yquake2remaster/src/refresh/gl_image.c

/*
 * Copyright (C) 1997-2001 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 the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

/*
Spalten in:
 - gl_pcx.c
 - gl_tga.c
 - gl_wal.c
*/
#include "header/local.h"

image_t gltextures [ MAX_GLTEXTURES ];
int numgltextures;
int base_textureid; /* gltextures[i] = base_textureid+i */
extern qboolean scrap_dirty;
extern byte scrap_texels [ MAX_SCRAPS ] [ BLOCK_WIDTH * BLOCK_HEIGHT ];

static byte intensitytable [ 256 ];
static unsigned char gammatable [ 256 ];

cvar_t      *intensity;

unsigned d_8to24table [ 256 ];

qboolean GL_Upload8 ( byte *data, int width, int height,  qboolean mipmap, qboolean is_sky );
qboolean GL_Upload32 ( unsigned *data, int width, int height,  qboolean mipmap );

int gl_solid_format = 3;
int gl_alpha_format = 4;

int gl_tex_solid_format = 3;
int gl_tex_alpha_format = 4;

int gl_filter_min = GL_LINEAR_MIPMAP_NEAREST;
int gl_filter_max = GL_LINEAR;

typedef struct
{
	char *name;
	int minimize, maximize;
} glmode_t;

glmode_t modes[] = {
	{ "GL_NEAREST", GL_NEAREST, GL_NEAREST },
	{ "GL_LINEAR", GL_LINEAR, GL_LINEAR },
	{ "GL_NEAREST_MIPMAP_NEAREST", GL_NEAREST_MIPMAP_NEAREST, GL_NEAREST },
	{ "GL_LINEAR_MIPMAP_NEAREST", GL_LINEAR_MIPMAP_NEAREST, GL_LINEAR },
	{ "GL_NEAREST_MIPMAP_LINEAR", GL_NEAREST_MIPMAP_LINEAR, GL_NEAREST },
	{ "GL_LINEAR_MIPMAP_LINEAR", GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR }
};

#define NUM_GL_MODES ( sizeof ( modes ) / sizeof ( glmode_t ) )

typedef struct
{
	char *name;
	int mode;
} gltmode_t;

gltmode_t gl_alpha_modes[] = {
	{ "default", 4 },
	{ "GL_RGBA", GL_RGBA },
	{ "GL_RGBA8", GL_RGBA8 },
	{ "GL_RGB5_A1", GL_RGB5_A1 },
	{ "GL_RGBA4", GL_RGBA4 },
	{ "GL_RGBA2", GL_RGBA2 },
};

#define NUM_GL_ALPHA_MODES ( sizeof ( gl_alpha_modes ) / sizeof ( gltmode_t ) )

gltmode_t gl_solid_modes[] = {
	{ "default", 3 },
	{ "GL_RGB", GL_RGB },
	{ "GL_RGB8", GL_RGB8 },
	{ "GL_RGB5", GL_RGB5 },
	{ "GL_RGB4", GL_RGB4 },
	{ "GL_R3_G3_B2", GL_R3_G3_B2 },
	{ "GL_RGB2", GL_RGB2_EXT },
};

#define NUM_GL_SOLID_MODES ( sizeof ( gl_solid_modes ) / sizeof ( gltmode_t ) )
 
void
GL_TexEnv ( GLenum mode )
{
	static int lastmodes [ 2 ] = { -1, -1 };

	if ( mode != lastmodes [ gl_state.currenttmu ] )
	{
		qglTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, mode );
		lastmodes [ gl_state.currenttmu ] = mode;
	}
}

void
GL_Bind ( int texnum )
{
	extern image_t *draw_chars;

	if ( gl_nobind->value && draw_chars ) /* performance evaluation option */
	{
		texnum = draw_chars->texnum;
	}

	if ( gl_state.currenttextures [ gl_state.currenttmu ] == texnum )
	{
		return;
	}

	gl_state.currenttextures [ gl_state.currenttmu ] = texnum;
	qglBindTexture( GL_TEXTURE_2D, texnum );
}

void
GL_MBind ( GLenum target, int texnum )
{
	if ( target == QGL_TEXTURE0 )
	{
		if ( gl_state.currenttextures [ 0 ] == texnum )
		{
			return;
		}
	}
	else
	{
		if ( gl_state.currenttextures [ 1 ] == texnum )
		{
			return;
		}
	}

