/* -*- Mode: C; tab-width: 4 -*- */
/* swarm --- swarm of bees */

#if !defined( lint ) && !defined( SABER )
static const char sccsid[] = "@(#)swarm.c	4.07 97/11/24 xlockmore";

#endif

/*-
 * Copyright (c) 1991 by Patrick J. Naughton.
 *
 * 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: Compatible with xscreensaver
 * 31-Aug-90: Adapted from xswarm by Jeff Butterworth <butterwo@ncsc.org>
 */

#ifdef STANDALONE
#define PROGCLASS "Swarm"
#define HACK_INIT init_swarm
#define HACK_DRAW draw_swarm
#define swarm_opts xlockmore_opts
#define DEFAULTS "*delay: 15000 \n" \
 "*count: 100 \n" \
 "*mouse: False \n"
#define BRIGHT_COLORS
#define SMOOTH_COLORS
#include "xlockmore.h"		/* from the xscreensaver distribution */
#include <X11/Xutil.h>
#else /* !STANDALONE */
#include "xlock.h"		/* from the xlockmore distribution */
#endif /* !STANDALONE */

ModeSpecOpt swarm_opts =
{0, NULL, 0, NULL, NULL};

#ifdef USE_MODULES
ModStruct   swarm_description =
{"swarm", "init_swarm", "draw_swarm", "release_swarm",
 "refresh_swarm", "init_swarm", NULL, &swarm_opts,
 15000, 100, 1, 1, 64, 1.0, "",
 "Shows a swarm of bees following a wasp", 0, NULL};

#endif

#define TIMES	4		/* number of time positions recorded */
#define BEEACC	2		/* acceleration of bees */
#define WASPACC 5		/* maximum acceleration of wasp */
#define BEEVEL	12		/* maximum bee velocity */
#define WASPVEL 10		/* maximum wasp velocity */

/* Macros */
#define X(t,b)	(sp->x[(t)*sp->beecount+(b)])
#define Y(t,b)	(sp->y[(t)*sp->beecount+(b)])
#define balance_rand(v)	((NRAND(v))-((v)/2))	/* random number around 0 */

typedef struct {
	int         pix;
	int         width;
	int         height;
	int         border;	/* wasp won't go closer than this to the edge */
	int         beecount;	/* number of bees */
	XSegment   *segs;	/* bee lines */
	XSegment   *old_segs;	/* old bee lines */
	short      *x;
	short      *y;		/* bee positions x[time][bee#] */
	short      *xv;
	short      *yv;		/* bee velocities xv[bee#] */
	short       wx[3];
	short       wy[3];
	short       wxv;
	short       wyv;
	Cursor      cursor;
} swarmstruct;

static swarmstruct *swarms = NULL;

void
init_swarm(ModeInfo * mi)
{
	Display    *display = MI_DISPLAY(mi);
	Window      window = MI_WINDOW(mi);
	swarmstruct *sp;
	int         b;

	if (swarms == NULL) {
		if ((swarms = (swarmstruct *) calloc(MI_NUM_SCREENS(mi),
					      sizeof (swarmstruct))) == NULL)
			return;
	}
	sp = &swarms[MI_SCREEN(mi)];

	sp->beecount = MI_COUNT(mi);
	if (sp->beecount < 0) {
		/* if sp->beecount is random ... the size can change */
		if (sp->segs != NULL) {
			(void) free((void *) sp->segs);
			sp->segs = NULL;
		}
		if (sp->old_segs != NULL) {
			(void) free((void *) sp->old_segs);
			sp->old_segs = NULL;
		}
		if (sp->x != NULL) {
			(void) free((void *) sp->x);
			sp->x = NULL;
		}
		if (sp->y != NULL) {
			(void) free((void *) sp->y);
			sp->y = NULL;
		}
		if (sp->xv != NULL) {
			(void) free((void *) sp->xv);
			sp->xv = NULL;
		}
		if (sp->yv != NULL) {
			(void) free((void *) sp->yv);
			sp->yv = NULL;
		}
		sp->beecount = NRAND(-sp->beecount) + 1;	/* Add 1 so its not too boring */
	}
	sp->width = MI_WIDTH(mi);
	sp->height = MI_HEIGHT(mi);
	sp->border = (sp->width + sp->height) / 50;

