/**
* File: TGA Input
*
* Read TGA images.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "gd_tga.h"
#include "gd.h"
#include "gd_errors.h"
#include "gdhelpers.h"
/*
Function: gdImageCreateFromTga
Creates a gdImage from a TGA file
Parameters:
infile - Pointer to TGA binary file
*/
BGD_DECLARE(gdImagePtr) gdImageCreateFromTga(FILE *fp)
{
gdImagePtr image;
gdIOCtx* in = gdNewFileCtx(fp);
if (in == NULL) return NULL;
image = gdImageCreateFromTgaCtx(in);
in->gd_free( in );
return image;
}
/*
Function: gdImageCreateFromTgaPtr
*/
BGD_DECLARE(gdImagePtr) gdImageCreateFromTgaPtr(int size, void *data)
{
gdImagePtr im;
gdIOCtx *in = gdNewDynamicCtxEx (size, data, 0);
if (in == NULL) return NULL;
im = gdImageCreateFromTgaCtx(in);
in->gd_free(in);
return im;
}
/*
Function: gdImageCreateFromTgaCtx
Creates a gdImage from a gdIOCtx referencing a TGA binary file.
Parameters:
ctx - Pointer to a gdIOCtx structure
*/
BGD_DECLARE(gdImagePtr) gdImageCreateFromTgaCtx(gdIOCtx* ctx)
{
int bitmap_caret = 0;
oTga *tga = NULL;
/* int pixel_block_size = 0;
int image_block_size = 0; */
volatile gdImagePtr image = NULL;
int x = 0;
int y = 0;
tga = (oTga *) gdMalloc(sizeof(oTga));
if (!tga) {
return NULL;
}
tga->bitmap = NULL;
tga->ident = NULL;
if (read_header_tga(ctx, tga) < 0) {
free_tga(tga);
return NULL;
}
/*TODO: Will this be used?
pixel_block_size = tga->bits / 8;
image_block_size = (tga->width * tga->height) * pixel_block_size;
*/
if (read_image_tga(ctx, tga) < 0) {
free_tga(tga);
return NULL;
}
image = gdImageCreateTrueColor((int)tga->width, (int)tga->height );
if (image == 0) {
free_tga( tga );
return NULL;
}
/*! \brief Populate GD image object
* Copy the pixel data from our tga bitmap buffer into the GD image
* Disable blending and save the alpha channel per default
*/
if (tga->alphabits) {
gdImageAlphaBlending(image, 0);
gdImageSaveAlpha(image, 1);
}
/* TODO: use alphabits as soon as we support 24bit and other alpha bps (ie != 8bits) */
for (y = 0; y < tga->height; y++) {
register int *tpix = image->tpixels[y];
for ( x = 0; x < tga->width; x++, tpix++) {
if (tga->bits == TGA_BPP_24) {
*tpix = gdTrueColor(tga->bitmap[bitmap_caret + 2], tga->bitmap[bitmap_caret + 1], tga->bitmap[bitmap_caret]);
bitmap_caret += 3;
} else if (tga->bits == TGA_BPP_32 && tga->alphabits) {
register int a = tga->bitmap[bitmap_caret + 3];
*tpix = gdTrueColorAlpha(tga->bitmap[bitmap_caret + 2], tga->bitmap[bitmap_caret + 1], tga->bitmap[bitmap_caret], gdAlphaMax - (a >> 1));
bitmap_caret += 4;
}
}
}
if (tga->flipv && tga->fliph) {
gdImageFlipBoth(image);
} else if (tga->flipv) {
gdImageFlipVertical(image);
} else if (tga->fliph) {
gdImageFlipHorizontal(image);
}
free_tga(tga);
return image;
}
/*! \brief Reads a TGA header.
* Reads the header block from a binary TGA file populating the referenced TGA structure.
* \param ctx Pointer to TGA binary file
* \param tga Pointer to TGA structure
* \return int 1 on sucess, -1 on failure
*/
int read_header_tga(gdIOCtx *ctx, oTga *tga)
{
unsigned char header[18];
if (gdGetBuf(header, sizeof(header), ctx) < 18) {
gd_error("fail to read header");
return -1;
}
tga->identsize = header[0];
tga->colormaptype = header[1];
tga->imagetype = header[2];
tga->colormapstart = header[3] + (header[4] << 8);
tga->colormaplength = header[5] + (header[6] << 8);
tga->colormapbits = header[7];
tga->xstart = header[8] + (header[9] << 8);
tga->ystart = header[10] + (header[11] << 8);
tga->width = header[12] + (header[13] << 8);
tga->height = header[14] + (header[15] << 8);
tga->bits = header[16];
tga->alphabits = header[17] & 0x0f;
tga->fliph = (header[17] & 0x10) ? 1 : 0;
tga->flipv = (header[17] & 0x20) ? 0 : 1;
#if DEBUG
printf("format bps: %i\n", tga->bits);
printf("flip h/v: %i / %i\n", tga->fliph, tga->flipv);
printf("alpha: %i\n", tga->alphabits);
printf("wxh: %i %i\n", tga->width, tga->height);
#endif
if (!((tga->bits == TGA_BPP_24 && tga->alphabits == 0)
|| (tga->bits == TGA_BPP_32 && tga->alphabits == 8)))
{
gd_error_ex(GD_WARNING, "gd-tga: %u bits per pixel with %u alpha bits not supported\n",
tga->bits, tga->alphabits);
return -1;
}
tga->ident = NULL;
if (tga->identsize > 0) {
tga->ident = (char *) gdMalloc(tga->identsize * sizeof(char));
if(tga->ident == NULL) {
return -1;
}
gdGetBuf(tga->ident, tga->identsize, ctx);
}
return 1;
}
/*! \brief Reads a TGA image data into buffer.
