gl_image.c

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/*
Copyright (C) 1997-2001 Id Software, Inc.
Copyright (C) 2018-2019 Krzysztof Kondrak
 
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.
 
*/
 
#include "gl_local.h"
 
image_t     gltextures[MAX_GLTEXTURES];
int         numgltextures;
int         base_textureid;     // gltextures[i] = base_textureid+i
 
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;
 
void GL_SetTexturePalette( unsigned palette[256] )
{
    int i;
    unsigned char temptable[768];
 
    if ( qglColorTableEXT && gl_ext_palettedtexture->value )
    {
        for ( i = 0; i < 256; i++ )
        {
            temptable[i*3+0] = ( palette[i] >> 0 ) & 0xff;
            temptable[i*3+1] = ( palette[i] >> 8 ) & 0xff;
            temptable[i*3+2] = ( palette[i] >> 16 ) & 0xff;
        }
 
        qglColorTableEXT( GL_SHARED_TEXTURE_PALETTE_EXT,
                           GL_RGB,
                           256,
                           GL_RGB,
                           GL_UNSIGNED_BYTE,
                           temptable );
    }
}
 
void GL_EnableMultitexture( qboolean enable )
{
    if ( !qglSelectTextureSGIS && !qglActiveTextureARB )
        return;
 
    if ( enable )
    {
        GL_SelectTexture( gl_texture1 );
        qglEnable( GL_TEXTURE_2D );
        GL_TexEnv( GL_REPLACE );
    }
    else
    {
        GL_SelectTexture( gl_texture1 );
        qglDisable( GL_TEXTURE_2D );
        GL_TexEnv( GL_REPLACE );
    }
    GL_SelectTexture( gl_texture0 );
    GL_TexEnv( GL_REPLACE );
}
 
void GL_SelectTexture( GLenum texture )
{
    int tmu;
 
    if ( !qglSelectTextureSGIS && !qglActiveTextureARB )
        return;
 
    if ( texture == gl_texture0 )
    {
        tmu = 0;
    }
    else
    {
        tmu = 1;
    }
 
    if ( tmu == gl_state.currenttmu )
    {
        return;
    }
 
    gl_state.currenttmu = tmu;
 
    if ( qglSelectTextureSGIS )
    {
        qglSelectTextureSGIS( texture );
    }
    else if ( qglActiveTextureARB )
    {
        qglActiveTextureARB( texture );
        qglClientActiveTextureARB( texture );
    }
}
 
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 )
{
    GL_SelectTexture( target );
    if ( target == gl_texture0 )
    {
        if ( gl_state.currenttextures[0] == texnum )
            return;
    }
    else
    {
        if ( gl_state.currenttextures[1] == texnum )
            return;
    }
    GL_Bind( texnum );
}
 
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},
#ifdef GL_RGB2_EXT
    {"GL_RGB2", GL_RGB2_EXT},
#endif
};
 
#define NUM_GL_SOLID_MODES (sizeof(gl_solid_modes) / sizeof (gltmode_t))
 
/*
===============
GL_TextureMode
===============
*/
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);
        }
    }
}
 
/*
===============
GL_TextureAlphaMode
===============
*/
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;
}
 
/*
===============
GL_TextureSolidMode
===============
*/
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;
}
 
/*
===============
GL_ImageList_f
===============
*/
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);
}
 
 
/*
=============================================================================
 
  scrap allocation
 
  Allocate all the little status bar obejcts into a single texture
  to crutch up inefficient hardware / drivers
 
=============================================================================
*/
 
#define MAX_SCRAPS      1
#define BLOCK_WIDTH     256
#define BLOCK_HEIGHT    256
 
int         scrap_allocated[MAX_SCRAPS][BLOCK_WIDTH];
byte        scrap_texels[MAX_SCRAPS][BLOCK_WIDTH*BLOCK_HEIGHT];
qboolean    scrap_dirty;
 