	GL_Bind( texnum );
}
 
void
GL_TextureMode ( char *string )
{
	int i;
	image_t *glt;

	for ( i = 0; i < NUM_GL_MODES; i++ )
	{
		if ( !Q_stricmp( modes [ i ].name, string ) )
		{
			break;
		}
	}

	if ( i == NUM_GL_MODES )
	{
		ri.Con_Printf( PRINT_ALL, "bad filter name\n" );
		return;
	}

	gl_filter_min = modes [ i ].minimize;
	gl_filter_max = modes [ i ].maximize;

	/* change all the existing mipmap texture objects */
	for ( i = 0, glt = gltextures; i < numgltextures; i++, glt++ )
	{
		if ( ( glt->type != it_pic ) && ( glt->type != it_sky ) )
		{
			GL_Bind( glt->texnum );
			qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min );
			qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max );
		}
	}
}

void
GL_TextureAlphaMode ( char *string )
{
	int i;

	for ( i = 0; i < NUM_GL_ALPHA_MODES; i++ )
	{
		if ( !Q_stricmp( gl_alpha_modes [ i ].name, string ) )
		{
			break;
		}
	}

	if ( i == NUM_GL_ALPHA_MODES )
	{
		ri.Con_Printf( PRINT_ALL, "bad alpha texture mode name\n" );
		return;
	}

	gl_tex_alpha_format = gl_alpha_modes [ i ].mode;
}

void
GL_TextureSolidMode ( char *string )
{
	int i;

	for ( i = 0; i < NUM_GL_SOLID_MODES; i++ )
	{
		if ( !Q_stricmp( gl_solid_modes [ i ].name, string ) )
		{
			break;
		}
	}

	if ( i == NUM_GL_SOLID_MODES )
	{
		ri.Con_Printf( PRINT_ALL, "bad solid texture mode name\n" );
		return;
	}

	gl_tex_solid_format = gl_solid_modes [ i ].mode;
}

void
GL_ImageList_f ( void )
{
	int i;
	image_t *image;
	int texels;
	const char *palstrings [ 2 ] = {
		"RGB",
		"PAL"
	};

	ri.Con_Printf( PRINT_ALL, "------------------\n" );
	texels = 0;

	for ( i = 0, image = gltextures; i < numgltextures; i++, image++ )
	{
		if ( image->texnum <= 0 )
		{
			continue;
		}

		texels += image->upload_width * image->upload_height;

		switch ( image->type )
		{
			case it_skin:
				ri.Con_Printf( PRINT_ALL, "M" );
				break;
			case it_sprite:
				ri.Con_Printf( PRINT_ALL, "S" );
				break;
			case it_wall:
				ri.Con_Printf( PRINT_ALL, "W" );
				break;
			case it_pic:
				ri.Con_Printf( PRINT_ALL, "P" );
				break;
			default:
				ri.Con_Printf( PRINT_ALL, " " );
				break;
		}

		ri.Con_Printf( PRINT_ALL,  " %3i %3i %s: %s\n",
				image->upload_width, image->upload_height, palstrings [ image->paletted ], image->name );
	}

	ri.Con_Printf( PRINT_ALL, "Total texel count (not counting mipmaps): %i\n", texels );
}

/*
 * Fill background pixels so mipmapping doesn't have haloes
 */

typedef struct
{
	short x, y;
} floodfill_t;

/* must be a power of 2 */
#define FLOODFILL_FIFO_SIZE 0x1000
#define FLOODFILL_FIFO_MASK ( FLOODFILL_FIFO_SIZE - 1 )

#define FLOODFILL_STEP( off, dx, dy ) \
	{ \
		if ( pos [ off ] == fillcolor )	\
		{ \
			pos [ off ] = 255; \
			fifo [ inpt ].x = x + ( dx ), fifo [ inpt ].y = y + ( dy );	\
			inpt = ( inpt + 1 ) & FLOODFILL_FIFO_MASK; \
		} \
		else if ( pos [ off ] != 255 ) \
		{ \
			fdc = pos [ off ]; \
		}												\
	}

void
R_FloodFillSkin ( byte *skin, int skinwidth, int skinheight )
{
	byte fillcolor = *skin; /* assume this is the pixel to fill */
	floodfill_t fifo [ FLOODFILL_FIFO_SIZE ];
	int inpt = 0, outpt = 0;
	int filledcolor = -1;
	int i;

	if ( filledcolor == -1 )
	{
		filledcolor = 0;

