/*
   Copyright (C) 1999-2006 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 <stdio.h>
#include "cmdlib.h"
#include "inout.h"
#include "mathlib.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;


void ByteSwapTri( tf_triangle *tri ){
	int i;

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

void LoadTriangleList( char *filename, triangle_t **pptri, int *numtriangles ){
	FILE        *input;
	float start;
	char name[256], tex[256];
	int i, count, magic;
	tf_triangle tri;
	triangle_t  *ptri;
	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 );
	}

	ptri = malloc( MAXTRIANGLES * sizeof( triangle_t ) );

	*pptri = ptri;

	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' );

//				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' );

//					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. */
				/* Mia culpa. */
				--iLevel;
				i = -1;
				do {
					++i;
					fread( &( name[i] ), sizeof( char ), 1, input );
				} while ( name[i] != '\0' );

//				indent();
//				fprintf(stdout,"OBJECT END: %s\n",name);
				continue;
			}
		}

//
// read the triangles
//
		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++;

			if ( ( ptri - *pptri ) >= MAXTRIANGLES ) {
				Error( "Error: too many triangles; increase MAXTRIANGLES\n" );
			}
		}
	}

	*numtriangles = ptri - *pptri;

	fclose( input );
}