/* ---------------------------------------------------------------------------
* Truevision Targa Reader/Writer
* 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 must 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.
* -------------------------------------------------------------------------*/
/*
* preso da http://dmr.ath.cx/gfx/targa/
* modificato da gmt
*
*/
/*@unused@*/ static const char rcsid[] =
"$Id: targa.c,v 1.7 2003/06/21 09:30:53 emikulic Exp $";
#define TGA_KEEP_MACROS /* BIT, htole16, letoh16 */
#include "targa.h"
#include <stdlib.h>
#include <string.h> /* memcpy, memcmp */
#define SANE_DEPTH(x) ((x) == 8 || (x) == 16 || (x) == 24 || (x) == 32)
#define UNMAP_DEPTH(x) ((x) == 16 || (x) == 24 || (x) == 32)
static const char tga_id[] =
"\0\0\0\0" /* extension area offset */
"\0\0\0\0" /* developer directory offset */
"TRUEVISION-XFILE.";
static const size_t tga_id_length = 26; /* tga_id + \0 */
/* helpers */
static tga_result tga_read_rle(tga_image *dest, FILE *fp);
static tga_result tga_write_row_RLE(FILE *fp,
const tga_image *src, const uint8_t *row);
typedef enum { RAW,
RLE } packet_type;
static packet_type rle_packet_type(const uint8_t *row, const uint16_t pos,
const uint16_t width, const uint16_t bpp);
static uint8_t rle_packet_len(const uint8_t *row, const uint16_t pos,
const uint16_t width, const uint16_t bpp, const packet_type type);
uint8_t tga_get_attribute_bits(const tga_image *tga)
{
return tga->image_descriptor & TGA_ATTRIB_BITS;
}
int tga_is_right_to_left(const tga_image *tga)
{
return (tga->image_descriptor & TGA_R_TO_L_BIT) != 0;
}
int tga_is_top_to_bottom(const tga_image *tga)
{
return (tga->image_descriptor & TGA_T_TO_B_BIT) != 0;
}
int tga_is_colormapped(const tga_image *tga)
{
return (
tga->image_type == TGA_IMAGE_TYPE_COLORMAP ||
tga->image_type == TGA_IMAGE_TYPE_COLORMAP_RLE);
}
int tga_is_rle(const tga_image *tga)
{
return (
tga->image_type == TGA_IMAGE_TYPE_COLORMAP_RLE ||
tga->image_type == TGA_IMAGE_TYPE_BGR_RLE ||
tga->image_type == TGA_IMAGE_TYPE_MONO_RLE);
}
int tga_is_mono(const tga_image *tga)
{
return (
tga->image_type == TGA_IMAGE_TYPE_MONO ||
tga->image_type == TGA_IMAGE_TYPE_MONO_RLE);
}
/* ---------------------------------------------------------------------------
* Convert the numerical <errcode> into a verbose error string.
*
* Returns: an error string
*/
const char *tga_error(const tga_result errcode)
{
switch (errcode) {
case TGA_NOERR:
return "no error";
case TGAERR_FOPEN:
return "error opening file";
case TGAERR_EOF:
return "premature end of file";
case TGAERR_WRITE:
return "error writing to file";
case TGAERR_CMAP_TYPE:
return "invalid color map type";
case TGAERR_IMG_TYPE:
return "invalid image type";
case TGAERR_NO_IMG:
return "no image data included";
case TGAERR_CMAP_MISSING:
return "color-mapped image without color map";
case TGAERR_CMAP_PRESENT:
return "non-color-mapped image with extraneous color map";
case TGAERR_CMAP_LENGTH:
return "color map has zero length";
case TGAERR_CMAP_DEPTH:
return "invalid color map depth";
case TGAERR_ZERO_SIZE:
return "the image dimensions are zero";
case TGAERR_PIXEL_DEPTH:
return "invalid pixel depth";
case TGAERR_NO_MEM:
return "out of memory";
case TGAERR_NOT_CMAP:
return "image is not color mapped";
case TGAERR_RLE:
return "RLE data is corrupt";
case TGAERR_INDEX_RANGE:
return "color map index out of range";
case TGAERR_MONO:
return "image is mono";
default:
return "unknown error code";
}
}
/* ---------------------------------------------------------------------------
* Read a Targa image from a file named <filename> to <dest>. This is just a
* wrapper around tga_read_from_FILE().
