--- /dev/null
+/* glknots, Copyright (c) 2003 Jamie Zawinski <jwz@jwz.org>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation. No representations are made about the suitability of this
+ * software for any purpose. It is provided "as is" without express or
+ * implied warranty.
+ *
+ * Generates some 3D knots (closed loops).
+ * Inspired by Paul Bourke <pbourke@swin.edu.au> at
+ * http://astronomy.swin.edu.au/~pbourke/curves/knot/
+ */
+
+#include <X11/Intrinsic.h>
+
+extern XtAppContext app;
+
+#define PROGCLASS "GLKnots"
+#define HACK_INIT init_knot
+#define HACK_DRAW draw_knot
+#define HACK_RESHAPE reshape_knot
+#define HACK_HANDLE_EVENT knot_handle_event
+#define EVENT_MASK PointerMotionMask
+#define sws_opts xlockmore_opts
+
+#define DEF_SPIN "XYZ"
+#define DEF_WANDER "True"
+#define DEF_SPEED "1.0"
+#define DEF_THICKNESS "0.3"
+#define DEF_SEGMENTS "800"
+#define DEF_DURATION "8"
+
+#define DEFAULTS "*delay: 30000 \n" \
+ "*showFPS: False \n" \
+ "*wireframe: False \n" \
+ "*speed: " DEF_SPEED " \n" \
+ "*spin: " DEF_SPIN "\n" \
+ "*wander: " DEF_WANDER "\n" \
+ "*thickness: " DEF_THICKNESS "\n" \
+ "*segments: " DEF_SEGMENTS "\n" \
+ "*duration: " DEF_DURATION "\n" \
+
+#undef countof
+#define countof(x) (sizeof((x))/sizeof((*x)))
+
+#include "xlockmore.h"
+#include "colors.h"
+#include "tube.h"
+#include "rotator.h"
+#include "gltrackball.h"
+#include <ctype.h>
+
+#ifdef USE_GL /* whole file */
+
+#include <GL/glu.h>
+
+typedef struct {
+ GLXContext *glx_context;
+ rotator *rot;
+ trackball_state *trackball;
+ Bool button_down_p;
+
+ GLuint knot_list;
+
+ int ncolors;
+ XColor *colors;
+ int ccolor;
+
+ int mode; /* 0 = normal, 1 = out, 2 = in */
+ int mode_tick;
+ Bool clear_p;
+
+} knot_configuration;
+
+static knot_configuration *bps = NULL;
+
+static char *do_spin;
+static GLfloat speed;
+static Bool do_wander;
+static GLfloat thickness;
+static int segments;
+static int duration;
+
+static XrmOptionDescRec opts[] = {
+ { "-spin", ".spin", XrmoptionSepArg, 0 },
+ { "+spin", ".spin", XrmoptionNoArg, "" },
+ { "-wander", ".wander", XrmoptionNoArg, "True" },
+ { "+wander", ".wander", XrmoptionNoArg, "False" },
+ { "-speed", ".speed", XrmoptionSepArg, 0 },
+ { "-thickness", ".thickness", XrmoptionSepArg, 0 },
+ { "-segments", ".segments", XrmoptionSepArg, 0 },
+ { "-duration", ".duration", XrmoptionSepArg, 0 },
+};
+
+static argtype vars[] = {
+ {(caddr_t *) &do_spin, "spin", "Spin", DEF_SPIN, t_String},
+ {(caddr_t *) &do_wander, "wander", "Wander", DEF_WANDER, t_Bool},
+ {(caddr_t *) &speed, "speed", "Speed", DEF_SPEED, t_Float},
+ {(caddr_t *) &thickness, "thickness", "Thickness", DEF_THICKNESS, t_Float},
+ {(caddr_t *) &segments, "segments", "Segments", DEF_SEGMENTS, t_Int},
+ {(caddr_t *) &duration, "duration", "Duration", DEF_DURATION, t_Int},
+};
+
+ModeSpecOpt sws_opts = {countof(opts), opts, countof(vars), vars, NULL};
+
+
+static void
+make_knot (ModeInfo *mi)
+{
+ int wire = MI_IS_WIREFRAME(mi);
+
+ GLfloat diam = (4 * thickness);
+ int faces = (wire ? 3 : 6);
+
+ int i;
+ double x, y, z, ox, oy, oz;
+ double mu;
+
+ double p[9];
+
+ Bool blobby_p = (0 == (random() % 5));
+ Bool type = (random() % 2);
+
+ for (i = 0; i < countof(p); i++)
+ {
+ p[i] = 1 + (random() % 4);
+ if (! (random() % 3))
+ p[i] += (random() % 5);
+ }
+
+ if (type == 1)
+ {
+ p[0] += 4;
+ p[1] *= ((p[0] + p[0]) / 10);