		/* attempt to find opaque black */
		for ( i = 0; i < 256; ++i )
		{
			if ( LittleLong( d_8to24table [ i ] ) == ( 255 << 0 ) ) /* alpha 1.0 */
			{
				filledcolor = i;
				break;
			}
		}
	}

	/* can't fill to filled color or to transparent color (used as visited marker) */
	if ( ( fillcolor == filledcolor ) || ( fillcolor == 255 ) )
	{
		return;
	}

	fifo [ inpt ].x = 0, fifo [ inpt ].y = 0;
	inpt = ( inpt + 1 ) & FLOODFILL_FIFO_MASK;

	while ( outpt != inpt )
	{
		int x = fifo [ outpt ].x, y = fifo [ outpt ].y;
		int fdc = filledcolor;
		byte *pos = &skin [ x + skinwidth * y ];

		outpt = ( outpt + 1 ) & FLOODFILL_FIFO_MASK;

		if ( x > 0 )
		{
			FLOODFILL_STEP( -1, -1, 0 );
		}

		if ( x < skinwidth - 1 )
		{
			FLOODFILL_STEP( 1, 1, 0 );
		}

		if ( y > 0 )
		{
			FLOODFILL_STEP( -skinwidth, 0, -1 );
		}

		if ( y < skinheight - 1 )
		{
			FLOODFILL_STEP( skinwidth, 0, 1 );
		}

		skin [ x + skinwidth * y ] = fdc;
	}
}

void
GL_ResampleTexture ( unsigned *in, int inwidth, int inheight, unsigned *out,  int outwidth, int outheight )
{
	int i, j;
	unsigned *inrow, *inrow2;
	unsigned frac, fracstep;
	unsigned p1 [ 1024 ], p2 [ 1024 ];
	byte *pix1, *pix2, *pix3, *pix4;

	fracstep = inwidth * 0x10000 / outwidth;

	frac = fracstep >> 2;

	for ( i = 0; i < outwidth; i++ )
	{
		p1 [ i ] = 4 * ( frac >> 16 );
		frac += fracstep;
	}

	frac = 3 * ( fracstep >> 2 );

	for ( i = 0; i < outwidth; i++ )
	{
		p2 [ i ] = 4 * ( frac >> 16 );
		frac += fracstep;
	}

	for ( i = 0; i < outheight; i++, out += outwidth )
	{
		inrow = in + inwidth * (int) ( ( i + 0.25 ) * inheight / outheight );
		inrow2 = in + inwidth * (int) ( ( i + 0.75 ) * inheight / outheight );
		frac = fracstep >> 1;

		for ( j = 0; j < outwidth; j++ )
		{
			pix1 = (byte *) inrow + p1 [ j ];
			pix2 = (byte *) inrow + p2 [ j ];
			pix3 = (byte *) inrow2 + p1 [ j ];
			pix4 = (byte *) inrow2 + p2 [ j ];
			( (byte *) ( out + j ) ) [ 0 ] = ( pix1 [ 0 ] + pix2 [ 0 ] + pix3 [ 0 ] + pix4 [ 0 ] ) >> 2;
			( (byte *) ( out + j ) ) [ 1 ] = ( pix1 [ 1 ] + pix2 [ 1 ] + pix3 [ 1 ] + pix4 [ 1 ] ) >> 2;
			( (byte *) ( out + j ) ) [ 2 ] = ( pix1 [ 2 ] + pix2 [ 2 ] + pix3 [ 2 ] + pix4 [ 2 ] ) >> 2;
			( (byte *) ( out + j ) ) [ 3 ] = ( pix1 [ 3 ] + pix2 [ 3 ] + pix3 [ 3 ] + pix4 [ 3 ] ) >> 2;
		}
	}
}

