q3rally/engine/code/renderer/tr_image_tga.c
2011-02-18 14:31:32 +00:00

320 lines
8.5 KiB
C

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
Quake III Arena source code 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
#include "tr_local.h"
/*
========================================================================
TGA files are used for 24/32 bit images
========================================================================
*/
typedef struct _TargaHeader {
unsigned char id_length, colormap_type, image_type;
unsigned short colormap_index, colormap_length;
unsigned char colormap_size;
unsigned short x_origin, y_origin, width, height;
unsigned char pixel_size, attributes;
} TargaHeader;
void R_LoadTGA ( const char *name, byte **pic, int *width, int *height)
{
unsigned columns, rows, numPixels;
byte *pixbuf;
int row, column;
byte *buf_p;
byte *end;
union {
byte *b;
void *v;
} buffer;
TargaHeader targa_header;
byte *targa_rgba;
int length;
*pic = NULL;
if(width)
*width = 0;
if(height)
*height = 0;
//
// load the file
//
length = ri.FS_ReadFile ( ( char * ) name, &buffer.v);
if (!buffer.b || length < 0) {
return;
}
if(length < 18)
{
ri.Error( ERR_DROP, "LoadTGA: header too short (%s)\n", name );
}
buf_p = buffer.b;
end = buffer.b + length;
targa_header.id_length = buf_p[0];
targa_header.colormap_type = buf_p[1];
targa_header.image_type = buf_p[2];
memcpy(&targa_header.colormap_index, &buf_p[3], 2);
memcpy(&targa_header.colormap_length, &buf_p[5], 2);
targa_header.colormap_size = buf_p[7];
memcpy(&targa_header.x_origin, &buf_p[8], 2);
memcpy(&targa_header.y_origin, &buf_p[10], 2);
memcpy(&targa_header.width, &buf_p[12], 2);
memcpy(&targa_header.height, &buf_p[14], 2);
targa_header.pixel_size = buf_p[16];
targa_header.attributes = buf_p[17];
targa_header.colormap_index = LittleShort(targa_header.colormap_index);
targa_header.colormap_length = LittleShort(targa_header.colormap_length);
targa_header.x_origin = LittleShort(targa_header.x_origin);
targa_header.y_origin = LittleShort(targa_header.y_origin);
targa_header.width = LittleShort(targa_header.width);
targa_header.height = LittleShort(targa_header.height);
buf_p += 18;
if (targa_header.image_type!=2
&& targa_header.image_type!=10
&& targa_header.image_type != 3 )
{
ri.Error (ERR_DROP, "LoadTGA: Only type 2 (RGB), 3 (gray), and 10 (RGB) TGA images supported\n");
}
if ( targa_header.colormap_type != 0 )
{
ri.Error( ERR_DROP, "LoadTGA: colormaps not supported\n" );
}
if ( ( targa_header.pixel_size != 32 && targa_header.pixel_size != 24 ) && targa_header.image_type != 3 )
{
ri.Error (ERR_DROP, "LoadTGA: Only 32 or 24 bit images supported (no colormaps)\n");
}
columns = targa_header.width;
rows = targa_header.height;
numPixels = columns * rows * 4;
if(!columns || !rows || numPixels > 0x7FFFFFFF || numPixels / columns / 4 != rows)
{
ri.Error (ERR_DROP, "LoadTGA: %s has an invalid image size\n", name);
}
targa_rgba = ri.Malloc (numPixels);
if (targa_header.id_length != 0)
{
if (buf_p + targa_header.id_length > end)
ri.Error( ERR_DROP, "LoadTGA: header too short (%s)\n", name );
buf_p += targa_header.id_length; // skip TARGA image comment
}
if ( targa_header.image_type==2 || targa_header.image_type == 3 )
{
if(buf_p + columns*rows*targa_header.pixel_size/8 > end)
{
ri.Error (ERR_DROP, "LoadTGA: file truncated (%s)\n", name);
}
// Uncompressed RGB or gray scale image
