
#if !defined( lint ) && !defined( SABER )
static const char sccsid[] = "@(#)rotor.c	4.00 97/01/01 xlockmore";

#endif

/*-
 * rotor.c - A swirly rotor for xlock, the X Window System lockscreen.
 *
 * Copyright (c) 1991 by Patrick J. Naughton.
 *
 * See xlock.c for copying information.
 *
 * Revision History:
 * 08-Mar-95: CAT stuff for ## was tripping up some C compilers.  Removed.
 * 01-Dec-93: added patch for AIXV3 from
 *            (Tom McConnell, tmcconne@sedona.intel.com)
 * 11-Nov-90: put into xlock (by Steve Zellers, zellers@sun.com)
 * 16-Oct-90: Received from Tom Lawrence (tcl@cs.brown.edu: 'flight' simulator)
 */

/* 
 * A 'batchcount' of 3 or 4 works best!
 */

#include "xlock.h"

#define MAXANGLE	10000.0	/* irrectangular */

/* How many segments to draw per cycle when redrawing */
#define REDRAWSTEP 3

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

typedef struct {
	float       angle;
	float       radius;
	float       start_radius;
	float       end_radius;
	float       radius_drift_max;
	float       radius_drift_now;

	float       ratio;
	float       start_ratio;
	float       end_ratio;
	float       ratio_drift_max;
	float       ratio_drift_now;
} elem;

typedef struct {
	int         pix;
	int         lastx, lasty;
	int         num, rotor, prev;
	int         nsave;
	float       angle;
	int         centerx, centery;
	int         prevcenterx, prevcentery;
	unsigned char firsttime;
	unsigned char iconifiedscreen;	/* for iconified view */
	unsigned char forward;
	unsigned char unused;
	elem       *elements;
	XPoint     *save;
	int         redrawing, redrawpos;
} rotorstruct;

static rotorstruct *rotors = NULL;

void
init_rotor(ModeInfo * mi)
{
	rotorstruct *rp;
	int         x;
	elem       *pelem;
	unsigned char wasiconified;

	if (rotors == NULL) {
		if ((rotors = (rotorstruct *) calloc(MI_NUM_SCREENS(mi),
					      sizeof (rotorstruct))) == NULL)
			return;
	}
	rp = &rotors[MI_SCREEN(mi)];

	rp->prevcenterx = rp->centerx;
	rp->prevcentery = rp->centery;

	rp->centerx = MI_WIN_WIDTH(mi) / 2;
	rp->centery = MI_WIN_HEIGHT(mi) / 2;

	rp->redrawing = 0;
	/*
	 * sometimes, you go into iconified view, only to see a really whizzy pattern
	 * that you would like to look more closely at. Normally, clicking in the
	 * icon reinitializes everything - but I don't, cuz I'm that kind of guy.
	 * HENCE, the wasiconified stuff you see here.
	 */

	wasiconified = rp->iconifiedscreen;
	rp->iconifiedscreen = MI_WIN_IS_ICONIC(mi);

	if (wasiconified && !rp->iconifiedscreen)
		rp->firsttime = True;
	else {

		/* This is a fudge is needed since prevcenter may not be set when it comes
		   from the the random mode and return is pressed (and its not the first
		   mode that was running). This assumes that the size of the lock screen
		   window / size of the icon window = 12 */
		if (!rp->prevcenterx)
			rp->prevcenterx = rp->centerx * 12;
		if (!rp->prevcentery)
			rp->prevcentery = rp->centery * 12;

		rp->num = MI_BATCHCOUNT(mi);
		if (rp->num < 0) {
			rp->num = NRAND(-rp->num) + 1;
			if (rp->elements != NULL) {
				(void) free((void *) rp->elements);
				rp->elements = NULL;
			}
		}
		if (rp->elements == NULL)
			rp->elements = (elem *) calloc(rp->num, sizeof (elem));
		rp->nsave = MI_CYCLES(mi);
		if (rp->nsave <= 1)
			rp->nsave = 2;
		if (rp->save == NULL)
			rp->save = (XPoint *) calloc(rp->nsave, sizeof (XPoint));

		pelem = rp->elements;

		for (x = rp->num; --x >= 0; pelem++) {
			pelem->radius_drift_max = 1.0;
			pelem->radius_drift_now = 1.0;

			pelem->end_radius = 100.0;

			pelem->ratio_drift_max = 1.0;
			pelem->ratio_drift_now = 1.0;
			pelem->end_ratio = 10.0;
		}
		if (MI_NPIXELS(mi) > 2)
			rp->pix = NRAND(MI_NPIXELS(mi));

		rp->rotor = 0;
		rp->prev = 1;
		rp->lastx = rp->centerx;
		rp->lasty = rp->centery;
		rp->angle = (float) NRAND((long) MAXANGLE) / 3.0;
		rp->forward = rp->firsttime = True;
	}
	XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
}

void
draw_rotor(ModeInfo * mi)
{
	Display    *display = MI_DISPLAY(mi);
	GC          gc = MI_GC(mi);
	register rotorstruct *rp = &rotors[MI_SCREEN(mi)];
	register elem *pelem;
	int         thisx, thisy;
	int         i;
	int         x_1, y_1, x_2, y_2;

