/*
===========================================================================
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
===========================================================================
*/
// tr_image.c
#include "tr_local.h"

/*
 * Include file for users of JPEG library.
 * You will need to have included system headers that define at least
 * the typedefs FILE and size_t before you can include jpeglib.h.
 * (stdio.h is sufficient on ANSI-conforming systems.)
 * You may also wish to include "jerror.h".
 */

#define JPEG_INTERNALS
#include "../jpeg-6/jpeglib.h"

#include "../qcommon/puff.h"


static void LoadBMP( const char *name, byte **pic, int *width, int *height );
static void LoadTGA( const char *name, byte **pic, int *width, int *height );
static void LoadJPG( const char *name, byte **pic, int *width, int *height );
static void LoadPNG( const char *name, byte **pic, int *width, int *height );

static byte          s_intensitytable[256];
static unsigned char s_gammatable[256];

int     gl_filter_min = GL_LINEAR_MIPMAP_NEAREST;
int     gl_filter_max = GL_LINEAR;

#define FILE_HASH_SIZE      1024
static  image_t*        hashTable[FILE_HASH_SIZE];

/*
** R_GammaCorrect
*/
void R_GammaCorrect( byte *buffer, int bufSize ) {
    int i;

    for ( i = 0; i < bufSize; i++ ) {
        buffer[i] = s_gammatable[buffer[i]];
    }
}

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

textureMode_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}
};

/*
================
return a hash value for the filename
================
*/
static long generateHashValue( const char *fname ) {
    int     i;
    long    hash;
    char    letter;

    hash = 0;
    i = 0;
    while (fname[i] != '\0') {
        letter = tolower(fname[i]);
        if (letter =='.') break;                // don't include extension
        if (letter =='\\') letter = '/';        // damn path names
        hash+=(long)(letter)*(i+119);
        i++;
    }
    hash &= (FILE_HASH_SIZE-1);
    return hash;
}

/*
===============
GL_TextureMode
===============
*/
void GL_TextureMode( const char *string ) {
    int     i;
    image_t *glt;

    for ( i=0 ; i< 6 ; i++ ) {
        if ( !Q_stricmp( modes[i].name, string ) ) {
            break;
        }
    }

    // hack to prevent trilinear from being set on voodoo,
    // because their driver freaks...
    if ( i == 5 && glConfig.hardwareType == GLHW_3DFX_2D3D ) {
        ri.Printf( PRINT_ALL, "Refusing to set trilinear on a voodoo.\n" );
        i = 3;
    }


    if ( i == 6 ) {
        ri.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 ; i < tr.numImages ; i++ ) {
        glt = tr.images[ i ];
        if ( glt->mipmap ) {
            GL_Bind (glt);
            qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min);
            qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
        }
    }
}

/*
===============
R_SumOfUsedImages
===============
*/
int R_SumOfUsedImages( void ) {
    int total;
    int i;

    total = 0;
    for ( i = 0; i < tr.numImages; i++ ) {
        if ( tr.images[i]->frameUsed == tr.frameCount ) {
            total += tr.images[i]->uploadWidth * tr.images[i]->uploadHeight;
        }
    }

    return total;
}

/*
===============
R_ImageList_f
===============
*/
void R_ImageList_f( void ) {
    int     i;
    image_t *image;
    int     texels;
    const char *yesno[] = {
        "no ", "yes"
    };

    ri.Printf (PRINT_ALL, "\n      -w-- -h-- -mm- -TMU- -if-- wrap --name-------\n");
    texels = 0;

    for ( i = 0 ; i < tr.numImages ; i++ ) {
        image = tr.images[ i ];

        texels += image->uploadWidth*image->uploadHeight;
        ri.Printf (PRINT_ALL,  "%4i: %4i %4i  %s   %d   ",
            i, image->uploadWidth, image->uploadHeight, yesno[image->mipmap], image->TMU );
        switch ( image->internalFormat ) {
        case 1:
            ri.Printf( PRINT_ALL, "I    " );
            break;
        case 2:
            ri.Printf( PRINT_ALL, "IA   " );
            break;
        case 3:
            ri.Printf( PRINT_ALL, "RGB  " );
            break;
        case 4:
            ri.Printf( PRINT_ALL, "RGBA " );
            break;
        case GL_RGBA8:
            ri.Printf( PRINT_ALL, "RGBA8" );
            break;
        case GL_RGB8:
            ri.Printf( PRINT_ALL, "RGB8" );
            break;
        case GL_RGB4_S3TC:
            ri.Printf( PRINT_ALL, "S3TC " );
            break;
        case GL_RGBA4:
            ri.Printf( PRINT_ALL, "RGBA4" );
            break;
        case GL_RGB5:
            ri.Printf( PRINT_ALL, "RGB5 " );
            break;
        default:
            ri.Printf( PRINT_ALL, "???? " );
        }

        switch ( image->wrapClampMode ) {
        case GL_REPEAT:
            ri.Printf( PRINT_ALL, "rept " );
            break;
        case GL_CLAMP:
            ri.Printf( PRINT_ALL, "clmp " );
            break;
        default:
            ri.Printf( PRINT_ALL, "%4i ", image->wrapClampMode );
            break;
        }

        ri.Printf( PRINT_ALL, " %s\n", image->imgName );
    }
    ri.Printf (PRINT_ALL, " ---------\n");
    ri.Printf (PRINT_ALL, " %i total texels (not including mipmaps)\n", texels);
    ri.Printf (PRINT_ALL, " %i total images\n\n", tr.numImages );
}

//=======================================================================

/*
================
ResampleTexture

Used to resample images in a more general than quartering fashion.

This will only be filtered properly if the resampled size
is greater than half the original size.

If a larger shrinking is needed, use the mipmap function
before or after.
================
*/
static void ResampleTexture( unsigned *in, int inwidth, int inheight, unsigned *out,
                            int outwidth, int outheight ) {
    int     i, j;
    unsigned    *inrow, *inrow2;
    unsigned    frac, fracstep;
    unsigned    p1[2048], p2[2048];
    byte        *pix1, *pix2, *pix3, *pix4;

    if (outwidth>2048)
        ri.Error(ERR_DROP, "ResampleTexture: max width");

    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;
        }
    }
}

/*
================
R_LightScaleTexture

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

            p = (byte *)in;

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

        p = (byte *)in;

        c = inwidth*inheight;

        if ( glConfig.deviceSupportsGamma )
        {
            for (i=0 ; i<c ; i++, p+=4)
            {
                p[0] = s_intensitytable[p[0]];
                p[1] = s_intensitytable[p[1]];
                p[2] = s_intensitytable[p[2]];
            }
        }
        else
        {
            for (i=0 ; i<c ; i++, p+=4)
            {
                p[0] = s_gammatable[s_intensitytable[p[0]]];
                p[1] = s_gammatable[s_intensitytable[p[1]]];
                p[2] = s_gammatable[s_intensitytable[p[2]]];
            }
        }
    }
}


/*
================
R_MipMap2

Operates in place, quartering the size of the texture
Proper linear filter
================
*/
static void R_MipMap2( unsigned *in, int inWidth, int inHeight ) {
    int         i, j, k;
    byte        *outpix;
    int         inWidthMask, inHeightMask;
    int         total;
    int         outWidth, outHeight;
    unsigned    *temp;

    outWidth = inWidth >> 1;
    outHeight = inHeight >> 1;
    temp = ri.Hunk_AllocateTempMemory( outWidth * outHeight * 4 );

    inWidthMask = inWidth - 1;
    inHeightMask = inHeight - 1;

    for ( i = 0 ; i < outHeight ; i++ ) {
        for ( j = 0 ; j < outWidth ; j++ ) {
            outpix = (byte *) ( temp + i * outWidth + j );
            for ( k = 0 ; k < 4 ; k++ ) {
                total =
                    1 * ((byte *)&in[ ((i*2-1)&inHeightMask)*inWidth + ((j*2-1)&inWidthMask) ])[k] +
                    2 * ((byte *)&in[ ((i*2-1)&inHeightMask)*inWidth + ((j*2)&inWidthMask) ])[k] +
                    2 * ((byte *)&in[ ((i*2-1)&inHeightMask)*inWidth + ((j*2+1)&inWidthMask) ])[k] +
                    1 * ((byte *)&in[ ((i*2-1)&inHeightMask)*inWidth + ((j*2+2)&inWidthMask) ])[k] +

                    2 * ((byte *)&in[ ((i*2)&inHeightMask)*inWidth + ((j*2-1)&inWidthMask) ])[k] +
                    4 * ((byte *)&in[ ((i*2)&inHeightMask)*inWidth + ((j*2)&inWidthMask) ])[k] +
                    4 * ((byte *)&in[ ((i*2)&inHeightMask)*inWidth + ((j*2+1)&inWidthMask) ])[k] +
                    2 * ((byte *)&in[ ((i*2)&inHeightMask)*inWidth + ((j*2+2)&inWidthMask) ])[k] +

                    2 * ((byte *)&in[ ((i*2+1)&inHeightMask)*inWidth + ((j*2-1)&inWidthMask) ])[k] +
                    4 * ((byte *)&in[ ((i*2+1)&inHeightMask)*inWidth + ((j*2)&inWidthMask) ])[k] +
                    4 * ((byte *)&in[ ((i*2+1)&inHeightMask)*inWidth + ((j*2+1)&inWidthMask) ])[k] +
                    2 * ((byte *)&in[ ((i*2+1)&inHeightMask)*inWidth + ((j*2+2)&inWidthMask) ])[k] +

                    1 * ((byte *)&in[ ((i*2+2)&inHeightMask)*inWidth + ((j*2-1)&inWidthMask) ])[k] +
                    2 * ((byte *)&in[ ((i*2+2)&inHeightMask)*inWidth + ((j*2)&inWidthMask) ])[k] +
                    2 * ((byte *)&in[ ((i*2+2)&inHeightMask)*inWidth + ((j*2+1)&inWidthMask) ])[k] +
                    1 * ((byte *)&in[ ((i*2+2)&inHeightMask)*inWidth + ((j*2+2)&inWidthMask) ])[k];
                outpix[k] = total / 36;
            }
        }
    }

    Com_Memcpy( in, temp, outWidth * outHeight * 4 );
    ri.Hunk_FreeTempMemory( temp );
}

/*
================
R_MipMap

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

    if ( !r_simpleMipMaps->integer ) {
        R_MipMap2( (unsigned *)in, width, height );
        return;
    }

    if ( width == 1 && height == 1 ) {
        return;
    }

    row = width * 4;
    out = in;
    width >>= 1;
    height >>= 1;

    if ( width == 0 || height == 0 ) {
        width += height;    // get largest
        for (i=0 ; i<width ; i++, out+=4, in+=8 ) {
            out[0] = ( in[0] + in[4] )>>1;
            out[1] = ( in[1] + in[5] )>>1;
            out[2] = ( in[2] + in[6] )>>1;
            out[3] = ( in[3] + in[7] )>>1;
        }
        return;
    }

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


/*
==================
R_BlendOverTexture

Apply a color blend over a set of pixels
==================
*/
static void R_BlendOverTexture( byte *data, int pixelCount, byte blend[4] ) {
    int     i;
    int     inverseAlpha;
    int     premult[3];

    inverseAlpha = 255 - blend[3];
    premult[0] = blend[0] * blend[3];
    premult[1] = blend[1] * blend[3];
    premult[2] = blend[2] * blend[3];

    for ( i = 0 ; i < pixelCount ; i++, data+=4 ) {
        data[0] = ( data[0] * inverseAlpha + premult[0] ) >> 9;
        data[1] = ( data[1] * inverseAlpha + premult[1] ) >> 9;
        data[2] = ( data[2] * inverseAlpha + premult[2] ) >> 9;
    }
}

byte    mipBlendColors[16][4] = {
    {0,0,0,0},
    {255,0,0,128},
    {0,255,0,128},
    {0,0,255,128},
    {255,0,0,128},
    {0,255,0,128},
    {0,0,255,128},
    {255,0,0,128},
    {0,255,0,128},
    {0,0,255,128},
    {255,0,0,128},
    {0,255,0,128},
    {0,0,255,128},
    {255,0,0,128},
    {0,255,0,128},
    {0,0,255,128},
};


/*
===============
Upload32

===============
*/
extern qboolean charSet;
static void Upload32( unsigned *data,
                          int width, int height,
                          qboolean mipmap,
                          qboolean picmip,
                            qboolean lightMap,
                          int *format,
                          int *pUploadWidth, int *pUploadHeight )
{
    int         samples;
    unsigned    *scaledBuffer = NULL;
    unsigned    *resampledBuffer = NULL;
    int         scaled_width, scaled_height;
    int         i, c;
    byte        *scan;
    GLenum      internalFormat = GL_RGB;
    float       rMax = 0, gMax = 0, bMax = 0;

    //
    // convert to exact power of 2 sizes
    //
    for (scaled_width = 1 ; scaled_width < width ; scaled_width<<=1)
        ;
    for (scaled_height = 1 ; scaled_height < height ; scaled_height<<=1)
        ;
    if ( r_roundImagesDown->integer && scaled_width > width )
        scaled_width >>= 1;
    if ( r_roundImagesDown->integer && scaled_height > height )
        scaled_height >>= 1;

    if ( scaled_width != width || scaled_height != height ) {
        resampledBuffer = ri.Hunk_AllocateTempMemory( scaled_width * scaled_height * 4 );
        ResampleTexture (data, width, height, resampledBuffer, scaled_width, scaled_height);
        data = resampledBuffer;
        width = scaled_width;
        height = scaled_height;
    }