/*
 * Scale up the pixel values in a
 * texture to increase the
 * lighting range
 */
void
GL_LightScaleTexture ( unsigned *in, int inwidth, int inheight, qboolean only_gamma )
{
	if ( only_gamma )
	{
		int i, c;
		byte    *p;

		p = (byte *) in;

		c = inwidth * inheight;

		for ( i = 0; i < c; i++, p += 4 )
		{
			p [ 0 ] = gammatable [ p [ 0 ] ];
			p [ 1 ] = gammatable [ p [ 1 ] ];
			p [ 2 ] = gammatable [ p [ 2 ] ];
		}
	}
	else
	{
		int i, c;
		byte    *p;

		p = (byte *) in;

		c = inwidth * inheight;

		for ( i = 0; i < c; i++, p += 4 )
		{
			p [ 0 ] = gammatable [ intensitytable [ p [ 0 ] ] ];
			p [ 1 ] = gammatable [ intensitytable [ p [ 1 ] ] ];
			p [ 2 ] = gammatable [ intensitytable [ p [ 2 ] ] ];
		}
	}
}

/*
 * Operates in place, quartering the size of the texture
 */
void
GL_MipMap ( byte *in, int width, int height )
{
	int i, j;
	byte    *out;

	width <<= 2;
	height >>= 1;
	out = in;

	for ( i = 0; i < height; i++, in += width )
	{
		for ( j = 0; j < width; j += 8, out += 4, in += 8 )
		{
			out [ 0 ] = ( in [ 0 ] + in [ 4 ] + in [ width + 0 ] + in [ width + 4 ] ) >> 2;
			out [ 1 ] = ( in [ 1 ] + in [ 5 ] + in [ width + 1 ] + in [ width + 5 ] ) >> 2;
			out [ 2 ] = ( in [ 2 ] + in [ 6 ] + in [ width + 2 ] + in [ width + 6 ] ) >> 2;
			out [ 3 ] = ( in [ 3 ] + in [ 7 ] + in [ width + 3 ] + in [ width + 7 ] ) >> 2;
		}
	}
}

/*
 * Returns has_alpha
 */
void
GL_BuildPalettedTexture ( unsigned char *paletted_texture, unsigned char *scaled, int scaled_width, int scaled_height )
{
	int i;

	for ( i = 0; i < scaled_width * scaled_height; i++ )
	{
		unsigned int r, g, b, c;

		r = ( scaled [ 0 ] >> 3 ) & 31;
		g = ( scaled [ 1 ] >> 2 ) & 63;
		b = ( scaled [ 2 ] >> 3 ) & 31;

		c = r | ( g << 5 ) | ( b << 11 );

		paletted_texture [ i ] = gl_state.d_16to8table [ c ];

		scaled += 4;
	}
}

int upload_width, upload_height;
qboolean uploaded_paletted;

qboolean
GL_Upload32 ( unsigned *data, int width, int height,  qboolean mipmap )
{
	int samples;
	unsigned scaled [ 256 * 256 ];
	int scaled_width, scaled_height;
	int i, c;
	byte        *scan;
	int comp;

	uploaded_paletted = false;

	for ( scaled_width = 1; scaled_width < width; scaled_width <<= 1 )
	{
	}

	if ( gl_round_down->value && ( scaled_width > width ) && mipmap )
	{
		scaled_width >>= 1;
	}

	for ( scaled_height = 1; scaled_height < height; scaled_height <<= 1 )
	{
	}

	if ( gl_round_down->value && ( scaled_height > height ) && mipmap )
	{
		scaled_height >>= 1;
	}

	/* let people sample down the world textures for speed */
	if ( mipmap )
	{
		scaled_width >>= (int) gl_picmip->value;
		scaled_height >>= (int) gl_picmip->value;
	}

	/* don't ever bother with >256 textures */
	if ( scaled_width > 256 )
	{
		scaled_width = 256;
	}

	if ( scaled_height > 256 )
	{
		scaled_height = 256;
	}

	if ( scaled_width < 1 )
	{
		scaled_width = 1;
	}

	if ( scaled_height < 1 )
	{
		scaled_height = 1;
	}

	upload_width = scaled_width;
	upload_height = scaled_height;

	if ( scaled_width * scaled_height > sizeof ( scaled ) / 4 )
	{
		ri.Sys_Error( ERR_DROP, "GL_Upload32: too big" );
	}

