libs/sig: add sig_ops_{add,sub}

1 files changed, 54 insertions, 0 deletions

diff --git a/src/libs/sig/ops_sub.c b/src/libs/sig/ops_sub.c
new file mode 100644
index 0000000..15fed1b
--- /dev/null
+++ b/src/libs/sig/ops_sub.c
@@ -0,0 +1,54 @@
+#include <assert.h>
+
+#include "sig.h"
+
+
+typedef struct ops_sub_ctxt_t {
+	sig_t	*a, *b;
+} ops_sub_ctxt_t;
+
+
+static size_t ops_sub_size(va_list ap)
+{
+	return sizeof(ops_sub_ctxt_t);
+}
+
+
+static void ops_sub_init(void *context, va_list ap)
+{
+	ops_sub_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	ctxt->a = va_arg(ap, sig_t *);
+	ctxt->b = va_arg(ap, sig_t *);
+}
+
+
+static void ops_sub_destroy(void *context)
+{
+	ops_sub_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	sig_free(ctxt->a);
+	sig_free(ctxt->b);
+}
+
+
+static float ops_sub_output(void *context, unsigned ticks_ms)
+{
+	ops_sub_ctxt_t	*ctxt = context;
+
+	assert(ctxt);
+
+	return sig_output(ctxt->a, ticks_ms) - sig_output(ctxt->b, ticks_ms);
+}
+
+
+sig_ops_t	sig_ops_sub = {
+	.size = ops_sub_size,
+	.init = ops_sub_init,
+	.destroy = ops_sub_destroy,
+	.output = ops_sub_output,
+};