tools/quake2/extra/common/trilib.c

   1 /*
   2 ===========================================================================
   3 Copyright (C) 1997-2006 Id Software, Inc.
   4
   5 This file is part of Quake 2 Tools source code.
   6
   7 Quake 2 Tools source code is free software; you can redistribute it
   8 and/or modify it under the terms of the GNU General Public License as
   9 published by the Free Software Foundation; either version 2 of the License,
  10 or (at your option) any later version.
  11
  12 Quake 2 Tools source code is distributed in the hope that it will be
  13 useful, 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 Quake 2 Tools source code; if not, write to the Free Software
  19 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20 ===========================================================================
  21 */
  22
  23 //
  24 // trilib.c: library for loading triangles from an Alias triangle file
  25 //
  26
  27 #include <stdio.h>
  28 #include "cmdlib.h"
  29 #include "mathlib.h"
  30 #include "trilib.h"
  31
  32 // on disk representation of a face
  33
  34
  35 #define FLOAT_START     99999.0
  36 #define FLOAT_END       -FLOAT_START
  37 #define MAGIC       123322
  38
  39 //#define NOISY 1
  40
  41 typedef struct {
  42         float v[3];
  43 } vector;
  44
  45 typedef struct
  46 {
  47         vector n;    /* normal */
  48         vector p;    /* point */
  49         vector c;    /* color */
  50         float  u;    /* u */
  51         float  v;    /* v */
  52 } aliaspoint_t;
  53
  54 typedef struct {
  55         aliaspoint_t    pt[3];
  56 } tf_triangle;
  57
  58
  59 void ByteSwapTri (tf_triangle *tri)
  60 {
  61         int             i;
  62
  63         for (i=0 ; i<sizeof(tf_triangle)/4 ; i++)
  64         {
  65                 ((int *)tri)[i] = BigLong (((int *)tri)[i]);
  66         }
  67 }
  68
  69 void LoadTriangleList (char *filename, triangle_t **pptri, int *numtriangles)
  70 {
  71         FILE        *input;
  72         float       start;
  73         char        name[256], tex[256];
  74         int         i, count, magic;
  75         tf_triangle     tri;
  76         triangle_t      *ptri;
  77         int                     iLevel;
  78         int                     exitpattern;
  79         float           t;
  80
  81         t = -FLOAT_START;
  82         *((unsigned char *)&exitpattern + 0) = *((unsigned char *)&t + 3);
  83         *((unsigned char *)&exitpattern + 1) = *((unsigned char *)&t + 2);
  84         *((unsigned char *)&exitpattern + 2) = *((unsigned char *)&t + 1);
  85         *((unsigned char *)&exitpattern + 3) = *((unsigned char *)&t + 0);
  86
  87         if ((input = fopen(filename, "rb")) == 0)
  88                 Error ("reader: could not open file '%s'", filename);
  89
  90         iLevel = 0;
  91
  92         fread(&magic, sizeof(int), 1, input);
  93         if (BigLong(magic) != MAGIC)
  94                 Error ("%s is not a Alias object separated triangle file, magic number is wrong.", filename);
  95
  96         ptri = malloc (MAXTRIANGLES * sizeof(triangle_t));
  97
  98         *pptri = ptri;
  99
 100         while (feof(input) == 0) {
 101                 if (fread(&start,  sizeof(float), 1, input) < 1)
 102                         break;
 103                 *(int *)&start = BigLong(*(int *)&start);
 104                 if (*(int *)&start != exitpattern)
 105                 {
 106                         if (start == FLOAT_START) {
 107                                 /* Start of an object or group of objects. */
 108                                 i = -1;
 109                                 do {
 110                                         /* There are probably better ways to read a string from */
 111                                         /* a file, but this does allow you to do error checking */
 112                                         /* (which I'm not doing) on a per character basis.      */
 113                                         ++i;
 114                                         fread( &(name[i]), sizeof( char ), 1, input);
 115                                 } while( name[i] != '\0' );
 116
 117 //                              indent();
 118 //                              fprintf(stdout,"OBJECT START: %s\n",name);
 119                                 fread( &count, sizeof(int), 1, input);
 120                                 count = BigLong(count);
 121                                 ++iLevel;
 122                                 if (count != 0) {
 123 //                                      indent();
 124 //                                      fprintf(stdout,"NUMBER OF TRIANGLES: %d\n",count);
 125
 126                                         i = -1;
 127                                         do {
 128                                                 ++i;
 129                                                 fread( &(tex[i]), sizeof( char ), 1, input);
 130                                         } while( tex[i] != '\0' );
 131
 132 //                                      indent();
 133 //                                      fprintf(stdout,"  Object texture name: '%s'\n",tex);
 134                                 }
 135
 136                                 /* Else (count == 0) this is the start of a group, and */
 137                                 /* no texture name is present. */
 138                         }
 139                         else if (start == FLOAT_END) {
 140                                 /* End of an object or group. Yes, the name should be */
 141                                 /* obvious from context, but it is in here just to be */
 142                                 /* safe and to provide a little extra information for */
 143                                 /* those who do not wish to write a recursive reader. */
 144                                 /* Mia culpa. */
 145                                 --iLevel;
 146                                 i = -1;
 147                                 do {
 148                                         ++i;
 149                                         fread( &(name[i]), sizeof( char ), 1, input);
 150                                 } while( name[i] != '\0' );
 151
 152 //                              indent();
 153 //                              fprintf(stdout,"OBJECT END: %s\n",name);
 154                                 continue;
 155                         }
 156                 }
 157
 158 //
 159 // read the triangles
 160 //
 161                 for (i = 0; i < count; ++i) {
 162                         int             j;
 163
 164                         fread( &tri, sizeof(tf_triangle), 1, input );
 165                         ByteSwapTri (&tri);
 166                         for (j=0 ; j<3 ; j++)
 167                         {
 168                                 int             k;
 169
 170                                 for (k=0 ; k<3 ; k++)
 171                                 {
 172                                         ptri->verts[j][k] = tri.pt[j].p.v[k];
 173                                 }
 174                         }
 175
 176                         ptri++;
 177
 178                         if ((ptri - *pptri) >= MAXTRIANGLES)
 179                                 Error ("Error: too many triangles; increase MAXTRIANGLES\n");
 180                 }
 181         }
 182
 183         *numtriangles = ptri - *pptri;
 184
 185         fclose (input);
 186 }
 187