From d2eec74a4d8c21aad495ba61539486b24d7ab8dc Mon Sep 17 00:00:00 2001
From: Guenter  Geiger <ggeiger@users.sourceforge.net>
Date: Wed, 9 Oct 2002 10:19:04 +0000
Subject: moved from zexy/zexy to zexy

svn path=/trunk/externals/zexy/; revision=169
---
 src/z_random.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 src/z_random.c

(limited to 'src/z_random.c')

diff --git a/src/z_random.c b/src/z_random.c
new file mode 100644
index 0000000..9a4bb9e
--- /dev/null
+++ b/src/z_random.c
@@ -0,0 +1,143 @@
+
+/* 1008:forum::für::umläute:2001 */
+
+/*
+  urn :  "generate random numbers without duplicates"
+  very max-like
+*/
+
+#include "zexy.h"
+
+/* ------------------------- urn ------------------------------- */
+
+static t_class *urn_class;
+
+typedef struct _urn
+{
+  t_object x_obj;
+  unsigned int x_seed;       /* the seed of the generator */
+
+  unsigned int x_range;      /* max. random-number + 1 */
+  unsigned int x_count;      /* how many random numbers have we generated ? */
+  char  *x_state;            /* has this number been generated already ? */
+
+  t_outlet *x_floatout, *x_bangout;
+  char x_noauto;
+} t_urn;
+
+static int makeseed(void)
+{
+  static unsigned int random_nextseed = 1489853723;
+  random_nextseed = random_nextseed * 435898247 + 938284287;
+  return (random_nextseed & 0x7fffffff);
+}
+
+static void makestate(t_urn *x, unsigned int newrange)
+{
+  if (x->x_range == newrange)return;
+
+  if (x->x_range && x->x_state) {
+    freebytes(x->x_state, sizeof(char)*x->x_range);
+    x->x_state=0;
+  }
+
+  x->x_range=newrange;
+  x->x_state=getbytes(sizeof(char)*x->x_range);
+}
+
+static void urn_clear(t_urn *x)
+{
+  unsigned int i=x->x_range;
+  char *dummy=x->x_state;
+  if (!dummy || !i)return;
+  while(i--)*dummy++=0;
+  x->x_count=0;
+}
+static void urn_bang(t_urn *x)
+{
+  int range = (x->x_range<1?1:x->x_range);
+  unsigned int randval = x->x_seed;
+
+  int nval, used=1;
+
+  if (x->x_count>=range){
+    outlet_bang(x->x_bangout);
+    if (x->x_noauto)return;
+    urn_clear(x);
+  }
+
+  while (used) {
+    randval = randval * 472940017 + 832416023;
+    nval = ((double)range) * ((double)randval)
+    	* (1./4294967296.);
+    if (nval >= range) nval = range-1;
+    used=x->x_state[nval];
+  }
+
+  x->x_count++;
+  x->x_state[nval]=1;
+  x->x_seed = randval;
+  outlet_float(x->x_floatout, nval);
+}
+
+static void urn_flt2(t_urn *x, t_float f)
+{
+  unsigned int range = (f<1)?1:f;
+  makestate(x, range);
+  urn_clear(x);
+}
+
+
+static void urn_seed(t_urn *x, t_float f)
+{
+  x->x_seed = f;
+}
+
+static void *urn_new(t_symbol *s, int argc, t_atom *argv)
+{
+  t_urn *x = (t_urn *)pd_new(urn_class);
+
+  t_float f=0.;
+
+  inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym(""));
+  x->x_floatout=outlet_new(&x->x_obj, &s_float);
+  x->x_bangout =outlet_new(&x->x_obj, &s_bang);
+
+  x->x_seed = makeseed();
+  x->x_noauto = 0;
+
+  while(argc--){
+    if (argv->a_type==A_SYMBOL) {
+      if (atom_getsymbol(argv)==gensym("no_auto")) {
+	x->x_noauto=1;
+      }
+    } else f = atom_getfloat(argv);
+    argv++;
+  }
+
+  if (f<1.0)f=1.0;
+  makestate(x, f);
+  x->x_range = f;
+  urn_clear(x);
+
+  return (x);
+}
+
+static void urn_setup(void)
+{
+  urn_class = class_new(gensym("urn"), (t_newmethod)urn_new, 
+			      0, sizeof(t_urn), 0, A_GIMME,  0);
+  
+  class_addbang (urn_class, urn_bang);
+  class_addmethod(urn_class, (t_method)urn_clear, gensym("clear"), 0);
+  class_addmethod(urn_class, (t_method)urn_flt2, gensym(""), A_DEFFLOAT, 0);
+  class_addmethod(urn_class, (t_method)urn_seed, gensym("seed"), A_DEFFLOAT, 0);
+  
+
+  class_sethelpsymbol(urn_class, gensym("zexy/urn"));
+}
+
+void z_random_setup(void)
+{
+  urn_setup();
+}
-- 
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