1 /* hypertorus --- Shows a hypertorus that rotates in 4d */
4 static const char sccsid[] = "@(#)hypertorus.c 1.2 05/09/28 xlockmore";
7 /* Copyright (c) 2003-2009 Carsten Steger <carsten@mirsanmir.org>. */
10 * Permission to use, copy, modify, and distribute this software and its
11 * documentation for any purpose and without fee is hereby granted,
12 * provided that the above copyright notice appear in all copies and that
13 * both that copyright notice and this permission notice appear in
14 * supporting documentation.
16 * This file is provided AS IS with no warranties of any kind. The author
17 * shall have no liability with respect to the infringement of copyrights,
18 * trade secrets or any patents by this file or any part thereof. In no
19 * event will the author be liable for any lost revenue or profits or
20 * other special, indirect and consequential damages.
23 * C. Steger - 03/05/18: Initial version
24 * C. Steger - 05/09/28: Added the spirals appearance mode
25 * and trackball support
26 * C. Steger - 07/01/23: Improved 4d trackball support
27 * C. Steger - 09/08/22: Removed check-config.pl warnings
31 * This program shows the Clifford torus as it rotates in 4d. The Clifford
32 * torus is a torus lies on the "surface" of the hypersphere in 4d. The
33 * program projects the 4d torus to 3d using either a perspective or an
34 * orthographic projection. Of the two alternatives, the perspecitve
35 * projection looks much more appealing. In orthographic projections the
36 * torus degenerates into a doubly covered cylinder for some angles. The
37 * projected 3d torus can then be projected to the screen either perspectively
38 * or orthographically. There are three display modes for the torus: mesh
39 * (wireframe), solid, or transparent. Furthermore, the appearance of the
40 * torus can be as a solid object or as a set of see-through bands or
41 * see-through spirals. Finally, the colors with with the torus is drawn can
42 * be set to either two-sided or to colorwheel. In the first case, the torus
43 * is drawn with red on the outside and green on the inside. This mode
44 * enables you to see that the torus turns inside-out as it rotates in 4d.
45 * The second mode draws the torus in a fully saturated color wheel. This
46 * gives a very nice effect when combined with the see-through bands or
47 * see-through spirals mode. The rotation speed for each of the six planes
48 * around which the torus rotates can be chosen. This program is very much
49 * inspired by Thomas Banchoff's book "Beyond the Third Dimension: Geometry,
50 * Computer Graphics, and Higher Dimensions", Scientific American Library,
55 #define M_PI 3.14159265358979323846
58 #define DISP_WIREFRAME 0
59 #define DISP_SURFACE 1
60 #define DISP_TRANSPARENT 2
62 #define APPEARANCE_SOLID 0
63 #define APPEARANCE_BANDS 1
64 #define APPEARANCE_SPIRALS 2
66 #define COLORS_TWOSIDED 0
67 #define COLORS_COLORWHEEL 1
69 #define DISP_3D_PERSPECTIVE 0
70 #define DISP_3D_ORTHOGRAPHIC 1
72 #define DISP_4D_PERSPECTIVE 0
73 #define DISP_4D_ORTHOGRAPHIC 1
75 #define DEF_DISPLAY_MODE "surface"
76 #define DEF_APPEARANCE "bands"
77 #define DEF_COLORS "colorwheel"
78 #define DEF_PROJECTION_3D "perspective"
