--- /dev/null
+/* -*- Mode: C; tab-width: 4 -*- */
+/* galaxy --- spinning galaxies */
+
+#if !defined( lint ) && !defined( SABER )
+static const char sccsid[] = "@(#)galaxy.c 4.04 97/07/28 xlockmore";
+#endif
+
+/* Originally done by Uli Siegmund <uli@wombat.okapi.sub.org> on Amiga
+ * for EGS in Cluster
+ * Port from Cluster/EGS to C/Intuition by Harald Backert
+ * Port to X11 and incorporation into xlockmore by Hubert Feyrer
+ * <hubert.feyrer@rz.uni-regensburg.de>
+ *
+ * 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:
+ * 10-May-97: jwz@jwz.org: turned into a standalone program.
+ * 18-Apr-97: Memory leak fixed by Tom Schmidt <tschmidt@micron.com>
+ * 07-Apr-97: Modified by Dave Mitchell <davem@magnet.com>
+ * 23-Oct-94: Modified by David Bagley <bagleyd@bigfoot.com>
+ * random star sizes
+ * colors change depending on velocity
+ * 10-Oct-94: Add colors by Hubert Feyer
+ * 30-Sep-94: Initial port by Hubert Feyer
+ * 09-Mar-94: VMS can generate a random number 0.0 which results in a
+ * division by zero, corrected by Jouk Jansen
+ * <joukj@crys.chem.uva.nl>
+ */
+
+#ifdef STANDALONE
+# define PROGCLASS "Galaxy"
+# define HACK_INIT init_galaxy
+# define HACK_DRAW draw_galaxy
+# define galaxy_opts xlockmore_opts
+# define DEFAULTS "*delay: 100 \n" \
+ "*count: -5 \n" \
+ "*cycles: 250 \n" \
+ "*size: -3 \n" \
+ "*ncolors: 64 \n"
+# define UNIFORM_COLORS
+# include "xlockmore.h" /* from the xscreensaver distribution */
+#else /* !STANDALONE */
+# include "xlock.h" /* from the xlockmore distribution */
+#endif /* !STANDALONE */
+
+static Bool tracks;
+
+#define DEF_TRACKS "False"
+
+static XrmOptionDescRec opts[] =
+{
+ {"-tracks", ".galaxy.tracks", XrmoptionNoArg, (caddr_t) "on"},
+ {"+tracks", ".galaxy.tracks", XrmoptionNoArg, (caddr_t) "off"}
+};
+
+static argtype vars[] =
+{
+ {(caddr_t *) & tracks, "tracks", "Tracks", DEF_TRACKS, t_Bool}
+};
+
+static OptionStruct desc[] =
+{
+ {"-/+tracks", "turn on/off star tracks"}
+};
+
+ModeSpecOpt galaxy_opts = { 2, opts, 1, vars, desc };
+
+
+#define FLOATRAND ((double) LRAND() / ((double) MAXRAND))
+
+#if 0
+#define WRAP 1 /* Warp around edges */
+#define BOUNCE 1 /* Bounce from borders */
+#endif
+
+#define MINSIZE 1
+#define MINGALAXIES 1
+#define MAX_STARS 300
+#define MAX_IDELTAT 50
+/* These come originally from the Cluster-version */
+#define DEFAULT_GALAXIES 2
+#define DEFAULT_STARS 1000
+#define DEFAULT_HITITERATIONS 7500
+#define DEFAULT_IDELTAT 200 /* 0.02 */
+#define EPSILON 0.00000001
+
+#define sqrt_EPSILON 0.0001
+
+#define DELTAT (MAX_IDELTAT * 0.0001)
+
+#define GALAXYRANGESIZE 0.1
+#define GALAXYMINSIZE 0.1
+#define QCONS 0.001
+
+/*-
+ * The following is enabled, it does not look that good for some.
+ * (But it looks great for me.) Maybe velocities should be measured
+ * relative to their galaxy-centers instead of absolute.