	if (MI_IS_MOUSE(mi) && !sp->cursor) {	/* Create an invisible cursor */
		Pixmap      bit;
		XColor      black;

		black.red = 0;
		black.green = 0;
		black.blue = 0;
		black.flags = DoRed | DoGreen | DoBlue;
		bit = XCreatePixmapFromBitmapData(display, window, "\000", 1, 1,
						  MI_BLACK_PIXEL(mi),
						  MI_BLACK_PIXEL(mi), 1);
		sp->cursor = XCreatePixmapCursor(display, bit, bit, &black, &black,
						 0, 0);
		XFreePixmap(display, bit);
	}
	XDefineCursor(display, window, sp->cursor);

	MI_CLEARWINDOW(mi);

	/* Allocate memory. */

	if (!sp->segs) {
		sp->segs = (XSegment *) malloc(sizeof (XSegment) * sp->beecount);
		sp->old_segs = (XSegment *) malloc(sizeof (XSegment) * sp->beecount);
		sp->x = (short *) malloc(sizeof (short) * sp->beecount * TIMES);
		sp->y = (short *) malloc(sizeof (short) * sp->beecount * TIMES);
		sp->xv = (short *) malloc(sizeof (short) * sp->beecount);
		sp->yv = (short *) malloc(sizeof (short) * sp->beecount);
	}
	/* Initialize point positions, velocities, etc. */
	if (MI_NPIXELS(mi) > 2)
		sp->pix = NRAND(MI_NPIXELS(mi));

	/* wasp */
	sp->wx[0] = sp->border + NRAND(sp->width - 2 * sp->border);
	sp->wy[0] = sp->border + NRAND(sp->height - 2 * sp->border);
	sp->wx[1] = sp->wx[0];
	sp->wy[1] = sp->wy[0];
	sp->wxv = 0;
	sp->wyv = 0;

	/* bees */
	for (b = 0; b < sp->beecount; b++) {
		X(0, b) = NRAND(sp->width);
		X(1, b) = X(0, b);
		Y(0, b) = NRAND(sp->height);
		Y(1, b) = Y(0, b);
		sp->xv[b] = balance_rand(7);
		sp->yv[b] = balance_rand(7);
	}
}

void
draw_swarm(ModeInfo * mi)
{
	Display    *display = MI_DISPLAY(mi);
	Window      window = MI_WINDOW(mi);
	GC          gc = MI_GC(mi);
	swarmstruct *sp = &swarms[MI_SCREEN(mi)];
	int         b;
	Bool        track_p = MI_IS_MOUSE(mi);
	int         cx, cy;

	MI_IS_DRAWN(mi) = True;

	if (track_p) {
		Window      r, c;
		int         rx, ry;
		unsigned int m;

		(void) XQueryPointer(display, window,
				     &r, &c, &rx, &ry, &cx, &cy, &m);
		if (cx <= sp->border || cy <= sp->border ||
		    cx >= MI_WIDTH(mi) - 1 - sp->border ||
		    cy >= MI_HEIGHT(mi) - 1 - sp->border)
			track_p = False;
	}
	/* <=- Wasp -=> */
	/* Age the arrays. */
	sp->wx[2] = sp->wx[1];
	sp->wx[1] = sp->wx[0];
	sp->wy[2] = sp->wy[1];
	sp->wy[1] = sp->wy[0];
	if (track_p) {
		sp->wx[0] = cx;
		sp->wy[0] = cy;
	} else {

		/* Accelerate */
		sp->wxv += balance_rand(WASPACC);
		sp->wyv += balance_rand(WASPACC);

		/* Speed Limit Checks */
		if (sp->wxv > WASPVEL)
			sp->wxv = WASPVEL;
		if (sp->wxv < -WASPVEL)
			sp->wxv = -WASPVEL;
		if (sp->wyv > WASPVEL)
			sp->wyv = WASPVEL;
		if (sp->wyv < -WASPVEL)
			sp->wyv = -WASPVEL;