// returns a texture number and the position inside it
int Scrap_AllocBlock (int w, int h, int *x, int *y)
{
    int     i, j;
    int     best, best2;
    int     texnum;
 
    for (texnum=0 ; texnum<MAX_SCRAPS ; texnum++)
    {
        best = BLOCK_HEIGHT;
 
        for (i=0 ; i<BLOCK_WIDTH-w ; i++)
        {
            best2 = 0;
 
            for (j=0 ; j<w ; j++)
            {
                if (scrap_allocated[texnum][i+j] >= best)
                    break;
                if (scrap_allocated[texnum][i+j] > best2)
                    best2 = scrap_allocated[texnum][i+j];
            }
            if (j == w)
            {   // this is a valid spot
                *x = i;
                *y = best = best2;
            }
        }
 
        if (best + h > BLOCK_HEIGHT)
            continue;
 
        for (i=0 ; i<w ; i++)
            scrap_allocated[texnum][*x + i] = best + h;
 
        return texnum;
    }
 
    return -1;
//  Sys_Error ("Scrap_AllocBlock: full");
}
 
int scrap_uploads;
 
void Scrap_Upload (void)
{
    scrap_uploads++;
    GL_Bind(TEXNUM_SCRAPS);
    GL_Upload8 (scrap_texels[0], BLOCK_WIDTH, BLOCK_HEIGHT, false, false );
    scrap_dirty = false;
}
 
/*
=================================================================
 
PCX LOADING
 
=================================================================
*/
 
 
/*
==============
LoadPCX
==============
*/
void LoadPCX (char *filename, byte **pic, byte **palette, int *width, int *height)
{
    byte    *raw;
    pcx_t   *pcx;
    int     x, y;
    int     len;
    int     dataByte, runLength;
    byte    *out, *pix;
 
    *pic = NULL;
    *palette = NULL;
 
    //
    // load the file
    //
    len = ri.FS_LoadFile (filename, (void **)&raw);
    if (!raw)
    {
        ri.Con_Printf (PRINT_DEVELOPER, "Bad pcx file %s\n", filename);
        return;
    }
 
    //
    // parse the PCX file
    //
    pcx = (pcx_t *)raw;
 
    pcx->xmin = LittleShort(pcx->xmin);
    pcx->ymin = LittleShort(pcx->ymin);
    pcx->xmax = LittleShort(pcx->xmax);
    pcx->ymax = LittleShort(pcx->ymax);
    pcx->hres = LittleShort(pcx->hres);
    pcx->vres = LittleShort(pcx->vres);
    pcx->bytes_per_line = LittleShort(pcx->bytes_per_line);
    pcx->palette_type = LittleShort(pcx->palette_type);
 
    raw = &pcx->data;
 
    if (pcx->manufacturer != 0x0a
        || pcx->version != 5
        || pcx->encoding != 1
        || pcx->bits_per_pixel != 8
        || pcx->xmax >= 640
        || pcx->ymax >= 480)
    {
        ri.Con_Printf (PRINT_ALL, "Bad pcx file %s\n", filename);
        return;
    }
 
    out = malloc ( (pcx->ymax+1) * (pcx->xmax+1) );
 
    *pic = out;
 
    pix = out;
 
    if (palette)
    {
        *palette = malloc(768);
        memcpy (*palette, (byte *)pcx + len - 768, 768);
    }
 
    if (width)
        *width = pcx->xmax+1;
    if (height)
        *height = pcx->ymax+1;
 
    for (y=0 ; y<=pcx->ymax ; y++, pix += pcx->xmax+1)
    {
        for (x=0 ; x<=pcx->xmax ; )
        {
            dataByte = *raw++;
 
            if((dataByte & 0xC0) == 0xC0)
            {
                runLength = dataByte & 0x3F;
                dataByte = *raw++;
            }
            else
                runLength = 1;
 
            while(runLength-- > 0)
                pix[x++] = dataByte;
        }
 
    }
 
    if ( raw - (byte *)pcx > len)
    {
        ri.Con_Printf (PRINT_DEVELOPER, "PCX file %s was malformed", filename);
        free (*pic);
        *pic = NULL;
    }
 
    ri.FS_FreeFile (pcx);
}
 
/*
=========================================================
 
TARGA LOADING
 
=========================================================
*/
 
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;
 
 
/*
=============
LoadTGA
=============
*/
void LoadTGA (char *name, byte **pic, int *width, int *height)
{
    int     columns, rows, numPixels;
    byte    *pixbuf;
    int     row, column;
    byte    *buf_p;
    byte    *buffer;
    int     length;
    TargaHeader     targa_header;
    byte            *targa_rgba;
    byte tmp[2];
 
    *pic = NULL;
 
