libs/sig: add sig_ops_clamp

Supply three sig_t *'s: value, min, max

3 files changed, 69 insertions, 1 deletions

diff --git a/src/libs/sig/Makefile.am b/src/libs/sig/Makefile.am
index de96772..ce99edc 100644
--- a/src/libs/sig/Makefile.am
+++ b/src/libs/sig/Makefile.am
@@ -1,3 +1,3 @@
 noinst_LIBRARIES = libsig.a
-libsig_a_SOURCES = ops_abs.c ops_ceil.c ops_const.c ops_floor.c ops_lerp.c ops_mult.c ops_pow.c ops_rand.c ops_round.c ops_sin.c sig.c sig.h
+libsig_a_SOURCES = ops_abs.c ops_ceil.c ops_clamp.c ops_const.c ops_floor.c ops_lerp.c ops_mult.c ops_pow.c ops_rand.c ops_round.c ops_sin.c sig.c sig.h
 libsig_a_CPPFLAGS = -I@top_srcdir@/src
diff --git a/src/libs/sig/ops_clamp.c b/src/libs/sig/ops_clamp.c
new file mode 100644
index 0000000..0afcf0c
--- /dev/null
+++ b/src/libs/sig/ops_clamp.c
@@ -0,0 +1,67 @@
+#include <assert.h>
+
+#include "sig.h"
+
+
+typedef struct ops_clamp_ctxt_t {
+	sig_t	*value, *min, *max;
+} ops_clamp_ctxt_t;
+
+
+static size_t ops_clamp_size(va_list ap)
+{
+	return sizeof(ops_clamp_ctxt_t);
+}
+
+
+static void ops_clamp_init(void *context, va_list ap)
+{
+	ops_clamp_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	ctxt->value = va_arg(ap, sig_t *);
+	ctxt->min = va_arg(ap, sig_t *);
+	ctxt->max = va_arg(ap, sig_t *);
+}
+
+
+static void ops_clamp_destroy(void *context)
+{
+	ops_clamp_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	sig_free(ctxt->value);
+	sig_free(ctxt->min);
+	sig_free(ctxt->max);
+}
+
+
+static float ops_clamp_output(void *context, unsigned ticks_ms)
+{
+	ops_clamp_ctxt_t	*ctxt = context;
+	float			value, min, max;
+
+	assert(ctxt);
+
+	value = sig_output(ctxt->value, ticks_ms);
+	min = sig_output(ctxt->min, ticks_ms);
+	max = sig_output(ctxt->max, ticks_ms);
+
+	if (value < min)
+		return min;
+
+	if (value > max)
+		return max;
+
+	return value;
+}
+
+
+sig_ops_t	sig_ops_clamp = {
+	.size = ops_clamp_size,
+	.init = ops_clamp_init,
+	.destroy = ops_clamp_destroy,
+	.output = ops_clamp_output,
+};
diff --git a/src/libs/sig/sig.h b/src/libs/sig/sig.h
index 1de4854..194bdcf 100644
--- a/src/libs/sig/sig.h
+++ b/src/libs/sig/sig.h
@@ -29,6 +29,7 @@ extern sig_ops_t	sig_ops_sqr;
 
 extern sig_ops_t	sig_ops_abs;
 extern sig_ops_t	sig_ops_ceil;
+extern sig_ops_t	sig_ops_clamp;
 extern sig_ops_t	sig_ops_floor;
 extern sig_ops_t	sig_ops_lerp;
 extern sig_ops_t	sig_ops_mult;