added libimago
[eradicate] / libs / imago / src / filetga.c
diff --git a/libs/imago/src/filetga.c b/libs/imago/src/filetga.c
new file mode 100644 (file)
index 0000000..97504ca
--- /dev/null
@@ -0,0 +1,250 @@
+/*
+libimago - a multi-format image file input/output library.
+Copyright (C) 2010-2015 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/>.
+*/
+
+/* -- Targa (tga) module -- */
+
+#include <string.h>
+#include <stdlib.h>
+#include "inttypes.h"
+#include "imago2.h"
+#include "ftmodule.h"
+
+
+#if  defined(__i386__) || defined(__ia64__) || defined(WIN32) || \
+    (defined(__alpha__) || defined(__alpha)) || \
+     defined(__arm__) || \
+    (defined(__mips__) && defined(__MIPSEL__)) || \
+     defined(__SYMBIAN32__) || \
+     defined(__x86_64__) || \
+     defined(__LITTLE_ENDIAN__)
+/* little endian */
+#define read_int16_le(f)       read_int16(f)
+#else
+/* big endian */
+#define read_int16_le(f)       read_int16_inv(f)
+#endif /* endian check */
+
+
+enum {
+       IMG_NONE,
+       IMG_CMAP,
+       IMG_RGBA,
+       IMG_BW,
+
+       IMG_RLE_CMAP = 9,
+       IMG_RLE_RGBA,
+       IMG_RLE_BW
+};
+
+#define IS_RLE(x)      ((x) >= IMG_RLE_CMAP)
+#define IS_RGBA(x)     ((x) == IMG_RGBA || (x) == IMG_RLE_RGBA)
+
+
+struct tga_header {
+       uint8_t idlen;                  /* id field length */
+       uint8_t cmap_type;              /* color map type (0:no color map, 1:color map present) */
+       uint8_t img_type;               /* image type:
+                                                        * 0: no image data
+                                                        *      1: uncomp. color-mapped          9: RLE color-mapped
+                                                        *      2: uncomp. true color           10: RLE true color
+                                                        *      3: uncomp. black/white          11: RLE black/white */
+       uint16_t cmap_first;    /* color map first entry index */
+       uint16_t cmap_len;              /* color map length */
+       uint8_t cmap_entry_sz;  /* color map entry size */
+       uint16_t img_x;                 /* X-origin of the image */
+       uint16_t img_y;                 /* Y-origin of the image */
+       uint16_t img_width;             /* image width */
+       uint16_t img_height;    /* image height */
+       uint8_t img_bpp;                /* bits per pixel */
+       uint8_t img_desc;               /* descriptor:
+                                                        * bits 0 - 3: alpha or overlay bits
+                                                        * bits 5 & 4: origin (0 = bottom/left, 1 = top/right)
+                                                        * bits 7 & 6: data interleaving */
+};
+
+struct tga_footer {
+       uint32_t ext_off;               /* extension area offset */
+       uint32_t devdir_off;    /* developer directory offset */
+       char sig[18];                           /* signature with . and \0 */
+};
+
+
+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);
+static int read_pixel(struct img_io *io, int rdalpha, uint32_t *pix);
+static int16_t read_int16(struct img_io *io);
+static int16_t read_int16_inv(struct img_io *io);
+
+int img_register_tga(void)
+{
+       static struct ftype_module mod = {".tga", check, read, write};
+       return img_register_module(&mod);
+}
+
+
+static int check(struct img_io *io)
+{
+       struct tga_footer foot;
+       int res = -1;
+       long pos = io->seek(0, SEEK_CUR, io->uptr);
+       io->seek(-18, SEEK_END, io->uptr);
+
+       if(io->read(foot.sig, 17, io->uptr) < 17) {
+               io->seek(pos, SEEK_SET, io->uptr);
+               return -1;
+       }
+
+       if(memcmp(foot.sig, "TRUEVISION-XFILE.", 17) == 0) {
+               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 int read(struct img_pixmap *img, struct img_io *io)
+{
+       struct tga_header hdr;
+       int x, y;
+       int i, c;
+       uint32_t ppixel = 0;
+       int rle_mode = 0, rle_pix_left = 0;
+       int rdalpha;
+
+       /* read header */
+       hdr.idlen = iofgetc(io);
