*/
 	printf("error allocating memory\n");
	exit (0);
   }
   for (count=0;count<w*h;count++)
	(*image)[count]=(long)picptr.pic[count];
} 

void savesunras(char *fname,long *image,int dx,int dy){
FILE *fp; 
unsigned char graymap[256];
long w,h,count;
unsigned char *cptr;
	
   /* if the pallettes are reversed then take out the
   "255-" from the following line */
   for (count=0;count<256;count++) graymap[count] = 255-count;

   w=dx;
   h=dy;
   fp=fopen(fname,"w");
   if (fp==NULL){
	/* place fopen error handler here*/
	printf("error opening save file\n"); 
        exit (0);
   }
   cptr=(unsigned char*)malloc(w*h*sizeof(unsigned char));
   if (cptr==NULL){
	/* place memory allocation error handler here*/
	printf("unable to allocate memory\n");
	exit (0);
   }
   for (count=0;count<h*w;count++)
	cptr[count]=(unsigned char) image[count];
   WriteSunRas(fp,cptr,0,dx,dy,graymap,graymap,graymap,256,1,0);
   free(cptr);
   return;
}