    //
    // perform optional picmip operation
    //
    if ( picmip ) {
        scaled_width >>= r_picmip->integer;
        scaled_height >>= r_picmip->integer;
    }

    //
    // clamp to minimum size
    //
    if (scaled_width < 1) {
        scaled_width = 1;
    }
    if (scaled_height < 1) {
        scaled_height = 1;
    }

    //
    // clamp to the current upper OpenGL limit
    // scale both axis down equally so we don't have to
    // deal with a half mip resampling
    //
    while ( scaled_width > glConfig.maxTextureSize
        || scaled_height > glConfig.maxTextureSize ) {
        scaled_width >>= 1;
        scaled_height >>= 1;
    }

    scaledBuffer = ri.Hunk_AllocateTempMemory( sizeof( unsigned ) * scaled_width * scaled_height );

    //
    // scan the texture for each channel's max values
    // and verify if the alpha channel is being used or not
    //
    c = width*height;
    scan = ((byte *)data);
    samples = 3;
    if (!lightMap) {
        for ( i = 0; i < c; i++ )
        {
            if ( scan[i*4+0] > rMax )
            {
                rMax = scan[i*4+0];
            }
            if ( scan[i*4+1] > gMax )
            {
                gMax = scan[i*4+1];
            }
            if ( scan[i*4+2] > bMax )
            {
                bMax = scan[i*4+2];
            }
            if ( scan[i*4 + 3] != 255 )
            {
                samples = 4;
                break;
            }
        }
        // select proper internal format
        if ( samples == 3 )
        {
            if ( glConfig.textureCompression == TC_S3TC )
            {
                internalFormat = GL_RGB4_S3TC;
            }
            else if ( r_texturebits->integer == 16 )
            {
                internalFormat = GL_RGB5;
            }
            else if ( r_texturebits->integer == 32 )
            {
                internalFormat = GL_RGB8;
            }
            else
            {
                internalFormat = 3;
            }
        }
        else if ( samples == 4 )
        {
            if ( r_texturebits->integer == 16 )
            {
                internalFormat = GL_RGBA4;
            }
            else if ( r_texturebits->integer == 32 )
            {
                internalFormat = GL_RGBA8;
            }
            else
            {
                internalFormat = 4;
            }
        }
    } else {
        internalFormat = 3;
    }
    // copy or resample data as appropriate for first MIP level
    if ( ( scaled_width == width ) &&
        ( scaled_height == height ) ) {
        if (!mipmap)
        {
            qglTexImage2D (GL_TEXTURE_2D, 0, internalFormat, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
            *pUploadWidth = scaled_width;
            *pUploadHeight = scaled_height;
            *format = internalFormat;

            goto done;
        }
        Com_Memcpy (scaledBuffer, data, width*height*4);
    }
    else
    {
        // use the normal mip-mapping function to go down from here
        while ( width > scaled_width || height > scaled_height ) {
            R_MipMap( (byte *)data, width, height );
            width >>= 1;
            height >>= 1;
            if ( width < 1 ) {
                width = 1;
            }
            if ( height < 1 ) {
                height = 1;
            }
        }
        Com_Memcpy( scaledBuffer, data, width * height * 4 );
    }

    R_LightScaleTexture (scaledBuffer, scaled_width, scaled_height, !mipmap );

    *pUploadWidth = scaled_width;
    *pUploadHeight = scaled_height;
    *format = internalFormat;

    qglTexImage2D (GL_TEXTURE_2D, 0, internalFormat, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaledBuffer );

    if (mipmap)
    {
        int     miplevel;

        miplevel = 0;
        while (scaled_width > 1 || scaled_height > 1)
        {
            R_MipMap( (byte *)scaledBuffer, 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 ( r_colorMipLevels->integer ) {
                R_BlendOverTexture( (byte *)scaledBuffer, scaled_width * scaled_height, mipBlendColors[miplevel] );
            }

            qglTexImage2D (GL_TEXTURE_2D, miplevel, internalFormat, scaled_width, scaled_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaledBuffer );
        }
    }
done:

    if (mipmap)
    {
        if ( textureFilterAnisotropic )
            qglTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT,
                    (GLint)Com_Clamp( 1, maxAnisotropy, r_ext_max_anisotropy->integer ) );

        qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gl_filter_min);
        qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gl_filter_max);
    }
    else
    {
        if ( textureFilterAnisotropic )
            qglTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1 );

        qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
        qglTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    }

    GL_CheckErrors();

    if ( scaledBuffer != 0 )
        ri.Hunk_FreeTempMemory( scaledBuffer );
    if ( resampledBuffer != 0 )
        ri.Hunk_FreeTempMemory( resampledBuffer );
}


/*
================
R_CreateImage

This is the only way any image_t are created
================
*/
image_t *R_CreateImage( const char *name, const byte *pic, int width, int height,
                       qboolean mipmap, qboolean allowPicmip, int glWrapClampMode ) {
    image_t     *image;
    qboolean    isLightmap = qfalse;
    long        hash;

    if (strlen(name) >= MAX_QPATH ) {
        ri.Error (ERR_DROP, "R_CreateImage: \"%s\" is too long\n", name);
    }
    if ( !strncmp( name, "*lightmap", 9 ) ) {
        isLightmap = qtrue;
    }

    if ( tr.numImages == MAX_DRAWIMAGES ) {
        ri.Error( ERR_DROP, "R_CreateImage: MAX_DRAWIMAGES hit\n");
    }

    image = tr.images[tr.numImages] = ri.Hunk_Alloc( sizeof( image_t ), h_low );
    image->texnum = 1024 + tr.numImages;
    tr.numImages++;

    image->mipmap = mipmap;
    image->allowPicmip = allowPicmip;

    strcpy (image->imgName, name);

    image->width = width;
    image->height = height;
    image->wrapClampMode = glWrapClampMode;

    // lightmaps are always allocated on TMU 1
    if ( qglActiveTextureARB && isLightmap ) {
        image->TMU = 1;
    } else {
        image->TMU = 0;
    }

    if ( qglActiveTextureARB ) {
        GL_SelectTexture( image->TMU );
    }

    GL_Bind(image);

    Upload32( (unsigned *)pic, image->width, image->height,
                                image->mipmap,
                                allowPicmip,
                                isLightmap,
                                &image->internalFormat,
                                &image->uploadWidth,
                                &image->uploadHeight );

    qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, glWrapClampMode );
    qglTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, glWrapClampMode );

    qglBindTexture( GL_TEXTURE_2D, 0 );

    if ( image->TMU == 1 ) {
        GL_SelectTexture( 0 );
    }

    hash = generateHashValue(name);
    image->next = hashTable[hash];
    hashTable[hash] = image;

    return image;
}


/*
=========================================================

BMP LOADING

=========================================================
*/
typedef struct
{
    char id[2];
    unsigned long fileSize;
    unsigned long reserved0;
    unsigned long bitmapDataOffset;
    unsigned long bitmapHeaderSize;
    unsigned long width;
    unsigned long height;
    unsigned short planes;
    unsigned short bitsPerPixel;
    unsigned long compression;
    unsigned long bitmapDataSize;
    unsigned long hRes;
    unsigned long vRes;
    unsigned long colors;
    unsigned long importantColors;
    unsigned char palette[256][4];
} BMPHeader_t;

static void LoadBMP( const char *name, byte **pic, int *width, int *height )
{
    int     columns, rows;
    unsigned    numPixels;
    byte    *pixbuf;
    int     row, column;
    byte    *buf_p;
    byte    *buffer;
    int     length;
    BMPHeader_t bmpHeader;
    byte        *bmpRGBA;

    *pic = NULL;

    //
    // load the file
    //
    length = ri.FS_ReadFile( ( char * ) name, (void **)&buffer);
    if (!buffer) {
        return;
    }

    buf_p = buffer;

    bmpHeader.id[0] = *buf_p++;
    bmpHeader.id[1] = *buf_p++;
    bmpHeader.fileSize = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.reserved0 = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.bitmapDataOffset = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.bitmapHeaderSize = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.width = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.height = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.planes = LittleShort( * ( short * ) buf_p );
    buf_p += 2;
    bmpHeader.bitsPerPixel = LittleShort( * ( short * ) buf_p );
    buf_p += 2;
    bmpHeader.compression = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.bitmapDataSize = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.hRes = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.vRes = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.colors = LittleLong( * ( long * ) buf_p );
    buf_p += 4;
    bmpHeader.importantColors = LittleLong( * ( long * ) buf_p );
    buf_p += 4;

    Com_Memcpy( bmpHeader.palette, buf_p, sizeof( bmpHeader.palette ) );

    if ( bmpHeader.bitsPerPixel == 8 )
        buf_p += 1024;

    if ( bmpHeader.id[0] != 'B' && bmpHeader.id[1] != 'M' )
    {
        ri.Error( ERR_DROP, "LoadBMP: only Windows-style BMP files supported (%s)\n", name );
    }
    if ( bmpHeader.fileSize != length )
    {
        ri.Error( ERR_DROP, "LoadBMP: header size does not match file size (%d vs. %d) (%s)\n", bmpHeader.fileSize, length, name );
    }
    if ( bmpHeader.compression != 0 )
    {
        ri.Error( ERR_DROP, "LoadBMP: only uncompressed BMP files supported (%s)\n", name );
    }
    if ( bmpHeader.bitsPerPixel < 8 )
    {
        ri.Error( ERR_DROP, "LoadBMP: monochrome and 4-bit BMP files not supported (%s)\n", name );
    }

    columns = bmpHeader.width;
    rows = bmpHeader.height;
    if ( rows < 0 )
        rows = -rows;
    numPixels = columns * rows;

    if(columns <= 0 || !rows || numPixels > 0x1FFFFFFF // 4*1FFFFFFF == 0x7FFFFFFC < 0x7FFFFFFF
        || ((numPixels * 4) / columns) / 4 != rows)
    {
      ri.Error (ERR_DROP, "LoadBMP: %s has an invalid image size\n", name);
    }

    if ( width )
        *width = columns;
    if ( height )
        *height = rows;

    bmpRGBA = ri.Malloc( numPixels * 4 );
    *pic = bmpRGBA;


    for ( row = rows-1; row >= 0; row-- )
    {
        pixbuf = bmpRGBA + row*columns*4;

        for ( column = 0; column < columns; column++ )
        {
            unsigned char red, green, blue, alpha;
            int palIndex;
            unsigned short shortPixel;

            switch ( bmpHeader.bitsPerPixel )
            {
            case 8:
                palIndex = *buf_p++;
                *pixbuf++ = bmpHeader.palette[palIndex][2];
                *pixbuf++ = bmpHeader.palette[palIndex][1];
                *pixbuf++ = bmpHeader.palette[palIndex][0];
                *pixbuf++ = 0xff;
                break;
            case 16:
                shortPixel = * ( unsigned short * ) pixbuf;
                pixbuf += 2;
                *pixbuf++ = ( shortPixel & ( 31 << 10 ) ) >> 7;
                *pixbuf++ = ( shortPixel & ( 31 << 5 ) ) >> 2;
                *pixbuf++ = ( shortPixel & ( 31 ) ) << 3;
                *pixbuf++ = 0xff;
                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++;
                alpha = *buf_p++;
                *pixbuf++ = red;
                *pixbuf++ = green;
                *pixbuf++ = blue;
                *pixbuf++ = alpha;
                break;
            default:
                ri.Error( ERR_DROP, "LoadBMP: illegal pixel_size '%d' in file '%s'\n", bmpHeader.bitsPerPixel, name );
                break;
            }
        }
    }

    ri.FS_FreeFile( buffer );

}


/*
=================================================================

PCX LOADING

=================================================================
*/


/*
==============
LoadPCX
==============
*/
static void LoadPCX ( const 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;
    unsigned        xmax, ymax;

    *pic = NULL;
    *palette = NULL;

    //
    // load the file
    //
    len = ri.FS_ReadFile( ( char * ) filename, (void **)&raw);
    if (!raw) {
        return;
    }

    //
    // parse the PCX file
    //
    pcx = (pcx_t *)raw;
    raw = &pcx->data;

    xmax = LittleShort(pcx->xmax);
    ymax = LittleShort(pcx->ymax);

    if (pcx->manufacturer != 0x0a
        || pcx->version != 5
        || pcx->encoding != 1
        || pcx->bits_per_pixel != 8
        || xmax >= 1024
        || ymax >= 1024)
    {
        ri.Printf (PRINT_ALL, "Bad pcx file %s (%i x %i) (%i x %i)\n", filename, xmax+1, ymax+1, pcx->xmax, pcx->ymax);
        return;
    }

    out = ri.Malloc ( (ymax+1) * (xmax+1) );

    *pic = out;

    pix = out;

    if (palette)
    {
        *palette = ri.Malloc(768);
        Com_Memcpy (*palette, (byte *)pcx + len - 768, 768);
    }

    if (width)
        *width = xmax+1;
    if (height)
        *height = ymax+1;
// FIXME: use bytes_per_line here?

    for (y=0 ; y<=ymax ; y++, pix += xmax+1)
    {
        for (x=0 ; x<=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.Printf (PRINT_DEVELOPER, "PCX file %s was malformed", filename);
        ri.Free (*pic);
        *pic = NULL;
    }

    ri.FS_FreeFile (pcx);
}


/*
==============
LoadPCX32
==============
*/
static void LoadPCX32 ( const char *filename, byte **pic, int *width, int *height) {
    byte    *palette;
    byte    *pic8;
    int     i, c, p;
    byte    *pic32;

