From d3a98cf6cbc3bd0b9efc570f58e8812c03931c18 Mon Sep 17 00:00:00 2001 From: Simon Rettberg Date: Tue, 16 Oct 2018 10:08:48 +0200 Subject: Original 5.40 --- hacks/glx/projectiveplane.c | 1550 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1550 insertions(+) create mode 100644 hacks/glx/projectiveplane.c (limited to 'hacks/glx/projectiveplane.c') diff --git a/hacks/glx/projectiveplane.c b/hacks/glx/projectiveplane.c new file mode 100644 index 0000000..2a1e566 --- /dev/null +++ b/hacks/glx/projectiveplane.c @@ -0,0 +1,1550 @@ +/* projectiveplane --- Shows a 4d embedding of the real projective plane + that rotates in 4d or on which you can walk */ + +#if 0 +static const char sccsid[] = "@(#)projectiveplane.c 1.1 14/01/01 xlockmore"; +#endif + +/* Copyright (c) 2005-2014 Carsten Steger . */ + +/* + * Permission to use, copy, modify, and distribute this software and its + * documentation for any purpose and without fee is hereby granted, + * provided that the above copyright notice appear in all copies and that + * both that copyright notice and this permission notice appear in + * supporting documentation. + * + * This file is provided AS IS with no warranties of any kind. The author + * shall have no liability with respect to the infringement of copyrights, + * trade secrets or any patents by this file or any part thereof. In no + * event will the author be liable for any lost revenue or profits or + * other special, indirect and consequential damages. + * + * REVISION HISTORY: + * C. Steger - 14/01/03: Initial version + * C. Steger - 14/10/03: Moved the curlicue texture to curlicue.h + */ + +/* + * This program shows a 4d embedding of the real projective plane. + * You can walk on the projective plane, see it turn in 4d, or walk on + * it while it turns in 4d. The fact that the surface is an embedding + * of the real projective plane in 4d can be seen in the depth colors + * mode: set all rotation speeds to 0 and the projection mode to 4d + * orthographic projection. In its default orientation, the embedding + * of the real projective plane will then project to the Roman + * surface, which has three lines of self-intersection. However, at + * the three lines of self-intersection the parts of the surface that + * intersect have different colors, i.e., different 4d depths. + * + * The real projective plane is a non-orientable surface. To make + * this apparent, the two-sided color mode can be used. + * Alternatively, orientation markers (curling arrows) can be drawn as + * a texture map on the surface of the projective plane. While + * walking on the projective plane, you will notice that the + * orientation of the curling arrows changes (which it must because + * the projective plane is non-orientable). + * + * The real projective plane is a model for the projective geometry in + * 2d space. One point can be singled out as the origin. A line can + * be singled out as the line at infinity, i.e., a line that lies at + * an infinite distance to the origin. The line at infinity is + * topologically a circle. Points on the line at infinity are also + * used to model directions in projective geometry. The origin can be + * visualized in different manners. When using distance colors, the + * origin is the point that is displayed as fully saturated red, which + * is easier to see as the center of the reddish area on the + * projective plane. Alternatively, when using distance bands, the + * origin is the center of the only band that projects to a disc. + * When using direction bands, the origin is the point where all + * direction bands collapse to a point. Finally, when orientation + * markers are being displayed, the origin the the point where all + * orientation markers are compressed to a point. The line at + * infinity can also be visualized in different ways. When using + * distance colors, the line at infinity is the line that is displayed + * as fully saturated magenta. When two-sided colors are used, the + * line at infinity lies at the points where the red and green "sides" + * of the projective plane meet (of course, the real projective plane + * only has one side, so this is a design choice of the + * visualization). Alternatively, when orientation markers are being + * displayed, the line at infinity is the place where the orientation + * markers change their orientation. + * + * Note that when the projective plane is displayed with bands, the + * orientation markers are placed in the middle of the bands. For + * distance bands, the bands are chosen in such a way that the band at + * the origin is only half as wide as the remaining bands, which + * results in a disc being displayed at the origin that has the same + * diameter as the remaining bands. This choice, however, also + * implies that the band at infinity is half as wide as the other + * bands. Since the projective plane is attached to itself (in a + * complicated fashion) at the line at infinity, effectively the band + * at infinity is again as wide as the remaining bands. However, + * since the orientation markers are displayed in the middle of the + * bands, this means that only one half of the orientation markers + * will be displayed twice at the line at infinity if distance bands + * are used. If direction bands are used or if the projective plane + * is displayed as a solid surface, the orientation markers are + * displayed fully at the respective sides of the line at infinity. + * + * The program projects the 4d projective plane to 3d using either a + * perspective or an orthographic projection. Which of the two + * alternatives looks more appealing is up to you. However, two + * famous surfaces are obtained if orthographic 4d projection is used: + * The Roman surface and the cross cap. If the projective plane is + * rotated in 4d, the result of the projection for certain rotations + * is a Roman surface and for certain rotations it is a cross cap. + * The easiest way to see this is to set all rotation speeds to 0 and + * the rotation speed around the yz plane to a value different from 0. + * However, for any 4d rotation speeds, the projections will generally + * cycle between the Roman surface and the cross cap. The difference + * is where the origin and the line at infinity will lie with respect + * to the self-intersections in the projections to 3d. + * + * The projected projective plane can then be projected to the screen + * either perspectively or orthographically. When using the walking + * modes, perspective projection to the screen will be used. + * + * There are three display modes for the projective plane: mesh + * (wireframe), solid, or transparent. Furthermore, the appearance of + * the projective plane can be as a solid object or as a set of + * see-through bands. The bands can be distance bands, i.e., bands + * that lie at increasing distances from the origin, or direction + * bands, i.e., bands that lie at increasing angles with respect to + * the origin. + * + * When the projective plane is displayed with direction bands, you + * will be able to see that each direction band (modulo the "pinching" + * at the origin) is a Moebius strip, which also shows that the + * projective plane is non-orientable. + * + * Finally, the colors with with the projective plane is drawn can be + * set to two-sided, distance, direction, or depth. In two-sided + * mode, the projective plane is drawn with red on one "side" and + * green on the "other side". As described above, the projective + * plane only has one side, so the color jumps from red to green along + * the line at infinity. This mode enables you to see that the + * projective plane is non-orientable. In distance mode, the + * projective plane is displayed with fully saturated colors that + * depend on the distance of the points on the projective plane to the + * origin. The origin is displayed in red, the line at infinity is + * displayed in magenta. If the projective plane is displayed as + * distance bands, each band will be displayed with a different color. + * In direction mode, the projective plane is displayed with fully + * saturated colors that depend on the angle of the points on the + * projective plane with respect to the origin. Angles in opposite + * directions to the origin (e.g., 15 and 205 degrees) are displayed + * in the same color since they are projectively equivalent. If the + * projective plane is displayed as direction bands, each band will be + * displayed with a different color. Finally, in depth mode the + * projective plane with colors chosen depending on the 4d "depth" + * (i.e., the w coordinate) of the points on the projective plane at + * its default orientation in 4d. As discussed above, this mode + * enables you to see that the projective plane does not intersect + * itself in 4d. + * + * The rotation speed for each of the six planes around which the + * projective plane rotates can be chosen. For the walk-and-turn + * more, only the rotation speeds around the true 4d planes are used + * (the xy, xz, and yz planes). + * + * Furthermore, in the walking modes the walking direction in the 2d + * base square of the projective plane and the walking speed can be + * chosen. The walking direction is measured as an angle in degrees + * in the 2d square that forms the coordinate system of the surface of + * the projective plane. A value of 0 or 180 means that the walk is + * along a circle at a randomly chosen distance from the origin + * (parallel to a distance band). A value of 90 or 270 means that the + * walk is directly from the origin to the line at infinity and back + * (analogous to a direction band). Any other value results in a + * curved path from the origin to the line at infinity and back. + * + * This program is somewhat inspired by Thomas Banchoff's book "Beyond + * the Third Dimension: Geometry, Computer Graphics, and Higher + * Dimensions", Scientific American Library, 1990. + */ + +#include "curlicue.h" + +#ifndef M_PI +#define M_PI 3.14159265358979323846 +#endif + +#define DISP_WIREFRAME 0 +#define DISP_SURFACE 1 +#define DISP_TRANSPARENT 2 +#define NUM_DISPLAY_MODES 3 + +#define APPEARANCE_SOLID 0 +#define APPEARANCE_DISTANCE_BANDS 1 +#define APPEARANCE_DIRECTION_BANDS 2 +#define NUM_APPEARANCES 3 + +#define COLORS_TWOSIDED 0 +#define COLORS_DISTANCE 1 +#define COLORS_DIRECTION 2 +#define COLORS_DEPTH 3 +#define NUM_COLORS 4 + +#define VIEW_WALK 0 +#define VIEW_TURN 1 +#define VIEW_WALKTURN 2 +#define NUM_VIEW_MODES 3 + +#define DISP_3D_PERSPECTIVE 0 +#define DISP_3D_ORTHOGRAPHIC 1 +#define NUM_DISP_3D_MODES 2 + +#define DISP_4D_PERSPECTIVE 0 +#define DISP_4D_ORTHOGRAPHIC 1 +#define NUM_DISP_4D_MODES 2 + +#define DEF_DISPLAY_MODE "random" +#define DEF_APPEARANCE "random" +#define DEF_COLORS "random" +#define DEF_VIEW_MODE "random" +#define DEF_MARKS "False" +#define DEF_PROJECTION_3D "random" +#define DEF_PROJECTION_4D "random" +#define DEF_SPEEDWX "1.1" +#define DEF_SPEEDWY "1.3" +#define DEF_SPEEDWZ "1.5" +#define DEF_SPEEDXY "1.7" +#define DEF_SPEEDXZ "1.9" +#define DEF_SPEEDYZ "2.1" +#define DEF_WALK_DIRECTION "83.0" +#define DEF_WALK_SPEED "20.0" + +#ifdef STANDALONE +# define DEFAULTS "*delay: 10000 \n" \ + "*showFPS: False \n" \ + +# define free_projectiveplane 0 +# define release_projectiveplane 0 +# include "xlockmore.h" /* from the xscreensaver distribution */ +#else /* !STANDALONE */ +# include "xlock.h" /* from the xlockmore distribution */ +#endif /* !STANDALONE */ + +#ifdef USE_GL + +#ifndef HAVE_JWXYZ +# include +#endif + +#include "gltrackball.h" + +#include + + +#ifdef USE_MODULES +ModStruct projectiveplane_description = +{"projectiveplane", "init_projectiveplane", "draw_projectiveplane", + NULL, "draw_projectiveplane", "change_projectiveplane", + NULL, &projectiveplane_opts, 25000, 1, 1, 1, 1.0, 4, "", + "Rotate a 4d embedding of the real projective plane in 4d or walk on it", + 0, NULL}; + +#endif + + +static char *mode; +static char *appear; +static char *color_mode; +static char *view_mode; +static Bool marks; +static char *proj_3d; +static char *proj_4d; +static float speed_wx; +static float speed_wy; +static float speed_wz; +static float speed_xy; +static float speed_xz; +static float speed_yz; +static float walk_direction; +static float walk_speed; + + +static XrmOptionDescRec opts[] = +{ + {"-mode", ".displayMode", XrmoptionSepArg, 0 }, + {"-wireframe", ".displayMode", XrmoptionNoArg, "wireframe" }, + {"-surface", ".displayMode", XrmoptionNoArg, "surface" }, + {"-transparent", ".displayMode", XrmoptionNoArg, "transparent" }, + {"-appearance", ".appearance", XrmoptionSepArg, 0 }, + {"-solid", ".appearance", XrmoptionNoArg, "solid" }, + {"-distance-bands", ".appearance", XrmoptionNoArg, "distance-bands" }, + {"-direction-bands", ".appearance", XrmoptionNoArg, "direction-bands" }, + {"-colors", ".colors", XrmoptionSepArg, 0 }, + {"-twosided-colors", ".colors", XrmoptionNoArg, "two-sided" }, + {"-distance-colors", ".colors", XrmoptionNoArg, "distance" }, + {"-direction-colors", ".colors", XrmoptionNoArg, "direction" }, + {"-depth-colors", ".colors", XrmoptionNoArg, "depth" }, + {"-view-mode", ".viewMode", XrmoptionSepArg, 0 }, + {"-walk", ".viewMode", XrmoptionNoArg, "walk" }, + {"-turn", ".viewMode", XrmoptionNoArg, "turn" }, + {"-walk-turn", ".viewMode", XrmoptionNoArg, "walk-turn" }, + {"-orientation-marks", ".marks", XrmoptionNoArg, "on"}, + {"+orientation-marks", ".marks", XrmoptionNoArg, "off"}, + {"-projection-3d", ".projection3d", XrmoptionSepArg, 0 }, + {"-perspective-3d", ".projection3d", XrmoptionNoArg, "perspective" }, + {"-orthographic-3d", ".projection3d", XrmoptionNoArg, "orthographic" }, + {"-projection-4d", ".projection4d", XrmoptionSepArg, 0 }, + {"-perspective-4d", ".projection4d", XrmoptionNoArg, "perspective" }, + {"-orthographic-4d", ".projection4d", XrmoptionNoArg, "orthographic" }, + {"-speed-wx", ".speedwx", XrmoptionSepArg, 0 }, + {"-speed-wy", ".speedwy", XrmoptionSepArg, 0 }, + {"-speed-wz", ".speedwz", XrmoptionSepArg, 0 }, + {"-speed-xy", ".speedxy", XrmoptionSepArg, 0 }, + {"-speed-xz", ".speedxz", XrmoptionSepArg, 0 }, + {"-speed-yz", ".speedyz", XrmoptionSepArg, 0 }, + {"-walk-direction", ".walkDirection", XrmoptionSepArg, 0 }, + {"-walk-speed", ".walkSpeed", XrmoptionSepArg, 0 } +}; + +static argtype vars[] = +{ + { &mode, "displayMode", "DisplayMode", DEF_DISPLAY_MODE, t_String }, + { &appear, "appearance", "Appearance", DEF_APPEARANCE, t_String }, + { &color_mode, "colors", "Colors", DEF_COLORS, t_String }, + { &view_mode, "viewMode", "ViewMode", DEF_VIEW_MODE, t_String }, + { &marks, "marks", "Marks", DEF_MARKS, t_Bool }, + { &proj_3d, "projection3d", "Projection3d", DEF_PROJECTION_3D, t_String }, + { &proj_4d, "projection4d", "Projection4d", DEF_PROJECTION_4D, t_String }, + { &speed_wx, "speedwx", "Speedwx", DEF_SPEEDWX, t_Float}, + { &speed_wy, "speedwy", "Speedwy", DEF_SPEEDWY, t_Float}, + { &speed_wz, "speedwz", "Speedwz", DEF_SPEEDWZ, t_Float}, + { &speed_xy, "speedxy", "Speedxy", DEF_SPEEDXY, t_Float}, + { &speed_xz, "speedxz", "Speedxz", DEF_SPEEDXZ, t_Float}, + { &speed_yz, "speedyz", "Speedyz", DEF_SPEEDYZ, t_Float}, + { &walk_direction, "walkDirection", "WalkDirection", DEF_WALK_DIRECTION, t_Float}, + { &walk_speed, "walkSpeed", "WalkSpeed", DEF_WALK_SPEED, t_Float} +}; + +ENTRYPOINT ModeSpecOpt projectiveplane_opts = +{sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, NULL}; + + +/* Offset by which we walk above the projective plane */ +#define DELTAY 0.01 + +/* Number of subdivisions of the projective plane */ +#define NUMU 128 +#define NUMV 128 + +/* Number of subdivisions per band */ +#define NUMB 8 + + +typedef struct { + GLint WindH, WindW; + GLXContext *glx_context; + /* Options */ + int display_mode; + int appearance; + int colors; + int view; + Bool marks; + int projection_3d; + int projection_4d; + /* 4D rotation angles */ + float alpha, beta, delta, zeta, eta, theta; + /* Movement parameters */ + float umove, vmove, dumove, dvmove; + int side, dir; + /* The viewing offset in 4d */ + float offset4d[4]; + /* The viewing offset in 3d */ + float offset3d[4]; + /* The 4d coordinates of the projective plane and their derivatives */ + float x[(NUMU+1)*(NUMV+1)][4]; + float xu[(NUMU+1)*(NUMV+1)][4]; + float xv[(NUMU+1)*(NUMV+1)][4]; + float pp[(NUMU+1)*(NUMV+1)][3]; + float pn[(NUMU+1)*(NUMV+1)][3]; + /* The precomputed colors of the projective plane */ + float col[(NUMU+1)*(NUMV+1)][4]; + /* The precomputed texture coordinates of the projective plane */ + float tex[(NUMU+1)*(NUMV+1)][2]; + /* The "curlicue" texture */ + GLuint tex_name; + /* Aspect ratio of the current window */ + float aspect; + /* Trackball states */ + trackball_state *trackballs[2]; + int current_trackball; + Bool