git.hungrycats.org Git - xscreensaver/blob - hacks/glx/tunnel_draw.c

   1 /* -*- Mode: C; tab-width: 4 -*- */
   2 /* atunnels --- OpenGL Advanced Tunnel Demo */
   3
   4 #if 0
   5 static const char sccsid[] = "@(#)tunnel_draw.c 5.13 2004/05/25 xlockmore";
   6 #endif
   7
   8 /* Copyright (c) E. Lassauge, 2002-2004. */
   9
  10 /*
  11  * Permission to use, copy, modify, and distribute this software and its
  12  * documentation for any purpose and without fee is hereby granted,
  13  * provided that the above copyright notice appear in all copies and that
  14  * both that copyright notice and this permission notice appear in
  15  * supporting documentation.
  16  *
  17  * This file is provided AS IS with no warranties of any kind.  The author
  18  * shall have no liability with respect to the infringement of copyrights,
  19  * trade secrets or any patents by this file or any part thereof.  In no
  20  * event will the author be liable for any lost revenue or profits or
  21  * other special, indirect and consequential damages.
  22  *
  23  * The original code for this mode was written by Roman Podobedov
  24  * Email: romka@ut.ee
  25  * WEB: http://romka.demonews.com
  26  *
  27  * Eric Lassauge  (May-25-2004) <lassauge@users.sourceforge.net>
  28  *                                  http://lassauge.free.fr/linux.html
  29  *
  30  * REVISION HISTORY:
  31  * E.Lassauge - 25-May-2004:
  32  *      - added more texture
  33  *      - random texture init
  34  *
  35  */
  36
  37 #ifdef HAVE_CONFIG_H
  38 #include <config.h>
  39 #endif
  40
  41 #ifdef USE_GL /* whole file */
  42
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <math.h>
  46
  47 #ifdef STANDALONE
  48 # ifndef HAVE_COCOA
  49 #  include <GL/gl.h>
  50 #  include <GL/glu.h>
  51 # endif
  52 #endif
  53
  54 #include "tunnel_draw.h"
  55
  56 #ifdef STANDALONE /* For NRAND() */
  57 #include "xlockmoreI.h"          /* in xscreensaver distribution */
  58 #else /* STANDALONE */
  59 #include "xlock.h"              /* in xlockmore distribution */
  60 #endif /* STANDALONE */
  61
  62 typedef struct
  63 {
  64   float x, y, z; /* Point coordinates */
  65 } cvPoint;
  66
  67 typedef struct _tnPath
  68 {
  69         cvPoint p;
  70         struct _tnPath *next;
  71 } tnPath;
  72
  73
  74 static const cvPoint initpath[]={
  75 {0.000000, 0.000000, 0.000000},
  76 {2.000000, 1.000000, 0.000000},
  77 {4.000000, 0.000000, 0.000000},
  78 {6.000000, 1.000000, 0.000000},
  79 {8.000000, 0.000000, 1.000000},
  80 {10.000000, 1.000000, 1.000000},
  81 {12.000000, 1.500000, 0.000000},
  82 {14.000000, 0.000000, 0.000000},
  83 {16.000000, 1.000000, 0.000000},
  84 {18.000000, 0.000000, 0.000000},
  85 {20.000000, 0.000000, 1.000000},
  86 {22.000000, 1.000000, 0.000000},
  87 {24.000000, 0.000000, 1.000000},
  88 {26.000000, 0.000000, 1.000000},
  89 {28.000000, 1.000000, 0.000000},
  90 {30.000000, 0.000000, 2.000000},
  91 {32.000000, 1.000000, 0.000000},
  92 {34.000000, 0.000000, 2.000000},
  93 {-1.000000, -1.000000, -1.000000}
  94 };
  95
  96
  97 struct tunnel_state {
  98
  99   tnPath *path;
 100
 101   float cam_t;                                  /* Camera variables */
 102   tnPath *cam_pos;
 103   float alpha;
 104
 105   int tFlag;                                    /* Tunnel Drawing Variables */
 106   cvPoint prev_points[10];
 107   int current_texture;
 108
 109   float ModeX;                                  /* Modes */
 110   int ModeXFlag;
 111 };
 112
 113 /*=================== Vector normalization ==================================*/
 114 static void normalize(cvPoint *V)
 115 {
 116   float d;
 117
 118   /* Vector length */
 119   d = (float)sqrt(V->x*V->x + V->y*V->y + V->z*V->z);
 120
 121   /* Normalization */
 122   V->x /= d;
 123   V->y /= d;
 124   V->z /= d;
 125 }
 126 /*=================== C = A x B  (Vector multiply) ==========================*/
 127 #if 0
 128 static void vect_mult(cvPoint *A, cvPoint *B, cvPoint *C)
 129 {
 130         /* Vector multiply */
 131         C->x = A->y*B->z - A->z*B->y;
 132         C->y = A->z*B->x - A->x*B->z;
 133         C->z = A->x*B->y - A->y*B->x;
 134 }
 135 #endif
 136
 137 /* Catmull-Rom Curve calculations */
 138 static void cvCatmullRom(cvPoint *p, float t, cvPoint *outp)
 139 {
 140         float t2, t3, t1;
 141
