--- /dev/null
+/*
+libimago - a multi-format image file input/output library.
+Copyright (C) 2010-2017 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 "imago2.h"
+#include "ftype_module.h"
+#include "byteord.h"
+
+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_tga(struct img_pixmap *img, struct img_io *io);
+static int write_tga(struct img_pixmap *img, struct img_io *io);
+static int read_pixel(struct img_io *io, int rdalpha, unsigned char *pix);
+
+int img_register_tga(void)
+{
+ static struct ftype_module mod = {".tga:.targa", check, read_tga, write_tga};
+ 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)
+{
+ int c = 0;
+ return io->read(&c, 1, io->uptr) < 1 ? -1 : c;
+}
+
+static int read_tga(struct img_pixmap *img, struct img_io *io)
+{
+ struct tga_header hdr;
+ unsigned long x, y;
+ int i, c;
+ int rle_mode = 0, rle_pix_left = 0;
+ int rdalpha;
+ int pixel_bytes;
+
+ /* read header */
+ hdr.idlen = iofgetc(io);
+ hdr.cmap_type = iofgetc(io);
+ hdr.img_type = iofgetc(io);
+ hdr.cmap_first = img_read_int16_le(io);
+ hdr.cmap_len = img_read_int16_le(io);
+ hdr.cmap_entry_sz = iofgetc(io);
+ hdr.img_x = img_read_int16_le(io);
+ hdr.img_y = img_read_int16_le(io);
+ hdr.img_width = img_read_int16_le(io);
+ hdr.img_height = img_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, "libimago: only true color tga images are supported\n");
+ return -1;
+ }
+
+ io->seek(hdr.idlen, SEEK_CUR, io->uptr); /* 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->uptr);
+ }
+
+ x = hdr.img_width;
+ y = hdr.img_height;
+ rdalpha = hdr.img_desc & 0xf;
+ pixel_bytes = rdalpha ? 4 : 3;
+
+ if(img_set_pixels(img, x, y, rdalpha ? IMG_FMT_RGBA32 : IMG_FMT_RGB24, 0) == -1) {
+ return -1;
+ }
+
+ for(i=0; i<y; i++) {
+ unsigned char *ptr;
+ int j, k;
+
+ ptr = (unsigned char*)img->pixels + ((hdr.img_desc & 0x20) ? i : y - (i + 1)) * x * pixel_bytes;
+
+ 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, ptr) == -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, ptr) == -1) {
+ return -1;
+ }
+ } else {
+ for(k=0; k<pixel_bytes; k++) {
+ ptr[k] = ptr[k - pixel_bytes];
+ }
+ }
+ --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, ptr) == -1) {
+ return -1;
+ }
+ }
+ }
+
+ ptr += pixel_bytes;
+ }
+ }
+
+ return 0;
+}
+
+static int write_tga(struct img_pixmap *img, struct img_io *io)
+{
+ return -1; /* TODO */
+}
+
+static int read_pixel(struct img_io *io, int rdalpha, unsigned char *pix)
+{
+ int r, g, b, a;
+ if((b = iofgetc(io)) == -1 || (g = iofgetc(io)) == -1 || (r = iofgetc(io)) == -1) {
+ return -1;
+ }
+
+ pix[0] = r;
+ pix[1] = g;
+ pix[2] = b;
+
+ if(rdalpha) {
+ if((a = iofgetc(io)) == -1) {
+ return -1;
+ }
+ pix[3] = a;
+ }
+ return 0;
+}
projects / demo_prior / blobdiff