libs/sig: add sig_ops_{max,min}

Supply two sig_t *'s: a, b

1 files changed, 62 insertions, 0 deletions

diff --git a/src/libs/sig/ops_min.c b/src/libs/sig/ops_min.c
new file mode 100644
index 0000000..bda80d9
--- /dev/null
+++ b/src/libs/sig/ops_min.c
@@ -0,0 +1,62 @@
+#include <assert.h>
+
+#include "sig.h"
+
+
+typedef struct ops_min_ctxt_t {
+	sig_t	*a, *b;
+} ops_min_ctxt_t;
+
+
+static size_t ops_min_size(va_list ap)
+{
+	return sizeof(ops_min_ctxt_t);
+}
+
+
+/* supply two sig_t's to be multiplied, this sig_t takes
+ * ownership of them so they'll be freed by the multiplier
+ * on destroy when that sig_t is freed.
+ */
+static void ops_min_init(void *context, va_list ap)
+{
+	ops_min_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	ctxt->a = va_arg(ap, sig_t *);
+	ctxt->b = va_arg(ap, sig_t *);
+}
+
+
+static void ops_min_destroy(void *context)
+{
+	ops_min_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	sig_free(ctxt->a);
+	sig_free(ctxt->b);
+}
+
+
+static float ops_min_output(void *context, unsigned ticks_ms)
+{
+	ops_min_ctxt_t	*ctxt = context;
+	float		a, b;
+
+	assert(ctxt);
+
+	a = sig_output(ctxt->a, ticks_ms);
+	b = sig_output(ctxt->b, ticks_ms);
+
+	return a < b ? a : b;
+}
+
+
+sig_ops_t	sig_ops_min = {
+	.size = ops_min_size,
+	.init = ops_min_init,
+	.destroy = ops_min_destroy,
+	.output = ops_min_output,
+};