X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hacks%2Fgrav.c;fp=hacks%2Fgrav.c;h=528bb1b9fc2cf63a03bfa0545199fe47dea5894b;hb=f3e0240915ed9f9b3a61781f5c7002d587563fe0;hp=0000000000000000000000000000000000000000;hpb=3ee611d60b5c560208c27e83b0c4930596fddd8b;p=xscreensaver diff --git a/hacks/grav.c b/hacks/grav.c new file mode 100644 index 00000000..528bb1b9 --- /dev/null +++ b/hacks/grav.c @@ -0,0 +1,322 @@ +/* -*- Mode: C; tab-width: 4 -*- + * grav --- simulation of a planetary system. + */ +#if !defined( lint ) && !defined( SABER ) +static const char sccsid[] = "@(#)grav.c 4.00 97/01/01 xlockmore"; +#endif + +/* Copyright (c) 1993 Greg Bowering + * + * 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@netscape.com: turned into a standalone program. + * 11-Jul-94: color version + * 06-Oct-93: by Greg Bowering + */ + +#ifdef STANDALONE +# define PROGCLASS "Grav" +# define HACK_INIT init_grav +# define HACK_DRAW draw_grav +# define grav_opts xlockmore_opts +# define DEFAULTS "*count: 12 \n" \ + "*delay: 10000 \n" \ + "*ncolors: 64 \n" +# define BRIGHT_COLORS +# include "xlockmore.h" /* from the xscreensaver distribution */ +#else /* !STANDALONE */ +# include "xlock.h" /* from the xlockmore distribution */ +#endif /* !STANDALONE */ + +#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))) + +#define DEF_DECAY "False" /* Damping for decaying orbits */ +#define DEF_TRAIL "False" /* For trails (works good in mono only) */ + +static Bool decay; +static Bool trail; + +static XrmOptionDescRec opts[] = +{ + {"-decay", ".grav.decay", XrmoptionNoArg, (caddr_t) "on"}, + {"+decay", ".grav.decay", XrmoptionNoArg, (caddr_t) "off"}, + {"-trail", ".grav.trail", XrmoptionNoArg, (caddr_t) "on"}, + {"+trail", ".grav.trail", XrmoptionNoArg, (caddr_t) "off"} +}; +static argtype vars[] = +{ + {(caddr_t *) & decay, "decay", "Decay", DEF_DECAY, t_Bool}, + {(caddr_t *) & trail, "trail", "Trail", DEF_TRAIL, t_Bool} +}; +static OptionStruct desc[] = +{ + {"-/+decay", "turn on/off decaying orbits"}, + {"-/+trail", "turn on/off trail dots"} +}; + +ModeSpecOpt grav_opts = { 4, opts, 2, vars, desc }; + +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 = NULL; + +static void +init_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)]; + + if (MI_NPIXELS(mi) > 2) + planet->colors = MI_PIXEL(mi, NRAND(MI_NPIXELS(mi))); + else + planet->colors = MI_WIN_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); + + /* Draw planets */ + Planet(planet->xi, planet->yi); +} + +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_WIN_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); +} + +void +init_grav(ModeInfo * mi) +{ + Display *display = MI_DISPLAY(mi); + GC gc = MI_GC(mi); + gravstruct *gp; + unsigned char ball; + + if (gravs == NULL) { + if ((gravs = (gravstruct *) calloc(MI_NUM_SCREENS(mi), + sizeof (gravstruct))) == NULL) + return; + } + gp = &gravs[MI_SCREEN(mi)]; + + gp->width = MI_WIN_WIDTH(mi); + gp->height = MI_WIN_HEIGHT(mi); + + gp->sr = STARRADIUS; + + gp->nplanets = MI_BATCHCOUNT(mi); + if (gp->nplanets < 0) { + if (gp->planets) { + (void) free((void *) gp->planets); + gp->planets = NULL; + } + gp->nplanets = NRAND(-gp->nplanets) + 1; /* Add 1 so its not too boring */ + } + if (!gp->planets) + gp->planets = (planetstruct *) calloc(gp->nplanets, sizeof (planetstruct)); + + XClearWindow(display, MI_WINDOW(mi)); + + if (MI_NPIXELS(mi) > 2) + gp->starcolor = MI_PIXEL(mi, NRAND(MI_NPIXELS(mi))); + else + gp->starcolor = MI_WIN_WHITE_PIXEL(mi); + for (ball = 0; ball < (unsigned char) gp->nplanets; ball++) + init_planet(mi, &gp->planets[ball]); + + /* 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); +} + +void +draw_grav(ModeInfo * mi) +{ + Display *display = MI_DISPLAY(mi); + Window window = MI_WINDOW(mi); + GC gc = MI_GC(mi); + gravstruct *gp = &gravs[MI_SCREEN(mi)]; + register unsigned char ball; + + /* Mask centrepoint */ + XSetForeground(display, gc, MI_WIN_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]); +} + +void +release_grav(ModeInfo * mi) +{ + if (gravs != NULL) { + int screen; + + for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) { + gravstruct *gp = &gravs[screen]; + + if (gp->planets) + (void) free((void *) gp->planets); + } + (void) free((void *) gravs); + gravs = NULL; + } +} + +void +refresh_grav(ModeInfo * mi) +{ + /* Do nothing, it will refresh by itself */ +}