*
* Returns: TGA_NOERR on success, or a matching TGAERR_* code on failure.
*/
tga_result tga_read(tga_image *dest, const char *filename)
{
tga_result result;
FILE *fp = fopen(filename, "rb");
if (fp == NULL)
return TGAERR_FOPEN;
result = tga_read_from_FILE(dest, fp);
fclose(fp);
return result;
}
/* ---------------------------------------------------------------------------
* Read a Targa image from <fp> to <dest>.
*
* Returns: TGA_NOERR on success, or a TGAERR_* code on failure. In the
* case of failure, the contents of dest are not guaranteed to be
* valid.
*/
tga_result tga_read_from_FILE(tga_image *dest, FILE *fp)
{
#define BARF(errcode) \
{ \
tga_free_buffers(dest); \
return errcode; \
}
#define READ(destptr, size) \
if (fread(destptr, size, 1, fp) != 1) \
BARF(TGAERR_EOF)
#define READ16(dest) \
{ \
if (fread(&(dest), 2, 1, fp) != 1) \
BARF(TGAERR_EOF); \
dest = letoh16(dest); \
}
dest->image_id = NULL;
dest->color_map_data = NULL;
dest->image_data = NULL;
READ(&dest->image_id_length, 1);
READ(&dest->color_map_type, 1);
if (dest->color_map_type != TGA_COLOR_MAP_ABSENT &&
dest->color_map_type != TGA_COLOR_MAP_PRESENT)
BARF(TGAERR_CMAP_TYPE);
READ(&dest->image_type, 1);
if (dest->image_type == TGA_IMAGE_TYPE_NONE)
BARF(TGAERR_NO_IMG);
if (dest->image_type != TGA_IMAGE_TYPE_COLORMAP &&
dest->image_type != TGA_IMAGE_TYPE_BGR &&
dest->image_type != TGA_IMAGE_TYPE_MONO &&
dest->image_type != TGA_IMAGE_TYPE_COLORMAP_RLE &&
dest->image_type != TGA_IMAGE_TYPE_BGR_RLE &&
dest->image_type != TGA_IMAGE_TYPE_MONO_RLE)
BARF(TGAERR_IMG_TYPE);
if (tga_is_colormapped(dest) &&
dest->color_map_type == TGA_COLOR_MAP_ABSENT)
BARF(TGAERR_CMAP_MISSING);
if (!tga_is_colormapped(dest) &&
dest->color_map_type == TGA_COLOR_MAP_PRESENT)
BARF(TGAERR_CMAP_PRESENT);
READ16(dest->color_map_origin);
READ16(dest->color_map_length);
READ(&dest->color_map_depth, 1);
if (dest->color_map_type == TGA_COLOR_MAP_PRESENT) {
if (dest->color_map_length == 0)
BARF(TGAERR_CMAP_LENGTH);
if (!UNMAP_DEPTH(dest->color_map_depth))
BARF(TGAERR_CMAP_DEPTH);
}
READ16(dest->origin_x);
READ16(dest->origin_y);
READ16(dest->width);
READ16(dest->height);
if (dest->width == 0 || dest->height == 0)
BARF(TGAERR_ZERO_SIZE);
READ(&dest->pixel_depth, 1);
if (!SANE_DEPTH(dest->pixel_depth) ||
(dest->pixel_depth != 8 && tga_is_colormapped(dest)))
BARF(TGAERR_PIXEL_DEPTH);
READ(&dest->image_descriptor, 1);
if (dest->image_id_length > 0) {
dest->image_id = (uint8_t *)malloc(dest->image_id_length);
if (dest->image_id == NULL)
BARF(TGAERR_NO_MEM);
READ(dest->image_id, dest->image_id_length);
}
if (dest->color_map_type == TGA_COLOR_MAP_PRESENT) {
dest->color_map_data = (uint8_t *)malloc(
(dest->color_map_origin + dest->color_map_length) *
dest->color_map_depth / 8);
if (dest->color_map_data == NULL)
BARF(TGAERR_NO_MEM);
READ(dest->color_map_data +
(dest->color_map_origin * dest->color_map_depth / 8),
dest->color_map_length * dest->color_map_depth / 8);
}
dest->image_data = (uint8_t *)malloc(
dest->width * dest->height * dest->pixel_depth / 8);
if (dest->image_data == NULL)
BARF(TGAERR_NO_MEM);
if (tga_is_rle(dest)) {
/* read RLE */
tga_result result = tga_read_rle(dest, fp);
if (result != TGA_NOERR)
BARF(result);
} else {
/* uncompressed */
READ(dest->image_data,
dest->width * dest->height * dest->pixel_depth / 8);
}
return TGA_NOERR;
#undef BARF
#undef READ
#undef READ16
}
/* ---------------------------------------------------------------------------
* Helper function for tga_read_from_FILE(). Decompresses RLE image data from
* <fp>. Assumes <dest> header fields are set correctly.
