1 /* hypertorus --- Shows a hypertorus that rotates in 4d */
3 #if !defined( lint ) && !defined( SABER )
4 static const char sccsid[] = "@(#)hypertorus.c 1.1 03/05/18 xlockmore";
8 /* Copyright (c) 2003 Carsten Steger <carsten@mirsanmir.org>. */
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.
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.
24 * C. Steger - 03/05/18: Initial version
28 * This program shows the Clifford torus as it rotates in 4d. The Clifford
29 * torus is a torus lies on the "surface" of the hypersphere in 4d. The
30 * program projects the 4d torus to 3d using either a perspective or an
31 * orthographic projection. Of the two alternatives, the perspecitve
32 * projection looks much more appealing. In orthographic projections the
33 * torus degenerates into a doubly covered cylinder for some angles. The
34 * projected 3d torus can then be projected to the screen either perspectively
35 * or orthographically. There are three display modes for the torus: mesh
36 * (wireframe), solid, or transparent. Furthermore, the appearance of the
37 * torus can be as a solid object or as a set of see-through bands. Finally,
38 * the colors with with the torus is drawn can be set to either two-sided or
39 * to colorwheel. In the first case, the torus is drawn with red on the
40 * outside and green on the inside. This mode enables you to see that the
41 * torus turns inside-out as it rotates in 4d. The second mode draws the
42 * torus in a fully saturated color wheel. This gives a very nice effect
43 * when combined with the see-through bands mode. The rotation speed for
44 * each of the six planes around which the torus rotates can be chosen.
45 * This program is very much inspired by Thomas Banchoff's book "Beyond the
46 * Third Dimension: Geometry, Computer Graphics, and Higher Dimensions",
47 * Scientific American Library, 1990.
51 #define M_PI 3.14159265358979323846
54 #define DISP_WIREFRAME 0
55 #define DISP_WIREFRAME_STR "0"
56 #define DISP_SURFACE 1
57 #define DISP_SURFACE_STR "1"
58 #define DISP_TRANSPARENT 2
59 #define DISP_TRANSPARENT_STR "2"
61 #define APPEARANCE_SOLID 0
62 #define APPEARANCE_SOLID_STR "0"
63 #define APPEARANCE_BANDS 1
64 #define APPEARANCE_BANDS_STR "1"
66 #define COLORS_TWOSIDED 0
67 #define COLORS_TWOSIDED_STR "0"
68 #define COLORS_COLORWHEEL 1
69 #define COLORS_COLORWHEEL_STR "1"
71 #define DISP_3D_PERSPECTIVE 0
72 #define DISP_3D_PERSPECTIVE_STR "0"
73 #define DISP_3D_ORTHOGRAPHIC 1
74 #define DISP_3D_ORTHOGRAPHIC_STR "1"
76 #define DISP_4D_PERSPECTIVE 0
77 #define DISP_4D_PERSPECTIVE_STR "0"
78 #define DISP_4D_ORTHOGRAPHIC 1
79 #define DISP_4D_ORTHOGRAPHIC_STR "1"
82 #define DALPHA_STR "1.1"
84 #define DBETA_STR "1.3"
86 #define DDELTA_STR "1.5"
88 #define DZETA_STR "1.7"
90 #define DETA_STR "1.9"
92 #define DTHETA_STR "2.1"
94 #define DEF_DISPLAY_MODE DISP_SURFACE_STR
95 #define DEF_APPEARANCE APPEARANCE_BANDS_STR
96 #define DEF_COLORS COLORS_COLORWHEEL_STR
97 #define DEF_3D_PROJECTION DISP_3D_PERSPECTIVE_STR
98 #define DEF_4D_PROJECTION DISP_4D_PERSPECTIVE_STR
99 #define DEF_DALPHA DALPHA_STR
100 #define DEF_DBETA DBETA_STR
101 #define DEF_DDELTA DDELTA_STR
102 #define DEF_DZETA DZETA_STR
103 #define DEF_DETA DETA_STR
104 #define DEF_DTHETA DTHETA_STR
107 # define PROGCLASS "Hypertorus"
108 # define HACK_INIT init_hypertorus
