X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hacks%2Fattraction.c;h=397aae389b7956ec35eaf76a27779a5211bc6139;hb=3c58fb6311db49c46f1670922933b27c6ea0c065;hp=1f93781df3673ac485d603044339651813930eda;hpb=88134d551a9911995c013c5ed06a32c2b1044b85;p=xscreensaver diff --git a/hacks/attraction.c b/hacks/attraction.c index 1f93781d..397aae38 100644 --- a/hacks/attraction.c +++ b/hacks/attraction.c @@ -1,4 +1,5 @@ -/* xscreensaver, Copyright (c) 1992 Jamie Zawinski +/* xscreensaver, Copyright (c) 1992, 1995, 1996, 1997, 1998, 2001 + * Jamie Zawinski * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that @@ -11,49 +12,95 @@ /* Simulation of a pair of quasi-gravitational fields, maybe sorta kinda a little like the strong and weak electromagnetic forces. Derived from - a Lispm screensaver by John Pezaris . + a Lispm screensaver by John Pezaris . Mouse control and + viscosity added by "Philip Edward Cutone, III" . John sez: - The simulation started out as a purely accurate gravitational simulation, - but, with constant simulation step size, I quickly realized the field being - simulated while grossly gravitational was, in fact, non-conservative. It - also had the rather annoying behavior of dealing very badly with colliding - orbs. Therefore, I implemented a negative-gravity region (with two - thresholds; as I read your code, you only implemented one) to prevent orbs - from every coming too close together, and added a viscosity factor if the - speed of any orb got too fast. This provides a nice stable system with - interesting behavior. - - I had experimented with a number of fields including the van der Waals - force (very interesting orbiting behavior) and 1/r^3 gravity (not as - interesting as 1/r^2). An even normal viscosity (rather than the - thresholded version to bleed excess energy) is also not interesting. - The 1/r^2, -1/r^2, -10/r^2 thresholds proved not only robust but also - interesting -- the orbs never collided and the threshold viscosity fixed - the non-conservational problem. - */ + The simulation started out as a purely accurate gravitational + simulation, but, with constant simulation step size, I quickly + realized the field being simulated while grossly gravitational + was, in fact, non-conservative. It also had the rather annoying + behavior of dealing very badly with colliding orbs. Therefore, + I implemented a negative-gravity region (with two thresholds; as + I read your code, you only implemented one) to prevent orbs from + every coming too close together, and added a viscosity factor if + the speed of any orb got too fast. This provides a nice stable + system with interesting behavior. + + I had experimented with a number of fields including the van der + Waals force (very interesting orbiting behavior) and 1/r^3 + gravity (not as interesting as 1/r^2). An even normal viscosity + (rather than the thresholded version to bleed excess energy) is + also not interesting. The 1/r^2, -1/r^2, -10/r^2 thresholds + proved not only robust but also interesting -- the orbs never + collided and the threshold viscosity fixed the + non-conservational problem. + + Philip sez: + > An even normal viscosity (rather than the thresholded version to + > bleed excess energy) is also not interesting. + + unless you make about 200 points.... set the viscosity to about .8 + and drag the mouse through it. it makes a nice wave which travels + through the field. + + And (always the troublemaker) Joe Keane sez: + + Despite what John sez, the field being simulated is always + conservative. The real problem is that it uses a simple hack, + computing acceleration *based only on the starting position*, + instead of a real differential equation solver. Thus you'll + always