*/
static tga_result tga_read_rle(tga_image *dest, FILE *fp)
{
#define RLE_BIT BIT(7)
#define READ(dest, size) \
if (fread(dest, size, 1, fp) != 1) \
return TGAERR_EOF
uint8_t *pos;
uint32_t p_loaded = 0,
p_expected = dest->width * dest->height;
uint8_t bpp = dest->pixel_depth / 8; /* bytes per pixel */
pos = dest->image_data;
while ((p_loaded < p_expected) && !feof(fp)) {
uint8_t b;
READ(&b, 1);
if (b & RLE_BIT) {
/* is an RLE packet */
uint8_t count, tmp[4], i;
count = (b & ~RLE_BIT) + 1;
READ(tmp, bpp);
for (i = 0; i < count; i++) {
p_loaded++;
if (p_loaded > p_expected)
return TGAERR_RLE;
memcpy(pos, tmp, bpp);
pos += bpp;
}
} else /* RAW packet */
{
uint8_t count;
count = (b & ~RLE_BIT) + 1;
if (p_loaded + count > p_expected)
return TGAERR_RLE;
p_loaded += count;
READ(pos, bpp * count);
pos += count * bpp;
}
}
return TGA_NOERR;
#undef RLE_BIT
#undef READ
}
/* ---------------------------------------------------------------------------
* Write a Targa image to a file named <filename> from <src>. This is just a
* wrapper around tga_write_to_FILE().
*
* Returns: TGA_NOERR on success, or a matching TGAERR_* code on failure.
*/
tga_result tga_write(const char *filename, const tga_image *src)
{
tga_result result;
FILE *fp = fopen(filename, "wb");
if (fp == NULL)
return TGAERR_FOPEN;
result = tga_write_to_FILE(fp, src);
fclose(fp);
return result;
}
/* ---------------------------------------------------------------------------
* Write one row of an image to <fp> using RLE. This is a helper function
* called from tga_write_to_FILE(). It assumes that <src> has its header
* fields set up correctly.
*/
#define PIXEL(ofs) (row + (ofs)*bpp)
static tga_result tga_write_row_RLE(FILE *fp,
const tga_image *src, const uint8_t *row)
{
#define WRITE(src, size) \
if (fwrite(src, size, 1, fp) != 1) \
return TGAERR_WRITE
uint16_t pos = 0;
uint16_t bpp = src->pixel_depth / 8;
while (pos < src->width) {
packet_type type = rle_packet_type(row, pos, src->width, bpp);
uint8_t len = rle_packet_len(row, pos, src->width, bpp, type);
uint8_t packet_header;
packet_header = len - 1;
if (type == RLE)
packet_header |= BIT(7);
WRITE(&packet_header, 1);
if (type == RLE) {
WRITE(PIXEL(pos), bpp);
} else /* type == RAW */
{
WRITE(PIXEL(pos), bpp * len);
}
pos += len;
}
return TGA_NOERR;
#undef WRITE
}
/* ---------------------------------------------------------------------------
* Determine whether the next packet should be RAW or RLE for maximum
* efficiency. This is a helper function called from rle_packet_len() and
* tga_write_row_RLE().
