nsaver.c

神龙卡开发原代码

		pos = (incr * (i - 1)) + (RANDRANGE(0, SAVER6_MAXZIGZAG) -
					((double)SAVER6_MAXZIGZAG / 2.0));
		if(pos < 0) pos = 0;
		if(pos > length) pos = length;
		nx = x - (pos * sin(angle));
		ny = y + pos * cos(angle);
		saver6_perturb(state, &nx, &ny, SAVER6_MAXZIGZAG);
		saver6_setvertices(s, bolt, fork, i, nx , ny);
	}
}

int saver6_makeforks(nstate *state, s6state *s, int bolt, int fork,
						int *vert, int *nextfork)
{
	int thisvert = 1, thisfork;
	double prob;

	if(*vert == (s->bolts[bolt].forks[fork].valid - 1)) return 0;
	if(*nextfork == SAVER6_MAXFORKS) return 0;

 	prob = (double)SAVER6_FORK_PROBABILITY * ((double)*vert /
				(double)s->bolts[bolt].forks[fork].valid) *
					(1.0 / ((double)fork + 1.0));
	if(RANDRANGE(0, 1) < prob) {
		thisfork = *nextfork;
		saver6_makefork(state, s, bolt, thisfork,
			s->bolts[bolt].forks[fork].vertices[0][*vert].x,
			s->bolts[bolt].forks[fork].vertices[0][*vert].y);
		*nextfork += 1;
		while(saver6_makeforks(state, s, bolt, thisfork, &thisvert,
								nextfork));
	}

	*vert += 1;

	return 1;
}

void saver6_makebolt(nstate *state, s6state *s, int bolt)
{
	GR_COORD x;
	int vert = 1, nextfork = 1, n;

	for(n = 0; n < SAVER6_MAXFORKS; n++)
		s->bolts[bolt].forks[n].valid = 0;

	x = (int)RANDRANGE(0, (state->si.cols - 1.0));

	saver6_makefork(state, s, bolt, 0, x, 0);

	while(saver6_makeforks(state, s, bolt, 0, &vert, &nextfork));
}

void saver6_newbolt(nstate *state, s6state *s)
{
	int i;

	for(i = 0; i < SAVER6_MAXBOLTS; i++) {
		if(!s->bolts[i].duration) {
			saver6_makebolt(state, s, i);
			s->bolts[i].duration = RANDRANGE(SAVER6_MINDURATION,
							SAVER6_MAXDURATION);
			saver6_drawbolt(state, s, i, 0);
			break;
		}
	}

	s->new_bolt_time = RANDRANGE(1, SAVER6_MAXNEWBOLTTIME);
}

void saver6_perturb_bolt(nstate *state, s6state *s, int bolt, int fork)
{
	int m, o;
	GR_COORD x, ox, y, oy;

	for(m = 1; m < s->bolts[bolt].forks[fork].valid; m++) {
		ox = x = s->bolts[bolt].forks[fork].vertices[0][m].x;
		oy = y = s->bolts[bolt].forks[fork].vertices[0][m].y;
		saver6_perturb(state, &x, &y, SAVER6_MAXZIGZAG);
		saver6_setvertices(s, bolt, fork, m, x, y);
		for(o = fork + 1; o < SAVER6_MAXFORKS; o++) {
			if((s->bolts[bolt].forks[o].vertices[0][0].x == ox) &&
				(s->bolts[bolt].forks[o].vertices[0][0].y
								== oy)) {
				saver6_setvertices(s, bolt, o, 0, x, y);
			}
		}
	}
}

void saver6_perturb_lightning(nstate *state, s6state *s)
{
	int i, n;

	for(i = 0; i < SAVER6_MAXBOLTS; i++) {
		if(!s->bolts[i].duration) continue;
		for(n = 0; n < SAVER6_MAXFORKS; n++) {
			if(!s->bolts[i].forks[n].valid) continue;
			saver6_perturb_bolt(state, s, i, n);
		}
	}
}

void saver6_animate(nstate *state)
{
	s6state *s = state->priv;

	saver6_drawlightning(state, s, 1);
	saver6_perturb_lightning(state, s);
	saver6_drawlightning(state, s, 0);

