+ FILE *fp;
+ int hdrline = 0;
+
+ if(!(fp = fopen(fname, "rb"))) {
+ fprintf(stderr, "failed to open pixmap: %s: %s\n", fname, strerror(errno));
+ return false;
+ }
+
+ /* read ppm header */
+ while(hdrline < 3) {
+ char buf[64];
+
+ if(!fgets(buf, sizeof buf, fp))
+ goto err;
+
+ /* skip comments */
+ if(buf[0] == '#')
+ continue;
+
+ switch(hdrline++) {
+ case 0:
+ /* first header line should be P6 */
+ if(strcmp(buf, "P6\n") != 0)
+ goto err;
+ break;
+
+ case 1:
+ /* second header line contains the pixmap dimensions */
+ if(sscanf(buf, "%d %d", &width, &height) != 2)
+ goto err;
+ break;
+ }
+ }
+
+ set_image(width, height, 0);
+
+ for(int i=0; i<width * height * 4; i++) {
+ int c;
+ if(i % 4 != 3) {
+ c = fgetc(fp);
+ if(c < 0)
+ goto err;
+ }
+ else {
+ c = 255;
+ }
+ pixels[i] = c;
+ }
+ fclose(fp);
+ return true;
+
+err:
+ fprintf(stderr, "failed to load pixmap: %s\n", fname);
+ fclose(fp);
+ return false;