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 # ifdef HAVE_COCOA
  49 #  include <OpenGL/gl.h>
  50 #  include <OpenGL/glu.h>
  51 # else
  52 #  include <GL/gl.h>
  53 #  include <GL/glu.h>
  54 # endif
  55 #endif
  56
  57 #include "tunnel_draw.h"
  58
  59 #ifdef STANDALONE /* For NRAND() */
  60 #include "xlockmoreI.h"          /* in xscreensaver distribution */
  61 #else /* STANDALONE */
  62 #include "xlock.h"              /* in xlockmore distribution */
  63 #endif /* STANDALONE */
  64
  65 typedef struct
  66 {
  67   float x, y, z; /* Point coordinates */
  68 } cvPoint;
  69
  70 typedef struct _tnPath
  71 {
  72         cvPoint p;
  73         struct _tnPath *next;
  74 } tnPath;
  75
  76
  77 static const cvPoint initpath[]={
  78 {0.000000, 0.000000, 0.000000},
  79 {2.000000, 1.000000, 0.000000},
  80 {4.000000, 0.000000, 0.000000},
  81 {6.000000, 1.000000, 0.000000},
  82 {8.000000, 0.000000, 1.000000},
  83 {10.000000, 1.000000, 1.000000},
  84 {12.000000, 1.500000, 0.000000},
  85 {14.000000, 0.000000, 0.000000},
  86 {16.000000, 1.000000, 0.000000},
  87 {18.000000, 0.000000, 0.000000},
  88 {20.000000, 0.000000, 1.000000},
  89 {22.000000, 1.000000, 0.000000},
  90 {24.000000, 0.000000, 1.000000},
  91 {26.000000, 0.000000, 1.000000},
  92 {28.000000, 1.000000, 0.000000},
  93 {30.000000, 0.000000, 2.000000},
  94 {32.000000, 1.000000, 0.000000},
  95 {34.000000, 0.000000, 2.000000},
  96 {-1.000000, -1.000000, -1.000000}
  97 };
  98
  99
 100 struct tunnel_state {
 101
 102   tnPath *path;
 103
 104   float cam_t;                                  /* Camera variables */
 105   tnPath *cam_pos;
 106   float alpha;
 107
 108   int tFlag;                                    /* Tunnel Drawing Variables */
 109   cvPoint prev_points[10];
 110   int current_texture;
 111
 112   float ModeX;                                  /* Modes */
 113   int ModeXFlag;
 114 };
 115
 116 /*=================== Vector normalization ==================================*/
 117 static void normalize(cvPoint *V)
 118 {
 119   float d;
 120
 121   /* Vector length */
 122   d = (float)sqrt(V->x*V->x + V->y*V->y + V->z*V->z);
 123
 124   /* Normalization */
 125   V->x /= d;
 126   V->y /= d;
 127   V->z /= d;
 128 }
 129 /*=================== C = A x B  (Vector multiply) ==========================*/
 130 #if 0
 131 static void vect_mult(cvPoint *A, cvPoint *B, cvPoint *C)
 132 {
 133         /* Vector multiply */
 134         C->x = A->y*B->z - A->z*B->y;
 135         C->y = A->z*B->x - A->x*B->z;
 136         C->z = A->x*B->y - A->y*B->x;
 137 }
 138 #endif
 139
 140 /* Catmull-Rom Curve calculations */
 141 static void cvCatmullRom(cvPoint *p, float t, cvPoint *outp)
 142 {
 143         float t2, t3, t1;
 144
 145         t2 = t*t;
 146         t3 = t*t*t;
 147         t1 = (1-t)*(1-t);
 148
 149         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;
 150         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;
 151         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;
 152 }
 153
 154 /*=================== Point Rotating Around Line ===========================
 155 // p    - original point
 156 // pp   - pivot point
 157 // pl   - pivot line (vector)
 158 // a    - angle to rotate in radians
 159 // outp - output point
 160 //==========================================================================
 161 */
 162 static void RotateAroundLine(cvPoint *p, cvPoint *pp, cvPoint *pl, float a, cvPoint *outp)
 163 {
 164         cvPoint p1, p2;
 165         float l, m, n, ca, sa;
 166
 167         p1.x = p->x - pp->x;
 168         p1.y = p->y - pp->y;
 169         p1.z = p->z - pp->z;
 170
 171         l = pl->x;
 172         m = pl->y;
 173         n = pl->z;
 174
 175         ca = cos(a);
 176         sa = sin(a);
 177
 178         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);
 179         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);
 180         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));
 181
 182         outp->x = p2.x + pp->x;
 183         outp->y = p2.y + pp->y;
 184         outp->z = p2.z + pp->z;
