From da1f0065d07250b86b9a761b012987e4825f491f Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <eighthave@users.sourceforge.net>
Date: Mon, 28 Nov 2005 16:53:25 +0000
Subject: This commit was generated by cvs2svn to compensate for changes in
 r4068, which included commits to RCS files with non-trunk default branches.

svn path=/trunk/externals/smlib/; revision=4069
---
 source/deltas.c | 181 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 source/deltas.c

(limited to 'source/deltas.c')

diff --git a/source/deltas.c b/source/deltas.c
new file mode 100644
index 0000000..edc3cb0
--- /dev/null
+++ b/source/deltas.c
@@ -0,0 +1,181 @@
+#include "defines.h"
+
+/*--------------- deltas ---------------*/
+
+static t_class *deltas_class;
+
+typedef struct _deltas
+{
+    t_object x_obj;
+	float m_lo;
+	float m_hi;
+	int m_buffer_size;
+	int m_buffer_index;
+	float *m_buffer;  // circular buffer
+} t_deltas;
+
+
+static void deltas_perform_float(t_deltas *x, t_float f)
+{
+	int index;
+	index=x->m_buffer_index+1;
+	index=(index==x->m_buffer_size)?0:index;
+	x->m_buffer_index=index;
+	x->m_buffer[index]=f;
+}
+
+static void deltas_bang(t_deltas *x)
+{
+	int lo,hi,n,index,size;
+	t_atom *ap,*app;
+	float last;
+	float *buffer, *bp;
+
+	lo=(int)x->m_lo;
+	hi=(int)x->m_hi;
+
+	n=hi-lo;
+	size=x->m_buffer_size;
+	index=x->m_buffer_index;
+    ap = (t_atom *)getbytes(sizeof(t_atom)*n);
+	app=ap;
+	buffer=x->m_buffer;
+	last=buffer[index];
+	bp=buffer+index-lo;
+	bp=(bp>=buffer)?bp:bp+size; // wrap
+	
+	if (bp-buffer>=n)
+	{ // no wrap-around needed
+		index=n;
+		while(index--){
+		  SETFLOAT(app, last-*bp--);
+		  app++;
+		}
+//		post("not wrapped, app-ap=%i",app-ap);
+	}
+	else // need to wrap
+	{
+		int ps, nn;
+		ps = bp-buffer;
+		nn=n;
+//		post("        nn=%i",nn);
+		for(;ps>=0;ps--)  // don't we miss one sample in signal??? 
+		{
+//			post("ps=%i",ps);
+ 			SETFLOAT(app, last-buffer[ps]);
+			app++;
+			nn--;
+		}
+		ps=size-1;
+//		post("       nn=%i",nn);
+		for(;nn>0;nn--)
+		{
+//			post("ps=%i",ps);
+ 			SETFLOAT(app, last-buffer[ps--]);
+			app++;
+		}
+
+/*
+		int i2;
+		index=bp-buffer;
+		i2=index;
+		post("first part %i",index);
+		while(index--){
+		  SETFLOAT(app, last-*bp--);
+		  app++;
+		}
+		index=n-i2;
+		post("2nd part %i",index);
+		bp=buffer+size-1;
+		while(index--){
+		  SETFLOAT(app, last-*bp--);
+		  app++;
+		}
+*/
+//		post("wrapped, app-ap=%i",app-ap);
+	}
+
+	outlet_list(x->x_obj.ob_outlet,gensym("list"),n,ap);
+	freebytes(ap, sizeof(t_atom)*n);
+}
+
+static void deltas_clear(t_deltas *x)
+{
+	int i,s;
+	float *f;
+	f=x->m_buffer;
+	s=x->m_buffer_size;
+	for (i=0;i<s;i++)
+		*f++=0.0f;
+}
+
+static void deltas_set(t_deltas *x, t_float lo, t_float hi, t_float size)
+{
+	if (size<1)
+	{
+		size=1;
+		post("deltas: size is minimum 1...");
+	}
+	if (hi>size)
+	{
+		post("deltas: higher bound cannot be higher than the buffer size...");	
+		hi=size;
+	}
+	if (lo<0)
+	{
+		post("deltas: lower bound cannot be negative...");	
+		lo=0;
+	}
+	if (hi<1)
+	{
+		post("deltas: higher bound cannot be smaller than one...");	
+		hi=1;
+	}
+	if (hi<=lo)
+	{
+		post("deltas: higher bound must be higher than lower bound...");	
+		lo=hi-1.0f;
+	}
+
+	freebytes(x->m_buffer, x->m_buffer_size);
+
+	x->m_hi=(float)((int)hi);
+	x->m_lo=(float)((int)lo);
+	x->m_buffer_size=(int)size;
+    x->m_buffer = (float*)getbytes(sizeof(float)*x->m_buffer_size);
+	deltas_clear(x);
+	x->m_buffer_index=0;
+}
+
+static void *deltas_new(t_float lo, t_float hi, t_float size)
+{
+	t_deltas *x=(t_deltas *)pd_new(deltas_class);
+	outlet_new(&x->x_obj, gensym("list"));
+	x->m_buffer_size=0;
+	x->m_buffer=0;
+	deltas_set(x, lo, hi, size);
+
+    floatinlet_new(&x->x_obj, &x->m_lo);
+    floatinlet_new(&x->x_obj, &x->m_hi);
+
+	return (void *)x;
+}
+
+static void deltas_free(t_deltas *x)
+{
+	freebytes(x->m_buffer, x->m_buffer_size);
+}
+
+void deltas_setup(void)
+{
+    deltas_class = class_new(gensym("deltas"),
+    	(t_newmethod)deltas_new, (t_method)deltas_free,
+		sizeof(t_deltas), 
+		CLASS_DEFAULT,
+	    A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT,0);
+
+	class_addmethod(deltas_class, (t_method)deltas_clear, gensym("clear"),0);
+    class_addfloat(deltas_class, (t_method)deltas_perform_float);
+    class_addbang(deltas_class, (t_method)deltas_bang);
+}
+
-- 
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