79 #define DEF_PROJECTION_4D "perspective"
80 #define DEF_SPEEDWX "1.1"
81 #define DEF_SPEEDWY "1.3"
82 #define DEF_SPEEDWZ "1.5"
83 #define DEF_SPEEDXY "1.7"
84 #define DEF_SPEEDXZ "1.9"
85 #define DEF_SPEEDYZ "2.1"
88 # define DEFAULTS "*delay: 25000 \n" \
89 "*showFPS: False \n" \
90 "*suppressRotationAnimation: True\n" \
92 # define free_hypertorus 0
93 # define release_hypertorus 0
94 # include "xlockmore.h" /* from the xscreensaver distribution */
95 #else /* !STANDALONE */
96 # include "xlock.h" /* from the xlockmore distribution */
97 #endif /* !STANDALONE */
101 #include "gltrackball.h"
105 ModStruct hypertorus_description =
106 {"hypertorus", "init_hypertorus", "draw_hypertorus", NULL,
107 "draw_hypertorus", "change_hypertorus", NULL, &hypertorus_opts,
108 25000, 1, 1, 1, 1.0, 4, "",
109 "Shows a hypertorus rotating in 4d", 0, NULL};
115 static int display_mode;
117 static int appearance;
118 static int num_spirals;
119 static char *color_mode;
121 static char *proj_3d;
122 static int projection_3d;
123 static char *proj_4d;
124 static int projection_4d;
125 static float speed_wx;
126 static float speed_wy;
127 static float speed_wz;
128 static float speed_xy;
129 static float speed_xz;
130 static float speed_yz;
132 static const float offset4d[4] = { 0.0, 0.0, 0.0, 2.0 };
133 static const float offset3d[4] = { 0.0, 0.0, -2.0, 0.0 };
136 static XrmOptionDescRec opts[] =
138 {"-mode", ".displayMode", XrmoptionSepArg, 0 },
139 {"-wireframe", ".displayMode", XrmoptionNoArg, "wireframe" },
140 {"-surface", ".displayMode", XrmoptionNoArg, "surface" },
141 {"-transparent", ".displayMode", XrmoptionNoArg, "transparent" },
142 {"-appearance", ".appearance", XrmoptionSepArg, 0 },
143 {"-solid", ".appearance", XrmoptionNoArg, "solid" },
144 {"-bands", ".appearance", XrmoptionNoArg, "bands" },
145 {"-spirals-1", ".appearance", XrmoptionNoArg, "spirals-1" },
146 {"-spirals-2", ".appearance", XrmoptionNoArg, "spirals-2" },
147 {"-spirals-4", ".appearance", XrmoptionNoArg, "spirals-4" },
148 {"-spirals-8", ".appearance", XrmoptionNoArg, "spirals-8" },
149 {"-spirals-16", ".appearance", XrmoptionNoArg, "spirals-16" },
150 {"-twosided", ".colors", XrmoptionNoArg, "twosided" },
151 {"-colorwheel", ".colors", XrmoptionNoArg, "colorwheel" },
152 {"-perspective-3d", ".projection3d", XrmoptionNoArg, "perspective" },
153 {"-orthographic-3d", ".projection3d", XrmoptionNoArg, "orthographic" },
154 {"-perspective-4d", ".projection4d", XrmoptionNoArg, "perspective" },
155 {"-orthographic-4d", ".projection4d", XrmoptionNoArg, "orthographic" },
156 {"-speed-wx", ".speedwx", XrmoptionSepArg, 0 },
157 {"-speed-wy", ".speedwy", XrmoptionSepArg, 0 },
158 {"-speed-wz", ".speedwz", XrmoptionSepArg, 0 },
159 {"-speed-xy", ".speedxy", XrmoptionSepArg, 0 },
160 {"-speed-xz", ".speedxz", XrmoptionSepArg, 0 },
161 {"-speed-yz", ".speedyz", XrmoptionSepArg, 0 }
164 static argtype vars[] =
166 { &mode, "displayMode", "DisplayMode", DEF_DISPLAY_MODE, t_String },
167 { &appear, "appearance", "Appearance", DEF_APPEARANCE, t_String },
168 { &color_mode, "colors", "Colors", DEF_COLORS, t_String },
169 { &proj_3d, "projection3d", "Projection3d", DEF_PROJECTION_3D, t_String },