have energy coming out of nowhere, although it's most + blatant when balls get close together. If it were done right, + you wouldn't need viscosity or artificial limits on how close + the balls can get. + + Matt sez: + + Added a switch to remove the walls. + + Added a switch to make the threshold viscosity optional. If + nomaxspeed is specified, then balls going really fast do not + recieve special treatment. + + I've made tail mode prettier by eliminating the first erase line + that drew from the upper left corner to the starting position of + each point. + + Made the balls in modes other than "balls" bounce exactly at the + walls. (Because the graphics for different modes are drawn + differently with respect to the "actual" position of the point, + they used to be able to run somewhat past the walls, or bounce + before hitting them.) + + Added an option to output each ball's speed in the form of a bar + graph drawn on the same window as the balls. If only x or y is + selected, they will be represented on the appropriate axis down + the center of the window. If both are selected, they will both + be displayed along the diagonal such that the x and y bars for + each point start at the same place. If speed is selected, the + speed will be displayed down the left side. */ -#include "screenhack.h" -#include "spline.h" #include #include -#if __STDC__ -#include -#endif +#include "screenhack.h" +#include "spline.h" struct ball { - float x, y; - float vx, vy; - float dx, dy; - float mass; + double x, y; + double vx, vy; + double dx, dy; + double mass; int size; - XColor color; + int pixel_index; int hue; }; -static unsigned int default_fg_pixel; static struct ball *balls; +static double *x_vels; +static double *y_vels; +static double *speeds; static int npoints; static int threshold; static int delay; @@ -61,31 +108,41 @@ static int global_size; static int segments; static Bool glow_p; static Bool orbit_p; +static Bool walls_p; +static Bool maxspeed_p; +static Bool cbounce_p; static XPoint *point_stack; -static int point_stack_size, point_stack_fp, pixel_stack_fp, pixel_stack_size; -static unsigned long *pixel_stack; -static unsigned int color_shift; +static int point_stack_size, point_stack_fp; +static XColor *colors; +static int ncolors; +static int fg_index; +static int color_shift; +Bool no_erase_yet; /* for tail mode fix */ + +/*flip mods for mouse interaction*/ +static Bool mouse_p; +int mouse_x, mouse_y, mouse_mass, root_x, root_y; +static double viscosity; static enum object_mode { ball_mode, line_mode, polygon_mode, spline_mode, spline_filled_mode, tail_mode } mode; -static enum color_mode { - cycle_mode, random_mode -} cmode; +static enum graph_mode { + graph_none, graph_x, graph_y, graph_both, graph_speed +} graph_mode; static GC draw_gc, erase_gc; +/* The normal (and max) width for a graph bar */ +#define BAR_SIZE 11 #define MAX_SIZE 16 - #define min(a,b) ((a)<(b)?(a):(b)) #define max(a,b) ((a)>(b)?(a):(b)) static void -init_balls (dpy, window) - Display *dpy; - Window window; +init_balls (Display *dpy, Window window) { int i; XWindowAttributes xgwa; @@ -93,43 +150,69 @@ init_balls (dpy, window) int xlim, ylim, midx, midy, r, vx, vy; double th; Colormap cmap; - char *mode_str; + char *mode_str, *graph_mode_str; + XGetWindowAttributes (dpy, window, &xgwa); xlim = xgwa.width; ylim = xgwa.height; cmap = xgwa.colormap; midx = xlim/2; midy = ylim/2; + walls_p = get_boolean_resource ("walls", "Boolean"); + + /* if there aren't walls, don't set a limit on the radius */ r = get_integer_resource ("radius", "Integer"); - if (r <= 0 || r > min (xlim/2, ylim/2)) + if (r <= 0 || (r > min (xlim/2, ylim/2) && walls_p) ) r = min (xlim/2, ylim/2) - 50; + vx = get_integer_resource ("vx", "Integer"); vy = get_integer_resource ("vy", "Integer"); + npoints = get_integer_resource ("points", "Integer"); if (npoints < 1) npoints = 3 + (random () % 5); balls = (struct ball *) malloc (npoints * sizeof (struct ball)); + + no_erase_yet = 1; /* for tail mode fix */ + segments = get_integer_resource ("segments", "Integer"); if (segments < 0) segments = 1; + threshold = get_integer_resource ("threshold", "Integer"); if (threshold < 0) threshold = 0; + delay = get_integer_resource ("delay", "Integer"); - if (delay < 0) delay = 0; + if (delay < 0) delay = 0; + global_size = get_integer_resource ("size", "Integer"); if (global_size < 0) global_size = 0; + glow_p = get_boolean_resource ("glow", "Boolean"); + orbit_p = get_boolean_resource ("orbit", "Boolean"); + + maxspeed_p = get_boolean_resource ("maxspeed", "Boolean"); + + cbounce_p = get_boolean_resource ("cbounce", "Boolean"); + color_shift = get_integer_resource ("colorShift", "Integer"); - if (color_shift >= 360) color_shift = 5; + if (color_shift <= 0) color_shift = 5; + + /*flip mods for mouse interaction*/ + mouse_p = get_boolean_resource ("mouse", "Boolean"); + mouse_mass = get_integer_resource ("mouseSize", "Integer"); + mouse_mass = mouse_mass * mouse_mass *10; + + viscosity = get_float_resource ("viscosity", "Float"); mode_str = get_string_resource ("mode", "Mode"); if (! mode_str) mode = ball_mode; - else if (!strcmp (mode_str, "balls")) mode = ball_mode; - else if (!strcmp (mode_str, "lines")) mode = line_mode; - else if (!strcmp (mode_str, "polygons")) mode = polygon_mode; - else if (!strcmp (mode_str, "tails")) mode = tail_mode; - else if (!strcmp (mode_str, "splines")) mode = spline_mode; - else if (!strcmp (mode_str, "filled-splines")) mode = spline_filled_mode; + else if (!strcmp (mode_str, "balls")) mode = ball_mode; + else if (!strcmp (mode_str, "lines")) mode = line_mode; + else if (!strcmp (mode_str, "polygons")) mode = polygon_mode; + else if (!strcmp (mode_str, "tails")) mode = tail_mode; + else if (!strcmp (mode_str, "splines")) mode = spline_mode; + else if (!strcmp (mode_str, "filled-splines"))mode = spline_filled_mode; else { fprintf (stderr, "%s: mode must be balls, lines, tails, polygons, splines, or\n\ @@ -138,34 +221,92 @@ init_balls (dpy, window) exit (1); } - mode_str = get_string_resource ("colorMode", "ColorMode"); - if (! mode_str) cmode = cycle_mode; - else if (!strcmp (mode_str, "cycle")) cmode = cycle_mode; - else if (!strcmp (mode_str, "random")) cmode = random_mode; + graph_mode_str = get_string_resource ("graphmode", "Mode"); + if (! graph_mode_str) graph_mode = graph_none; + else if (!strcmp (graph_mode_str, "x")) graph_mode = graph_x; + else if (!strcmp (graph_mode_str, "y")) graph_mode = graph_y; + else if (!strcmp (graph_mode_str, "both")) graph_mode = graph_both; + else if (!strcmp (graph_mode_str, "speed")) graph_mode = graph_speed; + else if (!strcmp (graph_mode_str, "none")) graph_mode = graph_none; else { - fprintf (stderr, "%s: colorMode must be cycle or random, not \"%s\"\n", - progname, mode_str); + fprintf (stderr, + "%s: graphmode must be speed, x, y, both, or none, not \"%s\"\n", + progname, graph_mode_str); exit (1); } + /* only allocate memory if it is needed */ + if(graph_mode != graph_none) + { + if(graph_mode == graph_x || graph_mode == graph_both) + x_vels = (double *) malloc (npoints * sizeof (double)); + if(graph_mode == graph_y || graph_mode == graph_both) + y_vels = (double *) malloc (npoints * sizeof (double)); + if(graph_mode == graph_speed) + speeds = (double *) malloc (npoints * sizeof (double)); + } + if (mode != ball_mode && mode != tail_mode) glow_p = False; if (mode == polygon_mode && npoints < 3) mode = line_mode; + ncolors = get_integer_resource ("colors", "Colors"); + if (ncolors < 2) ncolors = 2; + if (ncolors <= 2) mono_p = True; + colors = 0; + + if (!mono_p) + { + fg_index = 0; + switch (mode) + { + case ball_mode: + if (glow_p) + { + int H = random() % 360; + double S1 = 0.25; + double S2 = 1.00; + double V = frand(0.25) + 0.75; + colors = (XColor *) malloc(sizeof(*colors) * (ncolors+1)); + make_color_ramp (dpy, cmap, H, S1, V, H, S2, V, colors, &ncolors, + False, True, False); + } + else + { + ncolors = npoints; + colors = (XColor *) malloc(sizeof(*colors) * (ncolors+1)); + make_random_colormap (dpy, xgwa.visual, cmap, colors, &ncolors, + True, True, False, True); + } + break; + case line_mode: + case polygon_mode: + case spline_mode: + case spline_filled_mode: + case tail_mode: + colors = (XColor *) malloc(sizeof(*colors) * (ncolors+1)); + make_smooth_colormap (dpy, xgwa.visual, cmap, colors, &ncolors, + True, False, True); + break; + default: + abort (); + } + } + + if (!mono_p && ncolors <= 2) + { + if (colors) free (colors); + colors = 0; + mono_p = True; + } + if (mode != ball_mode) { int size = (segments ? segments : 1); point_stack_size = size * (npoints + 1); point_stack = (XPoint *) calloc (point_stack_size, sizeof (XPoint)); point_stack_fp = 0; - if (segments > 0) - pixel_stack_size = segments; - else - pixel_stack_size = (360 / color_shift); - pixel_stack = (unsigned long *) - calloc (pixel_stack_size, sizeof (unsigned int)); - pixel_stack_fp = 0; } gcv.line_width = (mode == tail_mode @@ -173,21 +314,15 @@ init_balls (dpy, window) : 1); gcv.cap_style = (mode == tail_mode ? CapRound : CapButt); - gcv.foreground = default_fg_pixel = - get_pixel_resource ("foreground", "Foreground", dpy, cmap); + if (mono_p) + gcv.foreground = get_pixel_resource("foreground", "Foreground", dpy, cmap); + else + gcv.foreground = colors[fg_index].pixel; draw_gc = XCreateGC (dpy, window, GCForeground|GCLineWidth|GCCapStyle, &gcv); - gcv.foreground = get_pixel_resource ("background", "Background", dpy, cmap); + + gcv.foreground = get_pixel_resource("background", "Background", dpy, cmap); erase_gc = XCreateGC (dpy, window, GCForeground|GCLineWidth|GCCapStyle,&gcv); - if (!mono_p && mode != ball_mode) - for (i = 0; i < pixel_stack_size; i++) - { - XColor color; - color.pixel = default_fg_pixel; - XQueryColor (dpy, cmap, &color); - if (!XAllocColor (dpy, cmap, &color)) abort (); - pixel_stack [i] = color.pixel; - } #define rand_size() min (MAX_SIZE, 8 + (random () % (MAX_SIZE - 9))) @@ -211,22 +346,28 @@ init_balls (dpy, window) balls [i].vx = vx ? vx : ((6.0 - (random () % 11)) / 8.0); balls [i].vy = vy ? vy : ((6.0 - (random () % 11)) / 8.0); } - balls [i].color.pixel = default_fg_pixel; - balls [i].color.flags = DoRed | DoGreen | DoBlue; - if (!mono_p) - { - if (i != 0 && (glow_p || mode != ball_mode)) - balls [i].hue = balls [0].hue; - else - balls [i].hue = random () % 360; - hsv_to_rgb (balls [i].hue, 1.0, 1.0, - &balls [i].color.red, &balls [i].color.green, - &balls [i].color.blue); - if (!XAllocColor (dpy, cmap, &balls [i].color)) - mono_p = True; /* just give up */ - } + if (mono_p || mode != ball_mode) + balls [i].pixel_index = -1; + else if (glow_p) + balls [i].pixel_index = 0; + else + balls [i].pixel_index = random() % ncolors; } + /* This lets modes where the points don't really have any size use the whole + window. Otherwise, since the points still have a positive size + assigned to them, they will be bounced somewhat early. Mass and size are + seperate, so this shouldn't cause problems. It's a bit kludgy, tho. + */ + if(mode == line_mode || mode == spline_mode || + mode == spline_filled_mode || mode == polygon_mode) + { + for(i = 1; i < npoints; i++) + { + balls[i].size = 0; + } + } + if (orbit_p) { double a = 0; @@ -263,21 +404,19 @@ init_balls (dpy, window) } if (mono_p) glow_p = False; + XClearWindow (dpy, window); } static void -compute_force (i, dx_ret, dy_ret) - int i; - float *dx_ret, *dy_ret; +compute_force (int i, double *dx_ret, double *dy_ret) { int j; + double x_dist, y_dist, dist, dist2; *dx_ret = 0; *dy_ret = 0; for (j = 0; j < npoints; j++) { - float x_dist, y_dist, dist, dist2; - if (i == j) continue; x_dist = balls [j].x - balls [i].x; y_dist = balls [j].y - balls [i].y; @@ -286,9 +425,31 @@ compute_force (i, dx_ret, dy_ret) if (dist > 0.1) /* the balls are not overlapping */ { - float new_acc = ((balls[j].mass / dist2) * - ((dist < threshold) ? -1.0 : 1.0)); - float new_acc_dist = new_acc / dist; + double new_acc = ((balls[j].mass / dist2) * + ((dist < threshold) ? -1.0 : 1.0)); + double new_acc_dist = new_acc / dist; + *dx_ret += new_acc_dist * x_dist; + *dy_ret += new_acc_dist * y_dist; + } + else + { /* the balls are overlapping; move randomly */ + *dx_ret += (frand (10.0) - 5.0); + *dy_ret += (frand (10.0) - 5.0); + } + } + + if (mouse_p) + { + x_dist = mouse_x - balls [i].x; + y_dist = mouse_y - balls [i].y; + dist2 = (x_dist * x_dist) + (y_dist * y_dist); + dist = sqrt (dist2); + + if (dist > 0.1) /* the balls are not overlapping */ + { + double new_acc = ((mouse_mass / dist2) * + ((dist < threshold) ? -1.0 : 1.0)); + double new_acc_dist = new_acc / dist; *dx_ret += new_acc_dist * x_dist; *dy_ret += new_acc_dist * y_dist; } @@ -300,15 +461,200 @@ compute_force (i, dx_ret, dy_ret) } } + +/* Draws meters along the diagonal for the x velocity */ +static void +draw_meter_x(Display *dpy, Window window, GC draw_gc, + struct ball *balls, int i, int alone) +{ + XWindowAttributes xgwa; + int x1,x2,y,w1,w2,h; + XGetWindowAttributes (dpy, window, &xgwa); + + /* set the width of the bars to use */ + if(xgwa.height < BAR_SIZE*npoints) + { + y = i*(xgwa.height/npoints); + h = (xgwa.height/npoints) - 2; + } + else + { + y = BAR_SIZE*i; + h = BAR_SIZE - 2; + } + + if(alone) + { + x1 = xgwa.width/2; + x2 = x1; + } + else + { + x1 = i*(h+2); + if(x1 < i) + x1 = i; + x2 = x1; + } + + if(y<1) y=i; + if(h<1) h=1; + + w1 = (int)(20*x_vels[i]); + w2 = (int)(20*balls[i].vx); + x_vels[i] = balls[i].vx; + + if (w1<0) { + w1=-w1; + x1=x1-w1; + } + if (w2<0) { + w2=-w2; + x2=x2-w2; + } + XDrawRectangle(dpy,window,erase_gc,x1+(h+2)/2,y,w1,h); + XDrawRectangle(dpy,window,draw_gc,x2+(h+2)/2,y,w2,h); +} + +/* Draws meters along the diagonal for the y velocity. + Is there some way to make draw_meter_x and draw_meter_y + one function instead of two without making them completely unreadable? +*/ +static void +draw_meter_y (Display *dpy, Window window, GC draw_gc, + struct ball *balls, int i, int alone) +{ + XWindowAttributes xgwa; + int y1,y2,x,h1,h2,w; + XGetWindowAttributes (dpy, window, &xgwa); + + if(xgwa.height < BAR_SIZE*npoints){ /*needs to be height still */ + x = i*(xgwa.height/npoints); + w = (xgwa.height/npoints) - 2; + } + else{ + x = BAR_SIZE*i; + w = BAR_SIZE - 2; + } + + if(alone) + { + y1 = xgwa.height/2; + y2 = y1; + } + else + { + y1 = i*(w+2); + if(y1 < i) + y1 = i; + y2 = y1; + } + + if(x < 1) x = i; + if(w < 1) w = 1; + + h1 = (int)(20*y_vels[i]); + h2 = (int)(20*balls[i].vy); + y_vels[i] = balls[i].vy; + + if (h1<0) { + h1=-h1; + y1=y1-h1; + } + if (h2<0) { + h2=-h2; + y2=y2-h2; + } + XDrawRectangle(dpy,window,erase_gc,x,y1+(w+2)/2,w,h1); + XDrawRectangle(dpy,window,draw_gc,x,y2+(w+2)/2,w,h2); +} + + +/* Draws meters of the total speed of the balls */ static void -run_balls (dpy, window) - Display *dpy; - Window window; +draw_meter_speed (Display *dpy, Window window, GC draw_gc, + struct ball *balls, int i) +{ + XWindowAttributes