109 # define HACK_DRAW draw_hypertorus
110 # define HACK_RESHAPE reshape_hypertorus
111 # define hypertorus_opts xlockmore_opts
112 # define DEFAULTS "*delay: 25000 \n" \
113 "*showFPS: False \n" \
114 "*wireframe: False \n" \
115 "*displayMode: " DEF_DISPLAY_MODE " \n" \
116 "*appearance: " DEF_APPEARANCE " \n" \
117 "*colors: " DEF_COLORS " \n" \
118 "*projection3d: " DEF_3D_PROJECTION " \n" \
119 "*projection4d: " DEF_4D_PROJECTION " \n" \
120 "speedwx: " DEF_DALPHA " \n" \
121 "speedwy: " DEF_DBETA " \n" \
122 "speedwz: " DEF_DDELTA " \n" \
123 "speedxy: " DEF_DZETA " \n" \
124 "speedxz: " DEF_DETA " \n" \
125 "speedyz: " DEF_DTHETA " \n"
126 # include "xlockmore.h" /* from the xscreensaver distribution */
127 #else /* !STANDALONE */
128 # include "xlock.h" /* from the xlockmore distribution */
129 #endif /* !STANDALONE */
138 ModStruct hypertorus_description =
139 {"hypertorus", "init_hypertorus", "draw_hypertorus", "release_hypertorus",
140 "draw_hypertorus", "change_hypertorus", NULL, &hypertorus_opts,
141 25000, 1, 1, 1, 1.0, 4, "",
142 "Shows a hypertorus rotating in 4d", 0, NULL};
147 static int display_mode;
148 static int appearance;
150 static int projection_3d;
151 static int projection_4d;
152 static float speed_wx;
153 static float speed_wy;
154 static float speed_wz;
155 static float speed_xy;
156 static float speed_xz;
157 static float speed_yz;
159 /* 4D rotation angles */
160 static float alpha, beta, delta, zeta, eta, theta;
163 static const float offset4d[4] = {
167 static const float offset3d[4] = {
172 static XrmOptionDescRec opts[] =
174 {"-mesh", ".hypertorus.displayMode", XrmoptionNoArg,
175 (caddr_t)DISP_WIREFRAME_STR },
176 {"-surface", ".hypertorus.displayMode", XrmoptionNoArg,
177 (caddr_t)DISP_SURFACE_STR },
178 {"-transparent", ".hypertorus.displayMode", XrmoptionNoArg,
179 (caddr_t)DISP_TRANSPARENT_STR },
180 {"-solid", ".hypertorus.appearance", XrmoptionNoArg,
181 (caddr_t)APPEARANCE_SOLID_STR },
182 {"-bands", ".hypertorus.appearance", XrmoptionNoArg,
183 (caddr_t)APPEARANCE_BANDS_STR },
184 {"-twosided", ".hypertorus.colors", XrmoptionNoArg,
185 (caddr_t)COLORS_TWOSIDED_STR },
186 {"-colorwheel", ".hypertorus.colors", XrmoptionNoArg,
187 (caddr_t)COLORS_COLORWHEEL_STR },
188 {"-perspective-3d", ".hypertorus.projection3d", XrmoptionNoArg,
189 (caddr_t)DISP_3D_PERSPECTIVE_STR },
190 {"-orthographic-3d", ".hypertorus.projection3d", XrmoptionNoArg,
191 (caddr_t)DISP_3D_ORTHOGRAPHIC_STR },
192 {"-perspective-4d", ".hypertorus.projection4d", XrmoptionNoArg,
193 (caddr_t)DISP_4D_PERSPECTIVE_STR },
194 {"-orthographic-4d", ".hypertorus.projection4d", XrmoptionNoArg,
195 (caddr_t)DISP_4D_ORTHOGRAPHIC_STR },
196 {"-speed-wx", ".hypertorus.speedwx", XrmoptionSepArg,
198 {"-speed-wy", ".hypertorus.speedwy", XrmoptionSepArg,
200 {"-speed-wz", ".hypertorus.speedwz", XrmoptionSepArg,
202 {"-speed-xy", ".hypertorus.speedxy", XrmoptionSepArg,
204 {"-speed-xz", ".hypertorus.speedxz", XrmoptionSepArg,
206 {"-speed-yz", ".hypertorus.speedyz", XrmoptionSepArg,
210 static argtype vars[] =
212 { (caddr_t *) &display_mode, "displayMode", "DisplayMode",
213 DEF_DISPLAY_MODE, t_Int },
214 { (caddr_t *) &appearance, "appearance", "Appearance",
215 DEF_APPEARANCE, t_Int },
216 { (caddr_t *) &colors, "colors", "Colors",