	/* scan the texture for any non-255 alpha */
	c = width * height;
	scan = ( (byte *) data ) + 3;
	samples = gl_solid_format;

	for ( i = 0; i < c; i++, scan += 4 )
	{
		if ( *scan != 255 )
		{
			samples = gl_alpha_format;
			break;
		}
	}

	if ( samples == gl_solid_format )
	{
		comp = gl_tex_solid_format;
	}
	else if ( samples == gl_alpha_format )
	{
		comp = gl_tex_alpha_format;
	}
	else
	{
		ri.Con_Printf( PRINT_ALL,
				"Unknown number of texture components %i\n",
				samples );
		comp = samples;
	}

	if ( ( scaled_width == width ) && ( scaled_height == height ) )
	{
		if ( !mipmap )
		{
			qglTexImage2D( GL_TEXTURE_2D, 0, comp, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data );
			goto done;
		}

		memcpy( scaled, data, width * height * 4 );
	}
	else
	{
		GL_ResampleTexture( data, width, height, scaled, scaled_width, scaled_height );
	}

	GL_LightScaleTexture( scaled, scaled_width, scaled_height, !mipmap );
	qglTexImage2D( GL_TEXTURE_2D, 0, comp, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled );

	if ( mipmap )
	{
		int miplevel;

		miplevel = 0;

		while ( scaled_width > 1 || scaled_height > 1 )
		{
			GL_MipMap( (byte *) scaled, scaled_width, scaled_height );
			scaled_width >>= 1;
			scaled_height >>= 1;

			if ( scaled_width < 1 )
			{
				scaled_width = 1;
			}

			if ( scaled_height < 1 )
			{
				scaled_height = 1;
			}

			miplevel++;
			qglTexImage2D( GL_TEXTURE_2D, miplevel, comp, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled );
		}
	}

done:;

	if ( mipmap )
	{
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max );
	}
	else
	{
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_max );
		qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max );
	}

	return ( samples == gl_alpha_format );
}

/*
 * Returns has_alpha
 */
qboolean
GL_Upload8 ( byte *data, int width, int height,  qboolean mipmap, qboolean is_sky )
{
	unsigned trans [ 512 * 256 ];
	int i, s;
	int p;

	s = width * height;

	if ( s > sizeof ( trans ) / 4 )
	{
		ri.Sys_Error( ERR_DROP, "GL_Upload8: too large" );
	}

	for ( i = 0; i < s; i++ )
	{
		p = data [ i ];
		trans [ i ] = d_8to24table [ p ];
             
		/* transparent, so scan around for another color
		   to avoid alpha fringes */ 
		if ( p == 255 )
		{   
			if ( ( i > width ) && ( data [ i - width ] != 255 ) )
			{
				p = data [ i - width ];
			}
			else if ( ( i < s - width ) && ( data [ i + width ] != 255 ) )
			{
				p = data [ i + width ];
			}
			else if ( ( i > 0 ) && ( data [ i - 1 ] != 255 ) )
			{
				p = data [ i - 1 ];
			}
			else if ( ( i < s - 1 ) && ( data [ i + 1 ] != 255 ) )
			{
				p = data [ i + 1 ];
			}
			else
			{
				p = 0;
			}

			/* copy rgb components */
			( (byte *) &trans [ i ] ) [ 0 ] = ( (byte *) &d_8to24table [ p ] ) [ 0 ];
			( (byte *) &trans [ i ] ) [ 1 ] = ( (byte *) &d_8to24table [ p ] ) [ 1 ];
			( (byte *) &trans [ i ] ) [ 2 ] = ( (byte *) &d_8to24table [ p ] ) [ 2 ];
		}
	}

	return ( GL_Upload32( trans, width, height, mipmap ) );
}

/*
 * This is also used as an entry point for the generated r_notexture
 */
image_t *
GL_LoadPic ( char *name, byte *pic, int width, int height, imagetype_t type, int bits )
{
	image_t     *image;
	int i;