    LoadPCX (filename, &pic8, &palette, width, height);
    if (!pic8) {
        *pic = NULL;
        return;
    }

    // LoadPCX32 ensures width, height < 1024
    c = (*width) * (*height);
    pic32 = *pic = ri.Malloc(4 * c );
    for (i = 0 ; i < c ; i++) {
        p = pic8[i];
        pic32[0] = palette[p*3];
        pic32[1] = palette[p*3 + 1];
        pic32[2] = palette[p*3 + 2];
        pic32[3] = 255;
        pic32 += 4;
    }

    ri.Free (pic8);
    ri.Free (palette);
}

/*
=========================================================

TARGA LOADING

=========================================================
*/

/*
=============
LoadTGA
=============
*/
static void LoadTGA ( const char *name, byte **pic, int *width, int *height)
{
    unsigned    columns, rows, numPixels;
    byte    *pixbuf;
    int     row, column;
    byte    *buf_p;
    byte    *buffer;
    TargaHeader targa_header;
    byte        *targa_rgba;

    *pic = NULL;

    //
    // load the file
    //
    ri.FS_ReadFile ( ( char * ) name, (void **)&buffer);
    if (!buffer) {
        return;
    }

    buf_p = buffer;

    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 (width)
        *width = columns;
    if (height)
        *height = rows;

    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);
    *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 || targa_header.image_type == 3 )
    {
        // 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; ) {
                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;
                        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
                    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);
  }

  ri.FS_FreeFile (buffer);
}

static void LoadJPG( const char *filename, unsigned char **pic, int *width, int *height ) {
  /* This struct contains the JPEG decompression parameters and pointers to
   * working space (which is allocated as needed by the JPEG library).
   */
  struct jpeg_decompress_struct cinfo = {NULL};
  /* We use our private extension JPEG error handler.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
  /* This struct represents a JPEG error handler.  It is declared separately
   * because applications often want to supply a specialized error handler
   * (see the second half of this file for an example).  But here we just
   * take the easy way out and use the standard error handler, which will
   * print a message on stderr and call exit() if compression fails.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
  struct jpeg_error_mgr jerr;
  /* More stuff */
  JSAMPARRAY buffer;        /* Output row buffer */
  unsigned row_stride;      /* physical row width in output buffer */
  unsigned pixelcount, memcount;
  unsigned char *out;
  byte  *fbuffer;
  byte  *buf;

  /* In this example we want to open the input file before doing anything else,
   * so that the setjmp() error recovery below can assume the file is open.
   * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
   * requires it in order to read binary files.
   */

  ri.FS_ReadFile ( ( char * ) filename, (void **)&fbuffer);
  if (!fbuffer) {
    return;
  }

  /* Step 1: allocate and initialize JPEG decompression object */

  /* We have to set up the error handler first, in case the initialization
   * step fails.  (Unlikely, but it could happen if you are out of memory.)
   * This routine fills in the contents of struct jerr, and returns jerr's
   * address which we place into the link field in cinfo.
   */
  cinfo.err = jpeg_std_error(&jerr);

  /* Now we can initialize the JPEG decompression object. */
  jpeg_create_decompress(&cinfo);

  /* Step 2: specify data source (eg, a file) */

  jpeg_stdio_src(&cinfo, fbuffer);

  /* Step 3: read file parameters with jpeg_read_header() */

  (void) jpeg_read_header(&cinfo, TRUE);
  /* We can ignore the return value from jpeg_read_header since
   *   (a) suspension is not possible with the stdio data source, and
   *   (b) we passed TRUE to reject a tables-only JPEG file as an error.
   * See libjpeg.doc for more info.
   */

  /* Step 4: set parameters for decompression */

  /* In this example, we don't need to change any of the defaults set by
   * jpeg_read_header(), so we do nothing here.
   */

  /* Step 5: Start decompressor */

  (void) jpeg_start_decompress(&cinfo);
  /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */

  /* We may need to do some setup of our own at this point before reading
   * the data.  After jpeg_start_decompress() we have the correct scaled
   * output image dimensions available, as well as the output colormap
   * if we asked for color quantization.
   * In this example, we need to make an output work buffer of the right size.
   */
  /* JSAMPLEs per row in output buffer */

  pixelcount = cinfo.output_width * cinfo.output_height;

  if(!cinfo.output_width || !cinfo.output_height
      || ((pixelcount * 4) / cinfo.output_width) / 4 != cinfo.output_height
      || pixelcount > 0x1FFFFFFF || cinfo.output_components > 4) // 4*1FFFFFFF == 0x7FFFFFFC < 0x7FFFFFFF
  {
    ri.Error (ERR_DROP, "LoadJPG: %s has an invalid image size: %dx%d*4=%d, components: %d\n", filename,
            cinfo.output_width, cinfo.output_height, pixelcount * 4, cinfo.output_components);
  }

  memcount = pixelcount * 4;
  row_stride = cinfo.output_width * cinfo.output_components;

  out = ri.Malloc(memcount);

  *width = cinfo.output_width;
  *height = cinfo.output_height;

  /* Step 6: while (scan lines remain to be read) */
  /*           jpeg_read_scanlines(...); */

  /* Here we use the library's state variable cinfo.output_scanline as the
   * loop counter, so that we don't have to keep track ourselves.
   */
  while (cinfo.output_scanline < cinfo.output_height) {
    /* jpeg_read_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could ask for
     * more than one scanline at a time if that's more convenient.
     */
    buf = ((out+(row_stride*cinfo.output_scanline)));
    buffer = &buf;
    (void) jpeg_read_scanlines(&cinfo, buffer, 1);
  }

  buf = out;

  // If we are processing an 8-bit JPEG (greyscale), we'll have to convert
  // the greyscale values to RGBA.
  if(cinfo.output_components == 1)
  {
    int sindex = pixelcount, dindex = memcount;
    unsigned char greyshade;

    // Only pixelcount number of bytes have been written.
    // Expand the color values over the rest of the buffer, starting
    // from the end.
    do
    {
        greyshade = buf[--sindex];

        buf[--dindex] = 255;
        buf[--dindex] = greyshade;
        buf[--dindex] = greyshade;
        buf[--dindex] = greyshade;
    } while(sindex);
  }
  else
  {
    // clear all the alphas to 255
    int i;

    for ( i = 3 ; i < memcount ; i+=4 )
    {
        buf[i] = 255;
    }
  }

  *pic = out;

  /* Step 7: Finish decompression */

  (void) jpeg_finish_decompress(&cinfo);
  /* We can ignore the return value since suspension is not possible
   * with the stdio data source.
   */

  /* Step 8: Release JPEG decompression object */

  /* This is an important step since it will release a good deal of memory. */
  jpeg_destroy_decompress(&cinfo);

  /* After finish_decompress, we can close the input file.
   * Here we postpone it until after no more JPEG errors are possible,
   * so as to simplify the setjmp error logic above.  (Actually, I don't
   * think that jpeg_destroy can do an error exit, but why assume anything...)
   */
  ri.FS_FreeFile (fbuffer);

  /* At this point you may want to check to see whether any corrupt-data
   * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
   */

  /* And we're done! */
}


/* Expanded data destination object for stdio output */

typedef struct {
  struct jpeg_destination_mgr pub; /* public fields */

  byte* outfile;        /* target stream */
  int   size;
} my_destination_mgr;

typedef my_destination_mgr * my_dest_ptr;


/*
 * Initialize destination --- called by jpeg_start_compress
 * before any data is actually written.
 */

void init_destination (j_compress_ptr cinfo)
{
  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;

  dest->pub.next_output_byte = dest->outfile;
  dest->pub.free_in_buffer = dest->size;
}


/*
 * Empty the output buffer --- called whenever buffer fills up.
 *
 * In typical applications, this should write the entire output buffer
 * (ignoring the current state of next_output_byte & free_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been dumped.
 *
 * In applications that need to be able to suspend compression due to output
 * overrun, a FALSE return indicates that the buffer cannot be emptied now.
 * In this situation, the compressor will return to its caller (possibly with
 * an indication that it has not accepted all the supplied scanlines).  The
 * application should resume compression after it has made more room in the
 * output buffer.  Note that there are substantial restrictions on the use of
 * suspension --- see the documentation.
 *
 * When suspending, the compressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_output_byte & free_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point will be regenerated after resumption, so do not
 * write it out when emptying the buffer externally.
 */

boolean empty_output_buffer (j_compress_ptr cinfo)
{
  return TRUE;
}


/*
 * Compression initialization.
 * Before calling this, all parameters and a data destination must be set up.
 *
 * We require a write_all_tables parameter as a failsafe check when writing
 * multiple datastreams from the same compression object.  Since prior runs
 * will have left all the tables marked sent_table=TRUE, a subsequent run
 * would emit an abbreviated stream (no tables) by default.  This may be what
 * is wanted, but for safety's sake it should not be the default behavior:
 * programmers should have to make a deliberate choice to emit abbreviated
 * images.  Therefore the documentation and examples should encourage people
 * to pass write_all_tables=TRUE; then it will take active thought to do the
 * wrong thing.
 */

GLOBAL void
jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
{
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  if (write_all_tables)
    jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */

  /* (Re)initialize error mgr and destination modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->dest->init_destination) (cinfo);
  /* Perform master selection of active modules */
  jinit_compress_master(cinfo);
  /* Set up for the first pass */
  (*cinfo->master->prepare_for_pass) (cinfo);
  /* Ready for application to drive first pass through jpeg_write_scanlines
   * or jpeg_write_raw_data.
   */
  cinfo->next_scanline = 0;
  cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
}


/*
 * Write some scanlines of data to the JPEG compressor.
 *
 * The return value will be the number of lines actually written.
 * This should be less than the supplied num_lines only in case that
 * the data destination module has requested suspension of the compressor,
 * or if more than image_height scanlines are passed in.
 *
 * Note: we warn about excess calls to jpeg_write_scanlines() since
 * this likely signals an application programmer error.  However,
 * excess scanlines passed in the last valid call are *silently* ignored,
 * so that the application need not adjust num_lines for end-of-image
 * when using a multiple-scanline buffer.
 */

GLOBAL JDIMENSION
jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines,
              JDIMENSION num_lines)
{
  JDIMENSION row_ctr, rows_left;

  if (cinfo->global_state != CSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_height)
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->next_scanline;
    cinfo->progress->pass_limit = (long) cinfo->image_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Give master control module another chance if this is first call to
   * jpeg_write_scanlines.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_scanlines.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Ignore any extra scanlines at bottom of image. */
  rows_left = cinfo->image_height - cinfo->next_scanline;
  if (num_lines > rows_left)
    num_lines = rows_left;

  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
  cinfo->next_scanline += row_ctr;
  return row_ctr;
}

/*
 * Terminate destination --- called by jpeg_finish_compress
 * after all data has been written.  Usually needs to flush buffer.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */

static int hackSize;

void term_destination (j_compress_ptr cinfo)
{
  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
  size_t datacount = dest->size - dest->pub.free_in_buffer;
  hackSize = datacount;
}


/*
 * Prepare for output to a stdio stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing compression.
 */

void jpegDest (j_compress_ptr cinfo, byte* outfile, int size)
{
  my_dest_ptr dest;

  /* The destination object is made permanent so that multiple JPEG images
   * can be written to the same file without re-executing jpeg_stdio_dest.
   * This makes it dangerous to use this manager and a different destination
   * manager serially with the same JPEG object, because their private object
   * sizes may be different.  Caveat programmer.
   */
  if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
    cinfo->dest = (struct jpeg_destination_mgr *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
                  sizeof(my_destination_mgr));
  }

  dest = (my_dest_ptr) cinfo->dest;
  dest->pub.init_destination = init_destination;
  dest->pub.empty_output_buffer = empty_output_buffer;
  dest->pub.term_destination = term_destination;
  dest->outfile = outfile;
  dest->size = size;
}

void SaveJPG(char * filename, int quality, int image_width, int image_height, unsigned char *image_buffer) {
  /* This struct contains the JPEG compression parameters and pointers to
   * working space (which is allocated as needed by the JPEG library).
   * It is possible to have several such structures, representing multiple
   * compression/decompression processes, in existence at once.  We refer
   * to any one struct (and its associated working data) as a "JPEG object".
   */
  struct jpeg_compress_struct cinfo;
  /* This struct represents a JPEG error handler.  It is declared separately
   * because applications often want to supply a specialized error handler
   * (see the second half of this file for an example).  But here we just
   * take the easy way out and use the standard error handler, which will
   * print a message on stderr and call exit() if compression fails.
   * Note that this struct must live as long as the main JPEG parameter
   * struct, to avoid dangling-pointer problems.
   */
  struct jpeg_error_mgr jerr;
  /* More stuff */
  JSAMPROW row_pointer[1];  /* pointer to JSAMPLE row[s] */
  int row_stride;       /* physical row width in image buffer */
  unsigned char *out;

  /* Step 1: allocate and initialize JPEG compression object */

  /* We have to set up the error handler first, in case the initialization
   * step fails.  (Unlikely, but it could happen if you are out of memory.)
   * This routine fills in the contents of struct jerr, and returns jerr's
   * address which we place into the link field in cinfo.
   */
  cinfo.err = jpeg_std_error(&jerr);
  /* Now we can initialize the JPEG compression object. */
  jpeg_create_compress(&cinfo);