 185 }
 186
 187
 188 /*=================== Load camera and tunnel path ==========================*/
 189 static void LoadPath(struct tunnel_state *st)
 190 {
 191         float x, y, z;
 192         tnPath *path1=NULL, *path2=NULL;
 193
 194         cvPoint *f = (cvPoint *)initpath;
 195
 196         while (f->x != -1.0)
 197         {
 198                 x = f->x;
 199                 y = f->y;
 200                 z = f->z;
 201                 f++;
 202
 203                 if (st->path == NULL)
 204                 {
 205                         st->path = (tnPath *)malloc(sizeof(tnPath));
 206                         path1 = st->path;
 207                 }
 208                 else
 209                 {
 210                         path2 = (tnPath *)malloc(sizeof(tnPath));
 211                         path1->next = path2;
 212                         path1 = path2;
 213                 }
 214
 215                 path1->next = NULL;
 216                 path1->p.x = x;
 217                 path1->p.y = y;
 218                 path1->p.z = z;
 219         }
 220
 221         st->cam_pos = st->path;
 222         st->cam_t = 0;
 223 }
 224
 225 /*=================== Tunnel Initialization ================================*/
 226 struct tunnel_state *
 227 InitTunnel(void)
 228 {
 229     struct tunnel_state *st = (struct tunnel_state *) calloc (1, sizeof(*st));
 230         LoadPath(st);
 231         st->current_texture = NRAND(MAX_TEXTURE);
 232     return st;
 233 }
 234
 235 void DrawTunnel(struct tunnel_state *st,
 236                 int do_texture, int do_light, GLuint *textures)
 237 {
 238         tnPath *p, *p1, *cmpos;
 239         cvPoint op, p4[4], T, ppp, ppp1, op1, op2;
 240         float t;
 241         int i, j, k, flag;
 242         cvPoint points[10];
 243         GLfloat light_position[4];
 244
 245
 246         /* Select current tunnel texture */
 247         if (do_texture)
 248                 glBindTexture(GL_TEXTURE_2D, textures[st->current_texture]);
 249
 250         cmpos = st->cam_pos;
 251         /* Get current curve */
 252         if (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                         return;
 346                 }
 347                 cvCatmullRom(p4, t, &op);
 348
 349                 ppp.x = op.x;
 350                 ppp.y = op.y;
 351                 ppp.z = op.z + 0.25;
 352
 353                 t += 0.1;
 354                 if (t >= 1.0)
 355                 {
 356                         t = t - 1;
 357                         k++;
 358                         p = p->next;
 359                 }
 360
 361                 if (p->next->next->next)
 362                 {
 363                         p1 = p;
 364                         for (i=0; i<4; i++)
 365                         {
 366                                 p4[i].x = p1->p.x;
 367                                 p4[i].y = p1->p.y;
 368                                 p4[i].z = p1->p.z;
 369                                 p1 = p1->next;
 370                         }
 371                 }
 372                 else
 373                 {
 374                         /*  End of tunnel */
 375                         st->ModeX = 1.0;
 376                         st->ModeXFlag = 0;
 377                         return;
 378                 }
 379
 380                 cvCatmullRom(p4, t, &op1);
 381
 382                 ppp1.x = op1.x;
 383                 ppp1.y = op1.y;
 384                 ppp1.z = op1.z + 0.25;
 385
 386                 T.x = op1.x - op.x;
 387                 T.y = op1.y - op.y;
 388                 T.z = op1.z - op.z;
 389
 390                 normalize(&T);
 391
 392                 for (i=0; i<10; i++)
 393                 {
 394                         RotateAroundLine(&ppp, &op, &T, ((float)i*36.0*M_PI/180.0), &op2);
 395                         points[i].x = op2.x;
 396                         points[i].y = op2.y;
 397                         points[i].z = op2.z;
 398                         if (!flag)
 399                         {
 400                                 st->prev_points[i].x = op2.x;
