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