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_JWXYZ
  49 #  include <GL/gl.h>
  50 #  include <GL/glu.h>
  51 # endif
  52 #endif
  53 #ifdef HAVE_ANDROID
  54 #include <GLES/gl.h>
  55 #endif
  56
  57
  58 #include "tunnel_draw.h"
  59
  60 #ifdef STANDALONE /* For NRAND() */
  61 #include "xlockmoreI.h"          /* in xscreensaver distribution */
  62 #else /* STANDALONE */
  63 #include "xlock.h"              /* in xlockmore distribution */
  64 #endif /* STANDALONE */
  65
  66 typedef struct
  67 {
  68   float x, y, z; /* Point coordinates */
  69 } cvPoint;
  70
  71 typedef struct _tnPath
  72 {
  73         cvPoint p;
  74         struct _tnPath *next;
  75 } tnPath;
  76
  77
  78 static const cvPoint initpath[]={
  79 {0.000000, 0.000000, 0.000000},
  80 {2.000000, 1.000000, 0.000000},
  81 {4.000000, 0.000000, 0.000000},
  82 {6.000000, 1.000000, 0.000000},
  83 {8.000000, 0.000000, 1.000000},
  84 {10.000000, 1.000000, 1.000000},
  85 {12.000000, 1.500000, 0.000000},
  86 {14.000000, 0.000000, 0.000000},
  87 {16.000000, 1.000000, 0.000000},
  88 {18.000000, 0.000000, 0.000000},
  89 {20.000000, 0.000000, 1.000000},
  90 {22.000000, 1.000000, 0.000000},
  91 {24.000000, 0.000000, 1.000000},
  92 {26.000000, 0.000000, 1.000000},
  93 {28.000000, 1.000000, 0.000000},
  94 {30.000000, 0.000000, 2.000000},
  95 {32.000000, 1.000000, 0.000000},
  96 {34.000000, 0.000000, 2.000000},
  97 {-1.000000, -1.000000, -1.000000}
  98 };
  99
 100
 101 struct tunnel_state {
 102
 103   tnPath *path;
 104
 105   float cam_t;                                  /* Camera variables */
 106   tnPath *cam_pos;
 107   float alpha;
 108
 109   int tFlag;                                    /* Tunnel Drawing Variables */
 110   cvPoint prev_points[10];
 111   int current_texture;
 112
 113   float ModeX;                                  /* Modes */
 114   int ModeXFlag;
 115 };
 116
 117 /*=================== Vector normalization ==================================*/
 118 static void
 119 normalize(cvPoint *V)
 120 {
 121   float d;
 122
 123   /* Vector length */
 124   d = (float)sqrt(V->x*V->x + V->y*V->y + V->z*V->z);
 125
 126   /* Normalization */
 127   V->x /= d;
 128   V->y /= d;
 129   V->z /= d;
 130 }
 131 /*=================== C = A x B  (Vector multiply) ==========================*/
 132 #if 0
 133 static void
 134 vect_mult(cvPoint *A, cvPoint *B, cvPoint *C)
 135 {
 136         /* Vector multiply */
 137         C->x = A->y*B->z - A->z*B->y;
 138         C->y = A->z*B->x - A->x*B->z;
 139         C->z = A->x*B->y - A->y*B->x;
 140 }
 141 #endif
 142
 143 /* Catmull-Rom Curve calculations */
 144 static void
 145 cvCatmullRom(cvPoint *p, float t, cvPoint *outp)
 146 {
 147         float t2, t3, t1;
 148
 149         t2 = t*t;
 150         t3 = t*t*t;
 151         t1 = (1-t)*(1-t);
 152
 153         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;
 154         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;
 155         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;
 156 }
 157
 158 /*=================== Point Rotating Around Line ===========================
 159 // p    - original point
 160 // pp   - pivot point
 161 // pl   - pivot line (vector)
 162 // a    - angle to rotate in radians
 163 // outp - output point
 164 //==========================================================================
 165 */
 166 static void
 167 RotateAroundLine(cvPoint *p, cvPoint *pp, cvPoint *pl, float a, cvPoint *outp)
 168 {
 169         cvPoint p1, p2;
 170         float l, m, n, ca, sa;
 171
 172         p1.x = p->x - pp->x;
 173         p1.y = p->y - pp->y;
 174         p1.z = p->z - pp->z;
 175
 176         l = pl->x;
 177         m = pl->y;
 178         n = pl->z;
 179
 180         ca = cos(a);
 181         sa = sin(a);
 182
 183         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);
