worldspawn/tools/common/trilib.c

/*
   Copyright (C) 1999-2007 id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; 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 "globaldefs.h"
#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

#if GDEF_OS_LINUX || GDEF_OS_MACOS
#define strlwr strlower
#endif

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 ){
	unsigned 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 );
}