	if(!s->new_bolt_time--) saver6_newbolt(state, s);
}

/* The algorithm used in saver7 was adapted from "grav" by Greg Bowering */

void saver7_drawstar(nstate *state, s7state *s)
{
	GrSetGCForeground(state->main_gc, SAVER7_STARCOLOUR);
	GrFillEllipse(state->main_window, state->main_gc, s->starx, s->stary,
				SAVER7_STARRADIUS, SAVER7_STARRADIUS);
}

void saver7_drawplanet(nstate *state, s7state *s, int planet, int erase)
{
	if(erase) GrSetGCForeground(state->main_gc, BLACK);
	else GrSetGCForeground(state->main_gc, s->planets[planet].colour);

	if((s->planets[planet].ax < 0) || (s->planets[planet].ay < 0) ||
			(s->planets[planet].ax >= state->si.cols) ||
			(s->planets[planet].ay >= state->si.rows)) {
		return;
	}

	GrFillEllipse(state->main_window, state->main_gc, s->planets[planet].ax,
				s->planets[planet].ay,
				SAVER7_PLANETRADIUS, SAVER7_PLANETRADIUS);
}

void saver7_calc_planet_position(nstate *state, s7state *s, int planet)
{
	if(s->planets[planet].r > -SAVER7_ALMOSTDIST) {
		s->planets[planet].ax = (int)((double) state->si.cols *
			(0.5 + (s->planets[planet].x / (s->planets[planet].r +
							SAVER7_DIST))));
		s->planets[planet].ay = (int)((double) state->si.rows *
			(0.5 + (s->planets[planet].y / (s->planets[planet].r +
							SAVER7_DIST))));
	} else {
		s->planets[planet].ax = -1;
		s->planets[planet].ay = -1;
	}
}

void saver7_init(nstate *state)
{
	int i;
	s7state *s = my_malloc(sizeof(s7state));
	state->priv = s;

	s->starx = state->si.cols / 2;
	s->stary = state->si.rows / 2;

	for(i = 0; i < SAVER7_PLANETS; i++) {
		s->planets[i].r = RANDRANGE(SAVER7_MIN_STARTDIM,
						SAVER7_MAX_STARTDIM);
		s->planets[i].x = RANDRANGE(SAVER7_MIN_STARTDIM,
						SAVER7_MAX_STARTDIM);
		s->planets[i].y = RANDRANGE(SAVER7_MIN_STARTDIM,
						SAVER7_MAX_STARTDIM);
		s->planets[i].rv = RANDRANGE(SAVER7_MIN_STARTVEL,
						SAVER7_MAX_STARTVEL);
		s->planets[i].xv = RANDRANGE(SAVER7_MIN_STARTVEL,
						SAVER7_MAX_STARTVEL);
		s->planets[i].yv = RANDRANGE(SAVER7_MIN_STARTVEL,
						SAVER7_MAX_STARTVEL);
		s->planets[i].colour = RANDRANGE(0, (state->si.ncolors - 1));
		saver7_calc_planet_position(state, s, i);
		saver7_drawplanet(state, s, i, 0);
	}

	saver7_drawstar(state, s);

	state->animate_interval = SAVER7_DELAY;
}

void saver7_exposure(nstate *state)
{
	int i;
	s7state *s = state->priv;

	GrClearWindow(state->main_window, 0);

	for(i = 0; i < SAVER7_PLANETS; i++)
		saver7_drawplanet(state, s, i, 0);

	saver7_drawstar(state, s);
}

void saver7_moveplanet(nstate *state, s7state *s, int planet)
{
	double dist;
	double accel;

	dist = (s->planets[planet].x * s->planets[planet].x) +
		(s->planets[planet].y * s->planets[planet].y) +
		(s->planets[planet].r * s->planets[planet].r);
	if(dist < SAVER7_COLLIDE) dist = SAVER7_COLLIDE;
	dist = sqrt(dist);
	dist = dist * dist * dist;