  /* Step 2: specify data destination (eg, a file) */
  /* Note: steps 2 and 3 can be done in either order. */

  /* Here we use the library-supplied code to send compressed data to a
   * stdio stream.  You can also write your own code to do something else.
   * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
   * requires it in order to write binary files.
   */
  out = ri.Hunk_AllocateTempMemory(image_width*image_height*4);
  jpegDest(&cinfo, out, image_width*image_height*4);

  /* Step 3: set parameters for compression */

  /* First we supply a description of the input image.
   * Four fields of the cinfo struct must be filled in:
   */
  cinfo.image_width = image_width;  /* image width and height, in pixels */
  cinfo.image_height = image_height;
  cinfo.input_components = 4;       /* # of color components per pixel */
  cinfo.in_color_space = JCS_RGB;   /* colorspace of input image */
  /* Now use the library's routine to set default compression parameters.
   * (You must set at least cinfo.in_color_space before calling this,
   * since the defaults depend on the source color space.)
   */
  jpeg_set_defaults(&cinfo);
  /* Now you can set any non-default parameters you wish to.
   * Here we just illustrate the use of quality (quantization table) scaling:
   */
  jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
  /* If quality is set high, disable chroma subsampling */
  if (quality >= 85) {
    cinfo.comp_info[0].h_samp_factor = 1;
    cinfo.comp_info[0].v_samp_factor = 1;
  }

  /* Step 4: Start compressor */

  /* TRUE ensures that we will write a complete interchange-JPEG file.
   * Pass TRUE unless you are very sure of what you're doing.
   */
  jpeg_start_compress(&cinfo, TRUE);

  /* Step 5: while (scan lines remain to be written) */
  /*           jpeg_write_scanlines(...); */

  /* Here we use the library's state variable cinfo.next_scanline as the
   * loop counter, so that we don't have to keep track ourselves.
   * To keep things simple, we pass one scanline per call; you can pass
   * more if you wish, though.
   */
  row_stride = image_width * 4; /* JSAMPLEs per row in image_buffer */

  while (cinfo.next_scanline < cinfo.image_height) {
    /* jpeg_write_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could pass
     * more than one scanline at a time if that's more convenient.
     */
    row_pointer[0] = & image_buffer[((cinfo.image_height-1)*row_stride)-cinfo.next_scanline * row_stride];
    (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
  }

  /* Step 6: Finish compression */

  jpeg_finish_compress(&cinfo);
  /* After finish_compress, we can close the output file. */
  ri.FS_WriteFile( filename, out, hackSize );

  ri.Hunk_FreeTempMemory(out);

  /* Step 7: release JPEG compression object */

  /* This is an important step since it will release a good deal of memory. */
  jpeg_destroy_compress(&cinfo);

  /* And we're done! */
}

/*
=================
SaveJPGToBuffer
=================
*/
int SaveJPGToBuffer( byte *buffer, int quality,
    int image_width, int image_height,
    byte *image_buffer )
{
  struct jpeg_compress_struct cinfo;
  struct jpeg_error_mgr jerr;
  JSAMPROW row_pointer[1];  /* pointer to JSAMPLE row[s] */
  int row_stride;       /* physical row width in image buffer */

  /* Step 1: allocate and initialize JPEG compression object */
  cinfo.err = jpeg_std_error(&jerr);
  /* Now we can initialize the JPEG compression object. */
  jpeg_create_compress(&cinfo);

  /* Step 2: specify data destination (eg, a file) */
  /* Note: steps 2 and 3 can be done in either order. */
  jpegDest(&cinfo, buffer, image_width*image_height*4);

  /* Step 3: set parameters for compression */
  cinfo.image_width = image_width;  /* image width and height, in pixels */
  cinfo.image_height = image_height;
  cinfo.input_components = 4;       /* # of color components per pixel */
  cinfo.in_color_space = JCS_RGB;   /* colorspace of input image */

  jpeg_set_defaults(&cinfo);
  jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
  /* If quality is set high, disable chroma subsampling */
  if (quality >= 85) {
    cinfo.comp_info[0].h_samp_factor = 1;
    cinfo.comp_info[0].v_samp_factor = 1;
  }

  /* Step 4: Start compressor */
  jpeg_start_compress(&cinfo, TRUE);

  /* Step 5: while (scan lines remain to be written) */
  /*           jpeg_write_scanlines(...); */
  row_stride = image_width * 4; /* JSAMPLEs per row in image_buffer */

  while (cinfo.next_scanline < cinfo.image_height) {
    /* jpeg_write_scanlines expects an array of pointers to scanlines.
     * Here the array is only one element long, but you could pass
     * more than one scanline at a time if that's more convenient.
     */
    row_pointer[0] = & image_buffer[((cinfo.image_height-1)*row_stride)-cinfo.next_scanline * row_stride];
    (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
  }

  /* Step 6: Finish compression */
  jpeg_finish_compress(&cinfo);

  /* Step 7: release JPEG compression object */
  jpeg_destroy_compress(&cinfo);

  /* And we're done! */
  return hackSize;
}

//===================================================================

/*
=================
PNG LOADING
=================
*/

/*
 *  Quake 3 image format : RGBA
 */

#define Q3IMAGE_BYTESPERPIXEL (4)

/*
 *  PNG specifications
 */

/*
 *  The first 8 Bytes of every PNG-File are a fixed signature
 *  to identify the file as a PNG.
 */

#define PNG_Signature "\x89\x50\x4E\x47\xD\xA\x1A\xA"
#define PNG_Signature_Size (8)

/*
 *  After the signature diverse chunks follow.
 *  A chunk consists of a header and if Length
 *  is bigger than 0 a body and a CRC of the body follow.
 */

struct PNG_ChunkHeader
{
    uint32_t Length;
    uint32_t Type;
};

#define PNG_ChunkHeader_Size (8)

typedef uint32_t PNG_ChunkCRC;

#define PNG_ChunkCRC_Size (4)

/*
 *  We use the following ChunkTypes.
 *  All others are ignored.
 */

#define MAKE_CHUNKTYPE(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | ((d)))

#define PNG_ChunkType_IHDR MAKE_CHUNKTYPE('I', 'H', 'D', 'R')
#define PNG_ChunkType_PLTE MAKE_CHUNKTYPE('P', 'L', 'T', 'E')
#define PNG_ChunkType_IDAT MAKE_CHUNKTYPE('I', 'D', 'A', 'T')
#define PNG_ChunkType_IEND MAKE_CHUNKTYPE('I', 'E', 'N', 'D')
#define PNG_ChunkType_tRNS MAKE_CHUNKTYPE('t', 'R', 'N', 'S')

/*
 *  Per specification the first chunk after the signature SHALL be IHDR.
 */

struct PNG_Chunk_IHDR
{
    uint32_t Width;
    uint32_t Height;
    uint8_t  BitDepth;
    uint8_t  ColourType;
    uint8_t  CompressionMethod;
    uint8_t  FilterMethod;
    uint8_t  InterlaceMethod;
};

#define PNG_Chunk_IHDR_Size (13)

/*
 *  ColourTypes
 */

#define PNG_ColourType_Grey      (0)
#define PNG_ColourType_True      (2)
#define PNG_ColourType_Indexed   (3)
#define PNG_ColourType_GreyAlpha (4)
#define PNG_ColourType_TrueAlpha (6)

/*
 *  number of colour components
 *
 *  Grey      : 1 grey
 *  True      : 1 R, 1 G, 1 B
 *  Indexed   : 1 index
 *  GreyAlpha : 1 grey, 1 alpha
 *  TrueAlpha : 1 R, 1 G, 1 B, 1 alpha
 */

#define PNG_NumColourComponents_Grey      (1)
#define PNG_NumColourComponents_True      (3)
#define PNG_NumColourComponents_Indexed   (1)
#define PNG_NumColourComponents_GreyAlpha (2)
#define PNG_NumColourComponents_TrueAlpha (4)

/*
 *  For the different ColourTypes
 *  different BitDepths are specified.
 */

#define PNG_BitDepth_1  ( 1)
#define PNG_BitDepth_2  ( 2)
#define PNG_BitDepth_4  ( 4)
#define PNG_BitDepth_8  ( 8)
#define PNG_BitDepth_16 (16)

/*
 *  Only one valid CompressionMethod is standardized.
 */

#define PNG_CompressionMethod_0 (0)

/*
 *  Only one valid FilterMethod is currently standardized.
 */

#define PNG_FilterMethod_0 (0)

/*
 *  This FilterMethod defines 5 FilterTypes
 */

#define PNG_FilterType_None    (0)
#define PNG_FilterType_Sub     (1)
#define PNG_FilterType_Up      (2)
#define PNG_FilterType_Average (3)
#define PNG_FilterType_Paeth   (4)

/*
 *  Two InterlaceMethods are standardized :
 *  0 - NonInterlaced
 *  1 - Interlaced
 */

#define PNG_InterlaceMethod_NonInterlaced (0)
#define PNG_InterlaceMethod_Interlaced    (1)

/*
 *  The Adam7 interlace method uses 7 passes.
 */

#define PNG_Adam7_NumPasses (7)

/*
 *  The compressed data starts with a header ...
 */

struct PNG_ZlibHeader
{
    uint8_t CompressionMethod;
    uint8_t Flags;
};

#define PNG_ZlibHeader_Size (2)

/*
 *  ... and is followed by a check value
 */

#define PNG_ZlibCheckValue_Size (4)

/*
 *  Some support functions for buffered files follow.
 */

/*
 *  buffered file representation
 */

struct BufferedFile
{
    byte *Buffer;
    int   Length;
    byte *Ptr;
    int   BytesLeft;
};

/*
 *  Read a file into a buffer.
 */

static struct BufferedFile *ReadBufferedFile(const char *name)
{
    struct BufferedFile *BF;

    /*
     *  input verification
     */

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

    /*
     *  Allocate control struct.
     */

    BF = ri.Malloc(sizeof(struct BufferedFile));
    if(!BF)
    {
        return(NULL);
    }

    /*
     *  Initialize the structs components.
     */

    BF->Length    = 0;
    BF->Buffer    = NULL;
    BF->Ptr       = NULL;
    BF->BytesLeft = 0;

    /*
     *  Read the file.
     */

    BF->Length = ri.FS_ReadFile((char *) name, (void **) &BF->Buffer);

    /*
     *  Did we get it? Is it big enough?
     */

    if(!(BF->Buffer && (BF->Length > 0)))
    {
        ri.Free(BF);

        return(NULL);
    }

    /*
     *  Set the pointers and counters.
     */

    BF->Ptr       = BF->Buffer;
    BF->BytesLeft = BF->Length;

    return(BF);
}

/*
 *  Close a buffered file.
 */

static void CloseBufferedFile(struct BufferedFile *BF)
{
    if(BF)
    {
        if(BF->Buffer)
        {
            ri.FS_FreeFile(BF->Buffer);
        }

        ri.Free(BF);
    }
}

/*
 *  Get a pointer to the requested bytes.
 */

static void *BufferedFileRead(struct BufferedFile *BF, int Length)
{
    void *RetVal;

    /*
     *  input verification
     */

    if(!(BF && Length))
    {
        return(NULL);
    }

    /*
     *  not enough bytes left
     */

    if(Length > BF->BytesLeft)
    {
        return(NULL);
    }

    /*
     *  the pointer to the requested data
     */

    RetVal = BF->Ptr;

    /*
     *  Raise the pointer and counter.
     */

    BF->Ptr       += Length;
    BF->BytesLeft -= Length;

    return(RetVal);
}

/*
 *  Rewind the buffer.
 */

static qboolean BufferedFileRewind(struct BufferedFile *BF, int Offset)
{
    int BytesRead;

    /*
     *  input verification
     */

    if(!BF)
    {
        return(qfalse);
    }

    /*
     *  special trick to rewind to the beginning of the buffer
     */

    if(Offset == -1)
    {
        BF->Ptr       = BF->Buffer;
        BF->BytesLeft = BF->Length;

        return(qtrue);
    }

    /*
     *  How many bytes do we have already read?
     */

    BytesRead = BF->Ptr - BF->Buffer;

    /*
     *  We can only rewind to the beginning of the BufferedFile.
     */

    if(Offset > BytesRead)
    {
        return(qfalse);
    }

    /*
     *  lower the pointer and counter.
     */

    BF->Ptr       -= Offset;
    BF->BytesLeft += Offset;

    return(qtrue);
}

/*
 *  Skip some bytes.
 */

static qboolean BufferedFileSkip(struct BufferedFile *BF, int Offset)
{
    /*
     *  input verification
     */

    if(!BF)
    {
        return(qfalse);
    }

    /*
     *  We can only skip to the end of the BufferedFile.
     */

    if(Offset > BF->BytesLeft)
    {
        return(qfalse);
    }

    /*
     *  lower the pointer and counter.
     */

    BF->Ptr       += Offset;
    BF->BytesLeft -= Offset;

    return(qtrue);
}

/*
 *  Find a chunk
 */

static qboolean FindChunk(struct BufferedFile *BF, uint32_t ChunkType)
{
    struct PNG_ChunkHeader *CH;

    uint32_t Length;
    uint32_t Type;