+ */
+#if 0
+#undef NO_VELOCITY_COLORING */ /* different colors for different speeds */
+#endif
+
+#define COLORBASE 8
+ /* Colors for stars start here */
+#define COLORSTEP (NUMCOLORS/COLORBASE) /* 8 colors per galaxy */
+
+#define drawStar(x,y,size) if(size<=1) XDrawPoint(display,window,gc,x,y);\
+ else XFillArc(display,window,gc,x,y,size,size,0,23040)
+
+typedef struct {
+ double pos[3], vel[3];
+ int px, py;
+ int color;
+ int size;
+} Star;
+
+typedef struct {
+ int mass;
+ int nstars;
+ Star *stars;
+ double pos[3], vel[3];
+ int galcol;
+} Galaxy;
+
+typedef struct {
+ struct {
+ int left; /* x minimum */
+ int right; /* x maximum */
+ int top; /* y minimum */
+ int bottom; /* y maximum */
+ } clip;
+ double mat[3][3]; /* Movement of stars(?) */
+ double scale; /* Scale */
+ int midx; /* Middle of screen, x */
+ int midy; /* Middle of screen, y */
+ double size; /* */
+ double diff[3]; /* */
+ Galaxy *galaxies; /* the Whole Universe */
+ int ngalaxies; /* # galaxies */
+ int f_hititerations; /* # iterations before restart */
+ int step; /* */
+} unistruct;
+
+static unistruct *universes = NULL;
+
+static void
+free_galaxies(unistruct * gp)
+{
+ if (gp->galaxies != NULL) {
+ int i;
+
+ for (i = 0; i < gp->ngalaxies; i++) {
+ Galaxy *gt = &gp->galaxies[i];
+
+ if (gt->stars != NULL)
+ (void) free((void *) gt->stars);
+ }
+ (void) free((void *) gp->galaxies);
+ gp->galaxies = NULL;
+ }
+}
+
+static void
+startover(ModeInfo * mi)
+{
+ unistruct *gp = &universes[MI_SCREEN(mi)];
+ int size = MI_SIZE(mi);
+ int i, j; /* more tmp */
+ double w1, w2; /* more tmp */
+ double d, v, w, h; /* yet more tmp */
+
+ gp->step = 0;
+
+ if (MI_BATCHCOUNT(mi) < -MINGALAXIES)
+ free_galaxies(gp);
+ gp->ngalaxies = MI_BATCHCOUNT(mi);
+ if (gp->ngalaxies < -MINGALAXIES)
+ gp->ngalaxies = NRAND(-gp->ngalaxies - MINGALAXIES + 1) + MINGALAXIES;
+ else if (gp->ngalaxies < MINGALAXIES)
+ gp->ngalaxies = MINGALAXIES;
+ if (gp->galaxies == NULL)
+ gp->galaxies = (Galaxy *) calloc(gp->ngalaxies, sizeof (Galaxy));
+
+ for (i = 0; i < gp->ngalaxies; ++i) {
+ Galaxy *gt = &gp->galaxies[i];
+ double sinw1, sinw2, cosw1, cosw2;
+
+ gt->galcol = NRAND(COLORBASE - 2);
+ if (gt->galcol > 1)
+ gt->galcol += 2; /* Mult 8; 16..31 no green stars */
+ /* Galaxies still may have some green stars but are not all green. */
+
+ if (gt->stars != NULL) {
+ (void) free((void *) gt->stars);
+ gt->stars = NULL;
+ }
+ gt->nstars = (NRAND(MAX_STARS / 2)) + MAX_STARS / 2;
+ gt->stars = (Star *) malloc(gt->nstars * sizeof (Star));
+ w1 = 2.0 * M_PI * FLOATRAND;
+ w2 = 2.0 * M_PI * FLOATRAND;
+ sinw1 = SINF(w1);
+ sinw2 = SINF(w2);
+ cosw1 = COSF(w1);
+ cosw2 = COSF(w2);
+
+ gp->mat[0][0] = cosw2;
+ gp->mat[0][1] = -sinw1 * sinw2;
+ gp->mat[0][2] = cosw1 * sinw2;
+ gp->mat[1][0] = 0.0;
+ gp->mat[1][1] = cosw1;
+ gp->mat[1][2] = sinw1;
+ gp->mat[2][0] = -sinw2;
+ gp->mat[2][1] = -sinw1 * cosw2;
+ gp->mat[2][2] = cosw1 * cosw2;
+
+ gt->vel[0] = FLOATRAND * 2.0 - 1.0;
+ gt->vel[1] = FLOATRAND * 2.0 - 1.0;
+ gt->vel[2] = FLOATRAND * 2.0 - 1.0;
+ gt->pos[0] = -gt->vel[0] * DELTAT *
