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