1 /*
2    Copyright (C) 1999-2006 Id Software, Inc. and contributors.
3    For a list of contributors, see the accompanying CONTRIBUTORS file.
4 
5    This file is part of GtkRadiant.
6 
7    GtkRadiant is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2 of the License, or
10    (at your option) any later version.
11 
12    GtkRadiant is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with GtkRadiant; if not, write to the Free Software
19    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
20  */
21 //
22 // trilib.c: library for loading triangles from an Alias triangle file
23 //
24 
25 #include <stdio.h>
26 #include "cmdlib.h"
27 #include "inout.h"
28 #include "mathlib.h"
29 #include "trilib.h"
30 
31 // on disk representation of a face
32 
33 
34 #define FLOAT_START 99999.0
35 #define FLOAT_END   -FLOAT_START
36 #define MAGIC       123322
37 
38 //#define NOISY 1
39 
40 typedef struct {
41 	float v[3];
42 } vector;
43 
44 typedef struct
45 {
46 	vector n;    /* normal */
47 	vector p;    /* point */
48 	vector c;    /* color */
49 	float u;     /* u */
50 	float v;     /* v */
51 } aliaspoint_t;
52 
53 typedef struct {
54 	aliaspoint_t pt[3];
55 } tf_triangle;
56 
57 
ByteSwapTri(tf_triangle * tri)58 void ByteSwapTri( tf_triangle *tri ){
59 	int i;
60 
61 	for ( i = 0 ; i < sizeof( tf_triangle ) / 4 ; i++ )
62 	{
63 		( (int *)tri )[i] = BigLong( ( (int *)tri )[i] );
64 	}
65 }
66 
LoadTriangleList(char * filename,triangle_t ** pptri,int * numtriangles)67 void LoadTriangleList( char *filename, triangle_t **pptri, int *numtriangles ){
68 	FILE        *input;
69 	float start;
70 	char name[256], tex[256];
71 	int i, count, magic;
72 	tf_triangle tri;
73 	triangle_t  *ptri;
74 	int iLevel;
75 	int exitpattern;
76 	float t;
77 
78 	t = -FLOAT_START;
79 	*( (unsigned char *)&exitpattern + 0 ) = *( (unsigned char *)&t + 3 );
80 	*( (unsigned char *)&exitpattern + 1 ) = *( (unsigned char *)&t + 2 );
81 	*( (unsigned char *)&exitpattern + 2 ) = *( (unsigned char *)&t + 1 );
82 	*( (unsigned char *)&exitpattern + 3 ) = *( (unsigned char *)&t + 0 );
83 
84 	if ( ( input = fopen( filename, "rb" ) ) == 0 ) {
85 		Error( "reader: could not open file '%s'", filename );
86 	}
87 
88 	iLevel = 0;
89 
90 	fread( &magic, sizeof( int ), 1, input );
91 	if ( BigLong( magic ) != MAGIC ) {
92 		Error( "%s is not a Alias object separated triangle file, magic number is wrong.", filename );
93 	}
94 
95 	ptri = malloc( MAXTRIANGLES * sizeof( triangle_t ) );
96 
97 	*pptri = ptri;
98 
99 	while ( feof( input ) == 0 ) {
100 		if ( fread( &start,  sizeof( float ), 1, input ) < 1 ) {
101 			break;
102 		}
103 		*(int *)&start = BigLong( *(int *)&start );
104 		if ( *(int *)&start != exitpattern ) {
105 			if ( start == FLOAT_START ) {
106 				/* Start of an object or group of objects. */
107 				i = -1;
108 				do {
109 					/* There are probably better ways to read a string from */
110 					/* a file, but this does allow you to do error checking */
111 					/* (which I'm not doing) on a per character basis.      */
112 					++i;
113 					fread( &( name[i] ), sizeof( char ), 1, input );
114 				} while ( name[i] != '\0' );
115 
116 //				indent();
117 //				fprintf(stdout,"OBJECT START: %s\n",name);
118 				fread( &count, sizeof( int ), 1, input );
119 				count = BigLong( count );
120 				++iLevel;
121 				if ( count != 0 ) {
122 //					indent();
123 //					fprintf(stdout,"NUMBER OF TRIANGLES: %d\n",count);
124 
125 					i = -1;
126 					do {
127 						++i;
128 						fread( &( tex[i] ), sizeof( char ), 1, input );
129 					} while ( tex[i] != '\0' );
130 
131 //					indent();
132 //					fprintf(stdout,"  Object texture name: '%s'\n",tex);
133 				}
134 
135 				/* Else (count == 0) this is the start of a group, and */
136 				/* no texture name is present. */
137 			}
138 			else if ( start == FLOAT_END ) {
139 				/* End of an object or group. Yes, the name should be */
140 				/* obvious from context, but it is in here just to be */
141 				/* safe and to provide a little extra information for */
142 				/* those who do not wish to write a recursive reader. */
143 				/* Mia culpa. */
144 				--iLevel;
145 				i = -1;
146 				do {
147 					++i;
148 					fread( &( name[i] ), sizeof( char ), 1, input );
149 				} while ( name[i] != '\0' );
150 
151 //				indent();
152 //				fprintf(stdout,"OBJECT END: %s\n",name);
153 				continue;
154 			}
155 		}
156 
157 //
158 // read the triangles
159 //
160 		for ( i = 0; i < count; ++i ) {
161 			int j;
162 
163 			fread( &tri, sizeof( tf_triangle ), 1, input );
164 			ByteSwapTri( &tri );
165 			for ( j = 0 ; j < 3 ; j++ )
166 			{
167 				int k;
168 
169 				for ( k = 0 ; k < 3 ; k++ )
170 				{
171 					ptri->verts[j][k] = tri.pt[j].p.v[k];
172 				}
173 			}
174 
175 			ptri++;
176 
177 			if ( ( ptri - *pptri ) >= MAXTRIANGLES ) {
178 				Error( "Error: too many triangles; increase MAXTRIANGLES\n" );
179 			}
180 		}
181 	}
182 
183 	*numtriangles = ptri - *pptri;
184 
185 	fclose( input );
186 }
187