    //
    // load the file
    //
    length = ri.FS_LoadFile (name, (void **)&buffer);
    if (!buffer)
    {
        ri.Con_Printf (PRINT_DEVELOPER, "Bad tga file %s\n", name);
        return;
    }
 
    buf_p = buffer;
 
    targa_header.id_length = *buf_p++;
    targa_header.colormap_type = *buf_p++;
    targa_header.image_type = *buf_p++;
    
    tmp[0] = buf_p[0];
    tmp[1] = buf_p[1];
    targa_header.colormap_index = LittleShort ( *((short *)tmp) );
    buf_p+=2;
    tmp[0] = buf_p[0];
    tmp[1] = buf_p[1];
    targa_header.colormap_length = LittleShort ( *((short *)tmp) );
    buf_p+=2;
    targa_header.colormap_size = *buf_p++;
    targa_header.x_origin = LittleShort ( *((short *)buf_p) );
    buf_p+=2;
    targa_header.y_origin = LittleShort ( *((short *)buf_p) );
    buf_p+=2;
    targa_header.width = LittleShort ( *((short *)buf_p) );
    buf_p+=2;
    targa_header.height = LittleShort ( *((short *)buf_p) );
    buf_p+=2;
    targa_header.pixel_size = *buf_p++;
    targa_header.attributes = *buf_p++;
 
    if (targa_header.image_type!=2 
        && targa_header.image_type!=10) 
        ri.Sys_Error (ERR_DROP, "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))
        ri.Sys_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;
 
    if (width)
        *width = columns;
    if (height)
        *height = rows;
 
    targa_rgba = malloc (numPixels*4);
    *pic = targa_rgba;
 
    if (targa_header.id_length != 0)
        buf_p += targa_header.id_length;  // 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++) {
                unsigned char red,green,blue,alphabyte;
                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;
                }
            }
        }
    }
    else if (targa_header.image_type==10) {   // Runlength encoded RGB images
        unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
        for(row=rows-1; row>=0; row--) {
            pixbuf = targa_rgba + row*columns*4;
            for(column=0; column<columns; ) {
                packetHeader= *buf_p++;
                packetSize = 1 + (packetHeader & 0x7f);
                if (packetHeader & 0x80) {        // run-length packet
                    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;
                    }
    
                    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 = *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;
                        }
                        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:;
        }
    }
 
    ri.FS_FreeFile (buffer);
}
 
 
/*
====================================================================
 
IMAGE FLOOD FILLING
 
====================================================================
*/
 
 
/*
=================
Mod_FloodFillSkin
 
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 (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))
    {
        //printf( "not filling skin from %d to %d\n", fillcolor, filledcolor );
        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;
    }
}
 
//=======================================================
 
 
/*
================
GL_ResampleTexture
================
*/
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;
        }
    }
}
 
/*
================
GL_LightScaleTexture
 
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]]];
        }
    }
}
 
/*
================
GL_MipMap
 
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;
        }
    }
}
 
/*
===============
GL_Upload32
 
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];
    unsigned char paletted_texture[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 0
    if (mipmap)
        gluBuild2DMipmaps (GL_TEXTURE_2D, samples, width, height, GL_RGBA, GL_UNSIGNED_BYTE, trans);
    else if (scaled_width == width && scaled_height == height)
        qglTexImage2D (GL_TEXTURE_2D, 0, comp, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
    else
    {
        gluScaleImage (GL_RGBA, width, height, GL_UNSIGNED_BYTE, trans,
            scaled_width, scaled_height, GL_UNSIGNED_BYTE, scaled);
        qglTexImage2D (GL_TEXTURE_2D, 0, comp, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
    }
#else
 
    if (scaled_width == width && scaled_height == height)
    {
        if (!mipmap)
        {
            if ( qglColorTableEXT && gl_ext_palettedtexture->value && samples == gl_solid_format )
            {
                uploaded_paletted = true;
                GL_BuildPalettedTexture( paletted_texture, ( unsigned char * ) data, scaled_width, scaled_height );
                qglTexImage2D( GL_TEXTURE_2D,
                              0,
                              GL_COLOR_INDEX8_EXT,
                              scaled_width,
                              scaled_height,
                              0,
                              GL_COLOR_INDEX,
                              GL_UNSIGNED_BYTE,
                              paletted_texture );
            }
            else
            {
                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 );
 
