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Diffstat (limited to 'hacks/grav.c')
| -rw-r--r-- | hacks/grav.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/hacks/grav.c b/hacks/grav.c new file mode 100644 index 0000000..305b8e8 --- /dev/null +++ b/hacks/grav.c @@ -0,0 +1,356 @@ +/* -*- Mode: C; tab-width: 4 -*- */ +/* grav --- planets spinning around a pulsar */ + +#if 0 +static const char sccsid[] = "@(#)grav.c 5.00 2000/11/01 xlockmore"; +#endif + +/*- + * Copyright (c) 1993 by Greg Boewring <gb@pobox.com> + * + * 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: + * 01-Nov-2000: Allocation checks + * 10-May-1997: Compatible with xscreensaver + * 11-Jul-1994: color version + * 06-Oct-1993: Written by Greg Bowering <gb@pobox.com> + */ + +#ifdef STANDALONE +#define MODE_grav +#define DEFAULTS "*delay: 10000 \n" \ + "*count: 12 \n" \ + "*ncolors: 64 \n" \ + "*fpsSolid: true \n" \ + "*ignoreRotation: True \n" \ + "*lowrez: True \n" \ + +#define BRIGHT_COLORS +# define release_grav 0 +# define grav_handle_event 0 +# include "xlockmore.h" /* in xscreensaver distribution */ +#else /* STANDALONE */ +# include "xlock.h" /* in xlockmore distribution */ +#endif /* STANDALONE */ + +#ifdef MODE_grav + +#define DEF_DECAY "True" /* Damping for decaying orbits */ +#define DEF_TRAIL "True" /* For trails (works good in mono only) */ + +static Bool decay; +static Bool trail; + +static XrmOptionDescRec opts[] = +{ + {"-decay", ".grav.decay", XrmoptionNoArg, "on"}, + {"+decay", ".grav.decay", XrmoptionNoArg, "off"}, + {"-trail", ".grav.trail", XrmoptionNoArg, "on"}, + {"+trail", ".grav.trail", XrmoptionNoArg, "off"} +}; +static argtype vars[] = +{ + {&decay, "decay", "Decay", DEF_DECAY, t_Bool}, + {&trail, "trail", "Trail", DEF_TRAIL, t_Bool} +}; +static OptionStruct desc[] = +{ + {"-/+decay", "turn on/off decaying orbits"}, + {"-/+trail", "turn on/off trail dots"} +}; + +ENTRYPOINT ModeSpecOpt grav_opts = +{sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, desc}; + +#ifdef USE_MODULES +ModStruct grav_description = +{"grav", "init_grav", "draw_grav", (char *) NULL, + "refresh_grav", "init_grav", "free_grav", &grav_opts, + 10000, -12, 1, 1, 64, 1.0, "", + "Shows orbiting planets", 0, NULL}; + +#endif + +#define GRAV -0.02 /* Gravitational constant */ +#define DIST 16.0 +#define COLLIDE 0.0001 +#define ALMOST 15.99 +#define HALF 0.5 +/* #define INTRINSIC_RADIUS 200.0 */ +#define INTRINSIC_RADIUS ((float) (gp->height/5)) +#define STARRADIUS (unsigned int)(gp->height/(2*DIST)) +#define AVG_RADIUS (INTRINSIC_RADIUS/DIST) +#define RADIUS (unsigned int)(INTRINSIC_RADIUS/(POS(Z)+DIST)) + +#define XR HALF*ALMOST +#define YR HALF*ALMOST +#define ZR HALF*ALMOST + +#define VR 0.04 + +#define DIMENSIONS 3 +#define X 0 +#define Y 1 +#define Z 2 + +#define DAMP 0.999999 +#define MaxA 0.1 /* Maximum acceleration (w/ damping) */ + +#define