From d3a98cf6cbc3bd0b9efc570f58e8812c03931c18 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Tue, 16 Oct 2018 10:08:48 +0200
Subject: Original 5.40

---
 hacks/whirlwindwarp.c | 506 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 506 insertions(+)
 create mode 100644 hacks/whirlwindwarp.c

(limited to 'hacks/whirlwindwarp.c')

diff --git a/hacks/whirlwindwarp.c b/hacks/whirlwindwarp.c
new file mode 100644
index 0000000..3525e49
--- /dev/null
+++ b/hacks/whirlwindwarp.c
@@ -0,0 +1,506 @@
+/* xscreensaver, Copyright (c) 2000 Paul "Joey" Clark <pclark@bris.ac.uk>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or
+ * implied warranty.
+ *
+ * 19971004: Johannes Keukelaar <johannes@nada.kth.se>: Use helix screen
+ *           eraser.
+ */
+
+/* WhirlwindWarp: moving stars.  Ported from QBasic by Joey.
+   Version 1.3.  Smooth with pretty colours.
+
+   This code adapted from original program by jwz/jk above.
+   Freely distrubtable.  Please keep this tag with
+   this code, and add your own if you contribute.
+   I would be delighted to hear if have made use of this code.
+   If you find this code useful or have any queries, please
+   contact me: pclark@cs.bris.ac.uk / joeyclark@usa.net
+   Paul "Joey" Clark, hacking for humanity, Feb 99
+   www.cs.bris.ac.uk/~pclark | www.changetheworld.org.uk */
+
+/* 15/May/05: Added colour rotation, limit on max FPS, scaling size dots, and smoother drivers.
+    4/Mar/01: Star colours are cycled when new colour can not be allocated.
+    4/Mar/01: Stars are plotted as squares with size relative to screen.
+   28/Nov/00: Submitted to xscreensaver as "whirlwindwarp".
+   10/Oct/00: Ported to xscreensaver as "twinkle".
+   19/Feb/98: Meters and interaction added for Ivor's birthday "stars11f".
+   11/Aug/97: Original QBasic program. */
+
+#include <math.h>
+
+#include "screenhack.h"
+#include "erase.h"
+#include "hsv.h"
+
+/* Maximum number of points, maximum tail length, and the number of forcefields/effects (hard-coded) */
+#define maxps 1000
+#define maxts 50
+#define fs 16
+/* TODO: change ps and ts arrays into pointers, for dynamic allocation at runtime. */
+
+struct state {
+  Display *dpy;
+  Window window;
+
+   GC draw_gc, erase_gc;
+   unsigned int default_fg_pixel;
+
+   int scrwid,scrhei;
+   int starsize;
+
+   float cx[maxps];	/* Current x,y of stars in realspace */
+   float cy[maxps];
+   int tx[maxps*maxts];	/* Previous x,y plots in pixelspace for removal later */
+   int ty[maxps*maxts];
+   char *name[fs];	/* The force fields and their parameters */
+
+   int fon[fs];     /* Is field on or off? */
+   float var[fs];   /* Current parameter */
+   float op[fs];    /* Optimum (central/mean) value */
+   float acc[fs];
+   float vel[fs];
+
+   int ps;	/* Number of points and tail length */
+   int ts;
+
+   Bool meters;
+
+   int initted;
+   XWindowAttributes xgwa;
+   int got_color;
+   XColor color[maxps]; /* The colour assigned to each star */
+   XColor bgcolor;
+   int p,f,nt, sx,sy, resets,lastresets,cnt;
+   int colsavailable;
+   int hue;
+
+  struct timeval lastframe;
+};
+
+
+static void *
+whirlwindwarp_init (Display *dpy, Window window)
+{
+  struct state *st = (struct state *) calloc (1, sizeof(*st));
+  XGCValues gcv;
+  Colormap cmap;
+
+  st->dpy = dpy;
+  st->window = window;
+
+  st->ps=500;
+  st->ts=5;
+
+  XGetWindowAttributes (st->dpy, st->window, &st->xgwa);
+  cmap = st->xgwa.colormap;