218 { (caddr_t *) &projection_3d, "projection3d", "Projection3d",
219 DEF_3D_PROJECTION, t_Int },
220 { (caddr_t *) &projection_4d, "projection4d", "Projection4d",
221 DEF_4D_PROJECTION, t_Int },
222 { (caddr_t *) &speed_wx, "speedwx", "Speedwx",
223 DEF_DALPHA, t_Float},
224 { (caddr_t *) &speed_wy, "speedwy", "Speedwy",
226 { (caddr_t *) &speed_wz, "speedwz", "Speedwz",
227 DEF_DDELTA, t_Float},
228 { (caddr_t *) &speed_xy, "speedxy", "Speedxy",
230 { (caddr_t *) &speed_xz, "speedxz", "Speedxz",
232 { (caddr_t *) &speed_yz, "speedyz", "Speedyz",
236 static OptionStruct desc[] =
238 { "-mesh", "display the torus as a wireframe mesh" },
239 { "-surface", "display the torus as a solid surface" },
240 { "-transparent", "display the torus as a transparent surface" },
241 { "-solid", "display the torus as a solid object" },
242 { "-bands", "display the torus as see-through bands" },
243 { "-twosided", "display the torus with two colors" },
244 { "-colorwheel", "display the torus with a smooth color wheel" },
245 { "-perspective-3d", "project the torus perspectively from 3d to 2d" },
246 { "-orthographic-3d", "project the torus orthographically from 3d to 2d" },
247 { "-perspective-4d", "project the torus perspectively from 4d to 3d" },
248 { "-orthographic-4d", "project the torus orthographically from 4d to 3d" },
249 { "-speed-wx <arg>", "rotation speed around the wx plane" },
250 { "-speed-wy <arg>", "rotation speed around the wy plane" },
251 { "-speed-wz <arg>", "rotation speed around the wz plane" },
252 { "-speed-xy <arg>", "rotation speed around the xy plane" },
253 { "-speed-xz <arg>", "rotation speed around the xz plane" },
254 { "-speed-yz <arg>", "rotation speed around the yz plane" }
257 ModeSpecOpt hypertorus_opts =
258 {sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, desc};
263 GLXContext *glx_context;
266 static hypertorusstruct *hyper = (hypertorusstruct *) NULL;
269 /* Add a rotation around the wx-plane to the matrix m. */
270 static void rotatewx(float m[4][4], float phi)
288 /* Add a rotation around the wy-plane to the matrix m. */
289 static void rotatewy(float m[4][4], float phi)
307 /* Add a rotation around the wz-plane to the matrix m. */
308 static void rotatewz(float m[4][4], float phi)
326 /* Add a rotation around the xy-plane to the matrix m. */
327 static void rotatexy(float m[4][4], float phi)
345 /* Add a rotation around the xz-plane to the matrix m. */
346 static void rotatexz(float m[4][4], float phi)
364 /* Add a rotation around the yz-plane to the matrix m. */
365 static void rotateyz(float m[4][4], float phi)
383 /* Compute a fully saturated and bright color based on an angle. */
384 static void color(double angle)
390 if (colors != COLORS_COLORWHEEL)
394 angle = fmod(angle,2*M_PI);
396 angle = fmod(angle,-2*M_PI);
397 s = floor(angle/(M_PI/3));
398 t = angle/(M_PI/3)-s;
434 if (display_mode == DISP_TRANSPARENT)
439 glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,color);
443 /* Draw a hyperturus projected into 3D. */
444 static void hypertorus(double umin, double umax, double vmin, double vmax,
447 static GLfloat mat_diff_red[] = { 1.0, 0.0, 0.0, 1.0 };
448 static GLfloat mat_diff_green[] = { 0.0, 1.0, 0.0, 1.0 };
449 static GLfloat mat_diff_trans_red[] = { 1.0, 0.0, 0.0, 0.5 };
450 static GLfloat mat_diff_trans_green[] = { 0.0, 1.0, 0.0, 0.5 };
