nuclear@0: #include <stdio.h>
nuclear@0: #include <stdlib.h>
nuclear@0: #include <string.h>
nuclear@0: #include <errno.h>
nuclear@0: #include "image.h"
nuclear@0: 
nuclear@0: struct image *load_image(const char *fname)
nuclear@0: {
nuclear@0: 	FILE *fp;
nuclear@0: 	int i, hdrline = 0;
nuclear@0: 	struct image *img = 0;
nuclear@0: 
nuclear@0: 	if(!(fp = fopen(fname, "rb"))) {
nuclear@0: 		fprintf(stderr, "failed to open pixmap: %s: %s\n", fname, strerror(errno));
nuclear@0: 		return 0;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(!(img = malloc(sizeof *img))) {
nuclear@0: 		perror("failed to allocate image structure");
nuclear@0: 		goto err;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* read ppm header */
nuclear@0: 	while(hdrline < 3) {
nuclear@0: 		char buf[64];
nuclear@0: 
nuclear@0: 		if(!fgets(buf, sizeof buf, fp)) {
nuclear@0: 			goto err;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		/* skip comments */
nuclear@0: 		if(buf[0] == '#')
nuclear@0: 			continue;
nuclear@0: 
nuclear@0: 		switch(hdrline++) {
nuclear@0: 		case 0:
nuclear@0: 			/* first header line should be P6 */
nuclear@0: 			if(strcmp(buf, "P6\n") != 0) {
nuclear@0: 				goto err;
nuclear@0: 			}
nuclear@0: 			break;
nuclear@0: 
nuclear@0: 		case 1:
nuclear@0: 			/* second header line contains the pixmap dimensions */
nuclear@0: 			if(sscanf(buf, "%d %d", &img->width, &img->height) != 2) {
nuclear@0: 				goto err;
nuclear@0: 			}
nuclear@0: 			break;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* allocate the image (each pixel is 3 bytes r, g, and b) */
nuclear@0: 	if(!(img->pixels = malloc(img->width * img->height * 3))) {
nuclear@0: 		goto err;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* read all pixels */
nuclear@0: 	for(i=0; i<img->width * img->height * 3; i++) {
nuclear@0: 		int c = fgetc(fp);
nuclear@0: 		if(c < 0) {
nuclear@0: 			goto err;
nuclear@0: 		}
nuclear@0: 		img->pixels[i] = c;
nuclear@0: 	}
nuclear@0: 	fclose(fp);
nuclear@0: 
nuclear@0: 	return img;
nuclear@0: 
nuclear@0: err:
nuclear@0: 	fprintf(stderr, "failed to load pixmap: %s\n", fname);
nuclear@0: 	if(img) {
nuclear@0: 		free(img->pixels);
nuclear@0: 		free(img);
nuclear@0: 	}
nuclear@0: 	if(fp) {
nuclear@0: 		fclose(fp);
nuclear@0: 	}
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: void free_image(struct image *img)
nuclear@0: {
nuclear@0: 	if(img) {
nuclear@0: 		free(img->pixels);
nuclear@0: 		free(img);
nuclear@0: 	}
nuclear@0: }