ViewScene/targa.h

/* ---------------------------------------------------------------------------
 * Truevision Targa Reader/Writer
 * $Id: targa.h,v 1.7 2003/06/21 09:30:53 emikulic Exp $
 *
 * Copyright (C) 2001-2003, Emil Mikulic.
 *
 * Source and binary redistribution of this code, with or without
 * changes, for free or for profit, is allowed as long as this copyright
 * notice is kept intact.  Modified versions have to be clearly marked
 * as modified.
 *
 * This code is provided without any warranty.  The copyright holder is
 * not liable for anything bad that might happen as a result of the
 * code.
 * -------------------------------------------------------------------------*/

#ifndef _TARGA_H_
#define _TARGA_H_

#include <stdio.h>
#ifndef _MSC_VER
# include <inttypes.h>
#else /* MSVC */
 typedef unsigned __int8  uint8_t;
 typedef unsigned __int16 uint16_t;
 typedef unsigned __int32 uint32_t;
#endif

#define BIT(index) (1 << (index))

#ifdef _BIG_ENDIAN
# define htole16(x) ( (((x) & 0x00FF) << 8) | (((x) & 0xFF00) >> 8) )
# define letoh16(x) htole16(x)
#else /* little endian */
# define htole16(x) (x)
# define letoh16(x) (x)
#endif /* endianness */

#ifdef __cplusplus 
extern "C" {
#endif

/* Targa image and header fields -------------------------------------------*/
typedef struct
{
    /* Note that Targa is stored in little-endian order */
    uint8_t     image_id_length;

    uint8_t     color_map_type;
    /* color map = palette */
    #define TGA_COLOR_MAP_ABSENT    0
    #define TGA_COLOR_MAP_PRESENT   1

    uint8_t     image_type;
    #define TGA_IMAGE_TYPE_NONE          0 /* no image data */
    #define TGA_IMAGE_TYPE_COLORMAP      1 /* uncompressed, color-mapped */
    #define TGA_IMAGE_TYPE_BGR           2 /* uncompressed, true-color */
    #define TGA_IMAGE_TYPE_MONO          3 /* uncompressed, black and white */
    #define TGA_IMAGE_TYPE_COLORMAP_RLE  9 /* run-length, color-mapped */
    #define TGA_IMAGE_TYPE_BGR_RLE      10 /* run-length, true-color */
    #define TGA_IMAGE_TYPE_MONO_RLE     11 /* run-length, black and white */

    /* color map specification */
    uint16_t    color_map_origin;   /* index of first entry */
    uint16_t    color_map_length;   /* number of entries included */
    uint8_t     color_map_depth;    /* number of bits per entry */

    /* image specification */
    uint16_t    origin_x;
    uint16_t    origin_y;
    uint16_t    width;
    uint16_t    height;
    uint8_t     pixel_depth;

    uint8_t     image_descriptor;
    /* bits 0,1,2,3 - attribute bits per pixel
     * bit  4       - set if image is stored right-to-left
     * bit  5       - set if image is stored top-to-bottom
     * bits 6,7     - unused (must be set to zero)
     */
    #define TGA_ATTRIB_BITS (uint8_t)(BIT(0)|BIT(1)|BIT(2)|BIT(3))
    #define TGA_R_TO_L_BIT  (uint8_t)BIT(4)
    #define TGA_T_TO_B_BIT  (uint8_t)BIT(5)
    #define TGA_UNUSED_BITS (uint8_t)(BIT(6)|BIT(7))
    /* Note: right-to-left order is not honored by some Targa readers */

    uint8_t *image_id;
    /* The length of this field is given in image_id_length, it's read raw
     * from the file so it's not not guaranteed to be zero-terminated.  If
     * it's not NULL, it needs to be deallocated.  see: tga_free_buffers()
     */

    uint8_t *color_map_data;
    /* See the "color map specification" fields above.  If not NULL, this
     * field needs to be deallocated.  see: tga_free_buffers()
     */

    uint8_t *image_data;
    /* Follows image specification fields (see above) */

    /* Extension area and developer area are silently ignored.  The Targa 2.0
     * spec says we're not required to read or write them.
     */