+  gcv.foreground = st->default_fg_pixel = get_pixel_resource (st->dpy, cmap, "foreground", "Foreground");
+  st->draw_gc = XCreateGC (st->dpy, st->window, GCForeground, &gcv);
+  gcv.foreground = get_pixel_resource (st->dpy, cmap, "background", "Background");
+  st->erase_gc = XCreateGC (st->dpy, st->window, GCForeground, &gcv);
+
+  st->ps = get_integer_resource (st->dpy, "points", "Integer");
+  st->ts = get_integer_resource (st->dpy, "tails", "Integer");
+  st->meters = get_boolean_resource (st->dpy, "meters", "Show meters");
+  if (st->ps > maxps) st->ps = maxps;
+  if (st->ts > maxts) st->ts = maxts;
+
+  return st;
+}
+
+static float myrnd(void)
+{ /* between -1.0 (inclusive) and +1.0 (exclusive) */
+  return 2.0*((float)((random()%10000000)/10000000.0)-0.5);
+}
+
+#if 0
+static float mysgn(float x)
+{
+  return ( x < 0 ? -1 :
+           x > 0 ? +1 :
+                    0 );
+}
+#endif
+
+static void stars_newp(struct state *st, int pp)
+{
+  st->cx[pp]=myrnd();
+  st->cy[pp]=myrnd();
+}
+
+/* Adjust a variable var about optimum op,
+     with damp = dampening about op
+         force = force of random perturbation */
+/* float stars_perturb(float var,float op,float damp,float force) {
+   return op+damp*(var-op)+force*myrnd()/4.0;
+ }*/
+#define stars_perturb(var,op,damp,force) \
+  ( (op) + (damp)*((var)-(op)) + (force)*myrnd()/4.0 )
+
+/* Get pixel coordinates of a star */
+static int stars_scrpos_x(struct state *st, int pp)
+{
+  return st->scrwid*(st->cx[pp]+1.0)/2.0;
+}
+
+static int stars_scrpos_y(struct state *st, int pp)
+{
+  return st->scrhei*(st->cy[pp]+1.0)/2.0;
+}
+
+/* Draw a meter of a forcefield's parameter */
+static void stars_draw_meter(struct state *st, int ff)
+{
+  int x,y,w,h;
+  x=st->scrwid/2;
+  y=ff*10;
+  w=(st->var[ff]-st->op[ff])*st->scrwid*4;
+  h=7;
+  if (w<0) {
+    w=-w;
+    x=x-w;
+  }
+  if (st->fon[ff])
+    XFillRectangle(st->dpy,st->window,st->draw_gc,x,y,w,h);
+  /* else
+     XDrawRectangle(dpy,window,draw_gc,x,y,w,h); */
+}
+
+/* Move a star according to acting forcefields */
+static void stars_move(struct state *st, int pp)
+{
+  float nx,ny;
+  float x=st->cx[pp];
+  float y=st->cy[pp];
+
+  /* In theory all these if checks are unneccessary,
+     since each forcefield effect should do nothing when its var = op.
+     But the if's are good for efficiency because this function
+     is called once for every point.
+
+    Squirge towards edges (makes a leaf shape, previously split the screen in 4 but now only 1 :)
+    These ones must go first, to avoid x+1.0 < 0
+   */
+  if (st->fon[6]) {
+    /* x = mysgn(x) * pow(fabs(x),var[6]);
+       y = mysgn(y) * pow(fabs(y),var[6]);*/
+    x = -1.0 + 2.0*pow((x + 1.0)/2.0,st->var[6]);
+  }
+  if (st->fon[7]) {
+    y = -1.0 + 2.0*pow((y + 1.0)/2.0,st->var[7]);
+  }
+
+  /* Warping in/out */
+  if (st->fon[1]) {
+    x = x * st->var[1]; y = y * st->var[1];
+  }
+
+  /* Rotation */
+  if (st->fon[2]) {
+    nx=x*cos(1.1*st->var[2])+y*sin(1.1*st->var[2]);
+    ny=-x*sin(1.1*st->var[2])+y*cos(1.1*st->var[2]);
+    x=nx;
+    y=ny;
+  }
+
+  /* Asymptotes (looks like a plane with a horizon; equivalent to 1D warp) */
+  if (st->fon[3]) { /* Horizontal asymptote */
+    y=y*st->var[3];
+  }
+  if (st->fon[4]) { /* Vertical asymptote */
+    x=x+st->var[4]*x; /* this is the same maths as the last, but with op=0 */
+  }
+  if (st->fon[5]) { /* Vertical asymptote at right of screen */