    if ( qglColorTableEXT && gl_ext_palettedtexture->value && ( samples == gl_solid_format ) )
    {
        uploaded_paletted = true;
        GL_BuildPalettedTexture( paletted_texture, ( unsigned char * ) scaled, scaled_width, scaled_height );
        qglTexImage2D( GL_TEXTURE_2D,
                      0,
                      GL_COLOR_INDEX8_EXT,
                      scaled_width,
                      scaled_height,
                      0,
                      GL_COLOR_INDEX,
                      GL_UNSIGNED_BYTE,
                      paletted_texture );
    }
    else
    {
        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++;
            if ( qglColorTableEXT && gl_ext_palettedtexture->value && samples == gl_solid_format )
            {
                uploaded_paletted = true;
                GL_BuildPalettedTexture( paletted_texture, ( unsigned char * ) scaled, scaled_width, scaled_height );
                qglTexImage2D( GL_TEXTURE_2D,
                              miplevel,
                              GL_COLOR_INDEX8_EXT,
                              scaled_width,
                              scaled_height,
                              0,
                              GL_COLOR_INDEX,
                              GL_UNSIGNED_BYTE,
                              paletted_texture );
            }
            else
            {
                qglTexImage2D (GL_TEXTURE_2D, miplevel, comp, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
            }
        }
    }
done: ;
#endif
 
 
    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);
}
 
/*
===============
GL_Upload8
 
Returns has_alpha
===============
*/
/*
static qboolean IsPowerOf2( int value )
{
    int i = 1;
 
 
    while ( 1 )
    {
        if ( value == i )
            return true;
        if ( i > value )
            return false;
        i <<= 1;
    }
}
*/
 
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");
 
    if ( qglColorTableEXT && 
         gl_ext_palettedtexture->value && 
         is_sky )
    {
        qglTexImage2D( GL_TEXTURE_2D,
                      0,
                      GL_COLOR_INDEX8_EXT,
                      width,
                      height,
                      0,
                      GL_COLOR_INDEX,
                      GL_UNSIGNED_BYTE,
                      data );
 
        qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_max);
        qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
    }
    else
    {
        for (i=0 ; i<s ; i++)
        {
            p = data[i];
            trans[i] = d_8to24table[p];
 
            if (p == 255)
            {   // transparent, so scan around for another color
                // to avoid alpha fringes
                // FIXME: do a full flood fill so mips work...
                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);
    }
 
    return true;
}
 
 
/*
================
GL_LoadPic
 
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;
}
 
 
/*
================
GL_LoadWal
================
*/
image_t *GL_LoadWal (char *name)
{
    miptex_t    *mt;
    int         width, height, ofs;
    image_t     *image;
 
    ri.FS_LoadFile (name, (void **)&mt);
    if (!mt)
    {
        ri.Con_Printf (PRINT_ALL, "GL_FindImage: can't load %s\n", name);
        return r_notexture;
    }
 
    width = LittleLong (mt->width);
    height = LittleLong (mt->height);
    ofs = LittleLong (mt->offsets[0]);
 
    image = GL_LoadPic (name, (byte *)mt + ofs, width, height, it_wall, 8);
 
    ri.FS_FreeFile ((void *)mt);
 
    return image;
}
 
/*
===============
GL_FindImage
 
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;
 
    if (!name)
        return NULL;    //  ri.Sys_Error (ERR_DROP, "GL_FindImage: NULL name");
    len = (int)strlen(name);
    if (len<5)
        return NULL;    //  ri.Sys_Error (ERR_DROP, "GL_FindImage: bad name: %s", name);
 
    // 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; // ri.Sys_Error (ERR_DROP, "GL_FindImage: can't load %s", name);
        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; // ri.Sys_Error (ERR_DROP, "GL_FindImage: can't load %s", name);
        image = GL_LoadPic (name, pic, width, height, type, 32);
    }
    else
        return NULL;    //  ri.Sys_Error (ERR_DROP, "GL_FindImage: bad extension on: %s", name);
 
 
    if (pic)
        free(pic);
    if (palette)
        free(palette);
 
    return image;
}
 
 
 
/*
===============
R_RegisterSkin
===============
*/
struct image_s *R_RegisterSkin (char *name)
{
    return GL_FindImage (name, it_skin);
}
 
 
/*
================
GL_FreeUnusedImages
 
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, &image->texnum);
        memset (image, 0, sizeof(*image));
    }
}
 
 
/*
===============
Draw_GetPalette
===============
*/
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;
}
 
 
/*
===============
GL_InitImages
===============
*/
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 )
        {
            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;
    }
}
 
/*
===============
GL_ShutdownImages
===============
*/
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, &image->texnum);
        memset (image, 0, sizeof(*image));
    }
}