+ gp->f_hititerations + FLOATRAND - 0.5;
+ gt->pos[1] = -gt->vel[1] * DELTAT *
+ gp->f_hititerations + FLOATRAND - 0.5;
+ gt->pos[2] = -gt->vel[2] * DELTAT *
+ gp->f_hititerations + FLOATRAND - 0.5;
+
+ gt->mass = (int) (FLOATRAND * 1000.0) + 1;
+
+ gp->size = GALAXYRANGESIZE * FLOATRAND + GALAXYMINSIZE;
+
+ for (j = 0; j < gt->nstars; ++j) {
+ Star *st = >->stars[j];
+ double sinw, cosw;
+
+ w = 2.0 * M_PI * FLOATRAND;
+ sinw = SINF(w);
+ cosw = COSF(w);
+ d = FLOATRAND * gp->size;
+ h = FLOATRAND * exp(-2.0 * (d / gp->size)) / 5.0 * gp->size;
+ if (FLOATRAND < 0.5)
+ h = -h;
+ st->pos[0] = gp->mat[0][0] * d * cosw + gp->mat[1][0] * d * sinw +
+ gp->mat[2][0] * h + gt->pos[0];
+ st->pos[1] = gp->mat[0][1] * d * cosw + gp->mat[1][1] * d * sinw +
+ gp->mat[2][1] * h + gt->pos[1];
+ st->pos[2] = gp->mat[0][2] * d * cosw + gp->mat[1][2] * d * sinw +
+ gp->mat[2][2] * h + gt->pos[2];
+
+ v = sqrt(gt->mass * QCONS / sqrt(d * d + h * h));
+ st->vel[0] = -gp->mat[0][0] * v * sinw + gp->mat[1][0] * v * cosw +
+ gt->vel[0];
+ st->vel[1] = -gp->mat[0][1] * v * sinw + gp->mat[1][1] * v * cosw +
+ gt->vel[1];
+ st->vel[2] = -gp->mat[0][2] * v * sinw + gp->mat[1][2] * v * cosw +
+ gt->vel[2];
+
+ st->vel[0] *= DELTAT;
+ st->vel[1] *= DELTAT;
+ st->vel[2] *= DELTAT;
+
+ st->px = 0;
+ st->py = 0;
+
+ if (size < -MINSIZE)
+ st->size = NRAND(-size - MINSIZE + 1) + MINSIZE;
+ else if (size < MINSIZE)
+ st->size = MINSIZE;
+ else
+ st->size = size;
+ }
+ }
+
+ XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
+
+#if 0
+ (void) printf("ngalaxies=%d, f_hititerations=%d\n",
+ gp->ngalaxies, gp->f_hititerations);
+ (void) printf("f_deltat=%g\n", DELTAT);
+ (void) printf("Screen: ");
+ (void) printf("%dx%d pixel (%d-%d, %d-%d)\n",
+ (gp->clip.right - gp->clip.left), (gp->clip.bottom - gp->clip.top),
+ gp->clip.left, gp->clip.right, gp->clip.top, gp->clip.bottom);
+#endif /*0 */
+}
+
+void
+init_galaxy(ModeInfo * mi)
+{
+ unistruct *gp;
+
+ if (universes == NULL) {
+ if ((universes = (unistruct *) calloc(MI_NUM_SCREENS(mi),
+ sizeof (unistruct))) == NULL)
+ return;
+ }
+ gp = &universes[MI_SCREEN(mi)];
+
+ gp->f_hititerations = MI_CYCLES(mi);
+
+ gp->clip.left = 0;
+ gp->clip.top = 0;
+ gp->clip.right = MI_WIN_WIDTH(mi);
+ gp->clip.bottom = MI_WIN_HEIGHT(mi);
+
+ gp->scale = (double) (gp->clip.right + gp->clip.bottom) / 8.0;
+ gp->midx = gp->clip.right / 2;
+ gp->midy = gp->clip.bottom / 2;
+ startover(mi);
+}
+
+void
+draw_galaxy(ModeInfo * mi)
+{
+ Display *display = MI_DISPLAY(mi);
+ Window window = MI_WINDOW(mi);
+ GC gc = MI_GC(mi);
+ unistruct *gp = &universes[MI_SCREEN(mi)];
+ double d; /* tmp */
+ int i, j, k; /* more tmp */
+
+ for (i = 0; i < gp->ngalaxies; ++i) {
+ Galaxy *gt = &gp->galaxies[i];
+
+ for (j = 0; j < gp->galaxies[i].nstars; ++j) {
+ Star *st = >->stars[j];
+ double v0 = st->vel[0];
+ double v1 = st->vel[1];
+ double v2 = st->vel[2];
+
+ for (k = 0; k < gp->ngalaxies; ++k) {
+ Galaxy *gtk = &gp->galaxies[k];
+ double d0 = gtk->pos[0] - st->pos[0];
+ double d1 = gtk->pos[1] - st->pos[1];
+ double d2 = gtk->pos[2] - st->pos[2];
+