button_pressed; + /* A random factor to modify the rotation speeds */ + float speed_scale; +} projectiveplanestruct; + +static projectiveplanestruct *projectiveplane = (projectiveplanestruct *) NULL; + + +/* Add a rotation around the wx-plane to the matrix m. */ +static void rotatewx(float m[4][4], float phi) +{ + float c, s, u, v; + int i; + + phi *= M_PI/180.0; + c = cos(phi); + s = sin(phi); + for (i=0; i<4; i++) + { + u = m[i][1]; + v = m[i][2]; + m[i][1] = c*u+s*v; + m[i][2] = -s*u+c*v; + } +} + + +/* Add a rotation around the wy-plane to the matrix m. */ +static void rotatewy(float m[4][4], float phi) +{ + float c, s, u, v; + int i; + + phi *= M_PI/180.0; + c = cos(phi); + s = sin(phi); + for (i=0; i<4; i++) + { + u = m[i][0]; + v = m[i][2]; + m[i][0] = c*u-s*v; + m[i][2] = s*u+c*v; + } +} + + +/* Add a rotation around the wz-plane to the matrix m. */ +static void rotatewz(float m[4][4], float phi) +{ + float c, s, u, v; + int i; + + phi *= M_PI/180.0; + c = cos(phi); + s = sin(phi); + for (i=0; i<4; i++) + { + u = m[i][0]; + v = m[i][1]; + m[i][0] = c*u+s*v; + m[i][1] = -s*u+c*v; + } +} + + +/* Add a rotation around the xy-plane to the matrix m. */ +static void rotatexy(float m[4][4], float phi) +{ + float c, s, u, v; + int i; + + phi *= M_PI/180.0; + c = cos(phi); + s = sin(phi); + for (i=0; i<4; i++) + { + u = m[i][2]; + v = m[i][3]; + m[i][2] = c*u+s*v; + m[i][3] = -s*u+c*v; + } +} + + +/* Add a rotation around the xz-plane to the matrix m. */ +static void rotatexz(float m[4][4], float phi) +{ + float c, s, u, v; + int i; + + phi *= M_PI/180.0; + c = cos(phi); + s = sin(phi); + for (i=0; i<4; i++) + { + u = m[i][1]; + v = m[i][3]; + m[i][1] = c*u-s*v; + m[i][3] = s*u+c*v; + } +} + + +/* Add a rotation around the yz-plane to the matrix m. */ +static void rotateyz(float m[4][4], float phi) +{ + float c, s, u, v; + int i; + + phi *= M_PI/180.0; + c = cos(phi); + s = sin(phi); + for (i=0; i<4; i++) + { + u = m[i][0]; + v = m[i][3]; + m[i][0] = c*u-s*v; + m[i][3] = s*u+c*v; + } +} + + +/* Compute the rotation matrix m from the rotation angles. */ +static void rotateall(float al, float be, float de, float ze, float et, + float th, float m[4][4]) +{ + int i, j; + + for (i=0; i<4; i++) + for (j=0; j<4; j++) + m[i][j] = (i==j); + rotatewx(m,al); + rotatewy(m,be); + rotatewz(m,de); + rotatexy(m,ze); + rotatexz(m,et); + rotateyz(m,th); +} + + +/* Compute the rotation matrix m from the 4d rotation angles. */ +static void rotateall4d(float ze, float et, float th, float m[4][4]) +{ + int i, j; + + for (i=0; i<4; i++) + for (j=0; j<4; j++) + m[i][j] = (i==j); + rotatexy(m,ze); + rotatexz(m,et); + rotateyz(m,th); +} + + +/* Multiply two rotation matrices: o=m*n. */ +static void mult_rotmat(float m[4][4], float n[4][4], float o[4][4]) +{ + int i, j, k; + + for (i=0; i<4; i++) + { + for (j=0; j<4; j++) + { + o[i][j] = 0.0; + for (k=0; k<4; k++) + o[i][j] += m[i][k]*n[k][j]; + } + } +} + + +/* Compute a 4D rotation matrix from two unit quaternions. */ +static void quats_to_rotmat(float p[4], float q[4], float m[4][4]) +{ + double al, be, de, ze, et, th; + double r00, r01, r02, r12, r22; + + r00 = 1.0-2.0*(p[1]*p[1]+p[2]*p[2]); + r01 = 2.0*(p[0]*p[1]+p[2]*p[3]); + r02 = 2.0*(p[2]*p[0]-p[1]*p[3]); + r12 = 2.0*(p[1]*p[2]+p[0]*p[3]); + r22 = 1.0-2.0*(p[1]*p[1]+p[0]*p[0]); + + al = atan2(-r12,r22)*180.0/M_PI; + be = atan2(r02,sqrt(r00*r00+r01*r01))*180.0/M_PI; + de = atan2(-r01,r00)*180.0/M_PI; + + r00 = 1.0-2.0*(q[1]*q[1]+q[2]*q[2]); + r01 = 2.0*(q[0]*q[1]+q[2]*q[3]); + r02 = 2.0*(q[2]*q[0]-q[1]*q[3]); + r12 = 2.0*(q[1]*q[2]+q[0]*q[3]); + r22 = 1.0-2.0*(q[1]*q[1]+q[0]*q[0]); + + et = atan2(-r12,r22)*180.0/M_PI; + th = atan2(r02,sqrt(r00*r00+r01*r01))*180.0/M_PI; + ze = atan2(-r01,r00)*180.0/M_PI; + + rotateall(al,be,de,ze,et,-th,m); +} + + +/* Compute a fully saturated and bright color based on an angle. */ +static void color(projectiveplanestruct *pp, double angle, float col[4]) +{ + int s; + double t; + + if (pp->colors == COLORS_TWOSIDED) + return; + + if (angle >= 0.0) + angle = fmod(angle,2.0*M_PI); + else + angle = fmod(angle,-2.0*M_PI); + s = floor(angle/(M_PI/3)); + t = angle/(M_PI/3)-s; + if (s >= 6) + s = 0; + switch (s) + { + case 0: + col[0] = 1.0; + col[1] = t; + col[2] = 0.0; + break; + case 1: + col[0] = 1.0-t; + col[1] = 1.0; + col[2] = 0.0; + break; + case 2: + col[0] = 0.0; + col[1] = 1.0; + col[2] = t; + break; + case 3: + col[0] = 0.0; + col[1] = 1.0-t; + col[2] = 1.0; + break; + case 4: + col[0] = t; + col[1] = 0.0; + col[2] = 1.0; + break; + case 5: + col[0] = 1.0; + col[1] = 0.0; + col[2] = 1.0-t; + break; + } + if (pp->display_mode == DISP_TRANSPARENT) + col[3] = 0.7; + else + col[3] = 1.0; +} + + +/* Set up the projective plane coordinates, colors, and texture. */ +static void setup_projective_plane(ModeInfo *mi, double umin, double umax, + double vmin, double vmax) +{ + int i, j, k; + double u, v, ur, vr; + double cu, su, cv2, sv2, cv4, sv4, c2u, s2u; + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + ur = umax-umin; + vr = vmax-vmin; + for (i=0; i<=NUMV; i++) + { + for (j=0; j<=NUMU; j++) + { + k = i*(NUMU+1)+j; + if (pp->appearance != APPEARANCE_DIRECTION_BANDS) + u = -ur*j/NUMU+umin; + else + u = ur*j/NUMU+umin; + v = vr*i/NUMV+vmin; + cu = cos(u); + su = sin(u); + c2u = cos(2.0*u); + s2u = sin(2.0*u); + sv2 = sin(0.5*v); + cv4 = cos(0.25*v); + sv4 = sin(0.25*v); + if (pp->colors == COLORS_DEPTH) + color(pp,((su*su*sv4*sv4-cv4*cv4)+1.0)*M_PI*2.0/3.0,pp->col[k]); + else if (pp->colors == COLORS_DIRECTION) + color(pp,2.0*M_PI+fmod(2.0*u,2.0*M_PI),pp->col[k]); + else /* pp->colors == COLORS_DISTANCE */ + color(pp,v*(5.0/6.0),pp->col[k]); + pp->tex[k][0] = -32*u/(2.0*M_PI); + if (pp->appearance != APPEARANCE_DISTANCE_BANDS) + pp->tex[k][1] = 32*v/(2.0*M_PI); + else + pp->tex[k][1] = 32*v/(2.0*M_PI)-0.5; + pp->x[k][0] = 0.5*s2u*sv4*sv4; + pp->x[k][1] = 0.5*su*sv2; + pp->x[k][2] = 0.5*cu*sv2; + pp->x[k][3] = 0.5*(su*su*sv4*sv4-cv4*cv4); + /* Avoid degenerate tangential plane basis vectors. */ + if (v < FLT_EPSILON) + v = FLT_EPSILON; + cv2 = cos(0.5*v); + sv2 = sin(0.5*v); + sv4 = sin(0.25*v); + pp->xu[k][0] = c2u*sv4*sv4; + pp->xu[k][1] = 0.5*cu*sv2; + pp->xu[k][2] = -0.5*su*sv2; + pp->xu[k][3] = 0.5*s2u*sv4*sv4; + pp->xv[k][0] = 0.125*s2u*sv2; + pp->xv[k][1] = 0.25*su*cv2; + pp->xv[k][2] = 0.25*cu*cv2; + pp->xv[k][3] = 0.125*(su*su+1.0)*sv2; + } + } +} + + +/* Draw a 4d embedding of the projective plane projected into 3D. */ +static int projective_plane(ModeInfo *mi, double umin, double umax, + double vmin, double vmax) +{ + int polys = 0; + static const GLfloat mat_diff_red[] = { 1.0, 0.0, 0.0, 1.0 }; + static const GLfloat mat_diff_green[] = { 0.0, 1.0, 0.0, 1.0 }; + static const GLfloat mat_diff_trans_red[] = { 1.0, 0.0, 0.0, 0.7 }; + static const GLfloat mat_diff_trans_green[] = { 0.0, 1.0, 0.0, 0.7 }; + float p[3], pu[3], pv[3], pm[3], n[3], b[3], mat[4][4]; + int i, j, k, l, m, o; + double u, v; + double xx[4], xxu[4], xxv[4], y[4], yu[4], yv[4]; + double q, r, s, t; + double cu, su, cv2, sv2, cv4, sv4, c2u, s2u; + float q1[4], q2[4], r1[4][4], r2[4][4]; + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + if (pp->view == VIEW_WALK || pp->view == VIEW_WALKTURN) + { + /* Compute the rotation that rotates the projective plane in 4D without + the trackball rotations. */ + rotateall4d(pp->zeta,pp->eta,pp->theta,mat); + + u = pp->umove; + v = pp->vmove; + cu = cos(u); + su = sin(u); + c2u = cos(2.0*u); + s2u = sin(2.0*u); + sv2 = sin(0.5*v); + cv4 = cos(0.25*v); + sv4 = sin(0.25*v); + xx[0] = 0.5*s2u*sv4*sv4; + xx[1] = 0.5*su*sv2; + xx[2] = 0.5*cu*sv2; + xx[3] = 0.5*(su*su*sv4*sv4-cv4*cv4); + /* Avoid degenerate tangential plane basis vectors. */ + if (v < FLT_EPSILON) + v = FLT_EPSILON; + cv2 = cos(0.5*v); + sv2 = sin(0.5*v); + sv4 = sin(0.25*v); + xxu[0] = c2u*sv4*sv4; + xxu[1] = 0.5*cu*sv2; + xxu[2] = -0.5*su*sv2; + xxu[3] = 0.5*s2u*sv4*sv4; + xxv[0] = 0.125*s2u*sv2; + xxv[1] = 0.25*su*cv2; + xxv[2] = 0.25*cu*cv2; + xxv[3] = 0.125*(su*su+1.0)*sv2; + for (l=0; l<4; l++) + { + y[l] = (mat[l][0]*xx[0]+mat[l][1]*xx[1]+ + mat[l][2]*xx[2]+mat[l][3]*xx[3]); + yu[l] = (mat[l][0]*xxu[0]+mat[l][1]*xxu[1]+ + mat[l][2]*xxu[2]+mat[l][3]*xxu[3]); + yv[l] = (mat[l][0]*xxv[0]+mat[l][1]*xxv[1]+ + mat[l][2]*xxv[2]+mat[l][3]*xxv[3]); + } + if (pp->projection_4d == DISP_4D_ORTHOGRAPHIC) + { + for (l=0; l<3; l++) + { + p[l] = y[l]+pp->offset4d[l]; + pu[l] = yu[l]; + pv[l] = yv[l]; + } + } + else + { + s = y[3]+pp->offset4d[3]; + q = 1.0/s; + t = q*q; + for (l=0; l<3; l++) + { + r = y[l]+pp->offset4d[l]; + p[l] = r*q; + pu[l] = (yu[l]*s-r*yu[3])*t; + pv[l] = (yv[l]*s-r*yv[3])*t; + } + } + n[0] = pu[1]*pv[2]-pu[2]*pv[1]; + n[1] = pu[2]*pv[0]-pu[0]*pv[2]; + n[2] = pu[0]*pv[1]-pu[1]*pv[0]; + t = 1.0/(pp->side*4.0*sqrt(n[0]*n[0]+n[1]*n[1]+n[2]*n[2])); + n[0] *= t; + n[1] *= t; + n[2] *= t; + pm[0] = pu[0]*pp->dumove+pv[0]*pp->dvmove; + pm[1] = pu[1]*pp->dumove+pv[1]*pp->dvmove; + pm[2] = pu[2]*pp->dumove+pv[2]*pp->dvmove; + t = 1.0/(4.0*sqrt(pm[0]*pm[0]+pm[1]*pm[1]+pm[2]*pm[2])); + pm[0] *= t; + pm[1] *= t; + pm[2] *= t; + b[0] = n[1]*pm[2]-n[2]*pm[1]; + b[1] = n[2]*pm[0]-n[0]*pm[2]; + b[2] = n[0]*pm[1]-n[1]*pm[0]; + t = 1.0/(4.0*sqrt(b[0]*b[0]+b[1]*b[1]+b[2]*b[2])); + b[0] *= t; + b[1] *= t; + b[2] *= t; + + /* Compute alpha, beta, delta from the three basis vectors. + | -b[0] -b[1] -b[2] | + m = | n[0] n[1] n[2] | + | -pm[0] -pm[1] -pm[2] | + */ + pp->alpha = atan2(-n[2],-pm[2])*180/M_PI; + pp->beta = atan2(-b[2],sqrt(b[0]*b[0]+b[1]*b[1]))*180/M_PI; + pp->delta = atan2(b[1],-b[0])*180/M_PI; + + /* Compute the rotation that rotates the projective plane in 4D. */ + rotateall(pp->alpha,pp->beta,pp->delta,pp->zeta,pp->eta,pp->theta,mat); + + u = pp->umove; + v = pp->vmove; + cu = cos(u); + su = sin(u); + s2u = sin(2.0*u); + sv2 = sin(0.5*v); + cv4 = cos(0.25*v); + sv4 = sin(0.25*v); + xx[0] = 0.5*s2u*sv4*sv4; + xx[1] = 0.5*su*sv2; + xx[2] = 0.5*cu*sv2; + xx[3] = 0.5*(su*su*sv4*sv4-cv4*cv4); + for (l=0; l<4; l++) + { + r = 0.0; + for (m=0; m<4; m++) + r += mat[l][m]*xx[m]; + y[l] = r; + } + if (pp->projection_4d == DISP_4D_ORTHOGRAPHIC) + { + for (l=0; l<3; l++) + p[l] = y[l]+pp->offset4d[l]; + } + else + { + s = y[3]+pp->offset4d[3]; + for (l=0; l<3; l++) + p[l] = (y[l]+pp->offset4d[l])/s; + } + + pp->offset3d[0] = -p[0]; + pp->offset3d[1] = -p[1]-DELTAY; + pp->offset3d[2] = -p[2]; + } + else + { + /* Compute the rotation that rotates the projective plane in 4D, + including the trackball rotations. */ + rotateall(pp->alpha,pp->beta,pp->delta,pp->zeta,pp->eta,pp->theta,r1); + + gltrackball_get_quaternion(pp->trackballs[0],q1); + gltrackball_get_quaternion(pp->trackballs[1],q2); + quats_to_rotmat(q1,q2,r2); + + mult_rotmat(r2,r1,mat); + } + + /* Project the points from 4D to 3D. */ + for (i=0; i<=NUMV; i++) + { + for (j=0; j<=NUMU; j++) + { + o = i*(NUMU+1)+j; + for (l=0; l<4; l++) + { + y[l] = (mat[l][0]*pp->x[o][0]+mat[l][1]*pp->x[o][1]+ + mat[l][2]*pp->x[o][2]+mat[l][3]*pp->x[o][3]); + yu[l] = (mat[l][0]*pp->xu[o][0]+mat[l][1]*pp->xu[o][1]+ + mat[l][2]*pp->xu[o][2]+mat[l][3]*pp->xu[o][3]); + yv[l] = (mat[l][0]*pp->xv[o][0]+mat[l][1]*pp->xv[o][1]+ + mat[l][2]*pp->xv[o][2]+mat[l][3]*pp->xv[o][3]); + } + if (pp->projection_4d == DISP_4D_ORTHOGRAPHIC) + { + for (l=0; l<3; l++) + { + pp->pp[o][l] = (y[l]+pp->offset4d[l])+pp->offset3d[l]; + pu[l] = yu[l]; + pv[l] = yv[l]; + } + } + else + { + s = y[3]+pp->offset4d[3]; + q = 1.0/s; + t = q*q; + for (l=0; l<3; l++) + { + r = y[l]+pp->offset4d[l]; + pp->pp[o][l] = r*q+pp->offset3d[l]; + pu[l] = (yu[l]*s-r*yu[3])*t; + pv[l] = (yv[l]*s-r*yv[3])*t; + } + } + pp->pn[o][0] = pu[1]*pv[2]-pu[2]*pv[1]; + pp->pn[o][1] = pu[2]*pv[0]-pu[0]*pv[2]; + pp->pn[o][2] = pu[0]*pv[1]-pu[1]*pv[0]; + t = 1.0/sqrt(pp->pn[o][0]*pp->pn[o][0]+pp->pn[o][1]*pp->pn[o][1]+ + pp->pn[o][2]*pp->pn[o][2]); + pp->pn[o][0] *= t; + pp->pn[o][1] *= t; + pp->pn[o][2] *= t; + } + } + + if (pp->colors == COLORS_TWOSIDED) + { + glColor3fv(mat_diff_red); + if (pp->display_mode == DISP_TRANSPARENT) + { + glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_red); + glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_trans_green); + } + else + { + glMaterialfv(GL_FRONT,GL_AMBIENT_AND_DIFFUSE,mat_diff_red); + glMaterialfv(GL_BACK,GL_AMBIENT_AND_DIFFUSE,mat_diff_green); + } + } + glBindTexture(GL_TEXTURE_2D,pp->tex_name); + + if (pp->appearance != APPEARANCE_DIRECTION_BANDS) + { + for (i=0; iappearance == APPEARANCE_DISTANCE_BANDS && + ((i & (NUMB-1)) >= NUMB/4) && ((i & (NUMB-1)) < 3*NUMB/4)) + continue; + if (pp->display_mode == DISP_WIREFRAME) + glBegin(GL_QUAD_STRIP); + else + glBegin(GL_TRIANGLE_STRIP); + for (j=0; j<=NUMU; j++) + { + for (k=0; k<=1; k++) + { + l = (i+k); + m = j; + o = l*(NUMU+1)+m; + glNormal3fv(pp->pn[o]); + glTexCoord2fv(pp->tex[o]); + if (pp->colors != COLORS_TWOSIDED) + { + glColor3fv(pp->col[o]); + glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,pp->col[o]); + } + glVertex3fv(pp->pp[o]); + polys++; + } + } + glEnd(); + } + } + else /* pp->appearance == APPEARANCE_DIRECTION_BANDS */ + { + for (j=0; j= NUMB/2) + continue; + if (pp->display_mode == DISP_WIREFRAME) + glBegin(GL_QUAD_STRIP); + else + glBegin(GL_TRIANGLE_STRIP); + for (i=0; i<=NUMV; i++) + { + for (k=0; k<=1; k++) + { + l = i; + m = (j+k); + o = l*(NUMU+1)+m; + glNormal3fv(pp->pn[o]); + glTexCoord2fv(pp->tex[o]); + if (pp->colors != COLORS_TWOSIDED) + { + glColor3fv(pp->col[o]); + glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,pp->col[o]); + } + glVertex3fv(pp->pp[o]); + polys++; + } + } + glEnd(); + } + } + + polys /= 2; + return polys; +} + + +/* Generate a texture image that shows the orientation reversal. */ +static void gen_texture(ModeInfo *mi) +{ + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + glGenTextures(1,&pp->tex_name); + glBindTexture(GL_TEXTURE_2D,pp->tex_name); + glPixelStorei(GL_UNPACK_ALIGNMENT,1); + glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT); + glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT); + glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); + glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); + glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE); + glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,TEX_DIMENSION,TEX_DIMENSION,0, + GL_LUMINANCE,GL_UNSIGNED_BYTE,texture); +} + + +static void init(ModeInfo *mi) +{ + static const GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 }; + static const GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 }; + static const GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 }; + static const GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 }; + static const GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 }; + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + if (walk_speed == 0.0) + walk_speed = 20.0; + + if (pp->view == VIEW_TURN) + { + pp->alpha = frand(360.0); + pp->beta = frand(360.0); + pp->delta = frand(360.0); + pp->zeta = 0.0; + pp->eta = 0.0; + pp->theta = 0.0; + } + else + { + pp->alpha = 0.0; + pp->beta = 0.0; + pp->delta = 0.0; + pp->zeta = 120.0; + pp->eta = 180.0; + pp->theta = 90.0; + } + pp->umove = frand(2.0*M_PI); + pp->vmove = frand(2.0*M_PI); + pp->dumove = 0.0; + pp->dvmove = 0.0; + pp->side = 1; + if (sin(walk_direction*M_PI/180.0) >= 0.0) + pp->dir = 1; + else + pp->dir = -1; + + pp->offset4d[0] = 0.0; + pp->offset4d[1] = 0.0; + pp->offset4d[2] = 0.0; + pp->offset4d[3] = 1.2; + pp->offset3d[0] = 0.0; + pp->offset3d[1] = 0.0; + pp->offset3d[2] = -1.2; + pp->offset3d[3] = 0.0; + + gen_texture(mi); + setup_projective_plane(mi,0.0,2.0*M_PI,0.0,2.0*M_PI); + + if (pp->marks) + glEnable(GL_TEXTURE_2D); + else + glDisable(GL_TEXTURE_2D); + + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + if (pp->projection_3d == DISP_3D_PERSPECTIVE || + pp->view == VIEW_WALK || pp->view == VIEW_WALKTURN) + { + if (pp->view == VIEW_WALK || pp->view == VIEW_WALKTURN) + gluPerspective(60.0,1.0,0.01,10.0); + else + gluPerspective(60.0,1.0,0.1,10.0); + } + else + { + glOrtho(-0.6,0.6,-0.6,0.6,0.1,10.0); + } + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + +# ifdef HAVE_JWZGLES /* #### glPolygonMode other than GL_FILL unimplemented */ + if (pp->display_mode == DISP_WIREFRAME) + pp->display_mode = DISP_SURFACE; +# endif + + if (pp->display_mode == DISP_SURFACE) + { + glEnable(GL_DEPTH_TEST); + glDepthFunc(GL_LESS); + glShadeModel(GL_SMOOTH); + glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); + glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE); + glEnable(GL_LIGHTING); + glEnable(GL_LIGHT0); + glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient); + glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse); + glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular); + glLightfv(GL_LIGHT0,GL_POSITION,light_position); + glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,mat_specular); + glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,50.0); + glDepthMask(GL_TRUE); + glDisable(GL_BLEND); + } + else