* Reads the image data block from a binary TGA file populating the referenced TGA structure.
* \param ctx Pointer to TGA binary file
* \param tga Pointer to TGA structure
* \return int 0 on sucess, -1 on failure
*/
int read_image_tga( gdIOCtx *ctx, oTga *tga )
{
int pixel_block_size = (tga->bits / 8);
int image_block_size = (tga->width * tga->height) * pixel_block_size;
int* decompression_buffer = NULL;
unsigned char* conversion_buffer = NULL;
int buffer_caret = 0;
int bitmap_caret = 0;
int i = 0;
int encoded_pixels;
int rle_size;
if(overflow2(tga->width, tga->height)) {
return -1;
}
if(overflow2(tga->width * tga->height, pixel_block_size)) {
return -1;
}
if(overflow2(image_block_size, sizeof(int))) {
return -1;
}
/*! \todo Add more image type support.
*/
if (tga->imagetype != TGA_TYPE_RGB && tga->imagetype != TGA_TYPE_RGB_RLE)
return -1;
/*! \brief Allocate memmory for image block
* Allocate a chunk of memory for the image block to be passed into.
*/
tga->bitmap = (int *) gdMalloc(image_block_size * sizeof(int));
if (tga->bitmap == NULL)
return -1;
switch (tga->imagetype) {
case TGA_TYPE_RGB:
/*! \brief Read in uncompressed RGB TGA
* Chunk load the pixel data from an uncompressed RGB type TGA.
*/
conversion_buffer = (unsigned char *) gdMalloc(image_block_size * sizeof(unsigned char));
if (conversion_buffer == NULL) {
return -1;
}
if (gdGetBuf(conversion_buffer, image_block_size, ctx) != image_block_size) {
gd_error("gd-tga: premature end of image data\n");
gdFree(conversion_buffer);
return -1;
}
while (buffer_caret < image_block_size) {
tga->bitmap[buffer_caret] = (int) conversion_buffer[buffer_caret];
buffer_caret++;
}
gdFree(conversion_buffer);
break;
case TGA_TYPE_RGB_RLE:
/*! \brief Read in RLE compressed RGB TGA
* Chunk load the pixel data from an RLE compressed RGB type TGA.
*/
decompression_buffer = (int*) gdMalloc(image_block_size * sizeof(int));
if (decompression_buffer == NULL) {
return -1;
}
conversion_buffer = (unsigned char *) gdMalloc(image_block_size * sizeof(unsigned char));
if (conversion_buffer == NULL) {
gd_error("gd-tga: premature end of image data\n");
gdFree( decompression_buffer );
return -1;
}
rle_size = gdGetBuf(conversion_buffer, image_block_size, ctx);
if (rle_size <= 0) {
gdFree(conversion_buffer);
gdFree(decompression_buffer);
return -1;
}
buffer_caret = 0;
while( buffer_caret < rle_size) {
decompression_buffer[buffer_caret] = (int)conversion_buffer[buffer_caret];
buffer_caret++;
}
buffer_caret = 0;
while( bitmap_caret < image_block_size ) {
if (buffer_caret + pixel_block_size > rle_size) {
gdFree( decompression_buffer );
gdFree( conversion_buffer );
return -1;
}
if ((decompression_buffer[buffer_caret] & TGA_RLE_FLAG) == TGA_RLE_FLAG) {
encoded_pixels = ( ( decompression_buffer[ buffer_caret ] & ~TGA_RLE_FLAG ) + 1 );
buffer_caret++;
if ((bitmap_caret + (encoded_pixels * pixel_block_size)) > image_block_size
|| buffer_caret + pixel_block_size > rle_size) {
gdFree( decompression_buffer );
gdFree( conversion_buffer );
return -1;
}
for (i = 0; i < encoded_pixels; i++) {
memcpy(tga->bitmap + bitmap_caret, decompression_buffer + buffer_caret, pixel_block_size * sizeof(int));
bitmap_caret += pixel_block_size;
}
buffer_caret += pixel_block_size;
} else {
encoded_pixels = decompression_buffer[ buffer_caret ] + 1;
buffer_caret++;
if ((bitmap_caret + (encoded_pixels * pixel_block_size)) > image_block_size
|| buffer_caret + (encoded_pixels * pixel_block_size) > rle_size) {
gdFree( decompression_buffer );
gdFree( conversion_buffer );
return -1;
}
memcpy(tga->bitmap + bitmap_caret, decompression_buffer + buffer_caret, encoded_pixels * pixel_block_size * sizeof(int));
bitmap_caret += (encoded_pixels * pixel_block_size);
buffer_caret += (encoded_pixels * pixel_block_size);
}
}
gdFree( decompression_buffer );
gdFree( conversion_buffer );
break;
}
return 1;
}
/*! \brief Cleans up a TGA structure.
* Dereferences the bitmap referenced in a TGA structure, then the structure itself
* \param tga Pointer to TGA structure
*/
void free_tga(oTga * tga)
{
if (tga) {
if (tga->ident)
gdFree(tga->ident);
if (tga->bitmap)
gdFree(tga->bitmap);
gdFree(tga);
}
}