+    x=(x-1.0)*st->var[5]+1.0;
+  }
+
+  /* Splitting (whirlwind effect): */
+  #define num_splits ( 2 + (int) (fabs(st->var[0]) * 1000) )
+  /* #define thru ( (float)(pp%num_splits)/(float)(num_splits-1) ) */
+  #define thru ( (float)((int)(num_splits*(float)(pp)/(float)(st->ps)))/(float)(num_splits-1) )
+  if (st->fon[8]) {
+    x=x+0.5*st->var[8]*(-1.0+2.0*thru);
+  }
+  if (st->fon[9]) {
+    y=y+0.5*st->var[9]*(-1.0+2.0*thru);
+  }
+
+  /* Waves */
+  if (st->fon[10]) {
+    y = y + 0.4*st->var[10]*sin(300.0*st->var[12]*x + 600.0*st->var[11]);
+  }
+  if (st->fon[13]) {
+    x = x + 0.4*st->var[13]*sin(300.0*st->var[15]*y + 600.0*st->var[14]);
+  }
+
+  st->cx[pp]=x;
+  st->cy[pp]=y;
+}
+
+/* Turns a forcefield on, and ensures its vars are suitable. */
+static void turn_on_field(struct state *st, int ff)
+{
+  if (!st->fon[ff]) {
+    /* acc[ff]=0.0; */
+    st->acc[ff]=0.02 * myrnd();
+    st->vel[ff]=0.0;
+    st->var[ff]=st->op[ff];
+  }
+  st->fon[ff] = 1;
+  if (ff == 10) {
+    turn_on_field(st, 11);
+    turn_on_field(st, 12);
+  }
+  if (ff == 13) {
+    turn_on_field(st, 14);
+    turn_on_field(st, 15);
+  }
+}
+
+static unsigned long
+whirlwindwarp_draw (Display *dpy, Window window, void *closure)
+{
+  struct state *st = (struct state *) closure;
+
+  /* time_t lastframe = time((time_t) 0); */
+
+  if (!st->initted) {
+    st->initted = 1;
+
+    XClearWindow (st->dpy, st->window);
+    XGetWindowAttributes (st->dpy, st->window, &st->xgwa);
+    st->scrwid = st->xgwa.width;
+    st->scrhei = st->xgwa.height;
+
+    st->starsize=st->scrhei/480;
+    if (st->starsize<=0)
+      st->starsize=1;
+
+    /* Setup colours */
+    hsv_to_rgb (0.0, 0.0, 0.0, &st->bgcolor.red, &st->bgcolor.green, &st->bgcolor.blue);
+    st->got_color = XAllocColor (st->dpy, st->xgwa.colormap, &st->bgcolor);
+    st->colsavailable=0;
+    for (st->p=0;st->p<st->ps;st->p++) {
+      if (!mono_p)
+        hsv_to_rgb (random()%360, .6+.4*myrnd(), .6+.4*myrnd(), &st->color[st->p].red, &st->color[st->p].green, &st->color[st->p].blue);
+      /* hsv_to_rgb (random()%360, 1.0, 1.0, &color[p].red, &color[p].green, &color[p].blue);   for stronger colours! */
+      if ((!mono_p) && (st->got_color = XAllocColor (st->dpy, st->xgwa.colormap, &st->color[st->p]))) {
+        st->colsavailable=st->p;
+      } else {
+        if (st->colsavailable>0) /* assign colours from those already allocated */
+          st->color[st->p]=st->color[ st->p % st->colsavailable ];
+        else
+          st->color[st->p].pixel=st->default_fg_pixel;
+      }
+    }
+
+  /* Set up central (optimal) points for each different forcefield */
+  st->op[1] = 1; st->name[1] = "Warp";
+  st->op[2] = 0; st->name[2] = "Rotation";
+  st->op[3] = 1; st->name[3] = "Horizontal asymptote";
+  st->op[4] = 0; st->name[4] = "Vertical asymptote";
+  st->op[5] = 1; st->name[5] = "Vertical asymptote right";
+  st->op[6] = 1; st->name[6] = "Squirge x";
+  st->op[7] = 1; st->name[7] = "Squirge y";
+  st->op[0] = 0; st->name[0] = "Split number (inactive)";
+  st->op[8] = 0; st->name[8] = "Split velocity x";
+  st->op[9] = 0; st->name[9] = "Split velocity y";
+  st->op[10] = 0; st->name[10] = "Horizontal wave amplitude";
+  st->op[11] = myrnd()*3.141; st->name[11] = "Horizontal wave phase (inactive)";
+  st->op[12] = 0.01; st->name[12] = "Horizontal wave frequency (inactive)";
+  st->op[13] = 0; st->name[13] = "Vertical wave amplitude";