 142         t2 = t*t;
 143         t3 = t*t*t;
 144         t1 = (1-t)*(1-t);
 145
 146         outp->x = (-t*t1*p[0].x + (2-5*t2+3*t3)*p[1].x + t*(1+4*t-3*t2)*p[2].x - t2*(1-t)*p[3].x)/2;
 147         outp->y = (-t*t1*p[0].y + (2-5*t2+3*t3)*p[1].y + t*(1+4*t-3*t2)*p[2].y - t2*(1-t)*p[3].y)/2;
 148         outp->z = (-t*t1*p[0].z + (2-5*t2+3*t3)*p[1].z + t*(1+4*t-3*t2)*p[2].z - t2*(1-t)*p[3].z)/2;
 149 }
 150
 151 /*=================== Point Rotating Around Line ===========================
 152 // p    - original point
 153 // pp   - pivot point
 154 // pl   - pivot line (vector)
 155 // a    - angle to rotate in radians
 156 // outp - output point
 157 //==========================================================================
 158 */
 159 static void RotateAroundLine(cvPoint *p, cvPoint *pp, cvPoint *pl, float a, cvPoint *outp)
 160 {
 161         cvPoint p1, p2;
 162         float l, m, n, ca, sa;
 163
 164         p1.x = p->x - pp->x;
 165         p1.y = p->y - pp->y;
 166         p1.z = p->z - pp->z;
 167
 168         l = pl->x;
 169         m = pl->y;
 170         n = pl->z;
 171
 172         ca = cos(a);
 173         sa = sin(a);
 174
 175         p2.x = p1.x*((l*l)+ca*(1-l*l)) + p1.y*(l*(1-ca)*m+n*sa) + p1.z*(l*(1-ca)*n-m*sa);
 176         p2.y = p1.x*(l*(1-ca)*m-n*sa) + p1.y*(m*m+ca*(1-m*m)) + p1.z*(m*(1-ca)*n+l*sa);
 177         p2.z = p1.x*(l*(1-ca)*n+m*sa) + p1.y*(m*(1-ca)*n-l*sa) + p1.z*(n*n+ca*(1-n*n));
 178
 179         outp->x = p2.x + pp->x;
 180         outp->y = p2.y + pp->y;
 181         outp->z = p2.z + pp->z;
 182 }
 183
 184
 185 /*=================== Load camera and tunnel path ==========================*/
 186 static void LoadPath(struct tunnel_state *st)
 187 {
 188         float x, y, z;
 189         tnPath *path1=NULL, *path2=NULL;
 190
 191         cvPoint *f = (cvPoint *)initpath;
 192
 193         while (f->x != -1.0)
 194         {
 195                 x = f->x;
 196                 y = f->y;
 197                 z = f->z;
 198                 f++;
 199
 200                 if (st->path == NULL)
 201                 {
 202                         st->path = (tnPath *)malloc(sizeof(tnPath));
 203                         path1 = st->path;
 204                 }
 205                 else
 206                 {
 207                         if (!path1) path1 = st->path;
 208                         path2 = (tnPath *)malloc(sizeof(tnPath));
 209                         path1->next = path2;
 210                         path1 = path2;
 211                 }
 212
 213                 path1->next = NULL;
 214                 path1->p.x = x;
 215                 path1->p.y = y;
 216                 path1->p.z = z;
 217         }
 218
 219         st->cam_pos = st->path;
 220         st->cam_t = 0;
 221 }
 222
 223 /*=================== Tunnel Initialization ================================*/
 224 struct tunnel_state *
 225 InitTunnel(void)
 226 {
 227     struct tunnel_state *st = (struct tunnel_state *) calloc (1, sizeof(*st));
 228         LoadPath(st);
 229         st->current_texture = NRAND(MAX_TEXTURE);
 230     return st;
 231 }
 232
 233 void DrawTunnel(struct tunnel_state *st,
 234                 int do_texture, int do_light, GLuint *textures)
 235 {
 236         tnPath *p, *p1, *cmpos;
 237         cvPoint op, p4[4], T, ppp, ppp1, op1, op2;
 238         float t;
 239         int i, j, k, flag;
 240         cvPoint points[10];
 241         GLfloat light_position[4];
 242
 243
 244         /* Select current tunnel texture */
 245         if (do_texture)
 246                 glBindTexture(GL_TEXTURE_2D, textures[st->current_texture]);
 247
 248         cmpos = st->cam_pos;
 249         /* Get current curve */
 250         if (st->cam_pos->next &&
 251             st->cam_pos->next->next &&
 252             st->cam_pos->next->next->next)
 253         {
 254                 p1 = st->cam_pos;
 255                 for (i=0; i<4; i++)
 256                 {
 257                         p4[i].x = p1->p.x;
 258                         p4[i].y = p1->p.y;
 259                         p4[i].z = p1->p.z;
 260                         p1 = p1->next;
 261                 }
 262         }
 263         else
 264         {
 265                 /* End of tunnel */
 266                 st->ModeX = 1.0;
 267                 st->ModeXFlag = 0;
 268                 return;
 269         };
