added libimago

[eradicate] / libs / imago / src / fileppm.c

diff --git a/libs/imago/src/fileppm.c b/libs/imago/src/fileppm.c
new file mode 100644 (file)
index 0000000..772c362
--- /dev/null
+++ b/libs/imago/src/fileppm.c
@@ -0,0 +1,153 @@
+/*
+libimago - a multi-format image file input/output library.
+Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published
+by the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* -- Portable Pixmap (PPM) module -- */
+
+#include <string.h>
+#include "imago2.h"
+#include "ftmodule.h"
+
+static int check(struct img_io *io);
+static int read(struct img_pixmap *img, struct img_io *io);
+static int write(struct img_pixmap *img, struct img_io *io);
+
+int img_register_ppm(void)
+{
+       static struct ftype_module mod = {".ppm", check, read, write};
+       return img_register_module(&mod);
+}
+
+
+static int check(struct img_io *io)
+{
+       char id[2];
+       int res = -1;
+       long pos = io->seek(0, SEEK_CUR, io->uptr);
+
+       if(io->read(id, 2, io->uptr) < 2) {
+               io->seek(pos, SEEK_SET, io->uptr);
+               return -1;
+       }
+
+       if(id[0] == 'P' && (id[1] == '6' || id[1] == '3')) {
+               res = 0;
+       }
+       io->seek(pos, SEEK_SET, io->uptr);
+       return res;
+}
+
+static int iofgetc(struct img_io *io)
+{
+       char c;
+       return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
+}
+
+static char *iofgets(char *buf, int size, struct img_io *io)
+{
+       int c;
+       char *ptr = buf;
+
+       while(--size > 0 && (c = iofgetc(io)) != -1) {
+               *ptr++ = c;
+               if(c == '\n') break;
+       }
+       *ptr = 0;
+
+       return ptr == buf ? 0 : buf;
+}
+
+/* TODO: implement P3 reading */
+static int read(struct img_pixmap *img, struct img_io *io)
+{
+       char buf[256];
+       int xsz, ysz, maxval, got_hdrlines = 1;
+
+       if(!iofgets(buf, sizeof buf, io)) {
+               return -1;
+       }
+       if(!(buf[0] == 'P' && (buf[1] == '6' || buf[1] == '3'))) {
+               return -1;
+       }
+
+       while(got_hdrlines < 3 && iofgets(buf, sizeof buf, io)) {
+               if(buf[0] == '#') continue;
+
+               switch(got_hdrlines) {
+               case 1:
+                       if(sscanf(buf, "%d %d\n", &xsz, &ysz) < 2) {
+                               return -1;
+                       }
+                       break;
+
+               case 2:
+                       if(sscanf(buf, "%d\n", &maxval) < 1) {
+                               return -1;
+                       }
+               default:
+                       break;
+               }
+               got_hdrlines++;
+       }
+
+       if(xsz < 1 || ysz < 1 || maxval != 255) {
+               return -1;
+       }
+
+       if(img_set_pixels(img, xsz, ysz, IMG_FMT_RGB24, 0) == -1) {
+               return -1;
+       }
+
+       if(io->read(img->pixels, xsz * ysz * 3, io->uptr) < (unsigned int)(xsz * ysz * 3)) {
+               return -1;
+       }
+       return 0;
+}
+
+static int write(struct img_pixmap *img, struct img_io *io)
+{
+       int sz;
+       char buf[256];
+       struct img_pixmap tmpimg;
+
+       img_init(&tmpimg);
+
+       if(img->fmt != IMG_FMT_RGB24) {
+               if(img_copy(&tmpimg, img) == -1) {
+                       return -1;
+               }
+               if(img_convert(&tmpimg, IMG_FMT_RGB24) == -1) {
+                       return -1;
+               }
+               img = &tmpimg;
+       }
+
+       sprintf(buf, "P6\n#written by libimago2\n%d %d\n255\n", img->width, img->height);
+       if(io->write(buf, strlen(buf), io->uptr) < strlen(buf)) {
+               img_destroy(&tmpimg);
+               return -1;
+       }
+
+       sz = img->width * img->height * 3;
+       if(io->write(img->pixels, sz, io->uptr) < (unsigned int)sz) {
+               img_destroy(&tmpimg);
+               return -1;
+       }
+
+       img_destroy(&tmpimg);
+       return 0;
+}