samples/opengl/penguin/lw.cpp

   1 /*
   2  * Copyright (C) 1998 Janne Löf <jlof@mail.student.oulu.fi>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library; if not, write to the Free
  16  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #ifdef __WXMSW__
  20 #include <windows.h>
  21 #endif
  22
  23 // For compilers that support precompilation, includes "wx.h".
  24 #include "wx/wxprec.h"
  25
  26 #ifdef __BORLANDC__
  27 #pragma hdrstop
  28 #endif
  29
  30 #ifndef WX_PRECOMP
  31 #include "wx/wx.h"
  32 #endif
  33
  34 #include "lw.h"
  35 #include <stdlib.h>
  36 #include <stdio.h>
  37 #include <math.h>
  38
  39 #ifndef FALSE
  40 #define FALSE 0
  41 #endif
  42
  43 #ifndef TRUE
  44 #define TRUE 1
  45 #endif
  46
  47 #define MK_ID(a,b,c,d) ((((wxUint32)(a))<<24)| \
  48                         (((wxUint32)(b))<<16)| \
  49                         (((wxUint32)(c))<< 8)| \
  50                         (((wxUint32)(d))    ))
  51
  52 #define ID_FORM MK_ID('F','O','R','M')
  53 #define ID_LWOB MK_ID('L','W','O','B')
  54 #define ID_PNTS MK_ID('P','N','T','S')
  55 #define ID_SRFS MK_ID('S','R','F','S')
  56 #define ID_SURF MK_ID('S','U','R','F')
  57 #define ID_POLS MK_ID('P','O','L','S')
  58 #define ID_COLR MK_ID('C','O','L','R')
  59
  60 static wxInt32 read_char(FILE *f)
  61 {
  62   int c = fgetc(f);
  63   return c;
  64 }
  65
  66 static wxInt32 read_short(FILE *f)
  67 {
  68     // the execution path was not always correct
  69     // when using the direct evaluation in the return statement
  70     wxInt32 first = read_char(f) ;
  71     wxInt32 second = read_char(f) ;
  72
  73   return (first<<8) | second ;
  74 }
  75
  76 static wxInt32 read_long(FILE *f)
  77 {
  78     // the execution path was not always correct
  79     // when using the direct evaluation in the return statement
  80     wxInt32 first = read_char(f) ;
  81     wxInt32 second = read_char(f) ;
  82     wxInt32 third = read_char(f) ;
  83     wxInt32 fourth = read_char(f) ;
  84   return (first<<24) | (second<<16) | (third<<8) | fourth ;
  85 }
  86
  87 static GLfloat read_float(FILE *f)
  88 {
  89   wxInt32 x = read_long(f);
  90   return *(GLfloat*)&x;
  91 }
  92
  93 static int read_string(FILE *f, char *s)
  94 {
  95   int c;
  96   int cnt = 0;
  97   do {
  98     c = read_char(f);
  99     if (cnt < LW_MAX_NAME_LEN)
 100       s[cnt] = c;
 101     else
 102       s[LW_MAX_NAME_LEN-1] = 0;
 103     cnt++;
 104   } while (c != 0);
 105   /* if length of string (including \0) is odd skip another byte */
 106   if (cnt%2) {
 107     read_char(f);
 108     cnt++;
 109   }
 110   return cnt;
 111 }
 112
 113 static void read_srfs(FILE *f, int nbytes, lwObject *lwo)
 114 {
 115   int guess_cnt = lwo->material_cnt;
 116
 117   while (nbytes > 0) {
 118     lwMaterial *material;
 119
 120     /* allocate more memory for materials if needed */
 121     if (guess_cnt <= lwo->material_cnt) {
 122       guess_cnt += guess_cnt/2 + 4;
 123       lwo->material = (lwMaterial*) realloc(lwo->material, sizeof(lwMaterial)*guess_cnt);
 124     }
 125     material = lwo->material + lwo->material_cnt++;
 126
 127     /* read name */
 128     nbytes -= read_string(f,material->name);
 129
 130     /* defaults */
 131     material->r = 0.7;
 132     material->g = 0.7;
 133     material->b = 0.7;
 134   }
 135   lwo->material = (lwMaterial*) realloc(lwo->material, sizeof(lwMaterial)*lwo->material_cnt);
 136 }
 137
 138
 139 static void read_surf(FILE *f, int nbytes, lwObject *lwo)
 140 {
 141   int i;
 142   char name[LW_MAX_NAME_LEN];
 143   lwMaterial *material = NULL;
 144
 145   /* read surface name */
 146   nbytes -= read_string(f,name);
 147
 148   /* find material */
 149   for (i=0; i< lwo->material_cnt; i++) {
 150     if (strcmp(lwo->material[i].name,name) == 0) {
 151       material = &lwo->material[i];
