nuclear@14: /*
nuclear@14: libimago - a multi-format image file input/output library.
nuclear@14: Copyright (C) 2010-2015 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: /* -- Targa (tga) module -- */
nuclear@14: 
nuclear@14: #include <string.h>
nuclear@14: #include <stdlib.h>
nuclear@14: #include <stdint.h>
nuclear@14: #include "imago2.h"
nuclear@14: #include "ftype_module.h"
nuclear@14: 
nuclear@14: 
nuclear@14: #if  defined(__i386__) || defined(__ia64__) || defined(WIN32) || \
nuclear@14:     (defined(__alpha__) || defined(__alpha)) || \
nuclear@14:      defined(__arm__) || \
nuclear@14:     (defined(__mips__) && defined(__MIPSEL__)) || \
nuclear@14:      defined(__SYMBIAN32__) || \
nuclear@14:      defined(__x86_64__) || \
nuclear@14:      defined(__LITTLE_ENDIAN__)
nuclear@14: /* little endian */
nuclear@14: #define read_int16_le(f)	read_int16(f)
nuclear@14: #else
nuclear@14: /* big endian */
nuclear@14: #define read_int16_le(f)	read_int16_inv(f)
nuclear@14: #endif	/* endian check */
nuclear@14: 
nuclear@14: 
nuclear@14: enum {
nuclear@14: 	IMG_NONE,
nuclear@14: 	IMG_CMAP,
nuclear@14: 	IMG_RGBA,
nuclear@14: 	IMG_BW,
nuclear@14: 
nuclear@14: 	IMG_RLE_CMAP = 9,
nuclear@14: 	IMG_RLE_RGBA,
nuclear@14: 	IMG_RLE_BW
nuclear@14: };
nuclear@14: 
nuclear@14: #define IS_RLE(x)	((x) >= IMG_RLE_CMAP)
nuclear@14: #define IS_RGBA(x)	((x) == IMG_RGBA || (x) == IMG_RLE_RGBA)
nuclear@14: 
nuclear@14: 
nuclear@14: struct tga_header {
nuclear@14: 	uint8_t idlen;			/* id field length */
nuclear@14: 	uint8_t cmap_type;		/* color map type (0:no color map, 1:color map present) */
nuclear@14: 	uint8_t img_type;		/* image type:
nuclear@14: 							 * 0: no image data
nuclear@14: 							 *	1: uncomp. color-mapped		 9: RLE color-mapped
nuclear@14: 							 *	2: uncomp. true color		10: RLE true color
nuclear@14: 							 *	3: uncomp. black/white		11: RLE black/white */
nuclear@14: 	uint16_t cmap_first;	/* color map first entry index */
nuclear@14: 	uint16_t cmap_len;		/* color map length */
nuclear@14: 	uint8_t cmap_entry_sz;	/* color map entry size */
nuclear@14: 	uint16_t img_x;			/* X-origin of the image */
nuclear@14: 	uint16_t img_y;			/* Y-origin of the image */
nuclear@14: 	uint16_t img_width;		/* image width */
nuclear@14: 	uint16_t img_height;	/* image height */
nuclear@14: 	uint8_t img_bpp;		/* bits per pixel */
nuclear@14: 	uint8_t img_desc;		/* descriptor:
nuclear@14: 							 * bits 0 - 3: alpha or overlay bits
nuclear@14: 							 * bits 5 & 4: origin (0 = bottom/left, 1 = top/right)
nuclear@14: 							 * bits 7 & 6: data interleaving */
nuclear@14: };
nuclear@14: 
nuclear@14: struct tga_footer {
nuclear@14: 	uint32_t ext_off;		/* extension area offset */
nuclear@14: 	uint32_t devdir_off;	/* developer directory offset */
nuclear@14: 	char sig[18];				/* signature with . and \0 */
nuclear@14: };
nuclear@14: 
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: static int read_pixel(struct img_io *io, int rdalpha, uint32_t *pix);
nuclear@14: static int16_t read_int16(struct img_io *io);
nuclear@14: static int16_t read_int16_inv(struct img_io *io);
nuclear@14: 
nuclear@14: int img_register_tga(void)
nuclear@14: {
nuclear@14: 	static struct ftype_module mod = {".tga", 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: 	struct tga_footer foot;
nuclear@14: 	int res = -1;
nuclear@14: 	long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@14: 	io->seek(-18, SEEK_END, io->uptr);
nuclear@14: 
nuclear@14: 	if(io->read(foot.sig, 17, io->uptr) < 17) {
nuclear@14: 		io->seek(pos, SEEK_SET, io->uptr);
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	if(memcmp(foot.sig, "TRUEVISION-XFILE.", 17) == 0) {
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 int read(struct img_pixmap *img, struct img_io *io)
nuclear@14: {
nuclear@14: 	struct tga_header hdr;
nuclear@14: 	unsigned long x, y;
nuclear@14: 	int i, c;
nuclear@14: 	uint32_t ppixel = 0;
nuclear@14: 	int rle_mode = 0, rle_pix_left = 0;
nuclear@14: 	int rdalpha;
nuclear@14: 
nuclear@14: 	/* read header */
