commit bd861c4e7af4398ec6472f4855e87cc01e0aea74
from: Sven M. Hallberg <pesco@khjk.org>
date: Mon Oct 23 15:21:31 2023 UTC

add raised inverted cosine (ric) shape

This is the sigmoid function (1 - cos(pi t)) / 2.
Also rename "icos" to "cos" to avoid confusion.

commit - 722fc85f05ae31a6d84079104fb5b93dafa1a243
commit + bd861c4e7af4398ec6472f4855e87cc01e0aea74
blob - 3f21008a02ae9a02df856b627a7a27d51da7faa5
blob + b1a1a579da6402e4aa92a262b573481040e38dc1
--- cw.c
+++ cw.c
@@ -37,7 +37,8 @@ struct shape { const char *name; rampfun_t *fun; } sha
 	{ "lin", ramp_lin },	/* linear ramp */
 	{ "sqr", ramp_sqr },	/* square function (parabola) */
 	{ "sin", ramp_sin },	/* quarter sine wave */
-	{ "icos", ramp_icos },	/* inverted cosine */
+	{ "cos", ramp_cos },	/* quarter cosine wave */
+	{ "ric", ramp_ric },	/* raised inverted cosine (sigmoid half wave) */
 	{ "exp", ramp_exp },	/* exponential ramp */
 	{ NULL, NULL }
 };
@@ -103,12 +104,18 @@ ramp_sin(double k)
 }
 
 double
-ramp_icos(double k)
+ramp_cos(double k)
 {
 	return 1 - cos(M_PI_2 * k);
 }
 
 double
+ramp_ric(double k)
+{
+	return (1 - cos(M_PI * k)) / 2;
+}
+
+double
 ramp_exp(double k)
 {
 	return exp(1 - 1 / k);
blob - a93e9bd903c317a83707d0cdf8113abc5f9409b6
blob + 2d3d791bba1a28abbb2bbd1057c0f377f037a8f0
--- cw.h
+++ cw.h
@@ -3,7 +3,7 @@
 
 /* envelope shapes - ramp functions (0, 1) -> (0, 1) */
 typedef double rampfun_t(double);
-rampfun_t ramp_lin, ramp_sqr, ramp_sin, ramp_icos, ramp_exp;
+rampfun_t ramp_lin, ramp_sqr, ramp_sin, ramp_cos, ramp_ric, ramp_exp;
 
 void cwinit(void);
 void cwstart(void);