170 { &proj_4d, "projection4d", "Projection4d", DEF_PROJECTION_4D, t_String },
171 { &speed_wx, "speedwx", "Speedwx", DEF_SPEEDWX, t_Float},
172 { &speed_wy, "speedwy", "Speedwy", DEF_SPEEDWY, t_Float},
173 { &speed_wz, "speedwz", "Speedwz", DEF_SPEEDWZ, t_Float},
174 { &speed_xy, "speedxy", "Speedxy", DEF_SPEEDXY, t_Float},
175 { &speed_xz, "speedxz", "Speedxz", DEF_SPEEDXZ, t_Float},
176 { &speed_yz, "speedyz", "Speedyz", DEF_SPEEDYZ, t_Float}
179 static OptionStruct desc[] =
181 { "-wireframe", "display the torus as a wireframe mesh" },
182 { "-surface", "display the torus as a solid surface" },
183 { "-transparent", "display the torus as a transparent surface" },
184 { "-solid", "display the torus as a solid object" },
185 { "-bands", "display the torus as see-through bands" },
186 { "-spirals-{1,2,4,8,16}", "display the torus as see-through spirals" },
187 { "-twosided", "display the torus with two colors" },
188 { "-colorwheel", "display the torus with a smooth color wheel" },
189 { "-perspective-3d", "project the torus perspectively from 3d to 2d" },
190 { "-orthographic-3d", "project the torus orthographically from 3d to 2d" },
191 { "-perspective-4d", "project the torus perspectively from 4d to 3d" },
192 { "-orthographic-4d", "project the torus orthographically from 4d to 3d" },
193 { "-speed-wx <arg>", "rotation speed around the wx plane" },
194 { "-speed-wy <arg>", "rotation speed around the wy plane" },
195 { "-speed-wz <arg>", "rotation speed around the wz plane" },
196 { "-speed-xy <arg>", "rotation speed around the xy plane" },
197 { "-speed-xz <arg>", "rotation speed around the xz plane" },
198 { "-speed-yz <arg>", "rotation speed around the yz plane" }
201 ENTRYPOINT ModeSpecOpt hypertorus_opts =
202 {sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, desc};
207 GLXContext *glx_context;
208 /* 4D rotation angles */
209 float alpha, beta, delta, zeta, eta, theta;
210 /* Aspect ratio of the current window */
212 /* Trackball states */
213 trackball_state *trackballs[2];
214 int current_trackball;
221 static hypertorusstruct *hyper = (hypertorusstruct *) NULL;
224 /* Add a rotation around the wx-plane to the matrix m. */
225 static void rotatewx(float m[4][4], float phi)
243 /* Add a rotation around the wy-plane to the matrix m. */
244 static void rotatewy(float m[4][4], float phi)
262 /* Add a rotation around the wz-plane to the matrix m. */
263 static void rotatewz(float m[4][4], float phi)
281 /* Add a rotation around the xy-plane to the matrix m. */
282 static void rotatexy(float m[4][4], float phi)
300 /* Add a rotation around the xz-plane to the matrix m. */
301 static void rotatexz(float m[4][4], float phi)
319 /* Add a rotation around the yz-plane to the matrix m. */
320 static void rotateyz(float m[4][4], float phi)
338 /* Compute the rotation matrix m from the rotation angles. */
339 static void rotateall(float al, float be, float de, float ze, float et,
340 float th, float m[4][4])
356 /* Multiply two rotation matrices: o=m*n. */
357 static void mult_rotmat(float m[4][4], float n[4][4], float o[4][4])
367 o[i][j] += m[i][k]*n[k][j];
373 /* Compute a 4D rotation matrix from two unit quaternions. */