+       hdr.cmap_type = iofgetc(io);
+       hdr.img_type = iofgetc(io);
+       hdr.cmap_first = read_int16_le(io);
+       hdr.cmap_len = read_int16_le(io);
+       hdr.cmap_entry_sz = iofgetc(io);
+       hdr.img_x = read_int16_le(io);
+       hdr.img_y = read_int16_le(io);
+       hdr.img_width = read_int16_le(io);
+       hdr.img_height = read_int16_le(io);
+       hdr.img_bpp = iofgetc(io);
+       if((c = iofgetc(io)) == -1) {
+               return -1;
+       }
+       hdr.img_desc = c;
+
+       if(!IS_RGBA(hdr.img_type)) {
+               fprintf(stderr, "only true color tga images supported\n");
+               return -1;
+       }
+
+       io->seek(hdr.idlen, SEEK_CUR, io);      /* skip the image ID */
+
+       /* skip the color map if it exists */
+       if(hdr.cmap_type == 1) {
+               io->seek(hdr.cmap_len * hdr.cmap_entry_sz / 8, SEEK_CUR, io);
+       }
+
+       x = hdr.img_width;
+       y = hdr.img_height;
+       rdalpha = hdr.img_desc & 0xf;
+
+       /* TODO make this IMG_FMT_RGB24 if there's no alpha channel */
+       if(img_set_pixels(img, x, y, IMG_FMT_RGBA32, 0) == -1) {
+               return -1;
+       }
+
+       for(i=0; i<y; i++) {
+               uint32_t *ptr;
+               int j;
+
+               ptr = (uint32_t*)img->pixels + ((hdr.img_desc & 0x20) ? i : y - (i + 1)) * x;
+
+               for(j=0; j<x; j++) {
+                       /* if the image is raw, then just read the next pixel */
+                       if(!IS_RLE(hdr.img_type)) {
+                               if(read_pixel(io, rdalpha, &ppixel) == -1) {
+                                       return -1;
+                               }
+                       } else {
+                               /* otherwise, for RLE... */
+
+                               /* if we have pixels left in the packet ... */
+                               if(rle_pix_left) {
+                                       /* if it's a raw packet, read the next pixel, otherwise keep the same */
+                                       if(!rle_mode) {
+                                               if(read_pixel(io, rdalpha, &ppixel) == -1) {
+                                                       return -1;
+                                               }
+                                       }
+                                       --rle_pix_left;
+                               } else {
+                                       /* read RLE packet header */
+                                       unsigned char phdr = iofgetc(io);
+                                       rle_mode = (phdr & 128);                /* last bit shows the mode for this packet (1: rle, 0: raw) */
+                                       rle_pix_left = (phdr & ~128);   /* the rest gives the count of pixels minus one (we also read one here, so no +1) */
+                                       /* and read the first pixel of the packet */
+                                       if(read_pixel(io, rdalpha, &ppixel) == -1) {
+                                               return -1;
+                                       }
+                               }
+                       }
+
+                       *ptr++ = ppixel;
+               }
+       }
+
+       return 0;
+}
+
+static int write(struct img_pixmap *img, struct img_io *io)
+{
+       return -1;      /* TODO */
+}
+
+#define PACK_COLOR32(r,g,b,a) \
+       ((((a) & 0xff) << 24) | \
+        (((r) & 0xff) << 0) | \
+        (((g) & 0xff) << 8) | \
+        (((b) & 0xff) << 16))
+
+static int read_pixel(struct img_io *io, int rdalpha, uint32_t *pix)
+{
+       int r, g, b, a;
+       b = iofgetc(io);
+       g = iofgetc(io);
+       r = iofgetc(io);
+       a = rdalpha ? iofgetc(io) : 0xff;
+       *pix = PACK_COLOR32(r, g, b, a);
+       return a == -1 || r == -1 ? -1 : 0;
+}
+
+static int16_t read_int16(struct img_io *io)
+{
+       int16_t v;
+       io->read(&v, 2, io);
+       return v;
+}
+
+static int16_t read_int16_inv(struct img_io *io)
+{
+       int16_t v;
+       io->read(&v, 2, io);
+       return ((v >> 8) & 0xff) | (v << 8);
+}