POS(c) planet->P[c] +#define VEL(c) planet->V[c] +#define ACC(c) planet->A[c] + +#define Planet(x,y)\ + if ((x) >= 0 && (y) >= 0 && (x) <= gp->width && (y) <= gp->height) {\ + if (planet->ri < 2)\ + XDrawPoint(display, window, gc, (x), (y));\ + else\ + XFillArc(display, window, gc,\ + (x) - planet->ri / 2, (y) - planet->ri / 2, planet->ri, planet->ri,\ + 0, 23040);\ + } + +#define FLOATRAND(min,max) ((min)+(LRAND()/MAXRAND)*((max)-(min))) + +typedef struct { + double P[DIMENSIONS], V[DIMENSIONS], A[DIMENSIONS]; + int xi, yi, ri; + unsigned long colors; +} planetstruct; + +typedef struct { + int width, height; + int x, y, sr, nplanets; + unsigned long starcolor; + planetstruct *planets; +} gravstruct; + +static gravstruct *gravs = (gravstruct *) NULL; + +static void +init_planet(ModeInfo * mi, planetstruct * planet) +{ + gravstruct *gp = &gravs[MI_SCREEN(mi)]; + +# ifdef HAVE_JWXYZ + jwxyz_XSetAntiAliasing (MI_DISPLAY(mi), MI_GC(mi), False); +# endif + + if (MI_NPIXELS(mi) > 2) + planet->colors = MI_PIXEL(mi, NRAND(MI_NPIXELS(mi))); + else + planet->colors = MI_WHITE_PIXEL(mi); + /* Initialize positions */ + POS(X) = FLOATRAND(-XR, XR); + POS(Y) = FLOATRAND(-YR, YR); + POS(Z) = FLOATRAND(-ZR, ZR); + + if (POS(Z) > -ALMOST) { + planet->xi = (int) + ((double) gp->width * (HALF + POS(X) / (POS(Z) + DIST))); + planet->yi = (int) + ((double) gp->height * (HALF + POS(Y) / (POS(Z) + DIST))); + } else + planet->xi = planet->yi = -1; + planet->ri = RADIUS; + + /* Initialize velocities */ + VEL(X) = FLOATRAND(-VR, VR); + VEL(Y) = FLOATRAND(-VR, VR); + VEL(Z) = FLOATRAND(-VR, VR); +} + +static void +draw_planet(ModeInfo * mi, planetstruct * planet) +{ + Display *display = MI_DISPLAY(mi); + Window window = MI_WINDOW(mi); + GC gc = MI_GC(mi); + gravstruct *gp = &gravs[MI_SCREEN(mi)]; + double D; /* A distance variable to work with */ + register unsigned char cmpt; + + D = POS(X) * POS(X) + POS(Y) * POS(Y) + POS(Z) * POS(Z); + if (D < COLLIDE) + D = COLLIDE; + D = sqrt(D); + D = D * D * D; + for (cmpt = X; cmpt < DIMENSIONS; cmpt++) { + ACC(cmpt) = POS(cmpt) * GRAV / D; + if (decay) { + if (ACC(cmpt) > MaxA) + ACC(cmpt) = MaxA; + else if (ACC(cmpt) < -MaxA) + ACC(cmpt) = -MaxA; + VEL(cmpt) = VEL(cmpt) + ACC(cmpt); + VEL(cmpt) *= DAMP; + } else { + /* update velocity */ + VEL(cmpt) = VEL(cmpt) + ACC(cmpt); + } + /* update position */ + POS(cmpt) = POS(cmpt) + VEL(cmpt); + } + + gp->x = planet->xi; + gp->y = planet->yi; + + if (POS(Z) > -ALMOST) { + planet->xi = (int) + ((double) gp->width * (HALF + POS(X) / (POS(Z) + DIST))); + planet->yi = (int) + ((double) gp->height * (HALF + POS(Y) / (POS(Z) + DIST))); + } else + planet->xi = planet->yi = -1; + + /* Mask */ + XSetForeground(display, gc, MI_BLACK_PIXEL(mi)); + Planet(gp->x, gp->y); + if (trail) { + XSetForeground(display, gc, planet->colors); + XDrawPoint(display, MI_WINDOW(mi), gc, gp->x, gp->y); + } + /* Move */ + gp->x = planet->xi; + gp->y = planet->yi; + planet->ri = RADIUS; + + /* Redraw */ + XSetForeground(display, gc, planet->colors); + Planet(gp->x, gp->y); +} + +ENTRYPOINT void +init_grav(ModeInfo * mi) +{ + unsigned char ball; + gravstruct *gp; + + MI_INIT (mi, gravs); + gp = &gravs[MI_SCREEN(mi)]; + + gp->width = MI_WIDTH(mi); + gp->height = MI_HEIGHT(mi); + + gp->sr = STARRADIUS; + + gp->nplanets = MI_COUNT(mi); + if (gp->nplanets < 0) { + if (gp->planets) { + (void) free((void *) gp->planets); + gp->planets = (planetstruct *) NULL; + } + gp->nplanets = NRAND(-gp->nplanets) + 1; /* Add 1 so its not too boring */ + } + if (gp->planets == NULL) { + if ((gp->planets = (planetstruct *) calloc(gp->nplanets, + sizeof (planetstruct))) == NULL) + return; + } + + MI_CLEARWINDOW(mi); + + if (MI_NPIXELS(mi) > 2) + gp->starcolor = MI_PIXEL(mi, NRAND(MI_NPIXELS(mi))); + else + gp->starcolor = MI_WHITE_PIXEL(mi); + for (ball = 0; ball < (unsigned char) gp->nplanets; ball++) + init_planet(mi, &gp->planets[ball]); +} + +ENTRYPOINT void +draw_grav(ModeInfo * mi) +{ + Display *display = MI_DISPLAY(mi); + Window window = MI_WINDOW(mi); + GC gc = MI_GC(mi); + register unsigned char ball; + gravstruct *gp; + + if (gravs == NULL) + return; + gp = &gravs[MI_SCREEN(mi)]; + if (gp->planets == NULL) + return; + + if (!MI_IS_DRAWN(mi)) { + for (ball = 0; ball < (unsigned char) gp->nplanets; ball++) { + planetstruct *planet = &gp->planets[ball]; + + /* Draw planets */ + Planet(planet->xi, planet->yi); + } + + /* Draw centrepoint */ + XDrawArc(display, MI_WINDOW(mi), gc, + gp->width / 2 - gp->sr / 2, gp->height / 2 - gp->sr / 2, gp->sr, gp->sr, + 0, 23040); + } + + MI_IS_DRAWN(mi) = True; + /* Mask centrepoint */ + XSetForeground(display, gc, MI_BLACK_PIXEL(mi)); + XDrawArc(display, window, gc, + gp->width / 2 - gp->sr / 2, gp->height / 2 - gp->sr / 2, gp->sr, gp->sr, + 0, 23040); + + /* Resize centrepoint */ + switch (NRAND(4)) { + case 0: + if (gp->sr < (int) STARRADIUS) + gp->sr++; + break; + case 1: + if (gp->sr > 2) + gp->sr--; + } + + /* Draw centrepoint */ + XSetForeground(display, gc, gp->starcolor); + XDrawArc(display, window, gc, + gp->width / 2 - gp->sr / 2, gp->height / 2 - gp->sr / 2, gp->sr, gp->sr, + 0, 23040); + + for (ball = 0; ball < (unsigned char) gp->nplanets; ball++) + draw_planet(mi, &gp->planets[ball]); +} + +ENTRYPOINT void +reshape_grav(ModeInfo * mi, int width, int height) +{ + gravstruct *gp = &gravs[MI_SCREEN(mi)]; + gp->width = width; + gp->height = height; + XClearWindow (MI_DISPLAY (mi), MI_WINDOW(mi)); +} + +ENTRYPOINT void +free_grav(ModeInfo * mi) +{ + gravstruct *gp = &gravs[MI_SCREEN(mi)]; + if (gp->planets) + (void) free((void *) gp->planets); +} + +#ifndef STANDALONE +ENTRYPOINT void +refresh_grav(ModeInfo * mi) +{ + MI_CLEARWINDOW(mi); +} +#endif + +XSCREENSAVER_MODULE ("Grav", grav) + +#endif /* MODE_grav */ |