*/
#define SAME(ofs1, ofs2) (memcmp(PIXEL(ofs1), PIXEL(ofs2), bpp) == 0)
static packet_type rle_packet_type(const uint8_t *row, const uint16_t pos,
const uint16_t width, const uint16_t bpp)
{
if (pos == width - 1)
return RAW; /* one pixel */
if (SAME(pos, pos + 1)) /* dupe pixel */
{
if (bpp > 1)
return RLE; /* inefficient for bpp=1 */
/* three repeats makes the bpp=1 case efficient enough */
if ((pos < width - 2) && SAME(pos + 1, pos + 2))
return RLE;
}
return RAW;
}
/* ---------------------------------------------------------------------------
* Find the length of the current RLE packet. This is a helper function
* called from tga_write_row_RLE().
*/
static uint8_t rle_packet_len(const uint8_t *row, const uint16_t pos,
const uint16_t width, const uint16_t bpp, const packet_type type)
{
uint8_t len = 2;
if (pos == width - 1)
return 1;
if (pos == width - 2)
return 2;
if (type == RLE) {
while (pos + len < width) {
if (SAME(pos, pos + len))
len++;
else
return len;
if (len == 128)
return 128;
}
} else /* type == RAW */
{
while (pos + len < width) {
if (rle_packet_type(row, pos + len, width, bpp) == RAW)
len++;
else
return len;
if (len == 128)
return 128;
}
}
return len; /* hit end of row (width) */
}
#undef SAME
#undef PIXEL
/* ---------------------------------------------------------------------------
* Writes a Targa image to <fp> from <src>.
*
* Returns: TGA_NOERR on success, or a TGAERR_* code on failure.
* On failure, the contents of the file are not guaranteed
* to be valid.
*/
tga_result tga_write_to_FILE(FILE *fp, const tga_image *src)
{
#define WRITE(srcptr, size) \
if (fwrite(srcptr, size, 1, fp) != 1) \
return TGAERR_WRITE
#define WRITE16(src) \
{ \
uint16_t _temp = htole16(src); \
if (fwrite(&_temp, 2, 1, fp) != 1) \
return TGAERR_WRITE; \
}
WRITE(&src->image_id_length, 1);
if (src->color_map_type != TGA_COLOR_MAP_ABSENT &&
src->color_map_type != TGA_COLOR_MAP_PRESENT)
return TGAERR_CMAP_TYPE;
WRITE(&src->color_map_type, 1);
if (src->image_type == TGA_IMAGE_TYPE_NONE)
return TGAERR_NO_IMG;
if (src->image_type != TGA_IMAGE_TYPE_COLORMAP &&
src->image_type != TGA_IMAGE_TYPE_BGR &&
src->image_type != TGA_IMAGE_TYPE_MONO &&
src->image_type != TGA_IMAGE_TYPE_COLORMAP_RLE &&
src->image_type != TGA_IMAGE_TYPE_BGR_RLE &&
src->image_type != TGA_IMAGE_TYPE_MONO_RLE)
return TGAERR_IMG_TYPE;
WRITE(&src->image_type, 1);
if (tga_is_colormapped(src) &&
src->color_map_type == TGA_COLOR_MAP_ABSENT)
return TGAERR_CMAP_MISSING;
if (!tga_is_colormapped(src) &&
src->color_map_type == TGA_COLOR_MAP_PRESENT)
return TGAERR_CMAP_PRESENT;
if (src->color_map_type == TGA_COLOR_MAP_PRESENT) {
if (src->color_map_length == 0)
return TGAERR_CMAP_LENGTH;
if (!UNMAP_DEPTH(src->color_map_depth))
return TGAERR_CMAP_DEPTH;
}
WRITE16(src->color_map_origin);
WRITE16(src->color_map_length);
WRITE(&src->color_map_depth, 1);
WRITE16(src->origin_x);
WRITE16(src->origin_y);
if (src->width == 0 || src->height == 0)
return TGAERR_ZERO_SIZE;
WRITE16(src->width);
WRITE16(src->height);
if (!SANE_DEPTH(src->pixel_depth) ||
(src->pixel_depth != 8 && tga_is_colormapped(src)))
return TGAERR_PIXEL_DEPTH;
WRITE(&src->pixel_depth, 1);
WRITE(&src->image_descriptor, 1);
if (src->image_id_length > 0)
WRITE(&src->image_id, src->image_id_length);
if (src->color_map_type == TGA_COLOR_MAP_PRESENT)
WRITE(src->color_map_data +
(src->color_map_origin * src->color_map_depth / 8),
src->color_map_length * src->color_map_depth / 8);
if (tga_is_rle(src)) {
uint16_t row;
for (row = 0; row < src->height; row++) {
tga_result result = tga_write_row_RLE(fp, src,
src->image_data + row * src->width * src->pixel_depth / 8);
if (result != TGA_NOERR)
return result;
}
} else {
/* uncompressed */
WRITE(src->image_data,
src->width * src->height * src->pixel_depth / 8);
}
WRITE(tga_id, tga_id_length);
return TGA_NOERR;
#undef WRITE
#undef WRITE16
}
/* Convenient writing functions --------------------------------------------*/
/*
* This is just a helper function to initialise the header fields in a
* tga_image struct.