#ifdef SAVER7_USE_DAMPING
	accel = s->planets[planet].r * SAVER7_G / dist;
	if(accel > SAVER7_MAX_ACCEL) accel = SAVER7_MAX_ACCEL;
	else if(accel < -SAVER7_MAX_ACCEL) accel = -SAVER7_MAX_ACCEL;
	s->planets[planet].rv = (s->planets[planet].rv + accel) *
						SAVER7_DAMPING_FACTOR;
	s->planets[planet].r += s->planets[planet].rv;
	accel = s->planets[planet].x * SAVER7_G / dist;
	if(accel > SAVER7_MAX_ACCEL) accel = SAVER7_MAX_ACCEL;
	else if(accel < -SAVER7_MAX_ACCEL) accel = -SAVER7_MAX_ACCEL;
	s->planets[planet].xv = (s->planets[planet].xv + accel) *
						SAVER7_DAMPING_FACTOR;
	s->planets[planet].x += s->planets[planet].xv;
	accel = s->planets[planet].y * SAVER7_G / dist;
	if(accel > SAVER7_MAX_ACCEL) accel = SAVER7_MAX_ACCEL;
	else if(accel < -SAVER7_MAX_ACCEL) accel = -SAVER7_MAX_ACCEL;
	s->planets[planet].yv = (s->planets[planet].yv + accel) *
						SAVER7_DAMPING_FACTOR;
	s->planets[planet].y += s->planets[planet].yv;
#else
	accel = s->planets[planet].r * SAVER7_G / dist;
	s->planets[planet].rv += accel;
	s->planets[planet].r += s->planets[planet].rv;
	accel = s->planets[planet].x * SAVER7_G / dist;
	s->planets[planet].xv += accel;
	s->planets[planet].x += s->planets[planet].xv;
	accel = s->planets[planet].y * SAVER7_G / dist;
	s->planets[planet].yv += accel;
	s->planets[planet].y += s->planets[planet].yv;
#endif
}

void saver7_animate(nstate *state)
{
	int i;
	s7state *s = state->priv;

	for(i = 0; i < SAVER7_PLANETS; i++) {
		saver7_moveplanet(state, s, i);
		saver7_drawplanet(state, s, i, 1);
		saver7_calc_planet_position(state, s, i);
		saver7_drawplanet(state, s, i, 0);
	}
	saver7_drawstar(state, s);
}

/* The algorithm used in saver8 is based on that found at: 
   http://www.go2net.com/internet/deep/1997/04/16/body.html */

void saver8_init(nstate *state)
{
	int red = 0, green = 0, blue = 0, step, i = 0;

	s8state *s = my_malloc(sizeof(s8state));
	state->priv = s;

	s->current_line = 0;

	step = 512 / SAVER8_NUMCOLOURS;

	for(green = 255; green > 0; green -= step, blue += step, i++)
		s->colours[i] = GR_RGB(0, green, blue);
	for(blue = 255; blue > 0; blue -= step, red += step, i++)
		s->colours[i] = GR_RGB(red, 0, blue);

	state->animate_interval = SAVER8_DELAY;
}

void saver8_drawpattern(nstate *state)
{
	int x, col, lines = SAVER8_LINES_PER_FRAME;
	s8state *s = state->priv;

	if(!s->current_line)
		s->factor = RANDRANGE(SAVER8_MINFACTOR, SAVER8_MAXFACTOR);

	while(s->current_line < state->si.rows) {
		if(!--lines) return;
		for(x = 0; x < state->si.cols; x++) {
			col = ((((x * x) + (s->current_line * s->current_line))
					/ s->factor) % SAVER8_NUMCOLOURS);
			GrSetGCForeground(state->main_gc, s->colours[col]);
			GrPoint(state->main_window, state->main_gc, x,
							s->current_line);
		}
		s->current_line++;
	}
	s->current_line = 0;
}

void saver8_exposure(nstate *state)
{
	s8state *s = state->priv;

	GrClearWindow(state->main_window, 0);
	s->current_line = 0;
	saver8_drawpattern(state);
}

void saver8_animate(nstate *state)
{
	saver8_drawpattern(state);
}

int init(nstate *state)
{
	GR_WM_PROPERTIES props;
	GR_BITMAP cursor = 0;

	if(!GrOpen()) {
		fprintf(stderr, "Couldn't connect to Nano-X server\n");
		return 3;
	}

	GrGetScreenInfo(&state->si);

	state->main_window = GrNewWindow(GR_ROOT_WINDOW_ID, 0, 0,
				state->si.cols, state->si.rows, 0, BLACK, 0);