 184         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);
 185         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));
 186
 187         outp->x = p2.x + pp->x;
 188         outp->y = p2.y + pp->y;
 189         outp->z = p2.z + pp->z;
 190 }
 191
 192
 193 /*=================== Load camera and tunnel path ==========================*/
 194 static void
 195 LoadPath(struct tunnel_state *st)
 196 {
 197         float x, y, z;
 198         tnPath *path1=NULL, *path2=NULL;
 199
 200         cvPoint *f = (cvPoint *)initpath;
 201
 202         while (f->x != -1.0)
 203         {
 204                 x = f->x;
 205                 y = f->y;
 206                 z = f->z;
 207                 f++;
 208
 209                 if (st->path == NULL)
 210                 {
 211                         st->path = (tnPath *)malloc(sizeof(tnPath));
 212                         path1 = st->path;
 213                 }
 214                 else
 215                 {
 216                         if (!path1) path1 = st->path;
 217                         path2 = (tnPath *)malloc(sizeof(tnPath));
 218                         path1->next = path2;
 219                         path1 = path2;
 220                 }
 221
 222                 path1->next = NULL;
 223                 path1->p.x = x;
 224                 path1->p.y = y;
 225                 path1->p.z = z;
 226         }
 227
 228         st->cam_pos = st->path;
 229         st->cam_t = 0;
 230 }
 231
 232 /*=================== Tunnel Initialization ================================*/
 233 struct tunnel_state *
 234 atunnel_InitTunnel(void)
 235 {
 236     struct tunnel_state *st = (struct tunnel_state *) calloc (1, sizeof(*st));
 237         LoadPath(st);
 238         st->current_texture = NRAND(MAX_TEXTURE);
 239     return st;
 240 }
 241
 242 void
 243 atunnel_DrawTunnel(struct tunnel_state *st,
 244                 int do_texture, int do_light, GLuint *textures)
 245 {
 246         tnPath *p, *p1, *cmpos;
 247         cvPoint op, p4[4], T, ppp, op1, op2;
 248         float t;
 249         int i, j, k, flag;
 250         cvPoint points[10];
 251         GLfloat light_position[4];
 252
 253
 254         /* Select current tunnel texture */
 255         if (do_texture)
 256                 glBindTexture(GL_TEXTURE_2D, textures[st->current_texture]);
 257
 258         cmpos = st->cam_pos;
 259         /* Get current curve */
 260         if (st->cam_pos->next &&
 261             st->cam_pos->next->next &&
 262             st->cam_pos->next->next->next)
 263         {
 264                 p1 = st->cam_pos;
 265                 for (i=0; i<4; i++)
 266                 {
 267                         p4[i].x = p1->p.x;
 268                         p4[i].y = p1->p.y;
 269                         p4[i].z = p1->p.z;
 270                         p1 = p1->next;
 271                 }
 272         }
 273         else
 274         {
 275                 /* End of tunnel */
 276                 st->ModeX = 1.0;
 277                 st->ModeXFlag = 0;
 278                 return;
 279         };
 280
 281         /* Get current camera position */
 282         cvCatmullRom(p4, st->cam_t, &op);
 283
 284         /* Next camera position */
 285         st->cam_t += 0.02f;
 286         if (st->cam_t >= 1)
 287         {
 288                 st->cam_t = st->cam_t - 1;
 289                 cmpos = st->cam_pos->next;
 290         }
 291
 292         /* Get curve for next camera position */
 293         if (cmpos->next->next->next)
 294         {
 295                 p1 = cmpos;
 296                 for (i=0; i<4; i++)
 297                 {
 298                         p4[i].x = p1->p.x;
 299                         p4[i].y = p1->p.y;
 300                         p4[i].z = p1->p.z;
 301                         p1 = p1->next;
 302                 }
 303         }
 304         else
 305         {