if (pp->display_mode == DISP_TRANSPARENT) + { + glDisable(GL_DEPTH_TEST); + glShadeModel(GL_SMOOTH); + glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); + glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE); + glEnable(GL_LIGHTING); + glEnable(GL_LIGHT0); + glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient); + glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse); + glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular); + glLightfv(GL_LIGHT0,GL_POSITION,light_position); + glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,mat_specular); + glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,50.0); + glDepthMask(GL_FALSE); + glEnable(GL_BLEND); + glBlendFunc(GL_SRC_ALPHA,GL_ONE); + } + else /* pp->display_mode == DISP_WIREFRAME */ + { + glDisable(GL_DEPTH_TEST); + glShadeModel(GL_FLAT); + glPolygonMode(GL_FRONT_AND_BACK,GL_LINE); + glDisable(GL_LIGHTING); + glDisable(GL_LIGHT0); + glDisable(GL_BLEND); + } +} + + +/* Redisplay the Klein bottle. */ +static void display_projectiveplane(ModeInfo *mi) +{ + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + if (!pp->button_pressed) + { + if (pp->view == VIEW_TURN) + { + pp->alpha += speed_wx * pp->speed_scale; + if (pp->alpha >= 360.0) + pp->alpha -= 360.0; + pp->beta += speed_wy * pp->speed_scale; + if (pp->beta >= 360.0) + pp->beta -= 360.0; + pp->delta += speed_wz * pp->speed_scale; + if (pp->delta >= 360.0) + pp->delta -= 360.0; + pp->zeta += speed_xy * pp->speed_scale; + if (pp->zeta >= 360.0) + pp->zeta -= 360.0; + pp->eta += speed_xz * pp->speed_scale; + if (pp->eta >= 360.0) + pp->eta -= 360.0; + pp->theta += speed_yz * pp->speed_scale; + if (pp->theta >= 360.0) + pp->theta -= 360.0; + } + if (pp->view == VIEW_WALKTURN) + { + pp->zeta += speed_xy * pp->speed_scale; + if (pp->zeta >= 360.0) + pp->zeta -= 360.0; + pp->eta += speed_xz * pp->speed_scale; + if (pp->eta >= 360.0) + pp->eta -= 360.0; + pp->theta += speed_yz * pp->speed_scale; + if (pp->theta >= 360.0) + pp->theta -= 360.0; + } + if (pp->view == VIEW_WALK || pp->view == VIEW_WALKTURN) + { + pp->dvmove = (pp->dir*sin(walk_direction*M_PI/180.0)* + walk_speed*M_PI/4096.0); + pp->vmove += pp->dvmove; + if (pp->vmove > 2.0*M_PI) + { + pp->vmove = 4.0*M_PI-pp->vmove; + pp->umove = pp->umove-M_PI; + if (pp->umove < 0.0) + pp->umove += 2.0*M_PI; + pp->side = -pp->side; + pp->dir = -pp->dir; + pp->dvmove = -pp->dvmove; + } + if (pp->vmove < 0.0) + { + pp->vmove = -pp->vmove; + pp->umove = pp->umove-M_PI; + if (pp->umove < 0.0) + pp->umove += 2.0*M_PI; + pp->dir = -pp->dir; + pp->dvmove = -pp->dvmove; + } + pp->dumove = cos(walk_direction*M_PI/180.0)*walk_speed*M_PI/4096.0; + pp->umove += pp->dumove; + if (pp->umove >= 2.0*M_PI) + pp->umove -= 2.0*M_PI; + if (pp->umove < 0.0) + pp->umove += 2.0*M_PI; + } + } + + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + if (pp->projection_3d == DISP_3D_PERSPECTIVE || + pp->view == VIEW_WALK || pp->view == VIEW_WALKTURN) + { + if (pp->view == VIEW_WALK || pp->view == VIEW_WALKTURN) + gluPerspective(60.0,pp->aspect,0.01,10.0); + else + gluPerspective(60.0,pp->aspect,0.1,10.0); + } + else + { + if (pp->aspect >= 1.0) + glOrtho(-0.6*pp->aspect,0.6*pp->aspect,-0.6,0.6,0.1,10.0); + else + glOrtho(-0.6,0.6,-0.6/pp->aspect,0.6/pp->aspect,0.1,10.0); + } + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + + mi->polygon_count = projective_plane(mi,0.0,2.0*M_PI,0.0,2.0*M_PI); +} + + +ENTRYPOINT void reshape_projectiveplane(ModeInfo *mi, int width, int height) +{ + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + pp->WindW = (GLint)width; + pp->WindH = (GLint)height; + glViewport(0,0,width,height); + pp->aspect = (GLfloat)width/(GLfloat)height; +} + + +ENTRYPOINT Bool projectiveplane_handle_event(ModeInfo *mi, XEvent *event) +{ + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + KeySym sym = 0; + char c = 0; + + if (event->xany.type == KeyPress || event->xany.type == KeyRelease) + XLookupString (&event->xkey, &c, 1, &sym, 0); + + if (event->xany.type == ButtonPress && + event->xbutton.button == Button1) + { + pp->button_pressed = True; + gltrackball_start(pp->trackballs[pp->current_trackball], + event->xbutton.x, event->xbutton.y, + MI_WIDTH(mi), MI_HEIGHT(mi)); + return True; + } + else if (event->xany.type == ButtonRelease && + event->xbutton.button == Button1) + { + pp->button_pressed = False; + return True; + } + else if (event->xany.type == KeyPress) + { + if (sym == XK_Shift_L || sym == XK_Shift_R) + { + pp->current_trackball = 1; + if (pp->button_pressed) + gltrackball_start(pp->trackballs[pp->current_trackball], + event->xbutton.x, event->xbutton.y, + MI_WIDTH(mi), MI_HEIGHT(mi)); + return True; + } + } + else if (event->xany.type == KeyRelease) + { + if (sym == XK_Shift_L || sym == XK_Shift_R) + { + pp->current_trackball = 0; + if (pp->button_pressed) + gltrackball_start(pp->trackballs[pp->current_trackball], + event->xbutton.x, event->xbutton.y, + MI_WIDTH(mi), MI_HEIGHT(mi)); + return True; + } + } + else if (event->xany.type == MotionNotify && pp->button_pressed) + { + gltrackball_track(pp->trackballs[pp->current_trackball], + event->xmotion.x, event->xmotion.y, + MI_WIDTH(mi), MI_HEIGHT(mi)); + return True; + } + + return False; +} + + +/* + *----------------------------------------------------------------------------- + *----------------------------------------------------------------------------- + * Xlock