+ blobby_p = False;
+ }
+
+ mi->polygon_count = 0;
+
+ for (i = 0; i <= segments; i++)
+ {
+ if (type == 0)
+ {
+ mu = i * (M_PI * 2) / segments;
+ x = 10 * (cos(mu) + cos(p[0]*mu)) + cos(p[1]*mu) + cos(p[2]*mu);
+ y = 6 * sin(mu) + 10 * sin(p[3]*mu);
+ z = 16 * sin(p[4]*mu) * sin(p[5]*mu/2) + p[6]*sin(p[7]*mu) -
+ 2 * sin(p[8]*mu);
+ }
+ else if (type == 1)
+ {
+ mu = i * (M_PI * 2) * p[0] / (double) segments;
+ x = 10 * cos(mu) * (1 + cos(p[1] * mu/ p[0]) / 2.0);
+ y = 25 * sin(p[1] * mu / p[0]) / 2.0;
+ z = 10 * sin(mu) * (1 + cos(p[1] * mu/ p[0]) / 2.0);
+ }
+ else
+ abort();
+
+ if (i != 0)
+ {
+ GLfloat dist = sqrt ((x-ox)*(x-ox) +
+ (y-oy)*(y-oy) +
+ (z-oz)*(z-oz));
+ GLfloat di;
+ if (!blobby_p)
+ di = diam;
+ else
+ {
+ di = dist * (segments / 500.0);
+ di = (di * di * 3);
+ }
+
+ tube (ox, oy, oz,
+ x, y, z,
+ di, dist/3,
+ faces, True, wire, wire);
+
+ mi->polygon_count += faces;
+ }
+
+ ox = x;
+ oy = y;
+ oz = z;
+ }
+}
+
+
+/* Window management, etc
+ */
+void
+reshape_knot (ModeInfo *mi, int width, int height)
+{
+ GLfloat h = (GLfloat) height / (GLfloat) width;
+
+ glViewport (0, 0, (GLint) width, (GLint) height);
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ gluPerspective (30.0, 1/h, 1.0, 100.0);
+
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ gluLookAt( 0.0, 0.0, 30.0,
+ 0.0, 0.0, 0.0,
+ 0.0, 1.0, 0.0);
+
+ glClear(GL_COLOR_BUFFER_BIT);
+}
+
+
+static void
+new_knot (ModeInfo *mi)
+{
+ knot_configuration *bp = &bps[MI_SCREEN(mi)];
+ int i;
+
+ bp->clear_p = !!(random() % 15);
+
+ bp->ncolors = 128;
+ bp->colors = (XColor *) calloc(bp->ncolors, sizeof(XColor));
+ make_smooth_colormap (0, 0, 0,
+ bp->colors, &bp->ncolors,
+ False, 0, False);
+
+ for (i = 0; i < bp->ncolors; i++)
+ {
+ /* make colors twice as bright */
+ bp->colors[i].red = (bp->colors[i].red >> 2) + 0x7FFF;
+ bp->colors[i].green = (bp->colors[i].green >> 2) + 0x7FFF;
+ bp->colors[i].blue = (bp->colors[i].blue >> 2) + 0x7FFF;
+ }
+
+ glNewList (bp->knot_list, GL_COMPILE);
+ make_knot (mi);
+ glEndList ();
+}
+
+
+Bool
+knot_handle_event (ModeInfo *mi, XEvent *event)
+{
+ knot_configuration *bp = &bps[MI_SCREEN(mi)];
+
+ if (event->xany.type == ButtonPress &&
+ event->xbutton.button & Button1)
+ {
+ bp->button_down_p = True;
+ gltrackball_start (bp->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)
+ {
+ bp->button_down_p = False;
+ return True;
+ }
+ else if (event->xany.type == MotionNotify &&
+ bp->button_down_p)
+ {
+ gltrackball_track (bp->trackball,
+ event->xmotion.x, event->xmotion.y,
+ MI_WIDTH (mi), MI_HEIGHT (mi));
+ return True;
+ }
+
+ return False;
+}
+
+
+
+void
+init_knot (ModeInfo *mi)
+{
+ knot_configuration *bp;
+ int wire = MI_IS_WIREFRAME(mi);
+
+ if (!bps) {
+ bps = (knot_configuration *)
+ calloc (MI_NUM_SCREENS(mi), sizeof (knot_configuration));
+ if (!bps) {
+ fprintf(stderr, "%s: out of memory\n", progname);
+ exit(1);
+ }
+
+ bp = &bps[MI_SCREEN(mi)];
+ }
+
+ bp = &bps[MI_SCREEN(mi)];
+
+ bp->glx_context = init_GL(mi);
+
+ if (thickness <= 0) thickness = 0.001;
+ else if (thickness > 1) thickness = 1;
+
+ if (segments < 10) segments = 10;
+
+ reshape_knot (mi, MI_WIDTH(mi), MI_HEIGHT(mi));
+
+ if (!wire)
+ {
+ GLfloat pos[4] = {1.0, 1.0, 1.0, 0.0};
+ GLfloat amb[4] = {0.0, 0.0, 0.0, 1.0};
+ GLfloat dif[4] = {1.0, 1.0, 1.0, 1.0};
+ GLfloat spc[4] = {0.0, 1.0, 1.0, 1.0};