nuclear@14: 	hdr.idlen = iofgetc(io);
nuclear@14: 	hdr.cmap_type = iofgetc(io);
nuclear@14: 	hdr.img_type = iofgetc(io);
nuclear@14: 	hdr.cmap_first = read_int16_le(io);
nuclear@14: 	hdr.cmap_len = read_int16_le(io);
nuclear@14: 	hdr.cmap_entry_sz = iofgetc(io);
nuclear@14: 	hdr.img_x = read_int16_le(io);
nuclear@14: 	hdr.img_y = read_int16_le(io);
nuclear@14: 	hdr.img_width = read_int16_le(io);
nuclear@14: 	hdr.img_height = read_int16_le(io);
nuclear@14: 	hdr.img_bpp = iofgetc(io);
nuclear@14: 	if((c = iofgetc(io)) == -1) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 	hdr.img_desc = c;
nuclear@14: 
nuclear@14: 	if(!IS_RGBA(hdr.img_type)) {
nuclear@14: 		fprintf(stderr, "only true color tga images supported\n");
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	io->seek(hdr.idlen, SEEK_CUR, io);	/* skip the image ID */
nuclear@14: 
nuclear@14: 	/* skip the color map if it exists */
nuclear@14: 	if(hdr.cmap_type == 1) {
nuclear@14: 		io->seek(hdr.cmap_len * hdr.cmap_entry_sz / 8, SEEK_CUR, io);
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	x = hdr.img_width;
nuclear@14: 	y = hdr.img_height;
nuclear@14: 	rdalpha = hdr.img_desc & 0xf;
nuclear@14: 
nuclear@14: 	/* TODO make this IMG_FMT_RGB24 if there's no alpha channel */
nuclear@14: 	if(img_set_pixels(img, x, y, IMG_FMT_RGBA32, 0) == -1) {
nuclear@14: 		return -1;
nuclear@14: 	}
nuclear@14: 
nuclear@14: 	for(i=0; i<y; i++) {
nuclear@14: 		uint32_t *ptr;
nuclear@14: 		int j;
nuclear@14: 
nuclear@14: 		ptr = (uint32_t*)img->pixels + ((hdr.img_desc & 0x20) ? i : y - (i + 1)) * x;
nuclear@14: 
nuclear@14: 		for(j=0; j<x; j++) {
nuclear@14: 			/* if the image is raw, then just read the next pixel */
nuclear@14: 			if(!IS_RLE(hdr.img_type)) {
nuclear@14: 				if(read_pixel(io, rdalpha, &ppixel) == -1) {
nuclear@14: 					return -1;
nuclear@14: 				}
nuclear@14: 			} else {
nuclear@14: 				/* otherwise, for RLE... */
nuclear@14: 
nuclear@14: 				/* if we have pixels left in the packet ... */
nuclear@14: 				if(rle_pix_left) {
nuclear@14: 					/* if it's a raw packet, read the next pixel, otherwise keep the same */
nuclear@14: 					if(!rle_mode) {
nuclear@14: 						if(read_pixel(io, rdalpha, &ppixel) == -1) {
nuclear@14: 							return -1;
nuclear@14: 						}
nuclear@14: 					}
nuclear@14: 					--rle_pix_left;
nuclear@14: 				} else {
nuclear@14: 					/* read RLE packet header */
nuclear@14: 					unsigned char phdr = iofgetc(io);
nuclear@14: 					rle_mode = (phdr & 128);		/* last bit shows the mode for this packet (1: rle, 0: raw) */
nuclear@14: 					rle_pix_left = (phdr & ~128);	/* the rest gives the count of pixels minus one (we also read one here, so no +1) */
nuclear@14: 					/* and read the first pixel of the packet */
nuclear@14: 					if(read_pixel(io, rdalpha, &ppixel) == -1) {
nuclear@14: 						return -1;
nuclear@14: 					}
nuclear@14: 				}
nuclear@14: 			}
nuclear@14: 
nuclear@14: 			*ptr++ = ppixel;
nuclear@14: 		}
nuclear@14: 	}
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: 	return -1;	/* TODO */
nuclear@14: }
nuclear@14: 
nuclear@14: #define PACK_COLOR32(r,g,b,a) \
nuclear@14: 	((((a) & 0xff) << 24) | \
nuclear@14: 	 (((r) & 0xff) << 0) | \
nuclear@14: 	 (((g) & 0xff) << 8) | \
nuclear@14: 	 (((b) & 0xff) << 16))
nuclear@14: 
nuclear@14: static int read_pixel(struct img_io *io, int rdalpha, uint32_t *pix)
nuclear@14: {
nuclear@14: 	int r, g, b, a;
nuclear@14: 	b = iofgetc(io);
nuclear@14: 	g = iofgetc(io);
nuclear@14: 	r = iofgetc(io);
nuclear@14: 	a = rdalpha ? iofgetc(io) : 0xff;
nuclear@14: 	*pix = PACK_COLOR32(r, g, b, a);
nuclear@14: 	return a == -1 || r == -1 ? -1 : 0;
nuclear@14: }
nuclear@14: 
nuclear@14: static int16_t read_int16(struct img_io *io)
nuclear@14: {
nuclear@14: 	int16_t v;
nuclear@14: 	io->read(&v, 2, io);
nuclear@14: 	return v;
nuclear@14: }
nuclear@14: 
nuclear@14: static int16_t read_int16_inv(struct img_io *io)
nuclear@14: {
nuclear@14: 	int16_t v;
nuclear@14: 	io->read(&v, 2, io);
nuclear@14: 	return ((v >> 8) & 0xff) | (v << 8);
nuclear@14: }