*/
static void init_tga_image(tga_image *img, uint8_t *image,
const uint16_t width, const uint16_t height, const uint8_t depth)
{
img->image_id_length = 0;
img->color_map_type = TGA_COLOR_MAP_ABSENT;
img->image_type = TGA_IMAGE_TYPE_NONE; /* override this below! */
img->color_map_origin = 0;
img->color_map_length = 0;
img->color_map_depth = 0;
img->origin_x = 0;
img->origin_y = 0;
img->width = width;
img->height = height;
img->pixel_depth = depth;
img->image_descriptor = TGA_T_TO_B_BIT;
img->image_id = NULL;
img->color_map_data = NULL;
img->image_data = image;
}
tga_result tga_write_mono(const char *filename, uint8_t *image,
const uint16_t width, const uint16_t height)
{
tga_image img;
init_tga_image(&img, image, width, height, 8);
img.image_type = TGA_IMAGE_TYPE_MONO;
return tga_write(filename, &img);
}
tga_result tga_write_mono_rle(const char *filename, uint8_t *image,
const uint16_t width, const uint16_t height)
{
tga_image img;
init_tga_image(&img, image, width, height, 8);
img.image_type = TGA_IMAGE_TYPE_MONO_RLE;
return tga_write(filename, &img);
}
tga_result tga_write_bgr(const char *filename, uint8_t *image,
const uint16_t width, const uint16_t height, const uint8_t depth)
{
tga_image img;
init_tga_image(&img, image, width, height, depth);
img.image_type = TGA_IMAGE_TYPE_BGR;
return tga_write(filename, &img);
}
tga_result tga_write_bgr_rle(const char *filename, uint8_t *image,
const uint16_t width, const uint16_t height, const uint8_t depth)
{
tga_image img;
init_tga_image(&img, image, width, height, depth);
img.image_type = TGA_IMAGE_TYPE_BGR_RLE;
return tga_write(filename, &img);
}
/* Note: this function will MODIFY <image> */
tga_result tga_write_rgb(const char *filename, uint8_t *image,
const uint16_t width, const uint16_t height, const uint8_t depth)
{
tga_image img;
init_tga_image(&img, image, width, height, depth);
img.image_type = TGA_IMAGE_TYPE_BGR;
(void)tga_swap_red_blue(&img);
return tga_write(filename, &img);
}
/* Note: this function will MODIFY <image> */
tga_result tga_write_rgb_rle(const char *filename, uint8_t *image,
const uint16_t width, const uint16_t height, const uint8_t depth)
{
tga_image img;
init_tga_image(&img, image, width, height, depth);
img.image_type = TGA_IMAGE_TYPE_BGR_RLE;
(void)tga_swap_red_blue(&img);
return tga_write(filename, &img);
}
/* Convenient manipulation functions ---------------------------------------*/
/* ---------------------------------------------------------------------------
* Horizontally flip the image in place. Reverses the right-to-left bit in
* the image descriptor.