374 static void quats_to_rotmat(float p[4], float q[4], float m[4][4])
376 double al, be, de, ze, et, th;
377 double r00, r01, r02, r12, r22;
379 r00 = 1.0-2.0*(p[1]*p[1]+p[2]*p[2]);
380 r01 = 2.0*(p[0]*p[1]+p[2]*p[3]);
381 r02 = 2.0*(p[2]*p[0]-p[1]*p[3]);
382 r12 = 2.0*(p[1]*p[2]+p[0]*p[3]);
383 r22 = 1.0-2.0*(p[1]*p[1]+p[0]*p[0]);
385 al = atan2(-r12,r22)*180.0/M_PI;
386 be = atan2(r02,sqrt(r00*r00+r01*r01))*180.0/M_PI;
387 de = atan2(-r01,r00)*180.0/M_PI;
389 r00 = 1.0-2.0*(q[1]*q[1]+q[2]*q[2]);
390 r01 = 2.0*(q[0]*q[1]+q[2]*q[3]);
391 r02 = 2.0*(q[2]*q[0]-q[1]*q[3]);
392 r12 = 2.0*(q[1]*q[2]+q[0]*q[3]);
393 r22 = 1.0-2.0*(q[1]*q[1]+q[0]*q[0]);
395 et = atan2(-r12,r22)*180.0/M_PI;
396 th = atan2(r02,sqrt(r00*r00+r01*r01))*180.0/M_PI;
397 ze = atan2(-r01,r00)*180.0/M_PI;
399 rotateall(al,be,de,ze,et,-th,m);
403 /* Compute a fully saturated and bright color based on an angle. */
404 static void color(double angle)
410 if (colors != COLORS_COLORWHEEL)
414 angle = fmod(angle,2*M_PI);
416 angle = fmod(angle,-2*M_PI);
417 s = floor(angle/(M_PI/3));
418 t = angle/(M_PI/3)-s;
454 if (display_mode == DISP_TRANSPARENT)
459 glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,color);
463 /* Draw a hypertorus projected into 3D. Note that the spirals appearance
464 will only work correctly if numu and numv are set to 64 or any higher
465 power of 2. Similarly, the banded appearance will only work correctly
466 if numu and numv are divisible by 4. */
467 static int hypertorus(ModeInfo *mi, double umin, double umax, double vmin,
468 double vmax, int numu, int numv)
471 static const GLfloat mat_diff_red[] = { 1.0, 0.0, 0.0, 1.0 };
472 static const GLfloat mat_diff_green[] = { 0.0, 1.0, 0.0, 1.0 };
473 static const GLfloat mat_diff_trans_red[] = { 1.0, 0.0, 0.0, 0.7 };
474 static const GLfloat mat_diff_trans_green[] = { 0.0, 1.0, 0.0, 0.7 };
475 float p[3], pu[3], pv[3], n[3], mat[4][4];
476 int i, j, k, l, m, b, skew;
478 double cu, su, cv, sv;
479 double xx[4], xxu[4], xxv[4], x[4], xu[4], xv[4];
481 float q1[4], q2[4], r1[4][4], r2[4][4];
482 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
484 rotateall(hp->alpha,hp->beta,hp->delta,hp->zeta,hp->eta,hp->theta,r1);
486 gltrackball_get_quaternion(hp->trackballs[0],q1);
487 gltrackball_get_quaternion(hp->trackballs[1],q2);
488 quats_to_rotmat(q1,q2,r2);
490 mult_rotmat(r2,r1,mat);
492 if (colors != COLORS_COLORWHEEL)
494 glColor3fv(mat_diff_red);
495 if (display_mode == DISP_TRANSPARENT)
497 glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_red);
498 glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_green);
502 glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_red);
503 glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_green);
507 #if 0 /* #### not working */
508 # ifdef HAVE_MOBILE /* Keep it the same relative size when rotated. */
510 GLfloat h = MI_HEIGHT(mi) / (GLfloat) MI_WIDTH(mi);
511 int o = (int) current_device_rotation();
512 if (o != 0 && o != 180 && o != -180)
513 glScalef (1/h, 1/h, 1/h);
521 for (i=0; i<numu; i++)
523 if ((appearance == APPEARANCE_BANDS ||
524 appearance == APPEARANCE_SPIRALS) && ((i & 3) >= 2))
526 if (display_mode == DISP_WIREFRAME)
