-/* -*- Mode: C; tab-width: 4 -*-
- * galaxy --- draw spinning, colliding galaxies.
- */
+/* -*- Mode: C; tab-width: 4 -*- */
+/* galaxy --- spinning galaxies */
+
#if !defined( lint ) && !defined( SABER )
-static const char sccsid[] = "@(#)galaxy.c 4.02 97/04/01 xlockmore";
+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
+/* 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,
* 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.
- * Port to X11 and incorporation into xlockmore by Hubert Feyrer
- * (hubert.feyrer@rz.uni-regensburg.de)
*
* Revision History:
* 10-May-97: jwz@netscape.com: turned into a standalone program.
# define HACK_INIT init_galaxy
# define HACK_DRAW draw_galaxy
# define galaxy_opts xlockmore_opts
-# define DEFAULTS "*count: 5 \n" \
+# define DEFAULTS "*delay: 100 \n" \
+ "*count: -5 \n" \
"*cycles: 250 \n" \
- "*delay: 100 \n" \
- "*size: 3 \n" \
+ "*size: -3 \n" \
"*ncolors: 64 \n"
# define UNIFORM_COLORS
# include "xlockmore.h" /* from the xscreensaver distribution */
# 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 DEFAULT_STARS 1000
#define DEFAULT_HITITERATIONS 7500
#define DEFAULT_IDELTAT 200 /* 0.02 */
-#define EPSILON 0.0000001
+#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)
-
-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 };
-
-
typedef struct {
double pos[3], vel[3];
int px, py;
double diff[3]; /* */
Galaxy *galaxies; /* the Whole Universe */
int ngalaxies; /* # galaxies */
- double f_deltat; /* quality of calculation, calc'd by d_ideltat */
int f_hititerations; /* # iterations before restart */
int step; /* */
} unistruct;
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] * gp->f_deltat *
+ gt->pos[0] = -gt->vel[0] * DELTAT *
gp->f_hititerations + FLOATRAND - 0.5;
- gt->pos[1] = -gt->vel[1] * gp->f_deltat *
+ gt->pos[1] = -gt->vel[1] * DELTAT *
gp->f_hititerations + FLOATRAND - 0.5;
- gt->pos[2] = -gt->vel[2] * gp->f_deltat *
+ gt->pos[2] = -gt->vel[2] * DELTAT *
gp->f_hititerations + FLOATRAND - 0.5;
gt->mass = (int) (FLOATRAND * 1000.0) + 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 0
(void) printf("ngalaxies=%d, f_hititerations=%d\n",
gp->ngalaxies, gp->f_hititerations);
- (void) printf("f_deltat=%g\n", gp->f_deltat);
+ (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 = &universes[MI_SCREEN(mi)];
gp->f_hititerations = MI_CYCLES(mi);
- gp->f_deltat = ((double) MAX_IDELTAT) / 10000.0;
gp->clip.left = 0;
gp->clip.top = 0;
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];
- gp->diff[0] = gtk->pos[0] - st->pos[0];
- gp->diff[1] = gtk->pos[1] - st->pos[1];
- gp->diff[2] = gtk->pos[2] - st->pos[2];
- d = gp->diff[0] * gp->diff[0] + gp->diff[1] * gp->diff[1] +
- gp->diff[2] * gp->diff[2];
- if (d < EPSILON)
- d = EPSILON;
- d = gt->mass / (d * sqrt(d)) * gp->f_deltat * QCONS;
- gp->diff[0] *= d;
- gp->diff[1] *= d;
- gp->diff[2] *= d;
- st->vel[0] += gp->diff[0];
- st->vel[1] += gp->diff[1];
- st->vel[2] += gp->diff[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->color = COLORSTEP * gt->galcol + ((int) ((st->vel[0] * st->vel[0] +
- st->vel[1] * st->vel[1] + st->vel[2] * st->vel[2]) / 3.0)) % COLORSTEP;
+ st->vel[0] = v0;
+ st->vel[1] = v1;
+ st->vel[2] = v2;
- st->pos[0] += st->vel[0] * gp->f_deltat;
- st->pos[1] += st->vel[1] * gp->f_deltat;
- st->pos[2] += st->vel[2] * gp->f_deltat;
+#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) {
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)
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];
- gp->diff[0] = gtk->pos[0] - gt->pos[0];
- gp->diff[1] = gtk->pos[1] - gt->pos[1];
- gp->diff[2] = gtk->pos[2] - gt->pos[2];
- d = gp->diff[0] * gp->diff[0] + gp->diff[1] * gp->diff[1] +
- gp->diff[2] * gp->diff[2];
- if (d < EPSILON)
- d = EPSILON;
- d = gt->mass * gt->mass / (d * sqrt(d)) * gp->f_deltat * QCONS;
- gp->diff[0] *= d;
- gp->diff[1] *= d;
- gp->diff[2] *= d;
- gt->vel[0] += gp->diff[0] / gt->mass;
- gt->vel[1] += gp->diff[1] / gt->mass;
- gt->vel[2] += gp->diff[2] / gt->mass;
- gtk->vel[0] -= gp->diff[0] / gtk->mass;
- gtk->vel[1] -= gp->diff[1] / gtk->mass;
- gtk->vel[2] -= gp->diff[2] / gtk->mass;
+ 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] * gp->f_deltat;
- gt->pos[1] += gt->vel[1] * gp->f_deltat;
- gt->pos[2] += gt->vel[2] * gp->f_deltat;
+ gt->pos[0] += gt->vel[0] * DELTAT;
+ gt->pos[1] += gt->vel[1] * DELTAT;
+ gt->pos[2] += gt->vel[2] * DELTAT;
}
gp->step++;
projects / xscreensaver / blobdiff