for(row=rows-1; row>=0; row--)
{
pixbuf = targa_rgba + row*columns*4;
for(column=0; column<columns; column++)
{
unsigned char red,green,blue,alphabyte;
switch (targa_header.pixel_size)
{
case 8:
blue = *buf_p++;
green = blue;
red = blue;
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 24:
blue = *buf_p++;
green = *buf_p++;
red = *buf_p++;
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 32:
blue = *buf_p++;
green = *buf_p++;
red = *buf_p++;
alphabyte = *buf_p++;
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = alphabyte;
break;
default:
ri.Error( ERR_DROP, "LoadTGA: illegal pixel_size '%d' in file '%s'\n", targa_header.pixel_size, name );
break;
}
}
}
}
else if (targa_header.image_type==10) { // Runlength encoded RGB images
unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
red = 0;
green = 0;
blue = 0;
alphabyte = 0xff;
for(row=rows-1; row>=0; row--) {
pixbuf = targa_rgba + row*columns*4;
for(column=0; column<columns; ) {
if(buf_p + 1 > end)
ri.Error (ERR_DROP, "LoadTGA: file truncated (%s)\n", name);
packetHeader= *buf_p++;
packetSize = 1 + (packetHeader & 0x7f);
if (packetHeader & 0x80) { // run-length packet
if(buf_p + targa_header.pixel_size/8 > end)
ri.Error (ERR_DROP, "LoadTGA: file truncated (%s)\n", name);
switch (targa_header.pixel_size) {
case 24:
blue = *buf_p++;
green = *buf_p++;
red = *buf_p++;
alphabyte = 255;
break;
case 32:
blue = *buf_p++;
green = *buf_p++;
red = *buf_p++;
alphabyte = *buf_p++;
break;
default:
ri.Error( ERR_DROP, "LoadTGA: illegal pixel_size '%d' in file '%s'\n", targa_header.pixel_size, name );
break;
}
for(j=0;j<packetSize;j++) {
*pixbuf++=red;
*pixbuf++=green;
*pixbuf++=blue;
*pixbuf++=alphabyte;
column++;
if (column==columns) { // run spans across rows
column=0;
if (row>0)
row--;
else
goto breakOut;
pixbuf = targa_rgba + row*columns*4;
}
}
}
else { // non run-length packet
if(buf_p + targa_header.pixel_size/8*packetSize > end)
ri.Error (ERR_DROP, "LoadTGA: file truncated (%s)\n", name);
for(j=0;j<packetSize;j++) {
switch (targa_header.pixel_size) {
case 24:
blue = *buf_p++;
green = *buf_p++;
red = *buf_p++;
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 32:
blue = *buf_p++;
green = *buf_p++;
red = *buf_p++;
alphabyte = *buf_p++;
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = alphabyte;
break;
default:
ri.Error( ERR_DROP, "LoadTGA: illegal pixel_size '%d' in file '%s'\n", targa_header.pixel_size, name );
break;
}
column++;
if (column==columns) { // pixel packet run spans across rows
column=0;
if (row>0)
row--;
else
goto breakOut;
pixbuf = targa_rgba + row*columns*4;
}
}
}
}
breakOut:;
}
}
#if 0
// TTimo: this is the chunk of code to ensure a behavior that meets TGA specs
// bit 5 set => top-down
if (targa_header.attributes & 0x20) {
unsigned char *flip = (unsigned char*)malloc (columns*4);
unsigned char *src, *dst;
for (row = 0; row < rows/2; row++) {
src = targa_rgba + row * 4 * columns;
dst = targa_rgba + (rows - row - 1) * 4 * columns;
memcpy (flip, src, columns*4);
memcpy (src, dst, columns*4);
memcpy (dst, flip, columns*4);
}
free (flip);
}
#endif
// instead we just print a warning
if (targa_header.attributes & 0x20) {
ri.Printf( PRINT_WARNING, "WARNING: '%s' TGA file header declares top-down image, ignoring\n", name);
}
if (width)
*width = columns;
if (height)
*height = rows;
*pic = targa_rgba;
ri.FS_FreeFile (buffer.v);
}