 306                 /*  End of tunnel */
 307                 st->ModeX = 1.0;
 308                 st->ModeXFlag = 0;
 309                 return;
 310         }
 311
 312         /*  Get next camera position */
 313         cvCatmullRom(p4, st->cam_t, &op1);
 314
 315         /*  Rotate camera */
 316         glRotatef(st->alpha, 0, 0, -1);
 317         st->alpha += 1;
 318         /*  Set camera position */
 319         gluLookAt(op.x, op.y, op.z, op1.x, op1.y, op1.z, 0, 1, 0);
 320
 321         /*  Set light position */
 322         if (do_light)
 323         {
 324                 light_position[0] = op.x;
 325                 light_position[1] = op.y;
 326                 light_position[2] = op.z;
 327                 light_position[3] = 1;
 328                 glLightfv(GL_LIGHT0, GL_POSITION, light_position);
 329         }
 330
 331         p = st->cam_pos;
 332         flag = 0;
 333         t = 0;
 334         k = 0;
 335         /*  Draw tunnel from current curve and next 2 curves */
 336         glBegin(GL_QUADS);
 337         while (k < 3)
 338         {
 339                 if (p->next->next->next)
 340                 {
 341                         p1 = p;
 342                         for (i=0; i<4; i++)
 343                         {
 344                                 p4[i].x = p1->p.x;
 345                                 p4[i].y = p1->p.y;
 346                                 p4[i].z = p1->p.z;
 347                                 p1 = p1->next;
 348                         }
 349                 }
 350                 else
 351                 {
 352                         /*  End of tunnel */
 353                         st->ModeX = 1.0;
 354                         st->ModeXFlag = 0;
 355             glEnd();
 356                         return;
 357                 }
 358                 cvCatmullRom(p4, t, &op);
 359
 360                 ppp.x = op.x;
 361                 ppp.y = op.y;
 362                 ppp.z = op.z + 0.25;
 363
 364                 t += 0.1;
 365                 if (t >= 1.0)
 366                 {
 367                         t = t - 1;
 368                         k++;
 369                         p = p->next;
 370                 }
 371
 372                 if (p->next->next->next)
 373                 {
 374                         p1 = p;
 375                         for (i=0; i<4; i++)
 376                         {
 377                                 p4[i].x = p1->p.x;
 378                                 p4[i].y = p1->p.y;
 379                                 p4[i].z = p1->p.z;
 380                                 p1 = p1->next;
 381                         }
 382                 }
 383                 else
 384                 {
 385                         /*  End of tunnel */
 386                         st->ModeX = 1.0;
 387                         st->ModeXFlag = 0;
 388             glEnd();
 389                         return;
 390                 }
 391
 392                 cvCatmullRom(p4, t, &op1);
 393
 394                 T.x = op1.x - op.x;
 395                 T.y = op1.y - op.y;
 396                 T.z = op1.z - op.z;
 397
 398                 normalize(&T);
 399
 400                 for (i=0; i<10; i++)
 401                 {
 402                         RotateAroundLine(&ppp, &op, &T, ((float)i*36.0*M_PI/180.0), &op2);
 403                         points[i].x = op2.x;
 404                         points[i].y = op2.y;
 405                         points[i].z = op2.z;
 406                         if (!flag)
 407                         {
 408                                 st->prev_points[i].x = op2.x;
 409                                 st->prev_points[i].y = op2.y;
 410                                 st->prev_points[i].z = op2.z;
 411                         }
 412                 }
 413
 414                 if (!flag)
 415                 {
 416                         flag = 1;