} tga_image;



/* For decoding header bits ------------------------------------------------*/
uint8_t tga_get_attribute_bits(const tga_image *tga);
int tga_is_right_to_left(const tga_image *tga);
int tga_is_top_to_bottom(const tga_image *tga);
int tga_is_colormapped(const tga_image *tga);
int tga_is_rle(const tga_image *tga);
int tga_is_mono(const tga_image *tga);



/* Error handling ----------------------------------------------------------*/
typedef enum {
    TGA_NOERR,
    TGAERR_FOPEN,
    TGAERR_EOF,
    TGAERR_WRITE,
    TGAERR_CMAP_TYPE,
    TGAERR_IMG_TYPE,
    TGAERR_NO_IMG,
    TGAERR_CMAP_MISSING,
    TGAERR_CMAP_PRESENT,
    TGAERR_CMAP_LENGTH,
    TGAERR_CMAP_DEPTH,
    TGAERR_ZERO_SIZE,
    TGAERR_PIXEL_DEPTH,
    TGAERR_NO_MEM,
    TGAERR_NOT_CMAP,
    TGAERR_RLE,
    TGAERR_INDEX_RANGE,
    TGAERR_MONO
} tga_result;

const char *tga_error(const tga_result errcode);



/* Load/save ---------------------------------------------------------------*/
tga_result tga_read(tga_image *dest, const char *filename);
tga_result tga_read_from_FILE(tga_image *dest, FILE *fp);
tga_result tga_write(const char *filename, const tga_image *src);
tga_result tga_write_to_FILE(FILE *fp, const tga_image *src);



/* Convenient writing functions --------------------------------------------*/
tga_result tga_write_mono(const char *filename, uint8_t *image,
    const uint16_t width, const uint16_t height);

tga_result tga_write_mono_rle(const char *filename, uint8_t *image,
    const uint16_t width, const uint16_t height);

tga_result tga_write_bgr(const char *filename, uint8_t *image,
    const uint16_t width, const uint16_t height, const uint8_t depth);

tga_result tga_write_bgr_rle(const char *filename, uint8_t *image,
    const uint16_t width, const uint16_t height, const uint8_t depth);

/* These functions will use tga_swap_red_blue to MODIFY your image data */
tga_result tga_write_rgb(const char *filename, uint8_t *image,
    const uint16_t width, const uint16_t height, const uint8_t depth);

tga_result tga_write_rgb_rle(const char *filename, uint8_t *image,
    const uint16_t width, const uint16_t height, const uint8_t depth);



/* Manipulation ------------------------------------------------------------*/
tga_result tga_flip_horiz(tga_image *img);
tga_result tga_flip_vert(tga_image *img);
tga_result tga_color_unmap(tga_image *img);

uint8_t *tga_find_pixel(const tga_image *img, uint16_t x, uint16_t y);
tga_result tga_unpack_pixel(const uint8_t *src, const uint8_t bits,
    uint8_t *b, uint8_t *g, uint8_t *r, uint8_t *a);
tga_result tga_pack_pixel(uint8_t *dest, const uint8_t bits,
    const uint8_t b, const uint8_t g, const uint8_t r, const uint8_t a);

tga_result tga_desaturate(tga_image *img,
        const int cr, const int cg, const int cb, const int dv);
tga_result tga_desaturate_rec_601_1(tga_image *img);
tga_result tga_desaturate_rec_709(tga_image *img);
tga_result tga_desaturate_itu(tga_image *img);
tga_result tga_desaturate_avg(tga_image *img);
tga_result tga_convert_depth(tga_image *img, const uint8_t bits);
tga_result tga_swap_red_blue(tga_image *img);

void tga_free_buffers(tga_image *img);



#ifndef TGA_KEEP_MACROS /* useful for targa.c */
# undef htole16
# undef letoh16
#endif

#ifdef __cplusplus
} // extern C
#endif

#endif /* !_TARGA_H_ */
/* vim:set tabstop=4 shiftwidth=4 textwidth=78 expandtab: */