xgwa; + int y,x1,x2,h,w1,w2; + XGetWindowAttributes (dpy, window, &xgwa); + + if(xgwa.height < BAR_SIZE*npoints) + { + y = i*(xgwa.height/npoints); + h = (xgwa.height/npoints) - 2; + } + else{ + y = BAR_SIZE*i; + h = BAR_SIZE - 2; + } + + x1 = 0; + x2 = x1; + + if(y < 1) y = i; + if(h < 1) h = 1; + + w1 = (int)(5*speeds[i]); + w2 = (int)(5*(balls[i].vy*balls[i].vy+balls[i].vx*balls[i].vx)); + speeds[i] = balls[i].vy*balls[i].vy+balls[i].vx*balls[i].vx; + + XDrawRectangle(dpy,window,erase_gc,x1,y,w1,h); + XDrawRectangle(dpy,window,draw_gc, x2,y,w2,h); +} + +static void +run_balls (Display *dpy, Window window, int total_ticks) { int last_point_stack_fp = point_stack_fp; static int tick = 500, xlim, ylim; static Colormap cmap; - int i; + + Window root1, child1; /*flip mods for mouse interaction*/ + unsigned int mask; + + int i, radius = global_size/2; + if(global_size == 0) + radius = (MAX_SIZE / 3); + + if(graph_mode != graph_none) + { + if(graph_mode == graph_both) + { + for(i = 0; i < npoints; i++) + { + draw_meter_x(dpy,window,draw_gc, balls, i, 0); + draw_meter_y(dpy,window,draw_gc, balls, i, 0); + } + } + else if(graph_mode == graph_x) + { + for(i = 0; i < npoints; i++) + { + draw_meter_x(dpy,window,draw_gc, balls, i, 1); + } + } + else if(graph_mode == graph_y) + { + for(i = 0; i < npoints; i++) + { + draw_meter_y(dpy,window,draw_gc, balls, i, 1); + } + } + else if(graph_mode == graph_speed) + { + for(i = 0; i < npoints; i++) + { + draw_meter_speed(dpy,window,draw_gc, balls, i); + } + } + + } + + if (mouse_p) + { + XQueryPointer(dpy, window, &root1, &child1, + &root_x, &root_y, &mouse_x, &mouse_y, &mask); + } if (tick++ == 500) { @@ -327,95 +673,142 @@ run_balls (dpy, window) /* move the balls according to the forces now in effect */ for (i = 0; i < npoints; i++) { - float old_x = balls[i].x; - float old_y = balls[i].y; - float new_x, new_y; + double old_x = balls[i].x; + double old_y = balls[i].y; + double new_x, new_y; int size = balls[i].size; balls[i].vx += balls[i].dx; balls[i].vy += balls[i].dy; - /* don't let them get too fast: impose a terminal velocity - (actually, make the medium have friction) */ - if (balls[i].vx > 10) + /* "don't let them get too fast: impose a terminal velocity + (actually, make the medium have friction)" + Well, what this first step really does is give the medium a + viscosity of .9 for balls going over the speed limit. Anyway, + this is now optional + */ + if (balls[i].vx > 10 && maxspeed_p) { balls[i].vx *= 0.9; balls[i].dx = 0; } - if (balls[i].vy > 10) + else if (viscosity != 1) + { + balls[i].vx *= viscosity; + } + + if (balls[i].vy > 10 && maxspeed_p) { balls[i].vy *= 0.9; balls[i].dy = 0; } + else if (viscosity != 1) + { + balls[i].vy *= viscosity; + } balls[i].x += balls[i].vx; balls[i].y += balls[i].vy; - /* bounce off the walls */ - if (balls[i].x >= (xlim - balls[i].size)) - { - balls[i].x = (xlim - balls[i].size - 1); - if (balls[i].vx > 0) - balls[i].vx = -balls[i].vx; - } - if (balls[i].y >= (ylim - balls[i].size)) - { - balls[i].y = (ylim - balls[i].size - 1); - if (balls[i].vy > 0) - balls[i].vy = -balls[i].vy; - } - if (balls[i].x <= 0) - { - balls[i].x = 0; - if (balls[i].vx < 0) - balls[i].vx = -balls[i].vx; - } - if (balls[i].y <= 0) - { - balls[i].y = 0; - if (balls[i].vy < 0) - balls[i].vy = -balls[i].vy; - } + /* bounce off the walls if desired + note: a ball is actually its upper left corner */ + if(walls_p) + { + if(cbounce_p) /* with correct bouncing */ + { + /* so long as it's out of range, keep bouncing */ + + while( (balls[i].x >= (xlim - balls[i].size)) || + (balls[i].y >= (ylim - balls[i].size)) || + (balls[i].x <= 0) || + (balls[i].y <= 0) ) + { + if (balls[i].x >= (xlim - balls[i].size)) + { + balls[i].x = (2*(xlim - balls[i].size) - balls[i].x); + balls[i].vx = -balls[i].vx; + } + if (balls[i].y >= (ylim - balls[i].size)) + { + balls[i].y = (2*(ylim - balls[i].size) - balls[i].y); + balls[i].vy = -balls[i].vy; + } + if (balls[i].x <= 0) + { + balls[i].x = -balls[i].x; + balls[i].vx = -balls[i].vx; + } + if (balls[i].y <= 0) + { + balls[i].y = -balls[i].y; + balls[i].vy = -balls[i].vy; + } + } + } + else /* with old bouncing */ + { + if (balls[i].x >= (xlim - balls[i].size)) + { + balls[i].x = (xlim - balls[i].size - 1); + if (balls[i].vx > 0) /* why is this check here? */ + balls[i].vx = -balls[i].vx; + } + if (balls[i].y >= (ylim - balls[i].size)) + { + balls[i].y = (ylim - balls[i].size - 1); + if (balls[i].vy > 0) + balls[i].vy = -balls[i].vy; + } + if (balls[i].x <= 0) + { + balls[i].x = 0; + if (balls[i].vx < 0) + balls[i].vx = -balls[i].vx; + } + if (balls[i].y <= 0) + { + balls[i].y = 0; + if (balls[i].vy < 0) + balls[i].vy = -balls[i].vy; + } + } + } new_x = balls[i].x; new_y = balls[i].y; - /* make color saturation be related to particle acceleration. */ - if (glow_p) + if (!mono_p) { - float limit = 0.5; - double s, v, fraction; - float vx = balls [i].dx; - float vy = balls [i].dy; - XColor new_color; - if (vx < 0) vx = -vx; - if (vy < 0) vy = -vy; - fraction = vx + vy; - if (fraction > limit) fraction = limit; - - s = 1 - (fraction / limit); - v = 1.0; - - s = (s * 0.75) + 0.25; - - hsv_to_rgb (balls [i].hue, s, v, - &new_color.red, &new_color.green, &new_color.blue); - if (XAllocColor (dpy, cmap, &new_color)) + if (mode == ball_mode) { - XFreeColors (dpy, cmap, &balls [i].color.pixel, 1, 0); - balls [i].color = new_color; + if (glow_p) + { + /* make color saturation be related to particle + acceleration. */ + double limit = 0.5; + double s, fraction; + double vx = balls [i].dx; + double vy = balls [i].dy; + if (vx < 0) vx = -vx; + if (vy < 0) vy = -vy; + fraction = vx + vy; + if (fraction > limit) fraction = limit; + + s = 1 - (fraction / limit); + balls[i].pixel_index = (ncolors * s); + } + XSetForeground (dpy, draw_gc, + colors[balls[i].pixel_index].pixel); } } if (mode == ball_mode) { - if (!mono_p) - XSetForeground (dpy, draw_gc, balls [i].color.pixel); XFillArc (dpy, window, erase_gc, (int) old_x, (int) old_y, size, size, 0, 360*64); XFillArc (dpy, window, draw_gc, (int) new_x, (int) new_y, size, size, 0, 360*64); } - if (mode != ball_mode) + else { point_stack [point_stack_fp].x = new_x; point_stack [point_stack_fp].y = new_y; @@ -435,34 +828,13 @@ run_balls (dpy, window) abort (); if (!mono_p) { - XColor color2; - color2 = balls [0].color; - switch (cmode) + static int tick = 0; + if (tick++ == color_shift) { - case cycle_mode: - cycle_hue (&color2, color_shift); - break; - case random_mode: - color2.red = random () % 65535; - color2.green = random () % 65535; - color2.blue = random () % 65535; - break; - default: - abort (); + tick = 0; + fg_index = (fg_index + 1) % ncolors; + XSetForeground (dpy, draw_gc, colors[fg_index].pixel); } - - if (!XAllocColor (dpy, cmap, &color2)) - { - color2 = balls [0].color; - if (!XAllocColor (dpy, cmap, &balls [0].color)) - abort (); - } - pixel_stack [pixel_stack_fp++] = balls [0].color.pixel; - if (pixel_stack_fp >= pixel_stack_size) - pixel_stack_fp = 0; - XFreeColors (dpy, cmap, pixel_stack + pixel_stack_fp, 1, 0); - balls [0].color = color2; - XSetForeground (dpy, draw_gc, balls [0].color.pixel); } } @@ -488,17 +860,30 @@ run_balls (dpy, window) break; case tail_mode: { - int i; for (i = 0; i < npoints; i++) { int index = point_stack_fp + i; int next_index = (index + (npoints + 1)) % point_stack_size; - XDrawLine (dpy, window, erase_gc, - point_stack [index].x, - point_stack [index].y, - point_stack [next_index].x, - point_stack [next_index].y); - + if(no_erase_yet == 1) + { + if(total_ticks >= segments) + { + no_erase_yet = 0; + XDrawLine (dpy, window, erase_gc, + point_stack [index].x + radius, + point_stack [index].y + radius, + point_stack [next_index].x + radius, + point_stack [next_index].y + radius); + } + } + else + { + XDrawLine (dpy, window, erase_gc, + point_stack [index].x + radius, + point_stack [index].y + radius, + point_stack [next_index].x + radius, + point_stack [next_index].y + radius); + } index = last_point_stack_fp + i; next_index = (index - (npoints + 1)) % point_stack_size; if (next_index < 0) next_index += point_stack_size; @@ -506,17 +891,16 @@ run_balls (dpy, window) point_stack [next_index].y == 0) continue; XDrawLine (dpy, window, draw_gc, - point_stack [index].x, - point_stack [index].y, - point_stack [next_index].x, - point_stack [next_index].y); + point_stack [index].x + radius, + point_stack [index].y + radius, + point_stack [next_index].x + radius, + point_stack [next_index].y + radius); } } break; case spline_mode: case spline_filled_mode: { - int i; static spline *s = 0; if (! s) s = make_spline (npoints); if (segments > 0) @@ -554,55 +938,79 @@ run_balls (dpy, window) abort (); } - XSync (dpy, True); + XSync (dpy, False); } char *progclass = "Attraction"; char *defaults [] = { - "*background: black", - "*foreground: white", + ".background: black", + ".foreground: white", "*mode: balls", + "*graphmode: none", "*points: 0", "*size: 0", + "*colors: 200", "*threshold: 100", "*delay: 10000", "*glow: false", + "*mouseSize: 10", + "*walls: true", + "*maxspeed: true", + "*cbounce: true", + "*mouse: false", + "*viscosity: 1", "*orbit: false", "*colorShift: 3", - "*segments: 100", + "*segments: 500", + "*vMult: 0.9", 0 }; XrmOptionDescRec options [] = { { "-mode", ".mode", XrmoptionSepArg, 0 }, + { "-graphmode", ".graphmode", XrmoptionSepArg, 0 }, + { "-colors", ".colors", XrmoptionSepArg, 0 }, { "-points", ".points", XrmoptionSepArg, 0 }, + { "-color-shift", ".colorShift", XrmoptionSepArg, 0 }, { "-threshold", ".threshold", XrmoptionSepArg, 0 }, { "-segments", ".segments", XrmoptionSepArg, 0 }, { "-delay", ".delay", XrmoptionSepArg, 0 }, { "-size", ".size", XrmoptionSepArg, 0 }, - { "-color-mode", ".colorMode", XrmoptionSepArg, 0 }, - { "-color-shift", ".colorShift", XrmoptionSepArg, 0 }, { "-radius", ".radius", XrmoptionSepArg, 0 }, { "-vx", ".vx", XrmoptionSepArg, 0 }, { "-vy", ".vy", XrmoptionSepArg, 0 }, { "-vmult", ".vMult", XrmoptionSepArg, 0 }, + { "-mouse-size", ".mouseSize", XrmoptionSepArg, 0 }, + { "-viscosity", ".viscosity", XrmoptionSepArg, 0 }, + { "-mouse", ".mouse", XrmoptionNoArg, "true" }, + { "-nomouse", ".mouse", XrmoptionNoArg, "false" }, { "-glow", ".glow", XrmoptionNoArg, "true" }, { "-noglow", ".glow", XrmoptionNoArg, "false" }, - { "-orbit", ".orbit", XrmoptionNoArg, "true" } + { "-orbit", ".orbit", XrmoptionNoArg, "true" }, + { "-nowalls", ".walls", XrmoptionNoArg, "false" }, + { "-walls", ".walls", XrmoptionNoArg, "true" }, + { "-nomaxspeed", ".maxspeed", XrmoptionNoArg, "false" }, + { "-maxspeed", ".maxspeed", XrmoptionNoArg, "true" }, + { "-correct-bounce", ".cbounce", XrmoptionNoArg, "false" }, + { "-fast-bounce", ".cbounce", XrmoptionNoArg, "true" }, + { 0, 0, 0, 0 } }; -int options_size = (sizeof (options) / sizeof (options[0])); void -screenhack (dpy, window) - Display *dpy; - Window window; +screenhack (Display *dpy, Window window) { + /* for tail mode fix */ + int total_ticks = 0; + init_balls (dpy, window); while (1) { - run_balls (dpy, window); - if (delay) usleep (delay); + total_ticks++; + run_balls (dpy, window, total_ticks); + screenhack_handle_events (dpy); + if (delay) + usleep (delay); } }