nuclear@14: /*
nuclear@14: libimago - a multi-format image file input/output library.
nuclear@14: Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
nuclear@14: 
nuclear@14: This program is free software: you can redistribute it and/or modify
nuclear@14: it under the terms of the GNU Lesser General Public License as published
nuclear@14: by the Free Software Foundation, either version 3 of the License, or
nuclear@14: (at your option) any later version.
nuclear@14: 
nuclear@14: This program is distributed in the hope that it will be useful,
nuclear@14: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@14: GNU Lesser General Public License for more details.
nuclear@14: 
nuclear@14: You should have received a copy of the GNU Lesser General Public License
nuclear@14: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@14: */
nuclear@14: 
nuclear@14: /* -- Portable Pixmap (PPM) module -- */
nuclear@14: 
nuclear@14: #include <string.h>
nuclear@14: #include "imago2.h"
nuclear@14: #include "ftype_module.h"
nuclear@14: 
nuclear@14: static int check(struct img_io *io);
nuclear@14: static int read(struct img_pixmap *img, struct img_io *io);
nuclear@14: static int write(struct img_pixmap *img, struct img_io *io);
nuclear@14: 
nuclear@14: int img_register_ppm(void)
nuclear@14: {
nuclear@14: 	static struct ftype_module mod = {".ppm", check, read, write};
nuclear@14: 	return img_register_module(&mod);
nuclear@14: }
nuclear@14: 
nuclear@14: 
nuclear@14: static int check(struct img_io *io)
nuclear@14: {
nuclear@14: 	char id[2];
nuclear@14: 	int res = -1;
nuclear@14: 	long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@14: 
nuclear@14: 	if(io->read(id, 2, io->uptr) < 2) {
nuclear@14: 		io->seek(pos, SEEK_SET, io->uptr);
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	if(id[0] == 'P' && (id[1] == '6' || id[1] == '3')) {
nuclear@14: 		res = 0;
nuclear@14: 	}
nuclear@14: 	io->seek(pos, SEEK_SET, io->uptr);
nuclear@14: 	return res;
nuclear@14: }
nuclear@14: 
nuclear@14: static int iofgetc(struct img_io *io)
nuclear@14: {
nuclear@14: 	char c;
nuclear@14: 	return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
nuclear@14: }
nuclear@14: 
nuclear@14: static char *iofgets(char *buf, int size, struct img_io *io)
nuclear@14: {
nuclear@14: 	int c;
nuclear@14: 	char *ptr = buf;
nuclear@14: 
nuclear@14: 	while(--size > 0 && (c = iofgetc(io)) != -1) {
nuclear@14: 		*ptr++ = c;
nuclear@14: 		if(c == '\n') break;
nuclear@14: 	}
nuclear@14: 	*ptr = 0;
nuclear@14: 
nuclear@14: 	return ptr == buf ? 0 : buf;
nuclear@14: }
nuclear@14: 
nuclear@14: /* TODO: implement P3 reading */
nuclear@14: static int read(struct img_pixmap *img, struct img_io *io)
nuclear@14: {
nuclear@14: 	char buf[256];
nuclear@14: 	int xsz, ysz, maxval, got_hdrlines = 1;
nuclear@14: 
nuclear@14: 	if(!iofgets(buf, sizeof buf, io)) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 	if(!(buf[0] == 'P' && (buf[1] == '6' || buf[1] == '3'))) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	while(got_hdrlines < 3 && iofgets(buf, sizeof buf, io)) {
nuclear@14: 		if(buf[0] == '#') continue;
nuclear@14: 
nuclear@14: 		switch(got_hdrlines) {
nuclear@14: 		case 1:
nuclear@14: 			if(sscanf(buf, "%d %d\n", &xsz, &ysz) < 2) {
nuclear@14: 				return -1;
nuclear@14: 			}
nuclear@14: 			break;
nuclear@14: 
nuclear@14: 		case 2:
nuclear@14: 			if(sscanf(buf, "%d\n", &maxval) < 1) {
nuclear@14: 				return -1;
nuclear@14: 			}
nuclear@14: 		default:
nuclear@14: 			break;
nuclear@14: 		}
nuclear@14: 		got_hdrlines++;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	if(xsz < 1 || ysz < 1 || maxval != 255) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	if(img_set_pixels(img, xsz, ysz, IMG_FMT_RGB24, 0) == -1) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	if(io->read(img->pixels, xsz * ysz * 3, io->uptr) < (unsigned int)(xsz * ysz * 3)) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 	return 0;
nuclear@14: }
nuclear@14: 
nuclear@14: static int write(struct img_pixmap *img, struct img_io *io)
nuclear@14: {
nuclear@14: 	int sz;
nuclear@14: 	char buf[256];
nuclear@14: 	struct img_pixmap tmpimg;
nuclear@14: 
nuclear@14: 	img_init(&tmpimg);
nuclear@14: 
nuclear@14: 	if(img->fmt != IMG_FMT_RGB24) {
nuclear@14: 		if(img_copy(&tmpimg, img) == -1) {
nuclear@14: 			return -1;
nuclear@14: 		}
nuclear@14: 		if(img_convert(&tmpimg, IMG_FMT_RGB24) == -1) {
nuclear@14: 			return -1;
nuclear@14: 		}
nuclear@14: 		img = &tmpimg;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	sprintf(buf, "P6\n#written by libimago2\n%d %d\n255\n", img->width, img->height);
nuclear@14: 	if(io->write(buf, strlen(buf), io->uptr) < strlen(buf)) {
nuclear@14: 		img_destroy(&tmpimg);
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	sz = img->width * img->height * 3;
nuclear@14: 	if(io->write(img->pixels, sz, io->uptr) < (unsigned int)sz) {
nuclear@14: 		img_destroy(&tmpimg);
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	img_destroy(&tmpimg);
nuclear@14: 	return 0;
nuclear@14: }