	/* find a free image_t */
	for ( i = 0, image = gltextures; i < numgltextures; i++, image++ )
	{
		if ( !image->texnum )
		{
			break;
		}
	}

	if ( i == numgltextures )
	{
		if ( numgltextures == MAX_GLTEXTURES )
		{
			ri.Sys_Error( ERR_DROP, "MAX_GLTEXTURES" );
		}

		numgltextures++;
	}

	image = &gltextures [ i ];

	if ( strlen( name ) >= sizeof ( image->name ) )
	{
		ri.Sys_Error( ERR_DROP, "Draw_LoadPic: \"%s\" is too long", name );
	}

	strcpy( image->name, name );
	image->registration_sequence = registration_sequence;

	image->width = width;
	image->height = height;
	image->type = type;

	if ( ( type == it_skin ) && ( bits == 8 ) )
	{
		R_FloodFillSkin( pic, width, height );
	}

	/* load little pics into the scrap */
	if ( ( image->type == it_pic ) && ( bits == 8 ) &&
		 ( image->width < 64 ) && ( image->height < 64 ) )
	{
		int x, y;
		int i, j, k;
		int texnum;

		texnum = Scrap_AllocBlock( image->width, image->height, &x, &y );

		if ( texnum == -1 )
		{
			goto nonscrap;
		}

		scrap_dirty = true;

		/* copy the texels into the scrap block */
		k = 0;

		for ( i = 0; i < image->height; i++ )
		{
			for ( j = 0; j < image->width; j++, k++ )
			{
				scrap_texels [ texnum ] [ ( y + i ) * BLOCK_WIDTH + x + j ] = pic [ k ];
			}
		}

		image->texnum = TEXNUM_SCRAPS + texnum;
		image->scrap = true;
		image->has_alpha = true;
		image->sl = ( x + 0.01 ) / (float) BLOCK_WIDTH;
		image->sh = ( x + image->width - 0.01 ) / (float) BLOCK_WIDTH;
		image->tl = ( y + 0.01 ) / (float) BLOCK_WIDTH;
		image->th = ( y + image->height - 0.01 ) / (float) BLOCK_WIDTH;
	}
	else
	{
	nonscrap:
		image->scrap = false;
		image->texnum = TEXNUM_IMAGES + ( image - gltextures );
		GL_Bind( image->texnum );

		if ( bits == 8 )
		{
			image->has_alpha = GL_Upload8( pic, width, height, ( image->type != it_pic && image->type != it_sky ),
					image->type == it_sky );
		}
		else
		{
			image->has_alpha = GL_Upload32( (unsigned *) pic, width, height, ( image->type != it_pic && image->type != it_sky ) );
		}

		image->upload_width = upload_width; /* after power of 2 and scales */
		image->upload_height = upload_height;
		image->paletted = uploaded_paletted;
		image->sl = 0;
		image->sh = 1;
		image->tl = 0;
		image->th = 1;
	}

	return ( image );
}

/*
 * Finds or loads the given image
 */
image_t *
GL_FindImage ( char *name, imagetype_t type )
{
	image_t *image;
	int i, len;
	byte    *pic, *palette;
	int width, height;
	char *ptr;

	if ( !name )
	{
		return ( NULL );
	}

	len = strlen( name );

	if ( len < 5 )
	{
		return ( NULL );
	}

	/* fix backslashes */
	while ( ( ptr = strchr( name, '\\' ) ) )
	{
		*ptr = '/';
	}

	/* look for it */
	for ( i = 0, image = gltextures; i < numgltextures; i++, image++ )
	{
		if ( !strcmp( name, image->name ) )
		{
			image->registration_sequence = registration_sequence;
			return ( image );
		}
	}

	/* load the pic from disk */
	pic = NULL;
	palette = NULL;

	if ( !strcmp( name + len - 4, ".pcx" ) )
	{
		LoadPCX( name, &pic, &palette, &width, &height );

		if ( !pic )
		{
			return ( NULL );
		}

		image = GL_LoadPic( name, pic, width, height, type, 8 );
	}
	else if ( !strcmp( name + len - 4, ".wal" ) )
	{
		image = GL_LoadWal( name );
	}
	else if ( !strcmp( name + len - 4, ".tga" ) )
	{
		LoadTGA( name, &pic, &width, &height );

		if ( !pic )
		{
			return ( NULL ); 
		}

		image = GL_LoadPic( name, pic, width, height, type, 32 );
	}
	else
	{
		return ( NULL );
	}

	if ( pic )
	{
		free( pic );
	}

	if ( palette )
	{
		free( palette );
	}

	return ( image );
}

struct image_s *
R_RegisterSkin ( char *name )
{
	return ( GL_FindImage( name, it_skin ) );
}