    /*
     *  input verification
     */

    if(!BF)
    {
        return(qfalse);
    }

    /*
     *  cycle trough the chunks
     */

    while(qtrue)
    {
        /*
         *  Read the chunk-header.
         */

        CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
        if(!CH)
        {
            return(qfalse);
        }

        /*
         *  Do not swap the original types
         *  they might be needed later.
         */

        Length = BigLong(CH->Length);
        Type   = BigLong(CH->Type);

        /*
         *  We found it!
         */

        if(Type == ChunkType)
        {
            /*
             *  Rewind to the start of the chunk.
             */

            BufferedFileRewind(BF, PNG_ChunkHeader_Size);

            break;
        }
        else
        {
            /*
             *  Skip the rest of the chunk.
             */

            if(Length)
            {
                if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
                {
                    return(qfalse);
                }
            }
        }
    }

    return(qtrue);
}

/*
 *  Decompress all IDATs
 */

static uint32_t DecompressIDATs(struct BufferedFile *BF, uint8_t **Buffer)
{
    uint8_t  *DecompressedData;
    uint32_t  DecompressedDataLength;

    uint8_t  *CompressedData;
    uint8_t  *CompressedDataPtr;
    uint32_t  CompressedDataLength;

    struct PNG_ChunkHeader *CH;

    uint32_t Length;
    uint32_t Type;

    int BytesToRewind;

    int32_t   puffResult;
    uint8_t  *puffDest;
    uint32_t  puffDestLen;
    uint8_t  *puffSrc;
    uint32_t  puffSrcLen;

    /*
     *  input verification
     */

    if(!(BF && Buffer))
    {
        return(-1);
    }

    /*
     *  some zeroing
     */

    DecompressedData = NULL;
    DecompressedDataLength = 0;
    *Buffer = DecompressedData;

    CompressedData = NULL;
    CompressedDataLength = 0;

    BytesToRewind = 0;

    /*
     *  Find the first IDAT chunk.
     */

    if(!FindChunk(BF, PNG_ChunkType_IDAT))
    {
        return(-1);
    }

    /*
     *  Count the size of the uncompressed data
     */

    while(qtrue)
    {
        /*
         *  Read chunk header
         */

        CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
        if(!CH)
        {
            /*
             *  Rewind to the start of this adventure
             *  and return unsuccessfull
             */

            BufferedFileRewind(BF, BytesToRewind);

            return(-1);
        }

        /*
         *  Length and Type of chunk
         */

        Length = BigLong(CH->Length);
        Type   = BigLong(CH->Type);

        /*
         *  We have reached the end of the IDAT chunks
         */

        if(!(Type == PNG_ChunkType_IDAT))
        {
            BufferedFileRewind(BF, PNG_ChunkHeader_Size);

            break;
        }

        /*
         *  Add chunk header to count.
         */

        BytesToRewind += PNG_ChunkHeader_Size;

        /*
         *  Skip to next chunk
         */

        if(Length)
        {
            if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
            {
                BufferedFileRewind(BF, BytesToRewind);

                return(-1);
            }

            BytesToRewind += Length + PNG_ChunkCRC_Size;
            CompressedDataLength += Length;
        }
    }

    BufferedFileRewind(BF, BytesToRewind);

    CompressedData = ri.Malloc(CompressedDataLength);
    if(!CompressedData)
    {
        return(-1);
    }

    CompressedDataPtr = CompressedData;

    /*
     *  Collect the compressed Data
     */

    while(qtrue)
    {
        /*
         *  Read chunk header
         */

        CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
        if(!CH)
        {
            ri.Free(CompressedData);

            return(-1);
        }

        /*
         *  Length and Type of chunk
         */

        Length = BigLong(CH->Length);
        Type   = BigLong(CH->Type);

        /*
         *  We have reached the end of the IDAT chunks
         */

        if(!(Type == PNG_ChunkType_IDAT))
        {
            BufferedFileRewind(BF, PNG_ChunkHeader_Size);

            break;
        }

        /*
         *  Copy the Data
         */

        if(Length)
        {
            uint8_t *OrigCompressedData;

            OrigCompressedData = BufferedFileRead(BF, Length);
            if(!OrigCompressedData)
            {
                ri.Free(CompressedData);

                return(-1);
            }

            if(!BufferedFileSkip(BF, PNG_ChunkCRC_Size))
            {
                ri.Free(CompressedData);

                return(-1);
            }

            memcpy(CompressedDataPtr, OrigCompressedData, Length);
            CompressedDataPtr += Length;
        }
    }

    /*
     *  Let puff() calculate the decompressed data length.
     */

    puffDest    = NULL;
    puffDestLen = 0;

    /*
     *  The zlib header and checkvalue don't belong to the compressed data.
     */

    puffSrc    = CompressedData + PNG_ZlibHeader_Size;
    puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;

    /*
     *  first puff() to calculate the size of the uncompressed data
     */

    puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
    if(!((puffResult == 0) && (puffDestLen > 0)))
    {
        ri.Free(CompressedData);

        return(-1);
    }

    /*
     *  Allocate the buffer for the uncompressed data.
     */

    DecompressedData = ri.Malloc(puffDestLen);
    if(!DecompressedData)
    {
        ri.Free(CompressedData);

        return(-1);
    }

    /*
     *  Set the input again in case something was changed by the last puff() .
     */

    puffDest   = DecompressedData;
    puffSrc    = CompressedData + PNG_ZlibHeader_Size;
    puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;

    /*
     *  decompression puff()
     */

    puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);

    /*
     *  The compressed data is not needed anymore.
     */

    ri.Free(CompressedData);

    /*
     *  Check if the last puff() was successfull.
     */

    if(!((puffResult == 0) && (puffDestLen > 0)))
    {
        ri.Free(DecompressedData);

        return(-1);
    }

    /*
     *  Set the output of this function.
     */

    DecompressedDataLength = puffDestLen;
    *Buffer = DecompressedData;

    return(DecompressedDataLength);
}

/*
 *  the Paeth predictor
 */

static uint8_t PredictPaeth(uint8_t a, uint8_t b, uint8_t c)
{
    /*
     *  a == Left
     *  b == Up
     *  c == UpLeft
     */

    uint8_t Pr;
    int p;
    int pa, pb, pc;

    Pr = 0;

    p  = ((int) a) + ((int) b) - ((int) c);
    pa = abs(p - ((int) a));
    pb = abs(p - ((int) b));
    pc = abs(p - ((int) c));

    if((pa <= pb) && (pa <= pc))
    {
        Pr = a;
    }
    else if(pb <= pc)
    {
        Pr = b;
    }
    else
    {
        Pr = c;
    }

    return(Pr);

}

/*
 *  Reverse the filters.
 */

static qboolean UnfilterImage(uint8_t  *DecompressedData,
                              uint32_t  ImageHeight,
                      uint32_t  BytesPerScanline,
                      uint32_t  BytesPerPixel)
{
    uint8_t   *DecompPtr;
    uint8_t   FilterType;
    uint8_t  *PixelLeft, *PixelUp, *PixelUpLeft;
    uint32_t  w, h, p;

    /*
     *  some zeros for the filters
     */

    uint8_t Zeros[8] = {0, 0, 0, 0, 0, 0, 0, 0};

    /*
     *  input verification
     *
     *  ImageHeight and BytesPerScanline are not checked,
     *  because these can be zero in some interlace passes.
     */

    if(!(DecompressedData && BytesPerPixel))
    {
    return(qfalse);
    }


    /*
     *  Set the pointer to the start of the decompressed Data.
     */

    DecompPtr = DecompressedData;

    /*
     *  Un-filtering is done in place.
     */

    /*
     *  Go trough all scanlines.
     */

    for(h = 0; h < ImageHeight; h++)
    {
        /*
         *  Every scanline starts with a FilterType byte.
         */

        FilterType = *DecompPtr;
        DecompPtr++;

        /*
         *  Left pixel of the first byte in a scanline is zero.
         */

        PixelLeft = Zeros;

        /*
         *  Set PixelUp to previous line only if we are on the second line or above.
         *
         *  Plus one byte for the FilterType
         */

        if(h > 0)
        {
            PixelUp = DecompPtr - (BytesPerScanline + 1);
        }
        else
        {
            PixelUp = Zeros;
        }

        /*
         * The pixel left to the first pixel of the previous scanline is zero too.
         */

        PixelUpLeft = Zeros;

        /*
         *  Cycle trough all pixels of the scanline.
         */

        for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
        {
            /*
             *  Cycle trough the bytes of the pixel.
             */

            for(p = 0; p < BytesPerPixel; p++)
            {
                switch(FilterType)
                {
                    case PNG_FilterType_None :
                    {
                        /*
                         *  The byte is unfiltered.
                         */

                        break;
                    }

                    case PNG_FilterType_Sub :
                    {
                        DecompPtr[p] += PixelLeft[p];

                        break;
                    }

            case PNG_FilterType_Up :
                    {
                        DecompPtr[p] += PixelUp[p];

                        break;
                    }

                    case PNG_FilterType_Average :
                    {
                        DecompPtr[p] += ((uint8_t) ((((uint16_t) PixelLeft[p]) + ((uint16_t) PixelUp[p])) / 2));

                        break;
                    }

                    case PNG_FilterType_Paeth :
                    {
                        DecompPtr[p] += PredictPaeth(PixelLeft[p], PixelUp[p], PixelUpLeft[p]);

                        break;
                    }

                    default :
                    {
                        return(qfalse);
                    }
                }
            }

            PixelLeft = DecompPtr;

            /*
             *  We only have a upleft pixel if we are on the second line or above.
             */

            if(h > 0)
            {
                PixelUpLeft = DecompPtr - (BytesPerScanline + 1);
            }

        /*
             *  Skip to the next pixel.
             */

            DecompPtr += BytesPerPixel;

            /*
             *  We only have a previous line if we are on the second line and above.
             */

            if(h > 0)
            {
                PixelUp = DecompPtr - (BytesPerScanline + 1);
            }
        }
    }

 return(qtrue);
}

/*
 *  Convert a raw input pixel to Quake 3 RGA format.
 */

static qboolean ConvertPixel(struct PNG_Chunk_IHDR *IHDR,
                 byte                  *OutPtr,
                 uint8_t               *DecompPtr,
                             qboolean               HasTransparentColour,
                             uint8_t               *TransparentColour,
                             uint8_t               *OutPal)
{
    /*
     *  input verification
     */

    if(!(IHDR && OutPtr && DecompPtr && TransparentColour && OutPal))
    {
     return(qfalse);
    }

    switch(IHDR->ColourType)
    {
        case PNG_ColourType_Grey :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_1 :
                case PNG_BitDepth_2 :
                case PNG_BitDepth_4 :
                {
                uint8_t Step;
                    uint8_t GreyValue;

                    Step = 0xFF / ((1 << IHDR->BitDepth) - 1);

                    GreyValue = DecompPtr[0] * Step;

                    OutPtr[0] = GreyValue;
                    OutPtr[1] = GreyValue;
                    OutPtr[2] = GreyValue;
                    OutPtr[3] = 0xFF;

                    /*
                     *  Grey supports full transparency for one specified colour
                     */

                    if(HasTransparentColour)
                    {
                        if(TransparentColour[1] == DecompPtr[0])
                        {
                            OutPtr[3] = 0x00;
                        }
                    }


                    break;
                }

                case PNG_BitDepth_8 :
                case PNG_BitDepth_16 :
                {
                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[0];
                    OutPtr[2] = DecompPtr[0];
                    OutPtr[3] = 0xFF;

                    /*
                     *  Grey supports full transparency for one specified colour
                     */

                    if(HasTransparentColour)
                    {
                        if(IHDR->BitDepth == PNG_BitDepth_8)
                        {
                            if(TransparentColour[1] == DecompPtr[0])
                            {
                                OutPtr[3] = 0x00;
                            }
                        }
                        else
                        {
                            if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]))
                            {
                                OutPtr[3] = 0x00;
                            }
                        }
                    }

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_True :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                {
                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[1];
                    OutPtr[2] = DecompPtr[2];
                    OutPtr[3] = 0xFF;

                    /*
                     *  True supports full transparency for one specified colour
                     */

                    if(HasTransparentColour)
                    {
                        if((TransparentColour[1] == DecompPtr[0]) &&
                           (TransparentColour[3] == DecompPtr[1]) &&
                           (TransparentColour[5] == DecompPtr[3]))
                        {
                            OutPtr[3] = 0x00;
                        }
                    }

                    break;
                }

                case PNG_BitDepth_16 :
                {
                    /*
                     *  We use only the upper byte.
                     */

                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[2];
                    OutPtr[2] = DecompPtr[4];
                    OutPtr[3] = 0xFF;

                    /*
                     *  True supports full transparency for one specified colour
                     */

                    if(HasTransparentColour)
                    {
                        if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]) &&
                           (TransparentColour[2] == DecompPtr[2]) && (TransparentColour[3] == DecompPtr[3]) &&
                           (TransparentColour[4] == DecompPtr[4]) && (TransparentColour[5] == DecompPtr[5]))
                        {
                            OutPtr[3] = 0x00;
                        }
                    }

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_Indexed :
        {
            OutPtr[0] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 0];
            OutPtr[1] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 1];
            OutPtr[2] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 2];
            OutPtr[3] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 3];

            break;
        }

        case PNG_ColourType_GreyAlpha :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                {
                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[0];
                    OutPtr[2] = DecompPtr[0];
                    OutPtr[3] = DecompPtr[1];

                    break;
                }

                case PNG_BitDepth_16 :
                {
                    /*
                     *  We use only the upper byte.
                     */

