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_down.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 src/z_down.c

(limited to 'src/z_down.c')

diff --git a/src/z_down.c b/src/z_down.c
new file mode 100644
index 0000000..9673385
--- /dev/null
+++ b/src/z_down.c
@@ -0,0 +1,121 @@
+#include <stdio.h>
+
+#include "zexy.h"
+
+#ifdef NT
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+
+/* down~ : down-code for a signal-object */
+
+/* ------------------------ down~ ----------------------------- */
+
+static t_class *down_class;
+
+typedef struct _down
+{
+  t_object x_obj;
+
+  t_int old_n;
+  t_int new_n;
+
+  t_int factor;
+  t_int wantedfactor;
+
+  t_float *buffer;
+} t_down;
+
+static t_int *down_perform_inplace(t_int *w)
+{
+  t_float *in = (t_float *)(w[1]);
+  t_float *out = (t_float *)(w[2]);
+  t_down *x = (t_down *) w[3];
+
+
+  t_int factor = x->factor;
+  int n = x->new_n;
+  t_float *buf = x->buffer;
+
+  while(n--) {
+    *buf++=*in;
+    in+=factor;
+  }
+
+  buf = x->buffer;
+  n=x->new_n;
+
+  while(n--){
+    *out++=*buf++;
+  }
+
+  return (w+4);
+}
+static t_int *down_perform(t_int *w)
+{
+  t_float *in = (t_float *)(w[1]);
+  t_float *out = (t_float *)(w[2]);
+  t_down *x = (t_down *) w[3];
+
+  t_int factor = x->factor;
+  int n = x->new_n;
+
+  while(n--) {
+    *out++=*in;
+    in+=factor;
+  }
+
+  return (w+4);
+}
+
+static void down_dsp(t_down *x, t_signal **sp)
+{
+  t_float f = sp[0]->s_n/(t_float)x->wantedfactor;
+
+  if (f != (int)f) { 
+    int faktor = x->wantedfactor;
+    while ((f = sp[0]->s_n/(t_float)faktor) != (int)f) faktor--;
+
+    error("bad downsampling factor %d, setting to %d", x->wantedfactor, faktor);
+    x->factor = faktor;
+  } else x->factor=x->wantedfactor;
+
+
+  freebytes(x->buffer, sizeof(t_float)*x->new_n);
+
+  x->old_n=sp[0]->s_n;
+  x->new_n=sp[0]->s_n/x->factor;
+
+  sp[0]->s_n=x->new_n;
+
+  x->buffer = getbytes (sizeof(t_float)*x->new_n);
+
+  if (sp[0]->s_vec!=sp[1]->s_vec)dsp_add(down_perform, 3, sp[0]->s_vec, sp[1]->s_vec, x);
+  else dsp_add(down_perform_inplace, 3, sp[0]->s_vec, sp[1]->s_vec, x);
+}
+
+static void *down_new(t_floatarg f)
+{
+  t_down *x = (t_down *)pd_new(down_class);
+  outlet_new(&x->x_obj, gensym("signal"));
+
+  x->wantedfactor=f;
+  if (x->wantedfactor<1)x->wantedfactor=1;
+
+  return (x);
+}
+static void down_setup(void)
+{
+  down_class = class_new(gensym("down~"), (t_newmethod)down_new, 0,
+			     sizeof(t_down), 0, A_DEFFLOAT, 0);
+  class_addmethod(down_class, nullfn, gensym("signal"), 0);
+  class_addmethod(down_class, (t_method)down_dsp, gensym("dsp"), 0);
+  
+  class_sethelpsymbol(down_class, gensym("zexy/down~"));
+}
+
+void z_down_setup(void)
+{
+  down_setup();
+}
+
-- 
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