hooks. + *----------------------------------------------------------------------------- + *----------------------------------------------------------------------------- + */ + +/* + *----------------------------------------------------------------------------- + * Initialize projectiveplane. Called each time the window changes. + *----------------------------------------------------------------------------- + */ + +ENTRYPOINT void init_projectiveplane(ModeInfo *mi) +{ + projectiveplanestruct *pp; + + MI_INIT(mi, projectiveplane); + pp = &projectiveplane[MI_SCREEN(mi)]; + + + pp->trackballs[0] = gltrackball_init(True); + pp->trackballs[1] = gltrackball_init(True); + pp->current_trackball = 0; + pp->button_pressed = False; + + /* Set the display mode. */ + if (!strcasecmp(mode,"random")) + { + pp->display_mode = random() % NUM_DISPLAY_MODES; + } + else if (!strcasecmp(mode,"wireframe")) + { + pp->display_mode = DISP_WIREFRAME; + } + else if (!strcasecmp(mode,"surface")) + { + pp->display_mode = DISP_SURFACE; + } + else if (!strcasecmp(mode,"transparent")) + { + pp->display_mode = DISP_TRANSPARENT; + } + else + { + pp->display_mode = random() % NUM_DISPLAY_MODES; + } + + /* Orientation marks don't make sense in wireframe mode. */ + pp->marks = marks; + if (pp->display_mode == DISP_WIREFRAME) + pp->marks = False; + + /* Set the appearance. */ + if (!strcasecmp(appear,"random")) + { + pp->appearance = random() % NUM_APPEARANCES; + } + else if (!strcasecmp(appear,"solid")) + { + pp->appearance = APPEARANCE_SOLID; + } + else if (!strcasecmp(appear,"distance-bands")) + { + pp->appearance = APPEARANCE_DISTANCE_BANDS; + } + else if (!strcasecmp(appear,"direction-bands")) + { + pp->appearance = APPEARANCE_DIRECTION_BANDS; + } + else + { + pp->appearance = random() % NUM_APPEARANCES; + } + + /* Set the color mode. */ + if (!strcasecmp(color_mode,"random")) + { + pp->colors = random() % NUM_COLORS; + } + else if (!strcasecmp(color_mode,"two-sided")) + { + pp->colors = COLORS_TWOSIDED; + } + else if (!strcasecmp(color_mode,"distance")) + { + pp->colors = COLORS_DISTANCE; + } + else if (!strcasecmp(color_mode,"direction")) + { + pp->colors = COLORS_DIRECTION; + } + else if (!strcasecmp(color_mode,"depth")) + { + pp->colors = COLORS_DEPTH; + } + else + { + pp->colors = random() % NUM_COLORS; + } + + /* Set the view mode. */ + if (!strcasecmp(view_mode,"random")) + { + pp->view = random() % NUM_VIEW_MODES; + } + else if (!strcasecmp(view_mode,"walk")) + { + pp->view = VIEW_WALK; + } + else if (!strcasecmp(view_mode,"turn")) + { + pp->view = VIEW_TURN; + } + else if (!strcasecmp(view_mode,"walk-turn")) + { + pp->view = VIEW_WALKTURN; + } + else + { + pp->view = random() % NUM_VIEW_MODES; + } + + /* Set the 3d projection mode. */ + if (!strcasecmp(proj_3d,"random")) + { + /* Orthographic projection only makes sense in turn mode. */ + if (pp->view == VIEW_TURN) + pp->projection_3d = random() % NUM_DISP_3D_MODES; + else + pp->projection_3d = DISP_3D_PERSPECTIVE; + } + else if (!strcasecmp(proj_3d,"perspective")) + { + pp->projection_3d = DISP_3D_PERSPECTIVE; + } + else if (!strcasecmp(proj_3d,"orthographic")) + { + pp->projection_3d = DISP_3D_ORTHOGRAPHIC; + } + else + { + /* Orthographic projection only makes sense in turn mode. */ + if (pp->view == VIEW_TURN) + pp->projection_3d = random() % NUM_DISP_3D_MODES; + else + pp->projection_3d = DISP_3D_PERSPECTIVE; + } + + /* Set the 4d projection mode. */ + if (!strcasecmp(proj_4d,"random")) + { + pp->projection_4d = random() % NUM_DISP_4D_MODES; + } + else if (!strcasecmp(proj_4d,"perspective")) + { + pp->projection_4d = DISP_4D_PERSPECTIVE; + } + else if (!strcasecmp(proj_4d,"orthographic")) + { + pp->projection_4d = DISP_4D_ORTHOGRAPHIC; + } + else + { + pp->projection_4d = random() % NUM_DISP_4D_MODES; + } + + /* Modify the speeds to a useful range in walk-and-turn mode. */ + if (pp->view == VIEW_WALKTURN) + { + speed_wx *= 0.2; + speed_wy *= 0.2; + speed_wz *= 0.2; + speed_xy *= 0.2; + speed_xz *= 0.2; + speed_yz *= 0.2; + } + + /* make multiple screens rotate at slightly different rates. */ + pp->speed_scale = 0.9 + frand(0.3); + + if ((pp->glx_context = init_GL(mi)) != NULL) + { + reshape_projectiveplane(mi,MI_WIDTH(mi),MI_HEIGHT(mi)); + glDrawBuffer(GL_BACK); + init(mi); + } + else + { + MI_CLEARWINDOW(mi); + } +} + +/* + *----------------------------------------------------------------------------- + * Called by the mainline code periodically to update the display. + *----------------------------------------------------------------------------- + */ +ENTRYPOINT void draw_projectiveplane(ModeInfo *mi) +{ + Display *display = MI_DISPLAY(mi); + Window window = MI_WINDOW(mi); + projectiveplanestruct *pp; + + if (projectiveplane == NULL) + return; + pp = &projectiveplane[MI_SCREEN(mi)]; + + MI_IS_DRAWN(mi) = True; + if (!pp->glx_context) + return; + + glXMakeCurrent(display,window,*(pp->glx_context)); + + glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); + glLoadIdentity(); + + display_projectiveplane(mi); + + if (MI_IS_FPS(mi)) + do_fps (mi); + + glFlush(); + + glXSwapBuffers(display,window); +} + + +#ifndef STANDALONE +ENTRYPOINT void change_projectiveplane(ModeInfo *mi) +{ + projectiveplanestruct *pp = &projectiveplane[MI_SCREEN(mi)]; + + if (!pp->glx_context) + return; + + glXMakeCurrent(MI_DISPLAY(mi),MI_WINDOW(mi),*(pp->glx_context)); + init(mi); +} +#endif /* !STANDALONE */ + +XSCREENSAVER_MODULE ("ProjectivePlane", projectiveplane) + +#endif /* USE_GL */ -- cgit v1.2.3-55-g7522