451 float p[3], pu[3], pv[3], n[3], mat[4][4];
454 double cu, su, cv, sv;
455 double xx[4], xxu[4], xxv[4], x[4], xu[4], xv[4];
458 /* Compute the rotation that rotates the hypercube in 4D. */
469 if (colors != COLORS_COLORWHEEL)
471 glColor3fv(mat_diff_red);
472 if (display_mode == DISP_TRANSPARENT)
474 glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_red);
475 glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_green);
479 glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_red);
480 glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_green);
486 for (i=0; i<numu; i++)
488 if (appearance == APPEARANCE_BANDS && ((i & 3) >= 2))
490 if (display_mode == DISP_WIREFRAME)
491 glBegin(GL_QUAD_STRIP);
493 glBegin(GL_TRIANGLE_STRIP);
494 for (j=0; j<=numv; j++)
526 r += mat[l][m]*xx[m];
527 s += mat[l][m]*xxu[m];
528 t += mat[l][m]*xxv[m];
534 if (projection_4d == DISP_4D_ORTHOGRAPHIC)
538 p[l] = (x[l]+offset4d[l])/1.5+offset3d[l];
545 s = x[3]+offset4d[3];
549 r = x[l]+offset4d[l];
550 p[l] = r/s+offset3d[l];
551 pu[l] = (xu[l]*s-r*xu[3])/t;
552 pv[l] = (xv[l]*s-r*xv[3])/t;
555 n[0] = pu[1]*pv[2]-pu[2]*pv[1];
556 n[1] = pu[2]*pv[0]-pu[0]*pv[2];
557 n[2] = pu[0]*pv[1]-pu[1]*pv[0];
558 t = sqrt(n[0]*n[0]+n[1]*n[1]+n[2]*n[2]);
571 static void init(ModeInfo *mi)
573 static GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
574 static GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
575 static GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
576 static GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
577 static GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
586 glMatrixMode(GL_PROJECTION);
588 if (projection_3d == DISP_3D_PERSPECTIVE)
589 gluPerspective(60.0,1.0,0.1,100.0);
591 glOrtho(-1.0,1.0,-1.0,1.0,0.1,100.0);;
592 glMatrixMode(GL_MODELVIEW);
595 if (display_mode == DISP_WIREFRAME)
597 glDisable(GL_DEPTH_TEST);
598 glShadeModel(GL_FLAT);
599 glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
600 glDisable(GL_LIGHTING);
601 glDisable(GL_LIGHT0);
604 else if (display_mode == DISP_SURFACE)
606 glEnable(GL_DEPTH_TEST);
607 glDepthFunc(GL_LESS);
608 glShadeModel(GL_SMOOTH);
609 glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
610 glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
611 glEnable(GL_LIGHTING);
613 glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient);
614 glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse);
615 glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular);
616 glLightfv(GL_LIGHT0,GL_POSITION,light_position);
617 glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,mat_specular);
618 glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,50.0);
619 glDepthMask(GL_TRUE);
622 else if (display_mode == DISP_TRANSPARENT)
624 glDisable(GL_DEPTH_TEST);
625 glShadeModel(GL_SMOOTH);
626 glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
627 glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
628 glEnable(GL_LIGHTING);
630 glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient);
631 glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse);
632 glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular);
633 glLightfv(GL_LIGHT0,GL_POSITION,light_position);
634 glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,mat_specular);
