newtree/source/tga.c

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/*
tga.c
targa image handling
Copyright (C) 1996-1997 Id Software, Inc.
This program 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.
This program 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 this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
$Id$
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "quakefs.h"
#include "sys.h"
#include "tga.h"
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;
static int
fgetLittleShort (QFile *f)
{
byte b1, b2;
b1 = Qgetc(f);
b2 = Qgetc(f);
return (short)(b1 + b2*256);
}
/*
static int
fgetLittleLong (QFile *f)
{
byte b1, b2, b3, b4;
b1 = Qgetc(f);
b2 = Qgetc(f);
b3 = Qgetc(f);
b4 = Qgetc(f);
return b1 + (b2<<8) + (b3<<16) + (b4<<24);
}
*/
/*
=============
LoadTGA
=============
*/
byte *
LoadTGA (QFile *fin)
{
int columns, rows, numPixels;
byte *pixbuf;
int row, column;
unsigned char red = 0, green = 0, blue = 0, alphabyte = 0;
TargaHeader targa_header;
byte *targa_rgba;
targa_header.id_length = Qgetc(fin);
targa_header.colormap_type = Qgetc(fin);
targa_header.image_type = Qgetc(fin);
targa_header.colormap_index = fgetLittleShort(fin);
targa_header.colormap_length = fgetLittleShort(fin);
targa_header.colormap_size = Qgetc(fin);
targa_header.x_origin = fgetLittleShort(fin);
targa_header.y_origin = fgetLittleShort(fin);
targa_header.width = fgetLittleShort(fin);
targa_header.height = fgetLittleShort(fin);
targa_header.pixel_size = Qgetc(fin);
targa_header.attributes = Qgetc(fin);
if (targa_header.image_type!=2
&& targa_header.image_type!=10)
Sys_Error ("LoadTGA: Only type 2 and 10 targa RGB images supported\n");
if (targa_header.colormap_type !=0
|| (targa_header.pixel_size!=32 && targa_header.pixel_size!=24))
Sys_Error ("Texture_LoadTGA: Only 32 or 24 bit images supported (no colormaps)\n");
columns = targa_header.width;
rows = targa_header.height;
numPixels = columns * rows;
targa_rgba = malloc (numPixels*4);
if (targa_header.id_length != 0)
Qseek(fin, targa_header.id_length, SEEK_CUR); // skip TARGA image comment
if (targa_header.image_type==2) { // Uncompressed, RGB images
for(row=rows-1; row>=0; row--) {
pixbuf = targa_rgba + row*columns*4;
for(column=0; column<columns; column++) {
switch (targa_header.pixel_size) {
case 24:
blue = Qgetc(fin);
green = Qgetc(fin);
red = Qgetc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 32:
blue = Qgetc(fin);
green = Qgetc(fin);
red = Qgetc(fin);
alphabyte = Qgetc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = alphabyte;
break;
}
}
}
}
else if (targa_header.image_type==10) { // Runlength encoded RGB images
unsigned char packetHeader, packetSize, j;
for(row=rows-1; row>=0; row--) {
pixbuf = targa_rgba + row*columns*4;
for(column=0; column<columns; ) {
packetHeader=Qgetc(fin);
packetSize = 1 + (packetHeader & 0x7f);
if (packetHeader & 0x80) { // run-length packet
switch (targa_header.pixel_size) {
case 24:
blue = Qgetc(fin);
green = Qgetc(fin);
red = Qgetc(fin);
alphabyte = 255;
break;
case 32:
blue = Qgetc(fin);
green = Qgetc(fin);
red = Qgetc(fin);
alphabyte = Qgetc(fin);
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
for(j=0;j<packetSize;j++) {
switch (targa_header.pixel_size) {
case 24:
blue = Qgetc(fin);
green = Qgetc(fin);
red = Qgetc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 32:
blue = Qgetc(fin);
green = Qgetc(fin);
red = Qgetc(fin);
alphabyte = Qgetc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = alphabyte;
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:;
}
}
Qclose(fin);
return targa_rgba;
}