 270
 271         /* Get current camera position */
 272         cvCatmullRom(p4, st->cam_t, &op);
 273
 274         /* Next camera position */
 275         st->cam_t += 0.02f;
 276         if (st->cam_t >= 1)
 277         {
 278                 st->cam_t = st->cam_t - 1;
 279                 cmpos = st->cam_pos->next;
 280         }
 281
 282         /* Get curve for next camera position */
 283         if (cmpos->next->next->next)
 284         {
 285                 p1 = cmpos;
 286                 for (i=0; i<4; i++)
 287                 {
 288                         p4[i].x = p1->p.x;
 289                         p4[i].y = p1->p.y;
 290                         p4[i].z = p1->p.z;
 291                         p1 = p1->next;
 292                 }
 293         }
 294         else
 295         {
 296                 /*  End of tunnel */
 297                 st->ModeX = 1.0;
 298                 st->ModeXFlag = 0;
 299                 return;
 300         }
 301
 302         /*  Get next camera position */
 303         cvCatmullRom(p4, st->cam_t, &op1);
 304
 305         /*  Rotate camera */
 306         glRotatef(st->alpha, 0, 0, -1);
 307         st->alpha += 1;
 308         /*  Set camera position */
 309         gluLookAt(op.x, op.y, op.z, op1.x, op1.y, op1.z, 0, 1, 0);
 310
 311         /*  Set light position */
 312         if (do_light)
 313         {
 314                 light_position[0] = op.x;
 315                 light_position[1] = op.y;
 316                 light_position[2] = op.z;
 317                 light_position[3] = 1;
 318                 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
 319         }
 320
 321         p = st->cam_pos;
 322         flag = 0;
 323         t = 0;
 324         k = 0;
 325         /*  Draw tunnel from current curve and next 2 curves */
 326         glBegin(GL_QUADS);
 327         while (k < 3)
 328         {
 329                 if (p->next->next->next)
 330                 {
 331                         p1 = p;
 332                         for (i=0; i<4; i++)
 333                         {
 334                                 p4[i].x = p1->p.x;
 335                                 p4[i].y = p1->p.y;
 336                                 p4[i].z = p1->p.z;
 337                                 p1 = p1->next;
 338                         }
 339                 }
 340                 else
 341                 {
 342                         /*  End of tunnel */
 343                         st->ModeX = 1.0;
 344                         st->ModeXFlag = 0;
 345             glEnd();
 346                         return;
 347                 }
 348                 cvCatmullRom(p4, t, &op);
 349
 350                 ppp.x = op.x;
 351                 ppp.y = op.y;
 352                 ppp.z = op.z + 0.25;
 353
 354                 t += 0.1;
 355                 if (t >= 1.0)
 356                 {
 357                         t = t - 1;
 358                         k++;
 359                         p = p->next;
 360                 }
 361
 362                 if (p->next->next->next)
 363                 {
 364                         p1 = p;
 365                         for (i=0; i<4; i++)
 366                         {
 367                                 p4[i].x = p1->p.x;
 368                                 p4[i].y = p1->p.y;
 369                                 p4[i].z = p1->p.z;
 370                                 p1 = p1->next;
 371                         }
 372                 }
 373                 else
 374                 {
 375                         /*  End of tunnel */
 376                         st->ModeX = 1.0;
 377                         st->ModeXFlag = 0;
 378             glEnd();
 379                         return;
 380                 }
 381
 382                 cvCatmullRom(p4, t, &op1);
 383
 384                 ppp1.x = op1.x;
 385                 ppp1.y = op1.y;
 386                 ppp1.z = op1.z + 0.25;
 387
 388                 T.x = op1.x - op.x;
 389                 T.y = op1.y - op.y;
 390                 T.z = op1.z - op.z;
 391
 392                 normalize(&T);
 393
 394                 for (i=0; i<10; i++)
 395                 {
 396                         RotateAroundLine(&ppp, &op, &T, ((float)i*36.0*M_PI/180.0), &op2);
 397                         points[i].x = op2.x;