 417                         continue;
 418                 }
 419
 420                 /*  Draw 10 polygons for current point */
 421                 for (i=0; i<10; i++)
 422                 {
 423                         j = i+1;
 424                         if (j > 9) j = 0;
 425                         glNormal3f(0, 0, 1); /*  Normal for lighting */
 426                         glTexCoord2f(0, 0); glVertex3f(st->prev_points[i].x, st->prev_points[i].y, st->prev_points[i].z);
 427                         glNormal3f(0, 0, 1);
 428                         glTexCoord2f(1, 0); glVertex3f(points[i].x, points[i].y, points[i].z);
 429                         glNormal3f(0, 0, 1);
 430                         glTexCoord2f(1, 1); glVertex3f(points[j].x, points[j].y, points[j].z);
 431                         glNormal3f(0, 0, 1);
 432                         glTexCoord2f(0, 1); glVertex3f(st->prev_points[j].x, st->prev_points[j].y, st->prev_points[j].z);
 433                 }
 434                 /*  Save current polygon coordinates for next position */
 435                 for (i=0; i<10; i++)
 436                 {
 437                         st->prev_points[i].x = points[i].x;
 438                         st->prev_points[i].y = points[i].y;
 439                         st->prev_points[i].z = points[i].z;
 440                 }
 441         }
 442         glEnd();
 443         st->cam_pos = cmpos;
 444 }
 445
 446 /* =================== Show splash screen =================================== */
 447 void
 448 atunnel_SplashScreen(struct tunnel_state *st,
 449                   int do_wire, int do_texture, int do_light)
 450 {
 451         if (st->ModeX > 0)
 452         {
 453                 /*  Reset tunnel and camera position */
 454                 if (!st->ModeXFlag)
 455                 {
 456                         st->cam_pos = st->path;
 457                         st->cam_t = 0;
 458                         st->tFlag = 0;
 459                         st->ModeXFlag = 1;
 460                         st->current_texture++;
 461                         if (st->current_texture >= MAX_TEXTURE) st->current_texture = 0;
 462                 }
 463                 /*  Now we want to draw splash screen */
 464                 glLoadIdentity();
 465                 /*  Disable all unused features */
 466                 glDisable(GL_DEPTH_TEST);
 467                 glDisable(GL_LIGHTING);
 468                 glDisable(GL_FOG);
 469                 glDisable(GL_CULL_FACE);
 470
 471                 glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
 472                 glEnable(GL_BLEND);
 473                 glDisable(GL_TEXTURE_2D);
 474                 glColor4f(1, 1, 1, st->ModeX);
 475
 476                 /*  Draw splash screen (simply quad) */
 477                 glBegin(GL_QUADS);
 478                 glVertex3f(-10, -10, -1);
 479                 glVertex3f(10, -10, -1);
 480                 glVertex3f(10, 10, -1);
 481                 glVertex3f(-10, 10, -1);
 482                 glEnd();
 483
 484                 st->ModeX -= 0.05;
 485                 if (st->ModeX <= 0)     st->ModeX = 0;
 486
 487                 if (!do_wire)
 488                 {
 489                         glEnable(GL_CULL_FACE);
 490                         glEnable(GL_DEPTH_TEST);
 491                 }
 492                 if (do_light)
 493                 {
 494                         glEnable(GL_LIGHTING);
 495                         glEnable(GL_FOG);
 496                 }
 497                 if (do_texture)
 498                 {
 499                         glEnable(GL_TEXTURE_2D);
 500                 }
 501                 glDisable(GL_BLEND);
 502                 glColor4f(1, 1, 1, 1);
 503         }
 504 }
 505
 506 void
 507 atunnel_FreeTunnel(struct tunnel_state *st)
 508 {
 509   free (st);
 510 }
 511
 512 #endif