+  st->op[14] = myrnd()*3.141; st->name[14] = "Vertical wave phase (inactive)";
+  st->op[15] = 0.01; st->name[15] = "Vertical wave frequency (inactive)";
+
+  /* Initialise parameters to optimum, all off */
+  for (st->f=0;st->f<fs;st->f++) {
+    st->var[st->f]=st->op[st->f];
+    st->fon[st->f]=( myrnd()>0.5 ? 1 : 0 );
+    st->acc[st->f]=0.02 * myrnd();
+    st->vel[st->f]=0;
+  }
+
+  /* Initialise stars */
+  for (st->p=0;st->p<st->ps;st->p++)
+    stars_newp(st, st->p);
+
+  /* tx[nt],ty[nt] remember earlier screen plots (tails of stars)
+     which are deleted when nt comes round again */
+  st->nt = 0;
+  st->resets = 0;
+
+  st->hue = 180 + 180*myrnd();
+
+  gettimeofday(&st->lastframe, NULL);
+
+  }
+
+
+    if (myrnd()>0.75) {
+      /* Change one of the allocated colours to something near the current hue. */
+      /* By changing a random colour, we sometimes get a tight colour spread, sometime a diverse one. */
+      int pp = st->colsavailable * (0.5+myrnd()/2);
+      hsv_to_rgb (st->hue, .6+.4*myrnd(), .6+.4*myrnd(), &st->color[pp].red, &st->color[pp].green, &st->color[pp].blue);
+      if ((!mono_p) && (st->got_color = XAllocColor (st->dpy, st->xgwa.colormap, &st->color[pp]))) {
+      }
+      st->hue = st->hue + 0.5 + myrnd()*9.0;
+      if (st->hue<0) st->hue+=360;
+      if (st->hue>=360) st->hue-=360;
+    }
+
+      /* Move current points */
+      st->lastresets=st->resets;
+      st->resets=0;
+      for (st->p=0;st->p<st->ps;st->p++) {
+        /* Erase old */
+        XSetForeground (st->dpy, st->draw_gc, st->bgcolor.pixel);
+        /* XDrawPoint(dpy,window,draw_gc,tx[nt],ty[nt]); */
+        XFillRectangle(st->dpy,st->window,st->draw_gc,st->tx[st->nt],st->ty[st->nt],st->starsize,st->starsize);
+
+        /* Move */
+        stars_move(st, st->p);
+        /* If moved off screen, create a new one */
+        if (st->cx[st->p]<=-0.9999 || st->cx[st->p]>=+0.9999 ||
+            st->cy[st->p]<=-0.9999 || st->cy[st->p]>=+0.9999 ||
+            fabs(st->cx[st->p])<.0001 || fabs(st->cy[st->p])<.0001) {
+          stars_newp(st, st->p);
+          st->resets++;
+        } else if (myrnd()>0.99) /* Reset at random */
+          stars_newp(st, st->p);
+
+        /* Draw point */
+        st->sx=stars_scrpos_x(st, st->p);
+        st->sy=stars_scrpos_y(st, st->p);
+        XSetForeground (st->dpy, st->draw_gc, st->color[st->p].pixel);
+        /* XDrawPoint(dpy,window,draw_gc,sx,sy); */
+        XFillRectangle(st->dpy,st->window,st->draw_gc,st->sx,st->sy,st->starsize,st->starsize);
+
+        /* Remember it for removal later */
+        st->tx[st->nt]=st->sx;
+        st->ty[st->nt]=st->sy;
+        st->nt=(st->nt+1)%(st->ps*st->ts);
+      }
+
+      /* Adjust force fields */
+      st->cnt=0;
+      for (st->f=0;st->f<fs;st->f++) {
+
+        if (st->meters) { /* Remove meter from display */
+          XSetForeground(st->dpy, st->draw_gc, st->bgcolor.pixel);
+          stars_draw_meter(st,st->f);
+        }
+
+        /* Adjust forcefield's parameter */
+        if (st->fon[st->f]) {
+          /* This configuration produces var[f]s usually below 0.01 */
+          st->acc[st->f]=stars_perturb(st->acc[st->f],0,0.98,0.005);
+          st->vel[st->f]=stars_perturb(st->vel[st->f]+0.03*st->acc[st->f],0,0.995,0.0);
+          st->var[st->f]=st->op[st->f]+(st->var[st->f]-st->op[st->f])*0.9995+0.001*st->vel[st->f];
+        }
