nuclear@2: /*
nuclear@2: libimago - a multi-format image file input/output library.
nuclear@2: Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
nuclear@2: 
nuclear@2: This program is free software: you can redistribute it and/or modify
nuclear@2: it under the terms of the GNU Lesser General Public License as published
nuclear@2: by the Free Software Foundation, either version 3 of the License, or
nuclear@2: (at your option) any later version.
nuclear@2: 
nuclear@2: This program is distributed in the hope that it will be useful,
nuclear@2: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@2: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@2: GNU Lesser General Public License for more details.
nuclear@2: 
nuclear@2: You should have received a copy of the GNU Lesser General Public License
nuclear@2: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@2: */
nuclear@2: 
nuclear@2: /* -- Portable Pixmap (PPM) module -- */
nuclear@2: 
nuclear@2: #include <string.h>
nuclear@2: #include "imago2.h"
nuclear@2: #include "ftype_module.h"
nuclear@2: 
nuclear@2: static int check(struct img_io *io);
nuclear@2: static int readppm(struct img_pixmap *img, struct img_io *io);
nuclear@2: static int writeppm(struct img_pixmap *img, struct img_io *io);
nuclear@2: 
nuclear@2: int img_register_ppm(void)
nuclear@2: {
nuclear@2: 	static struct ftype_module mod = {".ppm", check, readppm, writeppm};
nuclear@2: 	return img_register_module(&mod);
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: static int check(struct img_io *io)
nuclear@2: {
nuclear@2: 	char id[2];
nuclear@2: 	int res = -1;
nuclear@2: 	long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@2: 
nuclear@2: 	if(io->read(id, 2, io->uptr) < 2) {
nuclear@2: 		io->seek(pos, SEEK_SET, io->uptr);
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(id[0] == 'P' && (id[1] == '6' || id[1] == '3')) {
nuclear@2: 		res = 0;
nuclear@2: 	}
nuclear@2: 	io->seek(pos, SEEK_SET, io->uptr);
nuclear@2: 	return res;
nuclear@2: }
nuclear@2: 
nuclear@2: static int iofgetc(struct img_io *io)
nuclear@2: {
nuclear@2: 	char c;
nuclear@2: 	return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
nuclear@2: }
nuclear@2: 
nuclear@2: static char *iofgets(char *buf, int size, struct img_io *io)
nuclear@2: {
nuclear@2: 	int c;
nuclear@2: 	char *ptr = buf;
nuclear@2: 
nuclear@2: 	while(--size > 0 && (c = iofgetc(io)) != -1) {
nuclear@2: 		*ptr++ = c;
nuclear@2: 		if(c == '\n') break;
nuclear@2: 	}
nuclear@2: 	*ptr = 0;
nuclear@2: 
nuclear@2: 	return ptr == buf ? 0 : buf;
nuclear@2: }
nuclear@2: 
nuclear@2: /* TODO: implement P3 reading */
nuclear@2: static int readppm(struct img_pixmap *img, struct img_io *io)
nuclear@2: {
nuclear@2: 	char buf[256];
nuclear@2: 	int xsz, ysz, maxval, got_hdrlines = 1;
nuclear@2: 
nuclear@2: 	if(!iofgets(buf, sizeof buf, io)) {
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 	if(!(buf[0] == 'P' && (buf[1] == '6' || buf[1] == '3'))) {
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	while(got_hdrlines < 3 && iofgets(buf, sizeof buf, io)) {
nuclear@2: 		if(buf[0] == '#') continue;
nuclear@2: 
nuclear@2: 		switch(got_hdrlines) {
nuclear@2: 		case 1:
nuclear@2: 			if(sscanf(buf, "%d %d\n", &xsz, &ysz) < 2) {
nuclear@2: 				return -1;
nuclear@2: 			}
nuclear@2: 			break;
nuclear@2: 
nuclear@2: 		case 2:
nuclear@2: 			if(sscanf(buf, "%d\n", &maxval) < 1) {
nuclear@2: 				return -1;
nuclear@2: 			}
nuclear@2: 		default:
nuclear@2: 			break;
nuclear@2: 		}
nuclear@2: 		got_hdrlines++;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(xsz < 1 || ysz < 1 || maxval != 255) {
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(img_set_pixels(img, xsz, ysz, IMG_FMT_RGB24, 0) == -1) {
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	if(io->read(img->pixels, xsz * ysz * 3, io->uptr) < xsz * ysz * 3) {
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 	return 0;
nuclear@2: }
nuclear@2: 
nuclear@2: static int writeppm(struct img_pixmap *img, struct img_io *io)
nuclear@2: {
nuclear@2: 	int sz;
nuclear@2: 	char buf[256];
nuclear@2: 	struct img_pixmap tmpimg;
nuclear@2: 
nuclear@2: 	img_init(&tmpimg);
nuclear@2: 
nuclear@2: 	if(img->fmt != IMG_FMT_RGB24) {
nuclear@2: 		if(img_copy(&tmpimg, img) == -1) {
nuclear@2: 			return -1;
nuclear@2: 		}
nuclear@2: 		if(img_convert(&tmpimg, IMG_FMT_RGB24) == -1) {
nuclear@2: 			return -1;
nuclear@2: 		}
nuclear@2: 		img = &tmpimg;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	sprintf(buf, "P6\n#written by libimago2\n%d %d\n255\n", img->width, img->height);
nuclear@2: 	if(io->write(buf, strlen(buf), io->uptr) < strlen(buf)) {
nuclear@2: 		img_destroy(&tmpimg);
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	sz = img->width * img->height * 3;
nuclear@2: 	if(io->write(img->pixels, sz, io->uptr) < sz) {
nuclear@2: 		img_destroy(&tmpimg);
nuclear@2: 		return -1;
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	img_destroy(&tmpimg);
nuclear@2: 	return 0;
nuclear@2: }