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