 398                         points[i].y = op2.y;
 399                         points[i].z = op2.z;
 400                         if (!flag)
 401                         {
 402                                 st->prev_points[i].x = op2.x;
 403                                 st->prev_points[i].y = op2.y;
 404                                 st->prev_points[i].z = op2.z;
 405                         }
 406                 }
 407
 408                 if (!flag)
 409                 {
 410                         flag = 1;
 411                         continue;
 412                 }
 413
 414                 /*  Draw 10 polygons for current point */
 415                 for (i=0; i<10; i++)
 416                 {
 417                         j = i+1;
 418                         if (j > 9) j = 0;
 419                         glNormal3f(0, 0, 1); /*  Normal for lighting */
 420                         glTexCoord2f(0, 0); glVertex3f(st->prev_points[i].x, st->prev_points[i].y, st->prev_points[i].z);
 421                         glNormal3f(0, 0, 1);
 422                         glTexCoord2f(1, 0); glVertex3f(points[i].x, points[i].y, points[i].z);
 423                         glNormal3f(0, 0, 1);
 424                         glTexCoord2f(1, 1); glVertex3f(points[j].x, points[j].y, points[j].z);
 425                         glNormal3f(0, 0, 1);
 426                         glTexCoord2f(0, 1); glVertex3f(st->prev_points[j].x, st->prev_points[j].y, st->prev_points[j].z);
 427                 }
 428                 /*  Save current polygon coordinates for next position */
 429                 for (i=0; i<10; i++)
 430                 {
 431                         st->prev_points[i].x = points[i].x;
 432                         st->prev_points[i].y = points[i].y;
 433                         st->prev_points[i].z = points[i].z;
 434                 }
 435         }
 436         glEnd();
 437         st->cam_pos = cmpos;
 438 }
 439
 440 /* =================== Show splash screen =================================== */
 441 void SplashScreen(struct tunnel_state *st,
 442                   int do_wire, int do_texture, int do_light)
 443 {
 444         if (st->ModeX > 0)
 445         {
 446                 /*  Reset tunnel and camera position */
 447                 if (!st->ModeXFlag)
 448                 {
 449                         st->cam_pos = st->path;
 450                         st->cam_t = 0;
 451                         st->tFlag = 0;
 452                         st->ModeXFlag = 1;
 453                         st->current_texture++;
 454                         if (st->current_texture >= MAX_TEXTURE) st->current_texture = 0;
 455                 }
 456                 /*  Now we want to draw splash screen */
 457                 glLoadIdentity();
 458                 /*  Disable all unused features */
 459                 glDisable(GL_DEPTH_TEST);
 460                 glDisable(GL_LIGHTING);
 461                 glDisable(GL_FOG);
 462                 glDisable(GL_CULL_FACE);
 463
 464                 glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
 465                 glEnable(GL_BLEND);
 466                 glDisable(GL_TEXTURE_2D);
 467                 glColor4f(1, 1, 1, st->ModeX);
 468
 469                 /*  Draw splash screen (simply quad) */
 470                 glBegin(GL_QUADS);
 471                 glVertex3f(-10, -10, -1);
 472                 glVertex3f(10, -10, -1);
 473                 glVertex3f(10, 10, -1);
 474                 glVertex3f(-10, 10, -1);
 475                 glEnd();
 476
 477                 st->ModeX -= 0.05;
 478                 if (st->ModeX <= 0)     st->ModeX = 0;
 479
 480                 if (!do_wire)
 481                 {
 482                         glEnable(GL_CULL_FACE);
 483                         glEnable(GL_DEPTH_TEST);
 484                 }
 485                 if (do_light)
 486                 {
 487                         glEnable(GL_LIGHTING);
 488                         glEnable(GL_FOG);
 489                 }
 490                 if (do_texture)
 491                 {
 492                         glEnable(GL_TEXTURE_2D);
 493                 }
 494                 glDisable(GL_BLEND);
 495                 glColor4f(1, 1, 1, 1);
 496         }
 497 }
 498
 499 void FreeTunnel(struct tunnel_state *st)
 500 {
 501   free (st);
 502 }
 503
 504 #endif