                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[0];
                    OutPtr[2] = DecompPtr[0];
                    OutPtr[3] = DecompPtr[2];

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_TrueAlpha :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                {
                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[1];
                    OutPtr[2] = DecompPtr[2];
                    OutPtr[3] = DecompPtr[3];

                    break;
                }

                case PNG_BitDepth_16 :
                {
                    /*
                     *  We use only the upper byte.
                     */

                    OutPtr[0] = DecompPtr[0];
                    OutPtr[1] = DecompPtr[2];
                    OutPtr[2] = DecompPtr[4];
                    OutPtr[3] = DecompPtr[6];

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        default :
        {
            return(qfalse);
        }
    }

    return(qtrue);
}


/*
 *  Decode a non-interlaced image.
 */

static qboolean DecodeImageNonInterlaced(struct PNG_Chunk_IHDR *IHDR,
                                         byte                  *OutBuffer,
                                         uint8_t               *DecompressedData,
                                         uint32_t               DecompressedDataLength,
                                         qboolean               HasTransparentColour,
                                         uint8_t               *TransparentColour,
                                         uint8_t               *OutPal)
{
    uint32_t IHDR_Width;
    uint32_t IHDR_Height;
    uint32_t BytesPerScanline, BytesPerPixel, PixelsPerByte;
    uint32_t  w, h, p;
    byte *OutPtr;
    uint8_t *DecompPtr;

    /*
     *  input verification
     */

    if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
    {
    return(qfalse);
    }

    /*
     *  byte swapping
     */

    IHDR_Width  = BigLong(IHDR->Width);
    IHDR_Height = BigLong(IHDR->Height);

    /*
     *  information for un-filtering
     */

    switch(IHDR->ColourType)
    {
        case PNG_ColourType_Grey :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_1 :
                case PNG_BitDepth_2 :
                case PNG_BitDepth_4 :
                {
                    BytesPerPixel    = 1;
                    PixelsPerByte    = 8 / IHDR->BitDepth;

                    break;
                }

                case PNG_BitDepth_8  :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_True :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8  :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_Indexed :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_1 :
                case PNG_BitDepth_2 :
                case PNG_BitDepth_4 :
                {
                    BytesPerPixel    = 1;
                    PixelsPerByte    = 8 / IHDR->BitDepth;

                    break;
                }

                case PNG_BitDepth_8 :
                {
                    BytesPerPixel    = PNG_NumColourComponents_Indexed;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_GreyAlpha :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_TrueAlpha :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        default :
        {
            return(qfalse);
        }
    }

    /*
     *  Calculate the size of one scanline
     */

    BytesPerScanline = (IHDR_Width * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;

    /*
     *  Check if we have enough data for the whole image.
     */

    if(!(DecompressedDataLength == ((BytesPerScanline + 1) * IHDR_Height)))
    {
        return(qfalse);
    }

    /*
     *  Unfilter the image.
     */

    if(!UnfilterImage(DecompressedData, IHDR_Height, BytesPerScanline, BytesPerPixel))
    {
        return(qfalse);
    }

    /*
     *  Set the working pointers to the beginning of the buffers.
     */

    OutPtr = OutBuffer;
    DecompPtr = DecompressedData;

    /*
     *  Create the output image.
     */

    for(h = 0; h < IHDR_Height; h++)
    {
        /*
         *  Count the pixels on the scanline for those multipixel bytes
         */

        uint32_t CurrPixel;

        /*
         *  skip FilterType
         */

        DecompPtr++;

        /*
         *  Reset the pixel count.
         */

        CurrPixel = 0;

        for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
        {
        if(PixelsPerByte > 1)
        {
                uint8_t  Mask;
                uint32_t Shift;
        uint8_t  SinglePixel;

                for(p = 0; p < PixelsPerByte; p++)
                {
                    if(CurrPixel < IHDR_Width)
                    {
                        Mask  = (1 << IHDR->BitDepth) - 1;
                        Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;

                        SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);

            if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
            {
                return(qfalse);
            }

                        OutPtr += Q3IMAGE_BYTESPERPIXEL;
                        CurrPixel++;
                    }
                }

        }
        else
        {
        if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
        {
            return(qfalse);
        }


                OutPtr += Q3IMAGE_BYTESPERPIXEL;
        }

            DecompPtr += BytesPerPixel;
        }
    }

    return(qtrue);
}

/*
 *  Decode an interlaced image.
 */

static qboolean DecodeImageInterlaced(struct PNG_Chunk_IHDR *IHDR,
                                      byte                  *OutBuffer,
                                      uint8_t               *DecompressedData,
                                      uint32_t               DecompressedDataLength,
                                      qboolean               HasTransparentColour,
                                      uint8_t               *TransparentColour,
                                      uint8_t               *OutPal)
{
    uint32_t IHDR_Width;
    uint32_t IHDR_Height;
    uint32_t BytesPerScanline[PNG_Adam7_NumPasses], BytesPerPixel, PixelsPerByte;
    uint32_t PassWidth[PNG_Adam7_NumPasses], PassHeight[PNG_Adam7_NumPasses];
    uint32_t WSkip[PNG_Adam7_NumPasses], WOffset[PNG_Adam7_NumPasses], HSkip[PNG_Adam7_NumPasses], HOffset[PNG_Adam7_NumPasses];
    uint32_t w, h, p, a;
    byte *OutPtr;
    uint8_t *DecompPtr;
    uint32_t TargetLength;

    /*
     *  input verification
     */

    if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
    {
    return(qfalse);
    }

    /*
     *  byte swapping
     */

    IHDR_Width  = BigLong(IHDR->Width);
    IHDR_Height = BigLong(IHDR->Height);

    /*
     *  Skip and Offset for the passes.
     */

    WSkip[0]   = 8;
    WOffset[0] = 0;
    HSkip[0]   = 8;
    HOffset[0] = 0;

    WSkip[1]   = 8;
    WOffset[1] = 4;
    HSkip[1]   = 8;
    HOffset[1] = 0;

    WSkip[2]   = 4;
    WOffset[2] = 0;
    HSkip[2]   = 8;
    HOffset[2] = 4;

    WSkip[3]   = 4;
    WOffset[3] = 2;
    HSkip[3]   = 4;
    HOffset[3] = 0;

    WSkip[4]   = 2;
    WOffset[4] = 0;
    HSkip[4]   = 4;
    HOffset[4] = 2;

    WSkip[5]   = 2;
    WOffset[5] = 1;
    HSkip[5]   = 2;
    HOffset[5] = 0;

    WSkip[6]   = 1;
    WOffset[6] = 0;
    HSkip[6]   = 2;
    HOffset[6] = 1;

    /*
     *  Calculate the sizes of the passes.
     */

    PassWidth[0]  = (IHDR_Width  + 7) / 8;
    PassHeight[0] = (IHDR_Height + 7) / 8;

    PassWidth[1]  = (IHDR_Width  + 3) / 8;
    PassHeight[1] = (IHDR_Height + 7) / 8;

    PassWidth[2]  = (IHDR_Width  + 3) / 4;
    PassHeight[2] = (IHDR_Height + 3) / 8;

    PassWidth[3]  = (IHDR_Width  + 1) / 4;
    PassHeight[3] = (IHDR_Height + 3) / 4;

    PassWidth[4]  = (IHDR_Width  + 1) / 2;
    PassHeight[4] = (IHDR_Height + 1) / 4;

    PassWidth[5]  = (IHDR_Width  + 0) / 2;
    PassHeight[5] = (IHDR_Height + 1) / 2;

    PassWidth[6]  = (IHDR_Width  + 0) / 1;
    PassHeight[6] = (IHDR_Height + 0) / 2;

    /*
     *  information for un-filtering
     */

    switch(IHDR->ColourType)
    {
        case PNG_ColourType_Grey :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_1 :
                case PNG_BitDepth_2 :
                case PNG_BitDepth_4 :
                {
                    BytesPerPixel    = 1;
                    PixelsPerByte    = 8 / IHDR->BitDepth;

                    break;
                }

                case PNG_BitDepth_8  :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_True :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8  :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_Indexed :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_1 :
                case PNG_BitDepth_2 :
                case PNG_BitDepth_4 :
                {
                    BytesPerPixel    = 1;
                    PixelsPerByte    = 8 / IHDR->BitDepth;

                    break;
                }

                case PNG_BitDepth_8 :
                {
                    BytesPerPixel    = PNG_NumColourComponents_Indexed;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_GreyAlpha :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        case PNG_ColourType_TrueAlpha :
        {
            switch(IHDR->BitDepth)
            {
                case PNG_BitDepth_8 :
                case PNG_BitDepth_16 :
                {
                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
                    PixelsPerByte    = 1;

                    break;
                }

                default :
                {
                    return(qfalse);
                }
            }

            break;
        }

        default :
        {
            return(qfalse);
        }
    }

    /*
     *  Calculate the size of the scanlines per pass
     */

    for(a = 0; a < PNG_Adam7_NumPasses; a++)
    {
    BytesPerScanline[a] = (PassWidth[a] * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
    }

    /*
     *  Calculate the size of all passes
     */

    TargetLength = 0;

    for(a = 0; a < PNG_Adam7_NumPasses; a++)
    {
    TargetLength += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
    }

    /*
     *  Check if we have enough data for the whole image.
     */

    if(!(DecompressedDataLength == TargetLength))
    {
        return(qfalse);
    }

    /*
     *  Unfilter the image.
     */

    DecompPtr = DecompressedData;

    for(a = 0; a < PNG_Adam7_NumPasses; a++)
    {
        if(!UnfilterImage(DecompPtr, PassHeight[a], BytesPerScanline[a], BytesPerPixel))
        {
            return(qfalse);
        }

    DecompPtr += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
    }

    /*
     *  Set the working pointers to the beginning of the buffers.
     */

    DecompPtr = DecompressedData;

    /*
     *  Create the output image.
     */

    for(a = 0; a < PNG_Adam7_NumPasses; a++)
    {
        for(h = 0; h < PassHeight[a]; h++)
        {
            /*
             *  Count the pixels on the scanline for those multipixel bytes
             */

            uint32_t CurrPixel;

            /*
             *  skip FilterType
             */

            DecompPtr++;

            /*
             *  Reset the pixel count.
             */

            CurrPixel = 0;

            for(w = 0; w < (BytesPerScanline[a] / BytesPerPixel); w++)
            {
            if(PixelsPerByte > 1)
            {
                    uint8_t  Mask;
                    uint32_t Shift;
            uint8_t  SinglePixel;

                    for(p = 0; p < PixelsPerByte; p++)
                    {
                        if(CurrPixel < PassWidth[a])
                        {
                            Mask  = (1 << IHDR->BitDepth) - 1;
                            Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;

                            SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);

                    OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((CurrPixel * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);

                    if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
                {
                    return(qfalse);
                }

                            CurrPixel++;
                        }
                    }

            }
                else
            {
                OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((w * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);

            if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
            {
                return(qfalse);
            }
            }

                DecompPtr += BytesPerPixel;
            }
        }
    }

    return(qtrue);
}

/*
 *  The PNG loader
 */

static void LoadPNG(const char *name, byte **pic, int *width, int *height)
{
    struct BufferedFile *ThePNG;
    byte *OutBuffer;
    uint8_t *Signature;
    struct PNG_ChunkHeader *CH;
    uint32_t ChunkHeaderLength;
    uint32_t ChunkHeaderType;
    struct PNG_Chunk_IHDR *IHDR;
    uint32_t IHDR_Width;
    uint32_t IHDR_Height;
    PNG_ChunkCRC *CRC;
    uint8_t *InPal;
    uint8_t *DecompressedData;
    uint32_t DecompressedDataLength;
    uint32_t i;

    /*
     *  palette with 256 RGBA entries
     */

    uint8_t OutPal[1024];

    /*
     *  transparent colour from the tRNS chunk
     */

    qboolean HasTransparentColour = qfalse;
    uint8_t TransparentColour[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

    /*
     *  input verification
     */

    if(!(name && pic))
    {
        return;
    }

    /*
     *  Zero out return values.
     */

    *pic = NULL;

    if(width)
    {
        *width = 0;
    }

    if(height)
    {
        *height = 0;
    }

    /*
     *  Read the file.
     */

    ThePNG = ReadBufferedFile(name);
    if(!ThePNG)
    {
        return;
    }

    /*
     *  Read the siganture of the file.
     */

    Signature = BufferedFileRead(ThePNG, PNG_Signature_Size);
    if(!Signature)
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Is it a PNG?
     */

    if(memcmp(Signature, PNG_Signature, PNG_Signature_Size))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Read the first chunk-header.
     */

    CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
    if(!CH)
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  PNG multi-byte types are in Big Endian
     */

    ChunkHeaderLength = BigLong(CH->Length);
    ChunkHeaderType   = BigLong(CH->Type);

    /*
     *  Check if the first chunk is an IHDR.
     */

    if(!((ChunkHeaderType == PNG_ChunkType_IHDR) && (ChunkHeaderLength == PNG_Chunk_IHDR_Size)))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Read the IHDR.
     */

    IHDR = BufferedFileRead(ThePNG, PNG_Chunk_IHDR_Size);
    if(!IHDR)
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Read the CRC for IHDR
     */

    CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
    if(!CRC)
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Here we could check the CRC if we wanted to.
     */

    /*
     *  multi-byte type swapping
     */

    IHDR_Width  = BigLong(IHDR->Width);
    IHDR_Height = BigLong(IHDR->Height);