635 glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,50.0);
636 glDepthMask(GL_FALSE);
638 glBlendFunc(GL_SRC_ALPHA,GL_ONE);
642 glDisable(GL_DEPTH_TEST);
643 glShadeModel(GL_FLAT);
644 glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
645 glDisable(GL_LIGHTING);
646 glDisable(GL_LIGHT0);
652 /* Redisplay the hypertorus. */
653 static void display_hypertorus(void)
674 glMatrixMode(GL_PROJECTION);
676 if (projection_3d == DISP_3D_ORTHOGRAPHIC)
679 glOrtho(-aspect,aspect,-1.0,1.0,0.1,100.0);
681 glOrtho(-1.0,1.0,-1.0/aspect,1.0/aspect,0.1,100.0);
685 gluPerspective(60.0,aspect,0.1,100.0);
687 glMatrixMode(GL_MODELVIEW);
690 if (display_mode == DISP_WIREFRAME)
691 hypertorus(0.0,2.0*M_PI,0.0,2.0*M_PI,40,40);
693 hypertorus(0.0,2.0*M_PI,0.0,2.0*M_PI,60,60);
697 void reshape_hypertorus(ModeInfo * mi, int width, int height)
699 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
701 hp->WindW = (GLint)width;
702 hp->WindH = (GLint)height;
703 glViewport(0,0,width,height);
704 aspect = (GLfloat)width/(GLfloat)height;
709 *-----------------------------------------------------------------------------
710 *-----------------------------------------------------------------------------
712 *-----------------------------------------------------------------------------
713 *-----------------------------------------------------------------------------
717 *-----------------------------------------------------------------------------
718 * Initialize hypertorus. Called each time the window changes.
719 *-----------------------------------------------------------------------------
722 void init_hypertorus(ModeInfo * mi)
724 hypertorusstruct *hp;
728 hyper = (hypertorusstruct *)calloc(MI_NUM_SCREENS(mi),
729 sizeof(hypertorusstruct));
733 hp = &hyper[MI_SCREEN(mi)];
735 if ((hp->glx_context = init_GL(mi)) != NULL)
737 reshape_hypertorus(mi,MI_WIDTH(mi),MI_HEIGHT(mi));
738 glDrawBuffer(GL_BACK);
748 *-----------------------------------------------------------------------------
749 * Called by the mainline code periodically to update the display.
750 *-----------------------------------------------------------------------------
752 void draw_hypertorus(ModeInfo * mi)
754 Display *display = MI_DISPLAY(mi);
755 Window window = MI_WINDOW(mi);
756 hypertorusstruct *hp;
760 hp = &hyper[MI_SCREEN(mi)];
762 MI_IS_DRAWN(mi) = True;
763 if (!hp->glx_context)
766 glXMakeCurrent(display,window,*(hp->glx_context));
768 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
771 display_hypertorus();
778 glXSwapBuffers(display,window);
783 *-----------------------------------------------------------------------------
784 * The display is being taken away from us. Free up malloc'ed
785 * memory and X resources that we've alloc'ed. Only called
786 * once, we must zap everything for every screen.
787 *-----------------------------------------------------------------------------
790 void release_hypertorus(ModeInfo * mi)
796 for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
798 hypertorusstruct *hp = &hyper[screen];
801 hp->glx_context = (GLXContext *)NULL;
803 (void) free((void *)hyper);
804 hyper = (hypertorusstruct *)NULL;
809 void change_hypertorus(ModeInfo * mi)
811 hypertorusstruct *hp = &hyper[MI_SCREEN(mi)];
813 if (!hp->glx_context)
816 glXMakeCurrent(MI_DISPLAY(mi),MI_WINDOW(mi),*(hp->glx_context));