*/
tga_result tga_flip_horiz(tga_image *img)
{
uint16_t row;
size_t bpp;
uint8_t *left, *right;
int r_to_l;
if (!SANE_DEPTH(img->pixel_depth))
return TGAERR_PIXEL_DEPTH;
bpp = (size_t)(img->pixel_depth / 8); /* bytes per pixel */
for (row = 0; row < img->height; row++) {
left = img->image_data + row * img->width * bpp;
right = left + (img->width - 1) * bpp;
/* reverse from left to right */
while (left < right) {
uint8_t buffer[4];
/* swap */
memcpy(buffer, left, bpp);
memcpy(left, right, bpp);
memcpy(right, buffer, bpp);
left += bpp;
right -= bpp;
}
}
/* Correct image_descriptor's left-to-right-ness. */
r_to_l = tga_is_right_to_left(img);
img->image_descriptor &= ~TGA_R_TO_L_BIT; /* mask out r-to-l bit */
if (!r_to_l)
/* was l-to-r, need to set r_to_l */
img->image_descriptor |= TGA_R_TO_L_BIT;
/* else bit is already rubbed out */
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Vertically flip the image in place. Reverses the top-to-bottom bit in
* the image descriptor.
*/
tga_result tga_flip_vert(tga_image *img)
{
uint16_t col;
size_t bpp, line;
uint8_t *top, *bottom;
int t_to_b;
if (!SANE_DEPTH(img->pixel_depth))
return TGAERR_PIXEL_DEPTH;
bpp = (size_t)(img->pixel_depth / 8); /* bytes per pixel */
line = bpp * img->width; /* bytes per line */
for (col = 0; col < img->width; col++) {
top = img->image_data + col * bpp;
bottom = top + (img->height - 1) * line;
/* reverse from top to bottom */
while (top < bottom) {
uint8_t buffer[4];
/* swap */
memcpy(buffer, top, bpp);
memcpy(top, bottom, bpp);
memcpy(bottom, buffer, bpp);
top += line;
bottom -= line;
}
}
/* Correct image_descriptor's top-to-bottom-ness. */
t_to_b = tga_is_top_to_bottom(img);
img->image_descriptor &= ~TGA_T_TO_B_BIT; /* mask out t-to-b bit */
if (!t_to_b)
/* was b-to-t, need to set t_to_b */
img->image_descriptor |= TGA_T_TO_B_BIT;
/* else bit is already rubbed out */
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Convert a color-mapped image to unmapped BGR. Reallocates image_data to a
* bigger size, then converts the image backwards to avoid using a secondary
* buffer. Alters the necessary header fields and deallocates the color map.
*/
tga_result tga_color_unmap(tga_image *img)
{
uint8_t bpp = img->color_map_depth / 8; /* bytes per pixel */
int pos;
void *tmp;
if (!tga_is_colormapped(img))
return TGAERR_NOT_CMAP;
if (img->pixel_depth != 8)
return TGAERR_PIXEL_DEPTH;
if (!SANE_DEPTH(img->color_map_depth))
return TGAERR_CMAP_DEPTH;
tmp = realloc(img->image_data, img->width * img->height * bpp);
if (tmp == NULL)
return TGAERR_NO_MEM;
img->image_data = (uint8_t *)tmp;
for (pos = img->width * img->height - 1; pos >= 0; pos--) {
uint8_t c_index = img->image_data[pos];
uint8_t *c_bgr = img->color_map_data + (c_index * bpp);
if (c_index >= img->color_map_origin + img->color_map_length)
return TGAERR_INDEX_RANGE;
memcpy(img->image_data + (pos * bpp), c_bgr, (size_t)bpp);
}
/* clean up */
img->image_type = TGA_IMAGE_TYPE_BGR;
img->pixel_depth = img->color_map_depth;
free(img->color_map_data);
img->color_map_data = NULL;
img->color_map_type = TGA_COLOR_MAP_ABSENT;
img->color_map_origin = 0;
img->color_map_length = 0;
img->color_map_depth = 0;
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Return a pointer to a given pixel. Accounts for image orientation (T_TO_B,
* R_TO_L, etc). Returns NULL if the pixel is out of range.
