/* $Id: ppm.c,v 1.2 2001-09-05 14:30:46 bird Exp $ */

/*
** THIS SOFTWARE IS SUBJECT TO COPYRIGHT PROTECTION AND IS OFFERED ONLY
** PURSUANT TO THE 3DFX GLIDE GENERAL PUBLIC LICENSE. THERE IS NO RIGHT
** TO USE THE GLIDE TRADEMARK WITHOUT PRIOR WRITTEN PERMISSION OF 3DFX
** INTERACTIVE, INC. A COPY OF THIS LICENSE MAY BE OBTAINED FROM THE
** DISTRIBUTOR OR BY CONTACTING 3DFX INTERACTIVE INC(info@3dfx.com).
** THIS PROGRAM IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
** EXPRESSED OR IMPLIED. SEE THE 3DFX GLIDE GENERAL PUBLIC LICENSE FOR A
** FULL TEXT OF THE NON-WARRANTY PROVISIONS.
**
** USE, DUPLICATION OR DISCLOSURE BY THE GOVERNMENT IS SUBJECT TO
** RESTRICTIONS AS SET FORTH IN SUBDIVISION (C)(1)(II) OF THE RIGHTS IN
** TECHNICAL DATA AND COMPUTER SOFTWARE CLAUSE AT DFARS 252.227-7013,
** AND/OR IN SIMILAR OR SUCCESSOR CLAUSES IN THE FAR, DOD OR NASA FAR
** SUPPLEMENT. UNPUBLISHED RIGHTS RESERVED UNDER THE COPYRIGHT LAWS OF
** THE UNITED STATES.
**
** COPYRIGHT 3DFX INTERACTIVE, INC. 1999, ALL RIGHTS RESERVED
**
** $Revision: 1.2 $
** $Date: 2001-09-05 14:30:46 $
**
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "texusint.h"


FxBool
_txReadPPMHeader( FILE *stream, FxU32 cookie, TxMip *info)
{
    char buffer[256];
    FxU32 state = 1;
    FxBool done = FXFALSE;

    if ( stream == NULL ) {
    txPanic("PPM file: Bad file handle.");
    return FXFALSE;
    }

    while( !done && fgets( buffer, 256, stream ) ) {
    char *token;

    if ( buffer[0] == '#' ) continue;
    for (token = strtok( buffer, " \t\n\r" ); token != NULL;
            token = strtok( NULL, " \t\n\r" )) {
        switch( state ) {
        case 1: // Width
            info->width = atoi( token );
            state++;
            break;

        case 2: // height
            info->height = atoi( token );
            state++;
            break;

        case 3: // Color Depth
            info->format = atoi( token );
            if ( info->format != 255 ) {
                txPanic("Unsupported PPM format: max != 255\n");
                    return FXFALSE;
            }
            state++;
            done = FXTRUE;
            break;

        default:
            txPanic("PPM file: parse error\n");
            return FXFALSE;
            break;
        }
    }
    }

    if ( state < 4 ) {
        txPanic("PPM file: Read error before end of header.");
    return FXFALSE;
    }
    info->depth = 1;
    info->format = GR_TEXFMT_ARGB_8888;
    info->size = info->width * info->height * 4;
    return FXTRUE;
}

FxBool
_txReadPPMData( FILE *stream, TxMip *info)
{
    FxU32 numPixels;
    FxU32 *data32 = info->data[0];

    numPixels = info->width * info->height;

    if ( stream == NULL ) {
    txPanic("PPM file: Bad file handle.");
    return FXFALSE;
    }

    // Read in image data
    while (numPixels--) {
    int r, g, b;

    r = getc( stream );
    g = getc( stream );
    b = getc( stream );
    if ( b == EOF ) {
        txPanic("PPM file: Unexpected End of File.");
        return FXFALSE;
    }
    *data32++ = (0xFF << 24) | (r << 16) | (g << 8) | b;
    }
    return FXTRUE;
}