	if (!rp->iconifiedscreen) {
		thisx = rp->centerx;
		thisy = rp->centery;
	} else {
		thisx = rp->prevcenterx;
		thisy = rp->prevcentery;
	}
	for (i = rp->num, pelem = rp->elements; --i >= 0; pelem++) {
		if (pelem->radius_drift_max <= pelem->radius_drift_now) {
			pelem->start_radius = pelem->end_radius;
			pelem->end_radius = (float) NRAND(40000) / 100.0 - 200.0;
			pelem->radius_drift_max = (float) NRAND(100000) + 10000.0;
			pelem->radius_drift_now = 0.0;
		}
		if (pelem->ratio_drift_max <= pelem->ratio_drift_now) {
			pelem->start_ratio = pelem->end_ratio;
			pelem->end_ratio = (float) NRAND(2000) / 100.0 - 10.0;
			pelem->ratio_drift_max = (float) NRAND(100000) + 10000.0;
			pelem->ratio_drift_now = 0.0;
		}
		pelem->ratio = pelem->start_ratio +
			(pelem->end_ratio - pelem->start_ratio) /
			pelem->ratio_drift_max * pelem->ratio_drift_now;
		pelem->angle = rp->angle * pelem->ratio;
		pelem->radius = pelem->start_radius +
			(pelem->end_radius - pelem->start_radius) /
			pelem->radius_drift_max * pelem->radius_drift_now;

		thisx += (int) (COSF(pelem->angle) * pelem->radius);
		thisy += (int) (SINF(pelem->angle) * pelem->radius);

		pelem->ratio_drift_now += 1.0;
		pelem->radius_drift_now += 1.0;
	}
	if (rp->firsttime)
		rp->firsttime = False;
	else {
		XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(mi));

		x_1 = (int) rp->save[rp->rotor].x;
		y_1 = (int) rp->save[rp->rotor].y;
		x_2 = (int) rp->save[rp->prev].x;
		y_2 = (int) rp->save[rp->prev].y;

		if (rp->iconifiedscreen) {
			x_1 = x_1 * rp->centerx / rp->prevcenterx;
			x_2 = x_2 * rp->centerx / rp->prevcenterx;
			y_1 = y_1 * rp->centery / rp->prevcentery;
			y_2 = y_2 * rp->centery / rp->prevcentery;
		}
		XDrawLine(display, MI_WINDOW(mi), gc, x_1, y_1, x_2, y_2);

		if (MI_NPIXELS(mi) > 2) {
			XSetForeground(display, gc, MI_PIXEL(mi, rp->pix));
			if (++rp->pix >= MI_NPIXELS(mi))
				rp->pix = 0;
		} else
			XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));

		x_1 = rp->lastx;
		y_1 = rp->lasty;
		x_2 = thisx;
		y_2 = thisy;

		if (rp->iconifiedscreen) {
			x_1 = x_1 * rp->centerx / rp->prevcenterx;
			x_2 = x_2 * rp->centerx / rp->prevcenterx;
			y_1 = y_1 * rp->centery / rp->prevcentery;
			y_2 = y_2 * rp->centery / rp->prevcentery;
		}
		XDrawLine(display, MI_WINDOW(mi), gc, x_1, y_1, x_2, y_2);
	}
	rp->save[rp->rotor].x = rp->lastx = thisx;
	rp->save[rp->rotor].y = rp->lasty = thisy;

	++rp->rotor;
	rp->rotor %= rp->nsave;
	++rp->prev;
	rp->prev %= rp->nsave;
	if (rp->forward) {
		rp->angle += 0.01;
		if (rp->angle >= MAXANGLE) {
			rp->angle = MAXANGLE;
			rp->forward = False;
		}
	} else {
		rp->angle -= 0.1;
		if (rp->angle <= 0) {
			rp->angle = 0.0;
			rp->forward = True;
		}
	}
	if (rp->redrawing) {
		int         j;

		for (i = 0; i < REDRAWSTEP; i++) {
			j = (rp->rotor - rp->redrawpos + rp->nsave) % rp->nsave;

			x_1 = (int) rp->save[j].x;
			y_1 = (int) rp->save[j].y;
			x_2 = (int) rp->save[(j - 1 + rp->nsave) % rp->nsave].x;
			y_2 = (int) rp->save[(j - 1 + rp->nsave) % rp->nsave].y;

			if (rp->iconifiedscreen) {
				x_1 = x_1 * rp->centerx / rp->prevcenterx;
				x_2 = x_2 * rp->centerx / rp->prevcenterx;
				y_1 = y_1 * rp->centery / rp->prevcentery;
				y_2 = y_2 * rp->centery / rp->prevcentery;
			}
			XDrawLine(display, MI_WINDOW(mi), gc, x_1, y_1, x_2, y_2);

			if (++(rp->redrawpos) >= rp->nsave) {
				rp->redrawing = 0;
				break;
			}
		}
	}
}

void
release_rotor(ModeInfo * mi)
{
	if (rotors != NULL) {
		int         screen;

		for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
			rotorstruct *rp = &rotors[screen];

			if (rp->elements != NULL)
				(void) free((void *) rp->elements);
			if (rp->save != NULL)
				(void) free((void *) rp->save);
		}
		(void) free((void *) rotors);
		rotors = NULL;
	}
}

void
refresh_rotor(ModeInfo * mi)
{
	rotorstruct *rp = &rotors[MI_SCREEN(mi)];

	rp->redrawing = 1;
	rp->redrawpos = 1;
}