    /*
     *  Check if Width and Height are valid.
     */

    if(!((IHDR_Width > 0) && (IHDR_Height > 0)))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Do we need to check if the dimensions of the image are valid for Quake3?
     */

    /*
     *  Check if CompressionMethod and FilterMethod are valid.
     */

    if(!((IHDR->CompressionMethod == PNG_CompressionMethod_0) && (IHDR->FilterMethod == PNG_FilterMethod_0)))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Check if InterlaceMethod is valid.
     */

    if(!((IHDR->InterlaceMethod == PNG_InterlaceMethod_NonInterlaced)  || (IHDR->InterlaceMethod == PNG_InterlaceMethod_Interlaced)))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Read palette for an indexed image.
     */

    if(IHDR->ColourType == PNG_ColourType_Indexed)
    {
        /*
         *  We need the palette first.
         */

        if(!FindChunk(ThePNG, PNG_ChunkType_PLTE))
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Read the chunk-header.
         */

        CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
        if(!CH)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  PNG multi-byte types are in Big Endian
         */

        ChunkHeaderLength = BigLong(CH->Length);
        ChunkHeaderType   = BigLong(CH->Type);

        /*
         *  Check if the chunk is an PLTE.
         */

        if(!(ChunkHeaderType == PNG_ChunkType_PLTE))
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Check if Length is divisible by 3
         */

        if(ChunkHeaderLength % 3)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Read the raw palette data
         */

        InPal = BufferedFileRead(ThePNG, ChunkHeaderLength);
        if(!InPal)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Read the CRC for the palette
         */

        CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
        if(!CRC)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Set some default values.
         */

        for(i = 0; i < 256; i++)
        {
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = 0x00;
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = 0x00;
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = 0x00;
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;
        }

        /*
         *  Convert to the Quake3 RGBA-format.
         */

        for(i = 0; i < (ChunkHeaderLength / 3); i++)
        {
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = InPal[i*3+0];
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = InPal[i*3+1];
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = InPal[i*3+2];
            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;
        }
    }

    /*
     *  transparency information is sometimes stored in an tRNS chunk
     */

    /*
     *  Let's see if there is a tRNS chunk
     */

    if(FindChunk(ThePNG, PNG_ChunkType_tRNS))
    {
        uint8_t *Trans;

        /*
         *  Read the chunk-header.
         */

        CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
        if(!CH)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  PNG multi-byte types are in Big Endian
         */

        ChunkHeaderLength = BigLong(CH->Length);
        ChunkHeaderType   = BigLong(CH->Type);

        /*
         *  Check if the chunk is an tRNS.
         */

        if(!(ChunkHeaderType == PNG_ChunkType_tRNS))
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Read the transparency information.
         */

        Trans = BufferedFileRead(ThePNG, ChunkHeaderLength);
        if(!Trans)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Read the CRC.
         */

        CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
        if(!CRC)
        {
            CloseBufferedFile(ThePNG);

            return;
        }

        /*
         *  Only for Grey, True and Indexed ColourType should tRNS exist.
         */

        switch(IHDR->ColourType)
        {
            case PNG_ColourType_Grey :
            {
                if(!ChunkHeaderLength == 2)
                {
                    CloseBufferedFile(ThePNG);

                    return;
                }

                HasTransparentColour = qtrue;

        /*
         *  Grey can have one colour which is completely transparent.
         *  This colour is always stored in 16 bits.
         */

                TransparentColour[0] = Trans[0];
                TransparentColour[1] = Trans[1];

                break;
            }

            case PNG_ColourType_True :
            {
                if(!ChunkHeaderLength == 6)
                {
                    CloseBufferedFile(ThePNG);

                    return;
                }

                HasTransparentColour = qtrue;

        /*
         *  True can have one colour which is completely transparent.
         *  This colour is always stored in 16 bits.
         */

                TransparentColour[0] = Trans[0];
                TransparentColour[1] = Trans[1];
                TransparentColour[2] = Trans[2];
                TransparentColour[3] = Trans[3];
                TransparentColour[4] = Trans[4];
                TransparentColour[5] = Trans[5];

                break;
            }

            case PNG_ColourType_Indexed :
            {
                /*
         *  Maximum of 256 one byte transparency entries.
         */

        if(ChunkHeaderLength > 256)
                {
                    CloseBufferedFile(ThePNG);

                    return;
                }

                HasTransparentColour = qtrue;

                /*
                 *  alpha values for palette entries
                 */

                for(i = 0; i < ChunkHeaderLength; i++)
                {
                    OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = Trans[i];
                }

                break;
            }

            /*
             *  All other ColourTypes should not have tRNS chunks
             */

            default :
            {
                CloseBufferedFile(ThePNG);

                return;
            }
        }
    }

    /*
     *  Rewind to the start of the file.
     */

    if(!BufferedFileRewind(ThePNG, -1))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Skip the signature
     */

    if(!BufferedFileSkip(ThePNG, PNG_Signature_Size))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Decompress all IDAT chunks
     */

    DecompressedDataLength = DecompressIDATs(ThePNG, &DecompressedData);
    if(!(DecompressedDataLength && DecompressedData))
    {
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Allocate output buffer.
     */

    OutBuffer = ri.Malloc(IHDR_Width * IHDR_Height * Q3IMAGE_BYTESPERPIXEL);
    if(!OutBuffer)
    {
        ri.Free(DecompressedData);
        CloseBufferedFile(ThePNG);

        return;
    }

    /*
     *  Interlaced and Non-interlaced images need to be handled differently.
     */

    switch(IHDR->InterlaceMethod)
    {
    case PNG_InterlaceMethod_NonInterlaced :
    {
        if(!DecodeImageNonInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
        {
        ri.Free(OutBuffer);
            ri.Free(DecompressedData);
            CloseBufferedFile(ThePNG);

        return;
        }

        break;
    }

    case PNG_InterlaceMethod_Interlaced :
    {
        if(!DecodeImageInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
        {
        ri.Free(OutBuffer);
            ri.Free(DecompressedData);
            CloseBufferedFile(ThePNG);

        return;
        }

        break;
    }

    default :
    {
        ri.Free(OutBuffer);
            ri.Free(DecompressedData);
            CloseBufferedFile(ThePNG);

        return;
    }
    }

    /*
     *  update the pointer to the image data
     */

    *pic = OutBuffer;

    /*
     *  Fill width and height.
     */

    if(width)
    {
        *width = IHDR_Width;
    }

    if(height)
    {
        *height = IHDR_Height;
    }

    /*
     *  DecompressedData is not needed anymore.
     */

    ri.Free(DecompressedData);

    /*
     *  We have all data, so close the file.
     */

    CloseBufferedFile(ThePNG);
}

//===================================================================

typedef struct
{
    char *ext;
    void (*ImageLoader)( const char *, unsigned char **, int *, int * );
} imageExtToLoaderMap_t;

// Note that the ordering indicates the order of preference used
// when there are multiple images of different formats available
static imageExtToLoaderMap_t imageLoaders[ ] =
{
    { "tga",  LoadTGA },
    { "jpg",  LoadJPG },
    { "jpeg", LoadJPG },
    { "png",  LoadPNG },
    { "pcx",  LoadPCX32 },
    { "bmp",  LoadBMP }
};

static int numImageLoaders = sizeof( imageLoaders ) /
        sizeof( imageLoaders[ 0 ] );

/*
=================
R_LoadImage

Loads any of the supported image types into a cannonical
32 bit format.
=================
*/
void R_LoadImage( const char *name, byte **pic, int *width, int *height )
{
    qboolean orgNameFailed = qfalse;
    int i;
    char localName[ MAX_QPATH ];
    const char *ext;

    *pic = NULL;
    *width = 0;
    *height = 0;

    Q_strncpyz( localName, name, MAX_QPATH );

    ext = COM_GetExtension( localName );

    if( *ext )
    {
        // Look for the correct loader and use it
        for( i = 0; i < numImageLoaders; i++ )
        {
            if( !Q_stricmp( ext, imageLoaders[ i ].ext ) )
            {
                // Load
                imageLoaders[ i ].ImageLoader( localName, pic, width, height );
                break;
            }
        }

        // A loader was found
        if( i < numImageLoaders )
        {
            if( *pic == NULL )
            {
                // Loader failed, most likely because the file isn't there;
                // try again without the extension
                orgNameFailed = qtrue;
                COM_StripExtension( name, localName, MAX_QPATH );
            }
            else
            {
                // Something loaded
                return;
            }
        }
    }

    // Try and find a suitable match using all
    // the image formats supported
    for( i = 0; i < numImageLoaders; i++ )
    {
        char *altName = va( "%s.%s", localName, imageLoaders[ i ].ext );

        // Load
        imageLoaders[ i ].ImageLoader( altName, pic, width, height );

        if( *pic )
        {
            if( orgNameFailed )
            {
                ri.Printf( PRINT_DEVELOPER, "WARNING: %s not present, using %s instead\n",
                        name, altName );
            }

            break;
        }
    }
}


/*
===============
R_FindImageFile

Finds or loads the given image.
Returns NULL if it fails, not a default image.
==============
*/
image_t *R_FindImageFile( const char *name, qboolean mipmap, qboolean allowPicmip, int glWrapClampMode ) {
    image_t *image;
    int     width, height;
    byte    *pic;
    long    hash;

    if (!name) {
        return NULL;
    }

    hash = generateHashValue(name);

    //
    // see if the image is already loaded
    //
    for (image=hashTable[hash]; image; image=image->next) {
        if ( !strcmp( name, image->imgName ) ) {
            // the white image can be used with any set of parms, but other mismatches are errors
            if ( strcmp( name, "*white" ) ) {
                if ( image->mipmap != mipmap ) {
                    ri.Printf( PRINT_DEVELOPER, "WARNING: reused image %s with mixed mipmap parm\n", name );
                }
                if ( image->allowPicmip != allowPicmip ) {
                    ri.Printf( PRINT_DEVELOPER, "WARNING: reused image %s with mixed allowPicmip parm\n", name );
                }
                if ( image->wrapClampMode != glWrapClampMode ) {
                    ri.Printf( PRINT_ALL, "WARNING: reused image %s with mixed glWrapClampMode parm\n", name );
                }
            }
            return image;
        }
    }

    //
    // load the pic from disk
    //
    R_LoadImage( name, &pic, &width, &height );
    if ( pic == NULL ) {
        return NULL;
    }

    image = R_CreateImage( ( char * ) name, pic, width, height, mipmap, allowPicmip, glWrapClampMode );
    ri.Free( pic );
    return image;
}


/*
================
R_CreateDlightImage
================
*/
#define DLIGHT_SIZE 16
static void R_CreateDlightImage( void ) {
    int     x,y;
    byte    data[DLIGHT_SIZE][DLIGHT_SIZE][4];
    int     b;

    // make a centered inverse-square falloff blob for dynamic lighting
    for (x=0 ; x<DLIGHT_SIZE ; x++) {
        for (y=0 ; y<DLIGHT_SIZE ; y++) {
            float   d;

            d = ( DLIGHT_SIZE/2 - 0.5f - x ) * ( DLIGHT_SIZE/2 - 0.5f - x ) +
                ( DLIGHT_SIZE/2 - 0.5f - y ) * ( DLIGHT_SIZE/2 - 0.5f - y );
            b = 4000 / d;
            if (b > 255) {
                b = 255;
            } else if ( b < 75 ) {
                b = 0;
            }
            data[y][x][0] =
            data[y][x][1] =
            data[y][x][2] = b;
            data[y][x][3] = 255;
        }
    }
    tr.dlightImage = R_CreateImage("*dlight", (byte *)data, DLIGHT_SIZE, DLIGHT_SIZE, qfalse, qfalse, GL_CLAMP );
}


/*
=================
R_InitFogTable
=================
*/
void R_InitFogTable( void ) {
    int     i;
    float   d;
    float   exp;

    exp = 0.5;

    for ( i = 0 ; i < FOG_TABLE_SIZE ; i++ ) {
        d = pow ( (float)i/(FOG_TABLE_SIZE-1), exp );

        tr.fogTable[i] = d;
    }
}

/*
================
R_FogFactor

Returns a 0.0 to 1.0 fog density value
This is called for each texel of the fog texture on startup
and for each vertex of transparent shaders in fog dynamically
================
*/
float   R_FogFactor( float s, float t ) {
    float   d;

    s -= 1.0/512;
    if ( s < 0 ) {
        return 0;
    }
    if ( t < 1.0/32 ) {
        return 0;
    }
    if ( t < 31.0/32 ) {
        s *= (t - 1.0f/32.0f) / (30.0f/32.0f);
    }

    // we need to leave a lot of clamp range
    s *= 8;

    if ( s > 1.0 ) {
        s = 1.0;
    }

    d = tr.fogTable[ (int)(s * (FOG_TABLE_SIZE-1)) ];

    return d;
}

/*
================
R_CreateFogImage
================
*/
#define FOG_S   256
#define FOG_T   32
static void R_CreateFogImage( void ) {
    int     x,y;
    byte    *data;
    float   g;
    float   d;
    float   borderColor[4];

    data = ri.Hunk_AllocateTempMemory( FOG_S * FOG_T * 4 );

    g = 2.0;

