trilib.c

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/*
===========================================================================
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 Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
//
// trilib.c: library for loading triangles from an Alias triangle file
//

#include <stdio.h>
#include "cmdlib.h"
#include "mathlib.h"
#include "polyset.h"
#include "trilib.h"

// on disk representation of a face


#define FLOAT_START 99999.0
#define FLOAT_END   -FLOAT_START
#define MAGIC       123322

//#define NOISY 1

typedef struct {
    float v[3];
} vector;

typedef struct
{
    vector n;    /* normal */
    vector p;    /* point */
    vector c;    /* color */
    float  u;    /* u */
    float  v;    /* v */
} aliaspoint_t;

typedef struct {
    aliaspoint_t    pt[3];
} tf_triangle;


static void ByteSwapTri (tf_triangle *tri)
{
    int     i;
    
    for (i=0 ; i<sizeof(tf_triangle)/4 ; i++)
    {
        ((int *)tri)[i] = BigLong (((int *)tri)[i]);
    }
}

static void ReadPolysetGeometry( triangle_t *tripool, FILE *input, int count, triangle_t *ptri )
{
    tf_triangle tri;
    int i;

    for (i = 0; i < count; ++i) {
        int     j;

        fread( &tri, sizeof(tf_triangle), 1, input );
        ByteSwapTri (&tri);
        for (j=0 ; j<3 ; j++)
        {
            int     k;

            for (k=0 ; k<3 ; k++)
            {
                ptri->verts[j][k] = tri.pt[j].p.v[k];
                ptri->normals[j][k] = tri.pt[j].n.v[k];
//              ptri->colors[j][k] = tri.pt[j].c.v[k];
            }

            ptri->texcoords[j][0] = tri.pt[j].u;
            ptri->texcoords[j][1] = tri.pt[j].v;
        }

        ptri++;
        if ((ptri - tripool ) >= POLYSET_MAXTRIANGLES)
            Error ("Error: too many triangles; increase POLYSET_MAXTRIANGLES\n");
    }
}

void TRI_LoadPolysets( const char *filename, polyset_t **ppPSET, int *numpsets )
{
    FILE        *input;
    float       start;
    char        name[256], tex[256];
    int         i, count, magic, pset = 0;
    triangle_t  *ptri;
    polyset_t   *pPSET;
    int         iLevel;
    int         exitpattern;
    float       t;

    t = -FLOAT_START;
    *((unsigned char *)&exitpattern + 0) = *((unsigned char *)&t + 3);
    *((unsigned char *)&exitpattern + 1) = *((unsigned char *)&t + 2);
    *((unsigned char *)&exitpattern + 2) = *((unsigned char *)&t + 1);
    *((unsigned char *)&exitpattern + 3) = *((unsigned char *)&t + 0);

    if ((input = fopen(filename, "rb")) == 0)
        Error ("reader: could not open file '%s'", filename);

    iLevel = 0;

    fread(&magic, sizeof(int), 1, input);
    if (BigLong(magic) != MAGIC)
        Error ("%s is not a Alias object separated triangle file, magic number is wrong.", filename);

    pPSET = calloc( 1, POLYSET_MAXPOLYSETS * sizeof( polyset_t ) );
    ptri = calloc( 1, POLYSET_MAXTRIANGLES * sizeof( triangle_t ) );

    *ppPSET = pPSET;

    while (feof(input) == 0) {
        if (fread(&start,  sizeof(float), 1, input) < 1)
            break;
        *(int *)&start = BigLong(*(int *)&start);
        if (*(int *)&start != exitpattern)
        {
            if (start == FLOAT_START) {
                /* Start of an object or group of objects. */
                i = -1;
                do {
                    /* There are probably better ways to read a string from */
                    /* a file, but this does allow you to do error checking */
                    /* (which I'm not doing) on a per character basis.      */
                    ++i;
                    fread( &(name[i]), sizeof( char ), 1, input);
                } while( name[i] != '\0' );
    
                if ( i != 0 )
                    strncpy( pPSET[pset].name, name, sizeof( pPSET[pset].name ) - 1 );
                else
                    strcpy( pPSET[pset].name , "(unnamed)" );
                strlwr( pPSET[pset].name );

//              indent();
//              fprintf(stdout,"OBJECT START: %s\n",name);
                fread( &count, sizeof(int), 1, input);
                count = BigLong(count);
                ++iLevel;
                if (count != 0) {
//                  indent();
//                  fprintf(stdout,"NUMBER OF TRIANGLES: %d\n",count);
    
                    i = -1;
                    do {
                        ++i;
                        fread( &(tex[i]), sizeof( char ), 1, input);
                    } while( tex[i] != '\0' );

/*
                    if ( i != 0 )
                        strncpy( pPSET[pset].texname, tex, sizeof( pPSET[pset].texname ) - 1 );
                    else
                        strcpy( pPSET[pset].texname, "(unnamed)" );
                    strlwr( pPSET[pset].texname );
*/

//                  indent();
//                  fprintf(stdout,"  Object texture name: '%s'\n",tex);
                }
    
                /* Else (count == 0) this is the start of a group, and */
                /* no texture name is present. */
            }
            else if (start == FLOAT_END) {
                /* End of an object or group. Yes, the name should be */
                /* obvious from context, but it is in here just to be */
                /* safe and to provide a little extra information for */
                /* those who do not wish to write a recursive reader. */
                /* Mea culpa. */
                --iLevel;
                i = -1;
                do {
                    ++i;
                    fread( &(name[i]), sizeof( char ), 1, input);
                } while( name[i] != '\0' );

                if ( i != 0 )
                    strncpy( pPSET[pset].name, name, sizeof( pPSET[pset].name ) - 1 );
                else
                    strcpy( pPSET[pset].name , "(unnamed)" );

                strlwr( pPSET[pset].name );
    
//              indent();
//              fprintf(stdout,"OBJECT END: %s\n",name);
                continue;
            }
        }

//
// read the triangles
//      
        if ( count > 0 )
        {
            pPSET[pset].triangles = ptri;
            ReadPolysetGeometry( pPSET[0].triangles, input, count, ptri );
            ptri += count;
            pPSET[pset].numtriangles = count;
            if ( ++pset >= POLYSET_MAXPOLYSETS )
            {
                Error ("Error: too many polysets; increase POLYSET_MAXPOLYSETS\n");
            }
        }
    }

    *numpsets = pset;

    fclose (input);
}

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