*/
uint8_t *tga_find_pixel(const tga_image *img, uint16_t x, uint16_t y)
{
if (x >= img->width || y >= img->height)
return NULL;
if (!tga_is_top_to_bottom(img))
y = img->height - 1 - y;
if (tga_is_right_to_left(img))
x = img->width - 1 - x;
return img->image_data + (x + y * img->width) * img->pixel_depth / 8;
}
/* ---------------------------------------------------------------------------
* Unpack the pixel at the src pointer according to bits. Any of b,g,r,a can
* be set to NULL if not wanted. Returns TGAERR_PIXEL_DEPTH if a stupid
* number of bits is given.
*/
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)
{
switch (bits) {
case 32:
if (b)
*b = src[0];
if (g)
*g = src[1];
if (r)
*r = src[2];
if (a)
*a = src[3];
break;
case 24:
if (b)
*b = src[0];
if (g)
*g = src[1];
if (r)
*r = src[2];
if (a)
*a = 0;
break;
case 16: {
uint16_t src16 = (uint16_t)(src[1] << 8) | (uint16_t)src[0];
#define FIVE_BITS (BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4))
if (b)
*b = ((src16)&FIVE_BITS) << 3;
if (g)
*g = ((src16 >> 5) & FIVE_BITS) << 3;
if (r)
*r = ((src16 >> 10) & FIVE_BITS) << 3;
if (a)
*a = (uint8_t)((src16 & BIT(15)) ? 255 : 0);
#undef FIVE_BITS
break;
}
case 8:
if (b)
*b = *src;
if (g)
*g = *src;
if (r)
*r = *src;
if (a)
*a = 0;
break;
default:
return TGAERR_PIXEL_DEPTH;
}
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Pack the pixel at the dest pointer according to bits. Returns
* TGAERR_PIXEL_DEPTH if a stupid number of bits is given.
*/
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)
{
switch (bits) {
case 32:
dest[0] = b;
dest[1] = g;
dest[2] = r;
dest[3] = a;
break;
case 24:
dest[0] = b;
dest[1] = g;
dest[2] = r;
break;
case 16: {
uint16_t tmp;
#define FIVE_BITS (BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4))
tmp = (b >> 3) & FIVE_BITS;
tmp |= ((g >> 3) & FIVE_BITS) << 5;
tmp |= ((r >> 3) & FIVE_BITS) << 10;
if (a > 127)
tmp |= BIT(15);
#undef FIVE_BITS
dest[0] = (uint8_t)(tmp & 0x00FF);
dest[1] = (uint8_t)((tmp & 0xFF00) >> 8);
break;
}
default:
return TGAERR_PIXEL_DEPTH;
}
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Desaturate the specified Targa using the specified coefficients:
* output = ( red * cr + green * cg + blue * cb ) / dv
*/
tga_result tga_desaturate(tga_image *img, const int cr, const int cg,
const int cb, const int dv)
{
uint8_t bpp = img->pixel_depth / 8; /* bytes per pixel */
uint8_t *dest, *src, *tmp;
if (tga_is_mono(img))
return TGAERR_MONO;
if (tga_is_colormapped(img)) {
tga_result result = tga_color_unmap(img);
if (result != TGA_NOERR)
return result;
}
if (!UNMAP_DEPTH(img->pixel_depth))
return TGAERR_PIXEL_DEPTH;
dest = img->image_data;
for (src = img->image_data;
src < img->image_data + img->width * img->height * bpp;
src += bpp) {
uint8_t b, g, r;
(void)tga_unpack_pixel(src, img->pixel_depth, &b, &g, &r, NULL);
*dest = (uint8_t)(((int)b * cb +
(int)g * cg +
(int)r * cr) /
dv);
dest++;
}
/* shrink */
tmp = realloc(img->image_data, img->width * img->height);
if (tmp == NULL)
return TGAERR_NO_MEM;
img->image_data = tmp;
img->pixel_depth = 8;
img->image_type = TGA_IMAGE_TYPE_MONO;
return TGA_NOERR;
}
tga_result tga_desaturate_rec_601_1(tga_image *img)
{
return tga_desaturate(img, 2989, 5866, 1145, 10000);
}
tga_result tga_desaturate_rec_709(tga_image *img)
{
return tga_desaturate(img, 2126, 7152, 722, 10000);
}
tga_result tga_desaturate_itu(tga_image *img)
{
return tga_desaturate(img, 2220, 7067, 713, 10000);
}
tga_result tga_desaturate_avg(tga_image *img)
{
return tga_desaturate(img, 1, 1, 1, 3);
}
/* ---------------------------------------------------------------------------
* Convert an image to the given pixel depth. (one of 32, 24, 16) Avoids
* using a secondary buffer to do the conversion.
