diff options
Diffstat (limited to 'src/scale.c')
| -rw-r--r-- | src/scale.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/scale.c b/src/scale.c new file mode 100644 index 0000000..03f6b5f --- /dev/null +++ b/src/scale.c @@ -0,0 +1,133 @@ +/* ------------------------- scale ------------------------------------------ */
+/* */
+/* Scales input to lie within an output range. */
+/* Written by Olaf Matthes <olaf.matthes@gmx.de> */
+/* Get source at http://www.akustische-kunst.org/puredata/maxlib/ */
+/* */
+/* This program is free software; you can redistribute it and/or */
+/* modify it under the terms of the GNU General Public License */
+/* as published by the Free Software Foundation; either version 2 */
+/* of the License, or (at your option) any later version. */
+/* */
+/* This program is distributed in the hope that it will be useful, */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
+/* GNU General Public License for more details. */
+/* */
+/* You should have received a copy of the GNU General Public License */
+/* along with this program; if not, write to the Free Software */
+/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+/* */
+/* Based on PureData by Miller Puckette and others. */
+/* */
+/* ---------------------------------------------------------------------------- */
+
+#include "m_pd.h"
+#include <stdio.h>
+#include <math.h>
+
+static char *version = "scale v0.2, written by Olaf Matthes <olaf.matthes@gmx.de>";
+
+typedef struct scale
+{
+ t_object x_ob;
+ t_float x_f; /* current input value */
+ t_float x_il; /* low border of input range */
+ t_float x_ih; /* high border of input range */
+ t_float x_ol; /* low border of output range */
+ t_float x_oh; /* high border of output range */
+ t_float x_logcoeff; /* log-coefficient */
+ t_outlet *x_outlet1; /* result */
+} t_scale;
+
+static void scale_float(t_scale *x, t_floatarg f)
+{
+ t_float ir = x->x_ih - x->x_il;
+ t_float or = x->x_oh - x->x_ol;
+ double oq;
+ double result;
+ double k;
+ if(ir == 0)
+ {
+ post("scale: input range must not be 0");
+ return;
+ }
+ /* we accept an output range of 0 in case someone really wants this */
+ if(!x->x_logcoeff) /* linear */
+ {
+ k = (or / ir);
+ result = ((f - x->x_il) * k) + x->x_ol;
+ }
+ else /* logarythmical scale */
+ {
+ oq = x->x_oh / x->x_ol;
+ // k = (log((double)oq)/log(x->x_logcoeff))/((double)ir);
+ k = log((double)oq)/((double)ir);
+
+ if(x->x_ol)
+ {
+ // result = (double)x->x_ol*exp(k*(double)(f - x->x_il)*log(x->x_logcoeff));
+ result = (double)x->x_ol*exp(k*(double)(f - x->x_il));
+ }
+ else
+ {
+ /* in case the low output is 0 we have to cheat... */
+ /* okay, here's the chating: we calculate for a lower out limit
+ of 1 and remove this shift after the calculation */
+ result = ((double)(x->x_ol+1)*exp(k*(double)(f - x->x_il)))-1.0;
+ }
+ }
+
+ x->x_f = f; /* save current input value */
+
+ outlet_float(x->x_outlet1, result);
+}
+
+static void scale_bang(t_scale *x)
+{
+ scale_float(x, x->x_f); /* recalculate result */
+}
+
+static t_class *scale_class;
+
+static void *scale_new(t_floatarg fil, t_floatarg fih, t_floatarg fol, t_floatarg foh, t_floatarg flc)
+{
+ t_scale *x = (t_scale *)pd_new(scale_class);
+
+ floatinlet_new(&x->x_ob, &x->x_il);
+ floatinlet_new(&x->x_ob, &x->x_ih);
+ floatinlet_new(&x->x_ob, &x->x_ol);
+ floatinlet_new(&x->x_ob, &x->x_oh);
+ floatinlet_new(&x->x_ob, &x->x_logcoeff);
+
+ x->x_outlet1 = outlet_new(&x->x_ob, gensym("float"));
+
+ /* default values taken from Max's scale */
+ x->x_il = fil;
+ x->x_ih = fih;
+ if(!x->x_ih)x->x_ih = 127.0;
+ x->x_ol = fol;
+ x->x_oh = foh;
+ if(!x->x_oh)x->x_oh = 1.0;
+ x->x_logcoeff = flc;
+ x->x_f = 0;
+
+#ifndef MAXLIB
+ post(version);
+#endif
+ return (void *)x;
+}
+
+void scale_setup(void)
+{
+ scale_class = class_new(gensym("scale"), (t_newmethod)scale_new,
+ 0, sizeof(t_scale), 0, A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT, A_DEFFLOAT, 0);
+ class_addfloat(scale_class, scale_float);
+ class_addbang(scale_class, scale_bang);
+#ifndef MAXLIB
+ class_sethelpsymbol(scale_class, gensym("help-scale.pd"));
+#else
+ class_sethelpsymbol(scale_class, gensym("maxlib/help-scale.pd"));
+#endif
+}
+
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