527 glBegin(GL_QUAD_STRIP);
529 glBegin(GL_TRIANGLE_STRIP);
530 for (j=0; j<=numv; j++)
538 if (appearance == APPEARANCE_SPIRALS)
540 u += 4.0*skew/numv*v;
541 b = ((i/4)&(skew-1))*(numu/(4*skew));
542 color(ur*4*b/numu+umin);
571 r += mat[l][m]*xx[m];
572 s += mat[l][m]*xxu[m];
573 t += mat[l][m]*xxv[m];
579 if (projection_4d == DISP_4D_ORTHOGRAPHIC)
583 p[l] = (x[l]+offset4d[l])/1.5+offset3d[l];
590 s = x[3]+offset4d[3];
594 r = x[l]+offset4d[l];
595 p[l] = r/s+offset3d[l];
596 pu[l] = (xu[l]*s-r*xu[3])/t;
597 pv[l] = (xv[l]*s-r*xv[3])/t;
600 n[0] = pu[1]*pv[2]-pu[2]*pv[1];
601 n[1] = pu[2]*pv[0]-pu[0]*pv[2];
602 n[2] = pu[0]*pv[1]-pu[1]*pv[0];
603 t = sqrt(n[0]*n[0]+n[1]*n[1]+n[2]*n[2]);
619 static void init(ModeInfo *mi)
621 static const GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
622 static const GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
623 static const GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
624 static const GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
625 static const GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
626 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
635 glMatrixMode(GL_PROJECTION);
637 if (projection_3d == DISP_3D_PERSPECTIVE)
638 gluPerspective(60.0,1.0,0.1,100.0);
640 glOrtho(-1.0,1.0,-1.0,1.0,0.1,100.0);;
641 glMatrixMode(GL_MODELVIEW);
644 # ifdef HAVE_JWZGLES /* #### glPolygonMode other than GL_FILL unimplemented */
645 if (display_mode == DISP_WIREFRAME)
646 display_mode = DISP_SURFACE;
649 if (display_mode == DISP_SURFACE)
651 glEnable(GL_DEPTH_TEST);
652 glDepthFunc(GL_LESS);
653 glShadeModel(GL_SMOOTH);
654 glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
655 glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
656 glEnable(GL_LIGHTING);
658 glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient);
659 glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse);
660 glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular);
661 glLightfv(GL_LIGHT0,GL_POSITION,light_position);
662 glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,mat_specular);
663 glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,50.0);
664 glDepthMask(GL_TRUE);
667 else if (display_mode == DISP_TRANSPARENT)
669 glDisable(GL_DEPTH_TEST);
670 glShadeModel(GL_SMOOTH);
671 glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
672 glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
673 glEnable(GL_LIGHTING);
675 glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient);
676 glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse);
677 glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular);
678 glLightfv(GL_LIGHT0,GL_POSITION,light_position);
679 glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,mat_specular);
680 glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,50.0);
681 glDepthMask(GL_FALSE);
683 glBlendFunc(GL_SRC_ALPHA,GL_ONE);
685 else /* display_mode == DISP_WIREFRAME */
687 glDisable(GL_DEPTH_TEST);
688 glShadeModel(GL_FLAT);
689 glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
690 glDisable(GL_LIGHTING);
691 glDisable(GL_LIGHT0);
697 /* Redisplay the hypertorus. */
698 static void display_hypertorus(ModeInfo *mi)
