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-rw-r--r--src/iemlib1/sigiem_sqrt4.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/src/iemlib1/sigiem_sqrt4.c b/src/iemlib1/sigiem_sqrt4.c
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+++ b/src/iemlib1/sigiem_sqrt4.c
@@ -0,0 +1,117 @@
+/* For information on usage and redistribution, and for a DISCLAIMER OF ALL
+* WARRANTIES, see the file, "LICENSE.txt," in this distribution.
+
+iemlib1 written by Thomas Musil, Copyright (c) IEM KUG Graz Austria 2000 - 2003 */
+
+#ifdef NT
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+
+
+#include "m_pd.h"
+#include "iemlib.h"
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#define IEMSQRT4TAB1SIZE 256
+#define IEMSQRT4TAB2SIZE 1024
+
+/* ------------------------ iem_sqrt4~ ----------------------------- */
+
+float *iem_sqrt4_exptab=(float *)0L;
+float *iem_sqrt4_mantissatab=(float *)0L;
+
+static t_class *sigiem_sqrt4_class;
+
+typedef struct _sigiem_sqrt4
+{
+ t_object x_obj;
+ float x_msi;
+} t_sigiem_sqrt4;
+
+static t_int *sigiem_sqrt4_perform(t_int *w)
+{
+ t_float *in = (t_float *)(w[1]);
+ t_float *out = (t_float *)(w[2]);
+ t_int n = (t_int)(w[3])/4;
+
+ while(n--)
+ {
+ float f = *in;
+ float g, h;
+ long l = *(long *)(in);
+
+ if(f < 0.0f)
+ {
+ *out++ = 0.0f;
+ *out++ = 0.0f;
+ *out++ = 0.0f;
+ *out++ = 0.0f;
+ }
+ else
+ {
+ g = iem_sqrt4_exptab[(l >> 23) & 0xff] * iem_sqrt4_mantissatab[(l >> 13) & 0x3ff];
+ h = f * (1.5f * g - 0.5f * g * g * g * f);
+ *out++ = h;
+ *out++ = h;
+ *out++ = h;
+ *out++ = h;
+ }
+ in += 4;
+ }
+ return(w+4);
+}
+
+static void sigiem_sqrt4_dsp(t_sigiem_sqrt4 *x, t_signal **sp)
+{
+ dsp_add(sigiem_sqrt4_perform, 3, sp[0]->s_vec, sp[1]->s_vec, sp[0]->s_n);
+}
+
+static void sigiem_sqrt4_maketable(void)
+{
+ int i;
+ float f;
+ long l;
+
+ if(!iem_sqrt4_exptab)
+ {
+ iem_sqrt4_exptab = (float *)getbytes(sizeof(float) * IEMSQRT4TAB1SIZE);
+ for(i=0; i<IEMSQRT4TAB1SIZE; i++)
+ {
+ l = (i ? (i == IEMSQRT4TAB1SIZE-1 ? IEMSQRT4TAB1SIZE-2 : i) : 1)<< 23;
+ *(long *)(&f) = l;
+ iem_sqrt4_exptab[i] = 1.0f/sqrt(f);
+ }
+ }
+ if(!iem_sqrt4_mantissatab)
+ {
+ iem_sqrt4_mantissatab = (float *)getbytes(sizeof(float) * IEMSQRT4TAB2SIZE);
+ for(i=0; i<IEMSQRT4TAB2SIZE; i++)
+ {
+ f = 1.0f + (1.0f/(float)IEMSQRT4TAB2SIZE) * (float)i;
+ iem_sqrt4_mantissatab[i] = 1.0f/sqrt(f);
+ }
+ }
+}
+
+static void *sigiem_sqrt4_new(void)
+{
+ t_sigiem_sqrt4 *x = (t_sigiem_sqrt4 *)pd_new(sigiem_sqrt4_class);
+
+ outlet_new(&x->x_obj, gensym("signal"));
+ x->x_msi = 0;
+ return (x);
+}
+
+void sigiem_sqrt4_setup(void)
+{
+ sigiem_sqrt4_class = class_new(gensym("iem_sqrt4~"), (t_newmethod)sigiem_sqrt4_new, 0,
+ sizeof(t_sigiem_sqrt4), 0, 0);
+ CLASS_MAINSIGNALIN(sigiem_sqrt4_class, t_sigiem_sqrt4, x_msi);
+ class_addmethod(sigiem_sqrt4_class, (t_method)sigiem_sqrt4_dsp, gensym("dsp"), 0);
+ sigiem_sqrt4_maketable();
+ class_sethelpsymbol(sigiem_sqrt4_class, gensym("iemhelp/help-iem_sqrt4~"));
+}
+