#ifndef lint
static char sccsid[] = "@(#)swarm.c	3.9 96/05/25 xlockmore";

#endif

/*-
 * swarm.c - swarm of bees for xlock, the X Window System lockscreen.
 *
 * Copyright (c) 1991 by Patrick J. Naughton.
 *
 * Revision History:
 * 31-Aug-90: Adapted from xswarm by Jeff Butterworth. (butterwo@ncsc.org)
 */

#include "xlock.h"

#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)	((LRAND()%(v))-((v)/2))		/* random number around 0 */

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

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;
} swarmstruct;

static swarmstruct swarms[MAXSCREENS];

void
init_swarm(ModeInfo * mi)
{
	Window      win = MI_WINDOW(mi);
	swarmstruct *sp = &swarms[screen];
	int         b;

	sp->beecount = MI_BATCHCOUNT(mi);

	sp->width = MI_WIN_WIDTH(mi);
	sp->height = MI_WIN_HEIGHT(mi);
	sp->border = (sp->width + sp->height) / 50;

	/* Clear the background. */
	XSetForeground(dsp, Scr[screen].gc, BlackPixel(dsp, screen));
	XFillRectangle(dsp, win, Scr[screen].gc, 0, 0, sp->width, sp->height);

	/* 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. */

	/* wasp */
	sp->wx[0] = sp->border + LRAND() % (sp->width - 2 * sp->border);
	sp->wy[0] = sp->border + LRAND() % (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) = LRAND() % sp->width;
		X(1, b) = X(0, b);
		Y(0, b) = LRAND() % 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)
{
	Window      win = MI_WINDOW(mi);
	swarmstruct *sp = &swarms[screen];
	int         b;

	/* <=- 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];
	/* 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[LRAND() % sp->beecount] += balance_rand(3);
	sp->yv[LRAND() % 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(dsp, Scr[screen].gc, BlackPixel(dsp, screen));
	XDrawLine(dsp, win, Scr[screen].gc,
		  sp->wx[1], sp->wy[1], sp->wx[2], sp->wy[2]);
	XDrawSegments(dsp, win, Scr[screen].gc, sp->old_segs, sp->beecount);

	XSetForeground(dsp, Scr[screen].gc, WhitePixel(dsp, screen));
	XDrawLine(dsp, win, Scr[screen].gc,
		  sp->wx[0], sp->wy[0], sp->wx[1], sp->wy[1]);
	if (!MI_WIN_IS_MONO(mi) && MI_NPIXELS(mi) > 2) {
		XSetForeground(dsp, Scr[screen].gc, Scr[screen].pixels[sp->pix]);
		if (++sp->pix >= Scr[screen].npixels)
			sp->pix = 0;
	}
	XDrawSegments(dsp, win, Scr[screen].gc, sp->segs, sp->beecount);
}