*/
tga_result tga_convert_depth(tga_image *img, const uint8_t bits)
{
size_t src_size, dest_size;
uint8_t src_bpp, dest_bpp;
uint8_t *src, *dest;
if (!UNMAP_DEPTH(bits) ||
!SANE_DEPTH(img->pixel_depth))
return TGAERR_PIXEL_DEPTH;
if (tga_is_colormapped(img)) {
tga_result result = tga_color_unmap(img);
if (result != TGA_NOERR)
return result;
}
if (img->pixel_depth == bits)
return TGA_NOERR; /* no op, no err */
src_bpp = img->pixel_depth / 8;
dest_bpp = bits / 8;
src_size = (size_t)(img->width * img->height * src_bpp);
dest_size = (size_t)(img->width * img->height * dest_bpp);
if (src_size > dest_size) {
void *tmp;
/* convert forwards */
dest = img->image_data;
for (src = img->image_data;
src < img->image_data + img->width * img->height * src_bpp;
src += src_bpp) {
uint8_t r, g, b, a;
(void)tga_unpack_pixel(src, img->pixel_depth, &r, &g, &b, &a);
(void)tga_pack_pixel(dest, bits, r, g, b, a);
dest += dest_bpp;
}
/* shrink */
tmp = realloc(img->image_data, img->width * img->height * dest_bpp);
if (tmp == NULL)
return TGAERR_NO_MEM;
img->image_data = tmp;
} else {
/* expand */
void *tmp = realloc(img->image_data,
img->width * img->height * dest_bpp);
if (tmp == NULL)
return TGAERR_NO_MEM;
img->image_data = (uint8_t *)tmp;
/* convert backwards */
dest = img->image_data + (img->width * img->height - 1) * dest_bpp;
for (src = img->image_data + (img->width * img->height - 1) * src_bpp;
src >= img->image_data;
src -= src_bpp) {
uint8_t r, g, b, a;
(void)tga_unpack_pixel(src, img->pixel_depth, &r, &g, &b, &a);
(void)tga_pack_pixel(dest, bits, r, g, b, a);
dest -= dest_bpp;
}
}
img->pixel_depth = bits;
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Swap red and blue (RGB becomes BGR and vice verse). (in-place)
*/
tga_result tga_swap_red_blue(tga_image *img)
{
uint8_t *ptr;
uint8_t bpp = img->pixel_depth / 8;
if (!UNMAP_DEPTH(img->pixel_depth))
return TGAERR_PIXEL_DEPTH;
for (ptr = img->image_data;
ptr < img->image_data + (img->width * img->height - 1) * bpp;
ptr += bpp) {
uint8_t r, g, b, a;
(void)tga_unpack_pixel(ptr, img->pixel_depth, &b, &g, &r, &a);
(void)tga_pack_pixel(ptr, img->pixel_depth, r, g, b, a);
}
return TGA_NOERR;
}
/* ---------------------------------------------------------------------------
* Free the image_id, color_map_data and image_data buffers of the specified
* tga_image, if they're not already NULL.
*/
void tga_free_buffers(tga_image *img)
{
if (img->image_id != NULL) {
free(img->image_id);
img->image_id = NULL;
}
if (img->color_map_data != NULL) {
free(img->color_map_data);
img->color_map_data = NULL;
}
if (img->image_data != NULL) {
free(img->image_data);
img->image_data = NULL;
}
}
/* vim:set tabstop=4 shiftwidth=4 textwidth=78 expandtab: */