diff options
Diffstat (limited to 'source/harmgen~.c')
| -rw-r--r-- | source/harmgen~.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/source/harmgen~.c b/source/harmgen~.c new file mode 100644 index 0000000..2ab4851 --- /dev/null +++ b/source/harmgen~.c @@ -0,0 +1,161 @@ +/* sIgpAck
+ * for
+ * pure-data
+ * www.weiss-archiv.de */
+
+#include "m_pd.h"
+#include <math.h>
+#ifdef _MSC_VER
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+#define HARMONICS 11
+
+// ------------------------ sp.harmgen~ -----------------------------
+// harmonic generator
+// code from swh_plugins by steve harris www.plugins.org.uk
+
+static t_class *harmgen_tilde_class;
+
+typedef struct _harmgen_tilde
+{
+ t_object x_obj;
+ t_sample x_mag1;
+ t_sample x_mag2;
+ t_sample x_mag3;
+ t_sample x_mag4;
+ t_sample x_mag5;
+ t_sample x_mag6;
+ t_sample x_mag7;
+ t_sample x_mag8;
+ t_sample x_mag9;
+ t_sample x_mag10;
+ float x_itm;
+ float x_otm;
+ float x_f;
+} t_harmgen_tilde;
+
+static void *harmgen_tilde_new(t_floatarg mag1, t_floatarg mag2, t_floatarg mag3, t_floatarg mag4, t_floatarg mag5, t_floatarg mag6, t_floatarg mag7, t_floatarg mag8, t_floatarg mag9, t_floatarg mag10)
+{
+ t_harmgen_tilde *x = (t_harmgen_tilde *)pd_new(harmgen_tilde_class);
+ outlet_new(&x->x_obj, gensym("signal"));
+ floatinlet_new(&x->x_obj, &x->x_mag1);
+ floatinlet_new(&x->x_obj, &x->x_mag2);
+ floatinlet_new(&x->x_obj, &x->x_mag3);
+ floatinlet_new(&x->x_obj, &x->x_mag4);
+ floatinlet_new(&x->x_obj, &x->x_mag5);
+ floatinlet_new(&x->x_obj, &x->x_mag6);
+ floatinlet_new(&x->x_obj, &x->x_mag7);
+ floatinlet_new(&x->x_obj, &x->x_mag8);
+ floatinlet_new(&x->x_obj, &x->x_mag9);
+ floatinlet_new(&x->x_obj, &x->x_mag10);
+ x->x_f = 0;
+ if(mag1) x->x_mag1 = mag1;
+ else x->x_mag1 = 1;
+ if(mag2) x->x_mag2 = mag2;
+ else x->x_mag2 = 1;
+ if(mag3) x->x_mag3 = mag3;
+ else x->x_mag3 = 1;
+ if(mag4) x->x_mag4 = mag4;
+ else x->x_mag4 = 1;
+ if(mag5) x->x_mag5 = mag5;
+ else x->x_mag5 = 1;
+ if(mag6) x->x_mag6 = mag6;
+ else x->x_mag6 = 1;
+ if(mag7) x->x_mag7 = mag7;
+ else x->x_mag7 = 1;
+ if(mag8) x->x_mag8 = mag8;
+ else x->x_mag8 = 1;
+ if(mag9) x->x_mag9 = mag9;
+ else x->x_mag9 = 1;
+ if(mag10) x->x_mag10 = mag10;
+ else x->x_mag10 = 1;
+ return (x);
+}
+
+/* Calculate Chebychev coefficents from partial magnitudes, adapted from
+ * example in Num. Rec. */
+void chebpc(float c[], float d[])
+{
+ int k, j;
+ float sv, dd[HARMONICS];
+
+ for (j = 0; j < HARMONICS; j++) {
+ d[j] = dd[j] = 0.0;
+ }
+
+ d[0] = c[HARMONICS - 1];
+
+ for (j = HARMONICS - 2; j >= 1; j--) {
+ for (k = HARMONICS - j; k >= 1; k--) {
+ sv = d[k];
+ d[k] = 2.0 * d[k - 1] - dd[k];
+ dd[k] = sv;
+ }
+ sv = d[0];
+ d[0] = -dd[0] + c[j];
+ dd[0] = sv;
+ }
+
+ for (j = HARMONICS - 1; j >= 1; j--) {
+ d[j] = d[j - 1] - dd[j];
+ }
+ d[0] = -dd[0] + 0.5 * c[0];
+}
+
+static t_int *harmgen_tilde_perform(t_int *w)
+{
+ t_harmgen_tilde *x = (t_harmgen_tilde *)(w[1]);
+ t_float *in1 = (t_float *)(w[2]);
+ t_float *out = (t_float *)(w[3]);
+ int n = (int)(w[4]);
+ unsigned long i;
+ float mag_fix, y, f, value;
+ float mag[HARMONICS] = {0.0f, x->x_mag1, x->x_mag2, x->x_mag3, x->x_mag4, x->x_mag5, x->x_mag6,
+ x->x_mag7, x->x_mag8, x->x_mag9, x->x_mag10};
+ float p[HARMONICS];
+
+ // Normalise magnitudes
+ mag_fix = (fabs(x->x_mag1) + fabs(x->x_mag2) + fabs(x->x_mag3) + fabs(x->x_mag4) +
+ fabs(x->x_mag5) + fabs(x->x_mag6) + fabs(x->x_mag7) + fabs(x->x_mag8) +
+ fabs(x->x_mag9) + fabs(x->x_mag10));
+ if (mag_fix < 1.0f) {
+ mag_fix = 1.0f;
+ } else {
+ mag_fix = 1.0f / mag_fix;
+ }
+ for (i=0; i<HARMONICS; i++) {
+ mag[i] *= mag_fix;
+ }
+
+ // Calculate polynomial coefficients, using Chebychev aproximation
+ chebpc(mag, p);
+ while (n--)
+ {
+ f = *in1++;
+
+ // Calculate the polynomial using Horner's Rule
+ y = p[0] + (p[1] + (p[2] + (p[3] + (p[4] + (p[5] + (p[6] + (p[7] +
+ (p[8] + (p[9] + p[10] * f) * f) * f) * f) * f) * f) * f) * f) *
+ f) * f;
+
+ // DC offset remove (odd harmonics cause DC offset)
+ x->x_otm = 0.999f * x->x_otm + y - x->x_itm;
+ x->x_itm = y;
+ *out++ = x->x_otm;
+ }
+ return (w+5);
+}
+
+static void harmgen_tilde_dsp(t_harmgen_tilde *x, t_signal **sp)
+{
+ dsp_add(harmgen_tilde_perform, 4, x, sp[0]->s_vec, sp[1]->s_vec, sp[0]->s_n);
+}
+
+void harmgen_tilde_setup(void)
+{
+ harmgen_tilde_class = class_new(gensym("sp.harmgen~"), (t_newmethod)harmgen_tilde_new, 0,
+ sizeof(t_harmgen_tilde), 0, A_GIMME, 0);
+ CLASS_MAINSIGNALIN(harmgen_tilde_class, t_harmgen_tilde, x_f);
+ class_addmethod(harmgen_tilde_class, (t_method)harmgen_tilde_dsp, gensym("dsp"), 0);
+}
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