 152       break;
 153     }
 154   }
 155
 156   /* read values */
 157   while (nbytes > 0) {
 158     int id = read_long(f);
 159     int len = read_short(f);
 160     nbytes -= 6 + len + (len%2);
 161
 162     switch (id) {
 163     case ID_COLR:
 164       material->r = read_char(f) / 255.0;
 165       material->g = read_char(f) / 255.0;
 166       material->b = read_char(f) / 255.0;
 167       read_char(f); /* dummy */
 168       break;
 169     default:
 170       fseek(f, len+(len%2), SEEK_CUR);
 171     }
 172   }
 173 }
 174
 175
 176 static void read_pols(FILE *f, int nbytes, lwObject *lwo)
 177 {
 178   int guess_cnt = lwo->face_cnt;
 179
 180   while (nbytes > 0) {
 181     lwFace *face;
 182     int i;
 183
 184     /* allocate more memory for polygons if necessary */
 185     if (guess_cnt <= lwo->face_cnt) {
 186       guess_cnt += guess_cnt + 4;
 187       lwo->face = (lwFace*) realloc((void*) lwo->face, sizeof(lwFace)*guess_cnt);
 188     }
 189     face = lwo->face + lwo->face_cnt++;
 190
 191     /* number of points in this face */
 192     face->index_cnt = read_short(f);
 193     nbytes -= 2;
 194
 195     /* allocate space for points */
 196     face->index = (int*) calloc(sizeof(int)*face->index_cnt,1);
 197
 198     /* read points in */
 199     for (i=0; i<face->index_cnt; i++) {
 200       face->index[i] = read_short(f);
 201       nbytes -= 2;
 202     }
 203
 204     /* read surface material */
 205     face->material = read_short(f);
 206     nbytes -= 2;
 207
 208     /* skip over detail  polygons */
 209     if (face->material < 0) {
 210       int det_cnt;
 211       face->material = -face->material;
 212       det_cnt = read_short(f);
 213       nbytes -= 2;
 214       while (det_cnt-- > 0) {
 215         int cnt = read_short(f);
 216         fseek(f, cnt*2+2, SEEK_CUR);
 217         nbytes -= cnt*2+2;
 218       }
 219     }
 220     face->material -= 1;
 221   }
 222   /* readjust to true size */
 223   lwo->face = (lwFace*) realloc(lwo->face, sizeof(lwFace)*lwo->face_cnt);
 224 }
 225
 226
 227
 228 static void read_pnts(FILE *f, int nbytes, lwObject *lwo)
 229 {
 230   int i;
 231   lwo->vertex_cnt = nbytes / 12;
 232   lwo->vertex = (float*) calloc(sizeof(GLfloat)*lwo->vertex_cnt*3, 1);
 233   for (i=0; i<lwo->vertex_cnt; i++) {
 234     lwo->vertex[i*3+0] = read_float(f);
 235     lwo->vertex[i*3+1] = read_float(f);
 236     lwo->vertex[i*3+2] = read_float(f);
 237   }
 238 }
 239
 240
 241
 242
 243
 244
 245 int lw_is_lwobject(const char *lw_file)
 246 {
 247   FILE *f = fopen(lw_file, "rb");
 248   if (f) {
 249     wxInt32 form = read_long(f);
 250     wxInt32 nlen = read_long(f);
 251     wxInt32 lwob = read_long(f);
 252     fclose(f);
 253     if (form == ID_FORM && nlen != 0 && lwob == ID_LWOB)
 254       return TRUE;
 255   }
 256   return FALSE;
 257 }
 258
 259
 260 lwObject *lw_object_read(const char *lw_file)
 261 {
 262   FILE *f = NULL;
 263   lwObject *lw_object = NULL;
 264
 265   wxInt32 form_bytes = 0;
 266   wxInt32 read_bytes = 0;
 267
 268   /* open file */
 269   f = fopen(lw_file, "rb");
 270   if (f == NULL) {
 271     return NULL;
 272   }
 273
 274   /* check for headers */
 275   if (read_long(f) != ID_FORM) {
 276     fclose(f);
 277     return NULL;
 278   }
 279   form_bytes = read_long(f);
 280   read_bytes += 4;
 281
 282   if (read_long(f) != ID_LWOB) {
 283     fclose(f);
 284     return NULL;
 285   }
 286
 287   /* create new lwObject */
 288   lw_object = (lwObject*) calloc(sizeof(lwObject),1);
 289
 290   /* read chunks */
 291   while (read_bytes < form_bytes) {
 292     wxInt32  id     = read_long(f);
 293     wxInt32  nbytes = read_long(f);
 294     read_bytes += 8 + nbytes + (nbytes%2);
 295
 296     switch (id) {
 297     case ID_PNTS:
 298       read_pnts(f, nbytes, lw_object);
 299       break;
 300     case ID_POLS:
 301       read_pols(f, nbytes, lw_object);
 302       break;
 303     case ID_SRFS:
 304       read_srfs(f, nbytes, lw_object);
 305       break;
 306     case ID_SURF:
 307       read_surf(f, nbytes, lw_object);
 308       break;
 309     default:
 310       fseek(f, nbytes + (nbytes%2), SEEK_CUR);
 311     }
 312   }
 313
 314   fclose(f);
 315   return lw_object;
 316 }
 317
 318
 319
 320 void lw_object_free(lwObject *lw_object)
 321 {
 322   if (lw_object->face) {
 323     int i;
 324     for (i=0; i<lw_object->face_cnt; i++)
 325       free(lw_object->face[i].index);
 326     free(lw_object->face);
 327   }
 328   free(lw_object->material);
 329   free(lw_object->vertex);
 330   free(lw_object);
 331 }
 332
 333
 334
 335
 336
 337 #define PX(i) (lw_object->vertex[face->index[i]*3+0])
 338 #define PY(i) (lw_object->vertex[face->index[i]*3+1])
 339 #define PZ(i) (lw_object->vertex[face->index[i]*3+2])
 340 void lw_object_show(const lwObject *lw_object)
 341 {
 342   int i,j;
 343   int prev_index_cnt = -1;
 344   int prev_material  = -1;
 345   GLfloat prev_nx = 0;
 346   GLfloat prev_ny = 0;
 347   GLfloat prev_nz = 0;
 348
 349   for (i=0; i<lw_object->face_cnt; i++) {
 350     GLfloat ax,ay,az,bx,by,bz,nx,ny,nz,r;
 351     const lwFace *face = lw_object->face+i;
 352
 353     /* ignore faces with less than 3 points */
 354     if (face->index_cnt < 3)
 355       continue;
 356
 357     /* calculate normal */
 358     ax = PX(1) - PX(0);
 359     ay = PY(1) - PY(0);
 360     az = PZ(1) - PZ(0);
 361
 362     bx = PX(face->index_cnt-1) - PX(0);
 363     by = PY(face->index_cnt-1) - PY(0);
 364     bz = PZ(face->index_cnt-1) - PZ(0);
 365
 366     nx = ay * bz - az * by;
 367     ny = az * bx - ax * bz;
 368     nz = ax * by - ay * bx;
 369
 370     r = sqrt(nx*nx + ny*ny + nz*nz);
 371     if (r < 0.000001) /* avoid division by zero */
 372       continue;
 373     nx /= r;
 374     ny /= r;
 375     nz /= r;
 376
 377     /* glBegin/glEnd */
 378     if (prev_index_cnt != face->index_cnt || prev_index_cnt > 4) {
 379       if (prev_index_cnt > 0) glEnd();
 380       prev_index_cnt = face->index_cnt;
 381       switch (face->index_cnt) {
 382       case 3:
 383         glBegin(GL_TRIANGLES);
 384         break;
 385       case 4:
 386         glBegin(GL_QUADS);
 387         break;
 388       default:
 389         glBegin(GL_POLYGON);
 390       }
 391     }
 392
 393     /* update material if necessary */
 394     if (prev_material != face->material) {
 395       prev_material = face->material;
 396       glColor3f(lw_object->material[face->material].r,
 397                 lw_object->material[face->material].g,
 398                 lw_object->material[face->material].b);
 399     }
 400
 401     /* update normal if necessary */
 402     if (nx != prev_nx || ny != prev_ny || nz != prev_nz) {
 403       prev_nx = nx;
 404       prev_ny = ny;
 405       prev_nz = nz;
 406       glNormal3f(nx,ny,nz);
 407     }
 408
 409     /* draw polygon/triangle/quad */
 410     for (j=0; j<face->index_cnt; j++)
 411       glVertex3f(PX(j),PY(j),PZ(j));
 412
 413   }
 414
 415   /* if glBegin was called call glEnd */
 416   if (prev_index_cnt > 0)
 417     glEnd();
 418 }
 419
 420
 421 GLfloat lw_object_radius(const lwObject *lwo)
 422 {
 423   int i;
 424   double max_radius = 0.0;
 425
 426   for (i=0; i<lwo->vertex_cnt; i++) {
 427     GLfloat *v = &lwo->vertex[i*3];
 428     double r = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
 429     if (r > max_radius)
 430       max_radius = r;
 431   }
 432   return sqrt(max_radius);
 433 }
 434
 435 void lw_object_scale(lwObject *lwo, GLfloat scale)
 436 {
 437   int i;
 438
 439   for (i=0; i<lwo->vertex_cnt; i++) {
 440     lwo->vertex[i*3+0] *= scale;
 441     lwo->vertex[i*3+1] *= scale;
 442     lwo->vertex[i*3+2] *= scale;
 443   }
 444 }
 445
 446