	GrSelectEvents(state->main_window, GR_EVENT_MASK_EXPOSURE |
						GR_EVENT_MASK_BUTTON_UP |
						GR_EVENT_MASK_BUTTON_DOWN |
						GR_EVENT_MASK_MOUSE_MOTION |
						GR_EVENT_MASK_KEY_UP |
						GR_EVENT_MASK_KEY_DOWN |
						GR_EVENT_MASK_FOCUS_OUT |
						GR_EVENT_MASK_CLOSE_REQ);

	props.flags = GR_WM_FLAGS_PROPS;
	props.props = GR_WM_PROPS_NOMOVE | GR_WM_PROPS_NODECORATE |
			GR_WM_PROPS_NOAUTOMOVE | GR_WM_PROPS_NOAUTORESIZE;
	GrSetWMProperties(state->main_window, &props);

	state->main_gc = GrNewGC();
	GrSetGCForeground(state->main_gc, WHITE);
	GrSetGCBackground(state->main_gc, BLACK);

	state->animate_interval = 0;

	srand(time(0));

	init_functions[state->saver](state);

	calculate_timeout(state);

	GrSelectEvents(GR_ROOT_WINDOW_ID, GR_EVENT_MASK_SCREENSAVER);

	GrSetCursor(state->main_window, 1, 1, 1, 1, 0, 0, &cursor, &cursor);

	GrMapWindow(state->main_window);

	GrSetFocus(state->main_window);

	return 0;
}

void calculate_timeout(nstate *state)
{
	struct timeval t;
	long u;

	gettimeofday(&t, NULL);
	u = t.tv_usec + (state->animate_interval * 1000);
	state->timeout.tv_sec = t.tv_sec + (u / 1000000);
	state->timeout.tv_usec = u % 1000000;
}

unsigned long timeout_delay(nstate *state)
{
	struct timeval t;
	signed long s, m, ret;

	gettimeofday(&t, NULL);

	if(!state->animate_interval) return 0;

	if((t.tv_sec > state->timeout.tv_sec) ||
			((t.tv_sec == state->timeout.tv_sec) &&
			t.tv_usec >= state->timeout.tv_usec)) return 1;

	s = state->timeout.tv_sec - t.tv_sec;
	m = ((state->timeout.tv_usec - t.tv_usec) / 1000);
	ret = (unsigned long)((1000 * s) + m);

	if(ret <= 0) return 1;
	else return ret;
}

void do_animate(nstate *state)
{
	struct timeval t;

	if(!state->animate_interval) return;

	gettimeofday(&t, NULL);

	if((t.tv_sec > state->timeout.tv_sec) ||
			((t.tv_sec == state->timeout.tv_sec) &&
			(t.tv_usec >= state->timeout.tv_usec))) {
		animate_functions[state->saver](state);
		calculate_timeout(state);
	}
}

int do_screensaver_event(nstate *state)
{
	GR_EVENT_SCREENSAVER *event = &state->event.screensaver;

	if(event->activate != GR_FALSE) {
		fprintf(stderr, "Got a non-deactivate screensaver event\n");
		return 0;
	}

	return 1;
}

int handle_event(nstate *state)
{
	switch(state->event.type) {
		case GR_EVENT_TYPE_EXPOSURE:
			exposure_functions[state->saver](state);
		case GR_EVENT_TYPE_TIMEOUT:
		case GR_EVENT_TYPE_NONE:
			break;
		case GR_EVENT_TYPE_SCREENSAVER:
			if(do_screensaver_event(state)) return 0;
			break;
		case GR_EVENT_TYPE_CLOSE_REQ:
		case GR_EVENT_MASK_BUTTON_UP:
		case GR_EVENT_MASK_BUTTON_DOWN:
		case GR_EVENT_MASK_MOUSE_MOTION:
		case GR_EVENT_MASK_KEY_UP:
		case GR_EVENT_MASK_KEY_DOWN:
		case GR_EVENT_MASK_FOCUS_OUT:
			return 0;
		default:
			fprintf(stderr, "Got unknown event type %d\n",
							state->event.type);
			break;
	}
	do_animate(state);
	return(1);
}

int main(int argc, char *argv[])
{
	int ret;
	nstate *state = my_malloc(sizeof(nstate));

	if(argc == 2) {
		state->saver = atoi(argv[1]) - 1;
		if((state->saver) < 0 || (state->saver >= NUM_SAVERS)) {
			fprintf(stderr, "Invalid saver number \"%s\"\n",
								argv[1]);
			return 2;
		}
	} else state->saver = 0;

	if((ret = init(state))) return ret;

	do {
		GrGetNextEventTimeout(&state->event, timeout_delay(state));
	} while(handle_event(state));

	GrClose();

	return 0;
}