+        /* fprintf(stderr,"f=%i fon=%i acc=%f vel=%f var=%f\n",f,fon[f],acc[f],vel[f],var[f]); */
+
+        /* Decide whether to turn this forcefield on or off. */
+        /* prob_on makes the "splitting" effects less likely than the rest */
+        #define prob_on ( st->f==8 || st->f==9 ? 0.999975 : 0.9999 )
+        if ( st->fon[st->f]==0 && myrnd()>prob_on ) {
+          turn_on_field(st, st->f);
+        } else if ( st->fon[st->f]!=0 && myrnd()>0.99 && fabs(st->var[st->f]-st->op[st->f])<0.0005 && fabs(st->vel[st->f])<0.005 /* && fabs(acc[f])<0.01 */ ) {
+          /* We only turn it off if it has gently returned to its optimal (as opposed to rapidly passing through it). */
+          st->fon[st->f] = 0;
+        }
+
+        if (st->meters) { /* Redraw the meter */
+          XSetForeground(st->dpy, st->draw_gc, st->color[st->f].pixel);
+          stars_draw_meter(st,st->f);
+        }
+
+        if (st->fon[st->f])
+          st->cnt++;
+      }
+
+      /* Ensure at least three forcefields are on.
+       * BUG: Picking randomly might not be enough since 0,11,12,14 and 15 do nothing!
+       * But then what's wrong with a rare gentle twinkle?!
+      */
+      if (st->cnt<3) {
+        st->f=random() % fs;
+        turn_on_field(st, st->f);
+      }
+
+      if (st->meters) {
+        XSetForeground(st->dpy, st->draw_gc, st->bgcolor.pixel);
+        XDrawRectangle(st->dpy,st->window,st->draw_gc,0,0,st->lastresets*5,3);
+        XSetForeground(st->dpy, st->draw_gc, st->default_fg_pixel);
+        XDrawRectangle(st->dpy,st->window,st->draw_gc,0,0,st->resets*5,3);
+      }
+
+      /* Cap frames per second; do not go above specified fps: */
+      {
+        unsigned long this_delay = 0;
+        int maxfps = 200;
+        long utimeperframe = 1000000/maxfps;
+        struct timeval now;
+        long timediff;
+        gettimeofday(&now, NULL);
+        /* timediff = now.tv_sec*1000000 + now.tv_usec - st->lastframe.tv_sec*1000000 - st->lastframe.tv_usec; */
+        timediff = (now.tv_sec - st->lastframe.tv_sec) * 1000000 + now.tv_usec - st->lastframe.tv_usec;
+        if (timediff < utimeperframe) {
+          /* fprintf(stderr,"sleeping for %i\n",utimeperframe-timediff); */
+          this_delay = (utimeperframe-timediff);
+        }
+        st->lastframe = now;
+
+        return this_delay;
+      }
+}
+
+
+static void
+whirlwindwarp_reshape (Display *dpy, Window window, void *closure, 
+                 unsigned int w, unsigned int h)
+{
+  struct state *st = (struct state *) closure;
+  st->scrwid = w;
+  st->scrhei = h;
+}
+
+static Bool
+whirlwindwarp_event (Display *dpy, Window window, void *closure, XEvent *event)
+{
+  return False;
+}
+
+static void
+whirlwindwarp_free (Display *dpy, Window window, void *closure)
+{
+  struct state *st = (struct state *) closure;
+  free (st);
+}
+
+
+static const char *whirlwindwarp_defaults [] = {
+  ".background:	black",
+  ".foreground:	white",
+  "*fpsSolid:	true",
+  "*points:	400",
+  "*tails:	8",
+  "*meters:	false",
+#ifdef HAVE_MOBILE
+  "*ignoreRotation: True",
+#endif
+  0
+};
+
+static XrmOptionDescRec whirlwindwarp_options [] = {
+  { "-points",	".points",	XrmoptionSepArg, 0 },
+  { "-tails",	".tails",	XrmoptionSepArg, 0 },
+  { "-meters",	".meters",	XrmoptionNoArg, "true" },
+  { 0, 0, 0, 0 }
+};
+
+XSCREENSAVER_MODULE ("WhirlWindWarp", whirlwindwarp)
-- 
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