 401                                 st->prev_points[i].y = op2.y;
 402                                 st->prev_points[i].z = op2.z;
 403                         }
 404                 }
 405
 406                 if (!flag)
 407                 {
 408                         flag = 1;
 409                         continue;
 410                 }
 411
 412                 /*  Draw 10 polygons for current point */
 413                 for (i=0; i<10; i++)
 414                 {
 415                         j = i+1;
 416                         if (j > 9) j = 0;
 417                         glNormal3f(0, 0, 1); /*  Normal for lighting */
 418                         glTexCoord2f(0, 0); glVertex3f(st->prev_points[i].x, st->prev_points[i].y, st->prev_points[i].z);
 419                         glNormal3f(0, 0, 1);
 420                         glTexCoord2f(1, 0); glVertex3f(points[i].x, points[i].y, points[i].z);
 421                         glNormal3f(0, 0, 1);
 422                         glTexCoord2f(1, 1); glVertex3f(points[j].x, points[j].y, points[j].z);
 423                         glNormal3f(0, 0, 1);
 424                         glTexCoord2f(0, 1); glVertex3f(st->prev_points[j].x, st->prev_points[j].y, st->prev_points[j].z);
 425                 }
 426                 /*  Save current polygon coordinates for next position */
 427                 for (i=0; i<10; i++)
 428                 {
 429                         st->prev_points[i].x = points[i].x;
 430                         st->prev_points[i].y = points[i].y;
 431                         st->prev_points[i].z = points[i].z;
 432                 }
 433         }
 434         glEnd();
 435         st->cam_pos = cmpos;
 436 }
 437
 438 /* =================== Show splash screen =================================== */
 439 void SplashScreen(struct tunnel_state *st,
 440                   int do_wire, int do_texture, int do_light)
 441 {
 442         if (st->ModeX > 0)
 443         {
 444                 /*  Reset tunnel and camera position */
 445                 if (!st->ModeXFlag)
 446                 {
 447                         st->cam_pos = st->path;
 448                         st->cam_t = 0;
 449                         st->tFlag = 0;
 450                         st->ModeXFlag = 1;
 451                         st->current_texture++;
 452                         if (st->current_texture >= MAX_TEXTURE) st->current_texture = 0;
 453                 }
 454                 /*  Now we want to draw splash screen */
 455                 glLoadIdentity();
 456                 /*  Disable all unused features */
 457                 glDisable(GL_DEPTH_TEST);
 458                 glDisable(GL_LIGHTING);
 459                 glDisable(GL_FOG);
 460                 glDisable(GL_CULL_FACE);
 461
 462                 glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
 463                 glEnable(GL_BLEND);
 464                 glDisable(GL_TEXTURE_2D);
 465                 glColor4f(1, 1, 1, st->ModeX);
 466
 467                 /*  Draw splash screen (simply quad) */
 468                 glBegin(GL_QUADS);
 469                 glVertex3f(-10, -10, -1);
 470                 glVertex3f(10, -10, -1);
 471                 glVertex3f(10, 10, -1);
 472                 glVertex3f(-10, 10, -1);
 473                 glEnd();
 474
 475                 st->ModeX -= 0.05;
 476                 if (st->ModeX <= 0)     st->ModeX = 0;
 477
 478                 if (!do_wire)
 479                 {
 480                         glEnable(GL_CULL_FACE);
 481                         glEnable(GL_DEPTH_TEST);
 482                 }
 483                 if (do_light)
 484                 {
 485                         glEnable(GL_LIGHTING);
 486                         glEnable(GL_FOG);
 487                 }
 488                 if (do_texture)
 489                 {
 490                         glEnable(GL_TEXTURE_2D);
 491                 }
 492                 glDisable(GL_BLEND);
 493                 glColor4f(1, 1, 1, 1);
 494         }
 495 }
 496
 497 void FreeTunnel(struct tunnel_state *st)
 498 {
 499   free (st);
 500 }
 501
 502 #endif