/*
 * Any image that was not touched on 
 * this registration sequence
 * will be freed.
 */
void
GL_FreeUnusedImages ( void )
{
	int i;
	image_t *image;

	/* never free r_notexture or particle texture */
	r_notexture->registration_sequence = registration_sequence;
	r_particletexture->registration_sequence = registration_sequence;

	for ( i = 0, image = gltextures; i < numgltextures; i++, image++ )
	{
		if ( image->registration_sequence == registration_sequence )
		{
			continue; /* used this sequence */
		}

		if ( !image->registration_sequence )
		{
			continue; /* free image_t slot */
		}

		if ( image->type == it_pic )
		{
			continue; /* don't free pics */
		}

		/* free it */
		qglDeleteTextures( 1, (GLuint *) &image->texnum );
		memset( image, 0, sizeof ( *image ) );
	}
}

int
Draw_GetPalette ( void )
{
	int i;
	int r, g, b;
	unsigned v;
	byte    *pic, *pal;
	int width, height;

	/* get the palette */
	LoadPCX( "pics/colormap.pcx", &pic, &pal, &width, &height );

	if ( !pal )
	{
		ri.Sys_Error( ERR_FATAL, "Couldn't load pics/colormap.pcx" );
	}

	for ( i = 0; i < 256; i++ )
	{
		r = pal [ i * 3 + 0 ];
		g = pal [ i * 3 + 1 ];
		b = pal [ i * 3 + 2 ];

		v = ( 255 << 24 ) + ( r << 0 ) + ( g << 8 ) + ( b << 16 );
		d_8to24table [ i ] = LittleLong( v );
	}

	d_8to24table [ 255 ] &= LittleLong( 0xffffff );  /* 255 is transparent */

	free( pic );
	free( pal );

	return ( 0 );
}

void
GL_InitImages ( void )
{
	int i, j;
	float g = vid_gamma->value;

	registration_sequence = 1;

	/* init intensity conversions */
	intensity = ri.Cvar_Get( "intensity", "2", 0 );

	if ( intensity->value <= 1 )
	{
		ri.Cvar_Set( "intensity", "1" );
	}

	gl_state.inverse_intensity = 1 / intensity->value;

	Draw_GetPalette();

	if ( qglColorTableEXT )
	{
		ri.FS_LoadFile( "pics/16to8.dat", (void **) &gl_state.d_16to8table );

		if ( !gl_state.d_16to8table )
		{
			ri.Sys_Error( ERR_FATAL, "Couldn't load pics/16to8.pcx" );
		}
	}

	if ( gl_config.renderer & ( GL_RENDERER_VOODOO | GL_RENDERER_VOODOO2 ) )
	{
		g = 1.0F;
	}

	for ( i = 0; i < 256; i++ )
	{
		if ( ( g == 1 ) || gl_state.hwgamma )
		{
			gammatable [ i ] = i;
		}
		else
		{
			float inf;

			inf = 255 * pow( ( i + 0.5 ) / 255.5, g ) + 0.5;

			if ( inf < 0 )
			{
				inf = 0;
			}

			if ( inf > 255 )
			{
				inf = 255;
			}

			gammatable [ i ] = inf;
		}
	}

	for ( i = 0; i < 256; i++ )
	{
		j = i * intensity->value;

		if ( j > 255 )
		{
			j = 255;
		}

		intensitytable [ i ] = j;
	}
}

void
GL_ShutdownImages ( void )
{
	int i;
	image_t *image;

	for ( i = 0, image = gltextures; i < numgltextures; i++, image++ )
	{
		if ( !image->registration_sequence )
		{
			continue; /* free image_t slot */
		}

		/* free it */
		qglDeleteTextures( 1, (GLuint *) &image->texnum );
		memset( image, 0, sizeof ( *image ) );
	}
}