		/* Move */
		sp->wx[0] = sp->wx[1] + sp->wxv;
		sp->wy[0] = sp->wy[1] + sp->wyv;

		/* Bounce Checks */
		if ((sp->wx[0] < sp->border) || (sp->wx[0] > sp->width - sp->border - 1)) {
			sp->wxv = -sp->wxv;
			sp->wx[0] += sp->wxv;
		}
		if ((sp->wy[0] < sp->border) || (sp->wy[0] > sp->height - sp->border - 1)) {
			sp->wyv = -sp->wyv;
			sp->wy[0] += sp->wyv;
		}
		/* Don't let things settle down. */
		sp->xv[NRAND(sp->beecount)] += balance_rand(3);
		sp->yv[NRAND(sp->beecount)] += balance_rand(3);
	}
	/* <=- Bees -=> */
	for (b = 0; b < sp->beecount; b++) {
		int         distance, dx, dy;

		/* Age the arrays. */
		X(2, b) = X(1, b);
		X(1, b) = X(0, b);
		Y(2, b) = Y(1, b);
		Y(1, b) = Y(0, b);

		/* Accelerate */
		dx = sp->wx[1] - X(1, b);
		dy = sp->wy[1] - Y(1, b);
		distance = abs(dx) + abs(dy);	/* approximation */
		if (distance == 0)
			distance = 1;
		sp->xv[b] += (dx * BEEACC) / distance;
		sp->yv[b] += (dy * BEEACC) / distance;

		/* Speed Limit Checks */
		if (sp->xv[b] > BEEVEL)
			sp->xv[b] = BEEVEL;
		if (sp->xv[b] < -BEEVEL)
			sp->xv[b] = -BEEVEL;
		if (sp->yv[b] > BEEVEL)
			sp->yv[b] = BEEVEL;
		if (sp->yv[b] < -BEEVEL)
			sp->yv[b] = -BEEVEL;

		/* Move */
		X(0, b) = X(1, b) + sp->xv[b];
		Y(0, b) = Y(1, b) + sp->yv[b];

		/* Fill the segment lists. */
		sp->segs[b].x1 = X(0, b);
		sp->segs[b].y1 = Y(0, b);
		sp->segs[b].x2 = X(1, b);
		sp->segs[b].y2 = Y(1, b);
		sp->old_segs[b].x1 = X(1, b);
		sp->old_segs[b].y1 = Y(1, b);
		sp->old_segs[b].x2 = X(2, b);
		sp->old_segs[b].y2 = Y(2, b);
	}

	XSetForeground(display, gc, MI_BLACK_PIXEL(mi));
	XDrawLine(display, window, gc,
		  sp->wx[1], sp->wy[1], sp->wx[2], sp->wy[2]);
	XDrawSegments(display, window, gc, sp->old_segs, sp->beecount);

	XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
	XDrawLine(display, window, gc,
		  sp->wx[0], sp->wy[0], sp->wx[1], sp->wy[1]);
	if (MI_NPIXELS(mi) > 2) {
		XSetForeground(display, gc, MI_PIXEL(mi, sp->pix));
		if (++sp->pix >= MI_NPIXELS(mi))
			sp->pix = 0;
	}
	XDrawSegments(display, window, gc, sp->segs, sp->beecount);
}

void
release_swarm(ModeInfo * mi)
{
	if (swarms != NULL) {
		int         screen;

		for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
			swarmstruct *sp = &swarms[screen];

			if (sp->segs != NULL)
				(void) free((void *) sp->segs);
			if (sp->old_segs != NULL)
				(void) free((void *) sp->old_segs);
			if (sp->x != NULL)
				(void) free((void *) sp->x);
			if (sp->y != NULL)
				(void) free((void *) sp->y);
			if (sp->xv != NULL)
				(void) free((void *) sp->xv);
			if (sp->yv != NULL)
				(void) free((void *) sp->yv);
			if (sp->cursor)
				XFreeCursor(MI_DISPLAY(mi), sp->cursor);
		}
		(void) free((void *) swarms);
		swarms = NULL;
	}
}

void
refresh_swarm(ModeInfo * mi)
{
	MI_CLEARWINDOW(mi);
}