+
+ glEnable(GL_LIGHTING);
+ glEnable(GL_LIGHT0);
+ glEnable(GL_DEPTH_TEST);
+ glEnable(GL_CULL_FACE);
+
+ glLightfv(GL_LIGHT0, GL_POSITION, pos);
+ glLightfv(GL_LIGHT0, GL_AMBIENT, amb);
+ glLightfv(GL_LIGHT0, GL_DIFFUSE, dif);
+ glLightfv(GL_LIGHT0, GL_SPECULAR, spc);
+ }
+
+ {
+ Bool spinx=False, spiny=False, spinz=False;
+ double spin_speed = 2.0;
+ double wander_speed = 0.05;
+ double spin_accel = 0.2;
+
+ char *s = do_spin;
+ while (*s)
+ {
+ if (*s == 'x' || *s == 'X') spinx = True;
+ else if (*s == 'y' || *s == 'Y') spiny = True;
+ else if (*s == 'z' || *s == 'Z') spinz = True;
+ else
+ {
+ fprintf (stderr,
+ "%s: spin must contain only the characters X, Y, or Z (not \"%s\")\n",
+ progname, do_spin);
+ exit (1);
+ }
+ s++;
+ }
+
+ bp->rot = make_rotator (spinx ? spin_speed : 0,
+ spiny ? spin_speed : 0,
+ spinz ? spin_speed : 0,
+ spin_accel,
+ do_wander ? wander_speed : 0,
+ (spinx && spiny && spinz));
+ bp->trackball = gltrackball_init ();
+ }
+
+ bp->knot_list = glGenLists (1);
+ new_knot(mi);
+
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+}
+
+
+void
+draw_knot (ModeInfo *mi)
+{
+ knot_configuration *bp = &bps[MI_SCREEN(mi)];
+ Display *dpy = MI_DISPLAY(mi);
+ Window window = MI_WINDOW(mi);
+
+ static GLfloat bcolor[4] = {0.0, 0.0, 0.0, 1.0};
+ static GLfloat bspec[4] = {1.0, 1.0, 1.0, 1.0};
+ static GLfloat bshiny = 128.0;
+
+ static time_t last_time = 0;
+
+ if (!bp->glx_context)
+ return;
+
+ if (bp->mode == 0)
+ {
+ static int tick = 0;
+ if (tick++ > 10)
+ {
+ time_t now = time((time_t *) 0);
+ if (last_time == 0) last_time = now;
+ tick = 0;
+ if (!bp->button_down_p &&
+ now - last_time >= duration)
+ {
+ bp->mode = 1; /* go out */
+ bp->mode_tick = 10 * speed;
+ last_time = now;
+ }
+ }
+ }
+ else if (bp->mode == 1) /* out */
+ {
+ if (--bp->mode_tick <= 0)
+ {
+ new_knot (mi);
+ bp->mode_tick = 10 * speed;
+ bp->mode = 2; /* go in */
+ }
+ }
+ else if (bp->mode == 2) /* in */
+ {
+ if (--bp->mode_tick <= 0)
+ bp->mode = 0; /* normal */
+ }
+ else
+ abort();
+
+ glShadeModel(GL_SMOOTH);
+
+ glEnable(GL_DEPTH_TEST);
+ glEnable(GL_NORMALIZE);
+ glEnable(GL_CULL_FACE);
+
+ if (bp->clear_p)
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ glPushMatrix ();
+
+ {
+ double x, y, z;
+ get_position (bp->rot, &x, &y, &z, !bp->button_down_p);
+ glTranslatef((x - 0.5) * 8,
+ (y - 0.5) * 8,
+ (z - 0.5) * 15);
+
+ gltrackball_rotate (bp->trackball);
+
+ get_rotation (bp->rot, &x, &y, &z, !bp->button_down_p);
+
+ glRotatef (x * 360, 1.0, 0.0, 0.0);
+ glRotatef (y * 360, 0.0, 1.0, 0.0);
+ glRotatef (z * 360, 0.0, 0.0, 1.0);
+ }
+
+ bcolor[0] = bp->colors[bp->ccolor].red / 65536.0;
+ bcolor[1] = bp->colors[bp->ccolor].green / 65536.0;
+ bcolor[2] = bp->colors[bp->ccolor].blue / 65536.0;
+ bp->ccolor++;
+ if (bp->ccolor >= bp->ncolors) bp->ccolor = 0;
+
+ glMaterialfv (GL_FRONT, GL_SPECULAR, bspec);
+ glMateriali (GL_FRONT, GL_SHININESS, bshiny);
+ glMaterialfv (GL_FRONT, GL_AMBIENT_AND_DIFFUSE, bcolor);
+
+ glScalef(0.25, 0.25, 0.25);
+
+ if (bp->mode != 0)
+ {
+ GLfloat s = (bp->mode == 1
+ ? bp->mode_tick / (10 * speed)
+ : ((10 * speed) - bp->mode_tick + 1) / (10 * speed));
+ glScalef (s, s, s);
+ }
+
+ glCallList (bp->knot_list);
+
+ glPopMatrix ();
+
+ if (mi->fps_p) do_fps (mi);
+ glFinish();
+
+ glXSwapBuffers(dpy, window);
+}
+
+#endif /* USE_GL */
projects / xscreensaver / blobdiff