700 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
702 if (!hp->button_pressed)
704 hp->alpha += speed_wx * hp->speed_scale;
705 if (hp->alpha >= 360.0)
707 hp->beta += speed_wy * hp->speed_scale;
708 if (hp->beta >= 360.0)
710 hp->delta += speed_wz * hp->speed_scale;
711 if (hp->delta >= 360.0)
713 hp->zeta += speed_xy * hp->speed_scale;
714 if (hp->zeta >= 360.0)
716 hp->eta += speed_xz * hp->speed_scale;
717 if (hp->eta >= 360.0)
719 hp->theta += speed_yz * hp->speed_scale;
720 if (hp->theta >= 360.0)
724 glMatrixMode(GL_PROJECTION);
726 if (projection_3d == DISP_3D_ORTHOGRAPHIC)
728 if (hp->aspect >= 1.0)
729 glOrtho(-hp->aspect,hp->aspect,-1.0,1.0,0.1,100.0);
731 glOrtho(-1.0,1.0,-1.0/hp->aspect,1.0/hp->aspect,0.1,100.0);
735 gluPerspective(60.0,hp->aspect,0.1,100.0);
737 glMatrixMode(GL_MODELVIEW);
740 mi->polygon_count = hypertorus(mi,0.0,2.0*M_PI,0.0,2.0*M_PI,64,64);
744 ENTRYPOINT void reshape_hypertorus(ModeInfo *mi, int width, int height)
746 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
747 double h = (GLfloat) height / (GLfloat) width;
750 if (width > height * 5) { /* tiny window: show middle */
751 height = width * 9/16;
753 h = height / (GLfloat) width;
756 hp->WindW = (GLint)width;
757 hp->WindH = (GLint)height;
758 glViewport(0,y,width,height);
763 ENTRYPOINT Bool hypertorus_handle_event(ModeInfo *mi, XEvent *event)
765 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
769 if (event->xany.type == KeyPress || event->xany.type == KeyRelease)
770 XLookupString (&event->xkey, &c, 1, &sym, 0);
772 if (event->xany.type == ButtonPress &&
773 event->xbutton.button == Button1)
775 hp->button_pressed = True;
776 gltrackball_start(hp->trackballs[hp->current_trackball],
777 event->xbutton.x, event->xbutton.y,
778 MI_WIDTH(mi), MI_HEIGHT(mi));
781 else if (event->xany.type == ButtonRelease &&
782 event->xbutton.button == Button1)
784 hp->button_pressed = False;
787 else if (event->xany.type == KeyPress)
789 if (sym == XK_Shift_L || sym == XK_Shift_R)
791 hp->current_trackball = 1;
792 if (hp->button_pressed)
793 gltrackball_start(hp->trackballs[hp->current_trackball],
794 event->xbutton.x, event->xbutton.y,
795 MI_WIDTH(mi), MI_HEIGHT(mi));
799 else if (event->xany.type == KeyRelease)
801 if (sym == XK_Shift_L || sym == XK_Shift_R)
803 hp->current_trackball = 0;
804 if (hp->button_pressed)
805 gltrackball_start(hp->trackballs[hp->current_trackball],
806 event->xbutton.x, event->xbutton.y,
807 MI_WIDTH(mi), MI_HEIGHT(mi));
811 else if (event->xany.type == MotionNotify && hp->button_pressed)
813 gltrackball_track(hp->trackballs[hp->current_trackball],
814 event->xmotion.x, event->xmotion.y,
815 MI_WIDTH(mi), MI_HEIGHT(mi));
824 *-----------------------------------------------------------------------------
825 *-----------------------------------------------------------------------------
827 *-----------------------------------------------------------------------------
828 *-----------------------------------------------------------------------------
832 *-----------------------------------------------------------------------------
833 * Initialize hypertorus. Called each time the window changes.