+ d = d0 * d0 + d1 * d1 + d2 * d2;
+ if (d > EPSILON)
+ d = gt->mass / (d * sqrt(d)) * DELTAT * DELTAT * QCONS;
+ else
+ d = gt->mass / (EPSILON * sqrt_EPSILON) * DELTAT * DELTAT * QCONS;
+ v0 += d0 * d;
+ v1 += d1 * d;
+ v2 += d2 * d;
+ }
+
+ st->vel[0] = v0;
+ st->vel[1] = v1;
+ st->vel[2] = v2;
+
+#ifndef NO_VELOCITY_COLORING
+ d = (v0 * v0 + v1 * v1 + v2 * v2) / (3.0 * DELTAT * DELTAT);
+ if (d > (double) COLORSTEP)
+ st->color = COLORSTEP * gt->galcol + COLORSTEP - 1;
+ else
+ st->color = COLORSTEP * gt->galcol + ((int) d) % COLORSTEP;
+#endif
+ st->pos[0] += v0;
+ st->pos[1] += v1;
+ st->pos[2] += v2;
+
+ if (st->px >= gp->clip.left &&
+ st->px <= gp->clip.right - st->size &&
+ st->py >= gp->clip.top &&
+ st->py <= gp->clip.bottom - st->size) {
+ XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(mi));
+ drawStar(st->px, st->py, st->size);
+ }
+ st->px = (int) (st->pos[0] * gp->scale) + gp->midx;
+ st->py = (int) (st->pos[1] * gp->scale) + gp->midy;
+
+
+#ifdef WRAP
+ if (st->px < gp->clip.left) {
+ (void) printf("wrap l -> r\n");
+ st->px = gp->clip.right;
+ }
+ if (st->px > gp->clip.right) {
+ (void) printf("wrap r -> l\n");
+ st->px = gp->clip.left;
+ }
+ if (st->py > gp->clip.bottom) {
+ (void) printf("wrap b -> t\n");
+ st->py = gp->clip.top;
+ }
+ if (st->py < gp->clip.top) {
+ (void) printf("wrap t -> b\n");
+ st->py = gp->clip.bottom;
+ }
+#endif /*WRAP */
+
+
+ if (st->px >= gp->clip.left &&
+ st->px <= gp->clip.right - st->size &&
+ st->py >= gp->clip.top &&
+ st->py <= gp->clip.bottom - st->size) {
+ if (MI_NPIXELS(mi) > 2)
+#ifdef NO_VELOCITY_COLORING
+ XSetForeground(display, gc, MI_PIXEL(mi, COLORSTEP * gt->galcol));
+#else
+ XSetForeground(display, gc, MI_PIXEL(mi, st->color));
+#endif
+ else
+ XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
+ if (tracks)
+ drawStar(st->px + 1, st->py, st->size);
+ else
+ drawStar(st->px, st->py, st->size);
+ }
+ }
+
+ for (k = i + 1; k < gp->ngalaxies; ++k) {
+ Galaxy *gtk = &gp->galaxies[k];
+ double d0 = gtk->pos[0] - gt->pos[0];
+ double d1 = gtk->pos[1] - gt->pos[1];
+ double d2 = gtk->pos[2] - gt->pos[2];
+
+ d = d0 * d0 + d1 * d1 + d2 * d2;
+ if (d > EPSILON)
+ d = gt->mass * gt->mass / (d * sqrt(d)) * DELTAT * QCONS;
+ else
+ d = gt->mass * gt->mass / (EPSILON * sqrt_EPSILON) * DELTAT * QCONS;
+ d0 *= d;
+ d1 *= d;
+ d2 *= d;
+ gt->vel[0] += d0 / gt->mass;
+ gt->vel[1] += d1 / gt->mass;
+ gt->vel[2] += d2 / gt->mass;
+ gtk->vel[0] -= d0 / gtk->mass;
+ gtk->vel[1] -= d1 / gtk->mass;
+ gtk->vel[2] -= d2 / gtk->mass;
+ }
+ gt->pos[0] += gt->vel[0] * DELTAT;
+ gt->pos[1] += gt->vel[1] * DELTAT;
+ gt->pos[2] += gt->vel[2] * DELTAT;
+ }
+
+ gp->step++;
+ if (gp->step > gp->f_hititerations * 4)
+ startover(mi);
+}
+
+void
+release_galaxy(ModeInfo * mi)
+{
+ if (universes != NULL) {
+ int screen;
+
+ for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
+ free_galaxies(&universes[screen]);
+ (void) free((void *) universes);
+ universes = NULL;
+ }
+}
+
+void
+refresh_galaxy(ModeInfo * mi)
+{
+ /* Do nothing, it will refresh by itself */
+}
projects / xscreensaver / blobdiff