    // S is distance, T is depth
    for (x=0 ; x<FOG_S ; x++) {
        for (y=0 ; y<FOG_T ; y++) {
            d = R_FogFactor( ( x + 0.5f ) / FOG_S, ( y + 0.5f ) / FOG_T );

            data[(y*FOG_S+x)*4+0] =
            data[(y*FOG_S+x)*4+1] =
            data[(y*FOG_S+x)*4+2] = 255;
            data[(y*FOG_S+x)*4+3] = 255*d;
        }
    }
    // standard openGL clamping doesn't really do what we want -- it includes
    // the border color at the edges.  OpenGL 1.2 has clamp-to-edge, which does
    // what we want.
    tr.fogImage = R_CreateImage("*fog", (byte *)data, FOG_S, FOG_T, qfalse, qfalse, GL_CLAMP );
    ri.Hunk_FreeTempMemory( data );

    borderColor[0] = 1.0;
    borderColor[1] = 1.0;
    borderColor[2] = 1.0;
    borderColor[3] = 1;

    qglTexParameterfv( GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor );
}

/*
==================
R_CreateDefaultImage
==================
*/
#define DEFAULT_SIZE    16
static void R_CreateDefaultImage( void ) {
    int     x;
    byte    data[DEFAULT_SIZE][DEFAULT_SIZE][4];

    // the default image will be a box, to allow you to see the mapping coordinates
    Com_Memset( data, 32, sizeof( data ) );
    for ( x = 0 ; x < DEFAULT_SIZE ; x++ ) {
        data[0][x][0] =
        data[0][x][1] =
        data[0][x][2] =
        data[0][x][3] = 255;

        data[x][0][0] =
        data[x][0][1] =
        data[x][0][2] =
        data[x][0][3] = 255;

        data[DEFAULT_SIZE-1][x][0] =
        data[DEFAULT_SIZE-1][x][1] =
        data[DEFAULT_SIZE-1][x][2] =
        data[DEFAULT_SIZE-1][x][3] = 255;

        data[x][DEFAULT_SIZE-1][0] =
        data[x][DEFAULT_SIZE-1][1] =
        data[x][DEFAULT_SIZE-1][2] =
        data[x][DEFAULT_SIZE-1][3] = 255;
    }
    tr.defaultImage = R_CreateImage("*default", (byte *)data, DEFAULT_SIZE, DEFAULT_SIZE, qtrue, qfalse, GL_REPEAT );
}

/*
==================
R_CreateBuiltinImages
==================
*/
void R_CreateBuiltinImages( void ) {
    int     x,y;
    byte    data[DEFAULT_SIZE][DEFAULT_SIZE][4];

    R_CreateDefaultImage();

    // we use a solid white image instead of disabling texturing
    Com_Memset( data, 255, sizeof( data ) );
    tr.whiteImage = R_CreateImage("*white", (byte *)data, 8, 8, qfalse, qfalse, GL_REPEAT );

    // with overbright bits active, we need an image which is some fraction of full color,
    // for default lightmaps, etc
    for (x=0 ; x<DEFAULT_SIZE ; x++) {
        for (y=0 ; y<DEFAULT_SIZE ; y++) {
            data[y][x][0] =
            data[y][x][1] =
            data[y][x][2] = tr.identityLightByte;
            data[y][x][3] = 255;
        }
    }

    tr.identityLightImage = R_CreateImage("*identityLight", (byte *)data, 8, 8, qfalse, qfalse, GL_REPEAT );


    for(x=0;x<32;x++) {
        // scratchimage is usually used for cinematic drawing
        tr.scratchImage[x] = R_CreateImage("*scratch", (byte *)data, DEFAULT_SIZE, DEFAULT_SIZE, qfalse, qtrue, GL_CLAMP );
    }

    R_CreateDlightImage();
    R_CreateFogImage();
}


/*
===============
R_SetColorMappings
===============
*/
void R_SetColorMappings( void ) {
    int     i, j;
    float   g;
    int     inf;
    int     shift;

    // setup the overbright lighting
    tr.overbrightBits = r_overBrightBits->integer;
    if ( !glConfig.deviceSupportsGamma ) {
        tr.overbrightBits = 0;      // need hardware gamma for overbright
    }

    // never overbright in windowed mode
    if ( !glConfig.isFullscreen )
    {
        tr.overbrightBits = 0;
    }

    // allow 2 overbright bits in 24 bit, but only 1 in 16 bit
    if ( glConfig.colorBits > 16 ) {
        if ( tr.overbrightBits > 2 ) {
            tr.overbrightBits = 2;
        }
    } else {
        if ( tr.overbrightBits > 1 ) {
            tr.overbrightBits = 1;
        }
    }
    if ( tr.overbrightBits < 0 ) {
        tr.overbrightBits = 0;
    }

    tr.identityLight = 1.0f / ( 1 << tr.overbrightBits );
    tr.identityLightByte = 255 * tr.identityLight;


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

    if ( r_gamma->value < 0.5f ) {
        ri.Cvar_Set( "r_gamma", "0.5" );
    } else if ( r_gamma->value > 3.0f ) {
        ri.Cvar_Set( "r_gamma", "3.0" );
    }

    g = r_gamma->value;

    shift = tr.overbrightBits;

    for ( i = 0; i < 256; i++ ) {
        if ( g == 1 ) {
            inf = i;
        } else {
            inf = 255 * pow ( i/255.0f, 1.0f / g ) + 0.5f;
        }
        inf <<= shift;
        if (inf < 0) {
            inf = 0;
        }
        if (inf > 255) {
            inf = 255;
        }
        s_gammatable[i] = inf;
    }

    for (i=0 ; i<256 ; i++) {
        j = i * r_intensity->value;
        if (j > 255) {
            j = 255;
        }
        s_intensitytable[i] = j;
    }

    if ( glConfig.deviceSupportsGamma )
    {
        GLimp_SetGamma( s_gammatable, s_gammatable, s_gammatable );
    }
}

/*
===============
R_InitImages
===============
*/
void    R_InitImages( void ) {
    Com_Memset(hashTable, 0, sizeof(hashTable));
    // build brightness translation tables
    R_SetColorMappings();

    // create default texture and white texture
    R_CreateBuiltinImages();
}

/*
===============
R_DeleteTextures
===============
*/
void R_DeleteTextures( void ) {
    int     i;

    for ( i=0; i<tr.numImages ; i++ ) {
        qglDeleteTextures( 1, &tr.images[i]->texnum );
    }
    Com_Memset( tr.images, 0, sizeof( tr.images ) );

    tr.numImages = 0;

    Com_Memset( glState.currenttextures, 0, sizeof( glState.currenttextures ) );
    if ( qglActiveTextureARB ) {
        GL_SelectTexture( 1 );
        qglBindTexture( GL_TEXTURE_2D, 0 );
        GL_SelectTexture( 0 );
        qglBindTexture( GL_TEXTURE_2D, 0 );
    } else {
        qglBindTexture( GL_TEXTURE_2D, 0 );
    }
}

/*
============================================================================

SKINS

============================================================================
*/

/*
==================
CommaParse

This is unfortunate, but the skin files aren't
compatable with our normal parsing rules.
==================
*/
static char *CommaParse( char **data_p ) {
    int c = 0, len;
    char *data;
    static  char    com_token[MAX_TOKEN_CHARS];

    data = *data_p;
    len = 0;
    com_token[0] = 0;

    // make sure incoming data is valid
    if ( !data ) {
        *data_p = NULL;
        return com_token;
    }

    while ( 1 ) {
        // skip whitespace
        while( (c = *data) <= ' ') {
            if( !c ) {
                break;
            }
            data++;
        }


        c = *data;

        // skip double slash comments
        if ( c == '/' && data[1] == '/' )
        {
            while (*data && *data != '\n')
                data++;
        }
        // skip /* */ comments
        else if ( c=='/' && data[1] == '*' )
        {
            while ( *data && ( *data != '*' || data[1] != '/' ) )
            {
                data++;
            }
            if ( *data )
            {
                data += 2;
            }
        }
        else
        {
            break;
        }
    }

    if ( c == 0 ) {
        return "";
    }

    // handle quoted strings
    if (c == '\"')
    {
        data++;
        while (1)
        {
            c = *data++;
            if (c=='\"' || !c)
            {
                com_token[len] = 0;
                *data_p = ( char * ) data;
                return com_token;
            }
            if (len < MAX_TOKEN_CHARS)
            {
                com_token[len] = c;
                len++;
            }
        }
    }

    // parse a regular word
    do
    {
        if (len < MAX_TOKEN_CHARS)
        {
            com_token[len] = c;
            len++;
        }
        data++;
        c = *data;
    } while (c>32 && c != ',' );

    if (len == MAX_TOKEN_CHARS)
    {
//      Com_Printf ("Token exceeded %i chars, discarded.\n", MAX_TOKEN_CHARS);
        len = 0;
    }
    com_token[len] = 0;

    *data_p = ( char * ) data;
    return com_token;
}


/*
===============
RE_RegisterSkin

===============
*/
qhandle_t RE_RegisterSkin( const char *name ) {
    qhandle_t   hSkin;
    skin_t      *skin;
    skinSurface_t   *surf;
    char        *text, *text_p;
    char        *token;
    char        surfName[MAX_QPATH];

    if ( !name || !name[0] ) {
        Com_Printf( "Empty name passed to RE_RegisterSkin\n" );
        return 0;
    }

    if ( strlen( name ) >= MAX_QPATH ) {
        Com_Printf( "Skin name exceeds MAX_QPATH\n" );
        return 0;
    }


    // see if the skin is already loaded
    for ( hSkin = 1; hSkin < tr.numSkins ; hSkin++ ) {
        skin = tr.skins[hSkin];
        if ( !Q_stricmp( skin->name, name ) ) {
            if( skin->numSurfaces == 0 ) {
                return 0;       // default skin
            }
            return hSkin;
        }
    }

    // allocate a new skin
    if ( tr.numSkins == MAX_SKINS ) {
        ri.Printf( PRINT_WARNING, "WARNING: RE_RegisterSkin( '%s' ) MAX_SKINS hit\n", name );
        return 0;
    }
    tr.numSkins++;
    skin = ri.Hunk_Alloc( sizeof( skin_t ), h_low );
    tr.skins[hSkin] = skin;
    Q_strncpyz( skin->name, name, sizeof( skin->name ) );
    skin->numSurfaces = 0;

    // make sure the render thread is stopped
    R_SyncRenderThread();

    // If not a .skin file, load as a single shader
    if ( strcmp( name + strlen( name ) - 5, ".skin" ) ) {
        skin->numSurfaces = 1;
        skin->surfaces[0] = ri.Hunk_Alloc( sizeof(skin->surfaces[0]), h_low );
        skin->surfaces[0]->shader = R_FindShader( name, LIGHTMAP_NONE, qtrue );
        return hSkin;
    }

    // load and parse the skin file
    ri.FS_ReadFile( name, (void **)&text );
    if ( !text ) {
        return 0;
    }

    text_p = text;
    while ( text_p && *text_p ) {
        // get surface name
        token = CommaParse( &text_p );
        Q_strncpyz( surfName, token, sizeof( surfName ) );

        if ( !token[0] ) {
            break;
        }
        // lowercase the surface name so skin compares are faster
        Q_strlwr( surfName );

        if ( *text_p == ',' ) {
            text_p++;
        }

        if ( strstr( token, "tag_" ) ) {
            continue;
        }

        // parse the shader name
        token = CommaParse( &text_p );

        surf = skin->surfaces[ skin->numSurfaces ] = ri.Hunk_Alloc( sizeof( *skin->surfaces[0] ), h_low );
        Q_strncpyz( surf->name, surfName, sizeof( surf->name ) );
        surf->shader = R_FindShader( token, LIGHTMAP_NONE, qtrue );
        skin->numSurfaces++;
    }

    ri.FS_FreeFile( text );


    // never let a skin have 0 shaders
    if ( skin->numSurfaces == 0 ) {
        return 0;       // use default skin
    }

    return hSkin;
}


/*
===============
R_InitSkins
===============
*/
void    R_InitSkins( void ) {
    skin_t      *skin;

    tr.numSkins = 1;

    // make the default skin have all default shaders
    skin = tr.skins[0] = ri.Hunk_Alloc( sizeof( skin_t ), h_low );
    Q_strncpyz( skin->name, "<default skin>", sizeof( skin->name )  );
    skin->numSurfaces = 1;
    skin->surfaces[0] = ri.Hunk_Alloc( sizeof( *skin->surfaces ), h_low );
    skin->surfaces[0]->shader = tr.defaultShader;
}

/*
===============
R_GetSkinByHandle
===============
*/
skin_t  *R_GetSkinByHandle( qhandle_t hSkin ) {
    if ( hSkin < 1 || hSkin >= tr.numSkins ) {
        return tr.skins[0];
    }
    return tr.skins[ hSkin ];
}

/*
===============
R_SkinList_f
===============
*/
void    R_SkinList_f( void ) {
    int         i, j;
    skin_t      *skin;

    ri.Printf (PRINT_ALL, "------------------\n");

    for ( i = 0 ; i < tr.numSkins ; i++ ) {
        skin = tr.skins[i];

        ri.Printf( PRINT_ALL, "%3i:%s\n", i, skin->name );
        for ( j = 0 ; j < skin->numSurfaces ; j++ ) {
            ri.Printf( PRINT_ALL, "       %s = %s\n",
                skin->surfaces[j]->name, skin->surfaces[j]->shader->name );
        }
    }
    ri.Printf (PRINT_ALL, "------------------\n");
}