834 *-----------------------------------------------------------------------------
837 ENTRYPOINT void init_hypertorus(ModeInfo *mi)
839 hypertorusstruct *hp;
842 hp = &hyper[MI_SCREEN(mi)];
845 hp->trackballs[0] = gltrackball_init(True);
846 hp->trackballs[1] = gltrackball_init(True);
847 hp->current_trackball = 0;
848 hp->button_pressed = False;
850 /* Set the display mode. */
851 if (!strcasecmp(mode,"wireframe") || !strcasecmp(mode,"0"))
853 display_mode = DISP_WIREFRAME;
855 else if (!strcasecmp(mode,"surface") || !strcasecmp(mode,"1"))
857 display_mode = DISP_SURFACE;
859 else if (!strcasecmp(mode,"transparent") || !strcasecmp(mode,"2"))
861 display_mode = DISP_TRANSPARENT;
865 display_mode = DISP_SURFACE;
868 /* Set the appearance. */
869 if (!strcasecmp(appear,"solid") || !strcasecmp(appear,"0"))
871 appearance = APPEARANCE_SOLID;
873 else if (!strcasecmp(appear,"bands") || !strcasecmp(appear,"1"))
875 appearance = APPEARANCE_BANDS;
878 else if (!strcasecmp(appear,"spirals-1") || !strcasecmp(appear,"3"))
880 appearance = APPEARANCE_SPIRALS;
883 else if (!strcasecmp(appear,"spirals-2") || !strcasecmp(appear,"4"))
885 appearance = APPEARANCE_SPIRALS;
888 else if (!strcasecmp(appear,"spirals-4") || !strcasecmp(appear,"5"))
890 appearance = APPEARANCE_SPIRALS;
893 else if (!strcasecmp(appear,"spirals-8") || !strcasecmp(appear,"6"))
895 appearance = APPEARANCE_SPIRALS;
898 else if (!strcasecmp(appear,"spirals-16") || !strcasecmp(appear,"7"))
900 appearance = APPEARANCE_SPIRALS;
905 appearance = APPEARANCE_BANDS;
909 /* Set the color mode. */
910 if (!strcasecmp(color_mode,"twosided"))
912 colors = COLORS_TWOSIDED;
914 else if (!strcasecmp(color_mode,"colorwheel"))
916 colors = COLORS_COLORWHEEL;
920 colors = COLORS_COLORWHEEL;
923 /* Set the 3d projection mode. */
924 if (!strcasecmp(proj_3d,"perspective") || !strcasecmp(proj_3d,"0"))
926 projection_3d = DISP_3D_PERSPECTIVE;
928 else if (!strcasecmp(proj_3d,"orthographic") || !strcasecmp(proj_3d,"1"))
930 projection_3d = DISP_3D_ORTHOGRAPHIC;
934 projection_3d = DISP_3D_PERSPECTIVE;
937 /* Set the 4d projection mode. */
938 if (!strcasecmp(proj_4d,"perspective") || !strcasecmp(proj_4d,"0"))
940 projection_4d = DISP_4D_PERSPECTIVE;
942 else if (!strcasecmp(proj_4d,"orthographic") || !strcasecmp(proj_4d,"1"))
944 projection_4d = DISP_4D_ORTHOGRAPHIC;
948 projection_4d = DISP_4D_PERSPECTIVE;
951 /* make multiple screens rotate at slightly different rates. */
952 hp->speed_scale = 0.9 + frand(0.3);
954 if ((hp->glx_context = init_GL(mi)) != NULL)
956 reshape_hypertorus(mi,MI_WIDTH(mi),MI_HEIGHT(mi));
957 glDrawBuffer(GL_BACK);
967 *-----------------------------------------------------------------------------
968 * Called by the mainline code periodically to update the display.
969 *-----------------------------------------------------------------------------
971 ENTRYPOINT void draw_hypertorus(ModeInfo *mi)
973 Display *display = MI_DISPLAY(mi);
974 Window window = MI_WINDOW(mi);
975 hypertorusstruct *hp;
979 hp = &hyper[MI_SCREEN(mi)];
981 MI_IS_DRAWN(mi) = True;
982 if (!hp->glx_context)
985 glXMakeCurrent(display,window,*(hp->glx_context));
987 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
990 display_hypertorus(mi);
997 glXSwapBuffers(display,window);
1002 ENTRYPOINT void change_hypertorus(ModeInfo *mi)
1004 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
1006 if (!hp->glx_context)
1009 glXMakeCurrent(MI_DISPLAY(mi),MI_WINDOW(mi),*(hp->glx_context));
1012 #endif /* !STANDALONE */
1014 XSCREENSAVER_MODULE ("Hypertorus", hypertorus)