Add TogglerCounter class

Author: danngreen

tests/debouncer_tests.cc

@@ -0,0 +1,177 @@
+#include "doctest.h"
+#include "util/debouncer.hh"
+
+TEST_CASE("TogglerCounter starts low with zero count and no events") {
+	TogglerCounter t;
+
+	CHECK(t.is_high() == false);
+	CHECK(t.is_pressed() == false);
+	CHECK(bool(t) == false);
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_just_pressed() == false);
+	CHECK(t.is_just_released() == false);
+}
+
+TEST_CASE("TogglerCounter rising edge sets state and event, resets count") {
+	TogglerCounter t;
+
+	t.process(1);
+	CHECK(t.is_high() == true);
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_just_pressed() == true);
+	CHECK(t.is_just_pressed() == false); // event clears after read
+	CHECK(t.is_just_released() == false);
+}
+
+TEST_CASE("TogglerCounter steady state increments count without events") {
+	TogglerCounter t;
+
+	// staying low: count increments each call
+	t.process(0);
+	CHECK(t.steady_state_count() == 1);
+	CHECK(t.is_just_pressed() == false);
+	CHECK(t.is_just_released() == false);
+
+	t.process(0);
+	CHECK(t.steady_state_count() == 2);
+
+	t.process(0);
+	CHECK(t.steady_state_count() == 3);
+	CHECK(t.is_high() == false);
+}
+
+TEST_CASE("TogglerCounter falling edge resets count and fires event") {
+	TogglerCounter t;
+
+	t.process(1);
+	CHECK(t.steady_state_count() == 0);
+
+	t.process(1);
+	t.process(1);
+	CHECK(t.steady_state_count() == 2);
+
+	t.process(0);
+	// Count reset:
+	CHECK(t.steady_state_count() == 0);
+	// Event fired:
+	CHECK(t.is_just_released() == true);
+	CHECK(t.is_just_released() == false);
+}
+
+TEST_CASE("TogglerCounter count accumulates while steady high") {
+	TogglerCounter t;
+
+	// Start with button pressed
+	t.process(1);
+
+	for (unsigned i = 1; i <= 10; i++) {
+		t.process(1);
+		CHECK(t.steady_state_count() == i);
+	}
+}
+
+TEST_CASE("TogglerCounter count accumulates while steady low") {
+	TogglerCounter t;
+
+	for (unsigned i = 1; i <= 10; i++) {
+		t.process(0);
+		CHECK(t.steady_state_count() == i);
+	}
+}
+
+TEST_CASE("TogglerCounter register_state mirrors process") {
+	TogglerCounter t;
+
+	t.register_state(1);
+	CHECK(t.is_high() == true);
+	CHECK(t.steady_state_count() == 0);
+
+	t.register_state(1);
+	CHECK(t.steady_state_count() == 1);
+
+	t.register_state(0);
+	CHECK(t.is_high() == false);
+	CHECK(t.steady_state_count() == 0);
+}
+
+TEST_CASE("TogglerCounter reset_count clears count without affecting state") {
+	TogglerCounter t;
+
+	t.process(1);
+	t.process(1);
+	t.process(1);
+	t.process(1);
+	CHECK(t.steady_state_count() == 3);
+	CHECK(t.is_high() == true);
+
+	t.reset_count();
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_high() == true);
+
+	t.process(1);
+	CHECK(t.steady_state_count() == 1);
+}
+
+TEST_CASE("TogglerCounter reset clears state and events but not count") {
+	TogglerCounter t;
+
+	t.process(1);
+	t.process(1);
+	CHECK(t.steady_state_count() == 1);
+
+	t.reset();
+	CHECK(t.is_high() == false);
+	CHECK(t.is_just_pressed() == false);
+	CHECK(t.is_just_released() == false);
+
+	// after reset (state low) processing 0 increments steady count
+	t.process(0);
+	CHECK(t.steady_state_count() == 2);
+}
+
+TEST_CASE("TogglerCounter clear_events does not change state or count") {
+	TogglerCounter t;
+
+	t.process(1);
+	CHECK(t.is_high() == true);
+
+	t.clear_events();
+	CHECK(t.is_just_pressed() == false);
+	CHECK(t.is_just_released() == false);
+	CHECK(t.is_high() == true);
+
+	t.process(1);
+	CHECK(t.steady_state_count() == 1);
+}
+
+TEST_CASE("TogglerCounter alternating transitions reset count each edge") {
+	TogglerCounter t;
+
+	t.process(1);
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_just_pressed() == true);
+
+	t.process(0);
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_just_released() == true);
+
+	t.process(1);
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_just_pressed() == true);
+
+	t.process(0);
+	CHECK(t.steady_state_count() == 0);
+	CHECK(t.is_just_released() == true);
+}
+
+TEST_CASE("TogglerCounter is_just_pressed cleared after read across steady samples") {
+	TogglerCounter t;
+
+	t.process(1);
+	t.process(1);
+	t.process(1);
+	CHECK(t.is_just_pressed() == true);
+	CHECK(t.is_just_pressed() == false);
+	CHECK(t.steady_state_count() == 2);
+	CHECK(t.is_high() == true);
+}

util/debouncer.hh

@@ -126,6 +126,38 @@ public:
 	}
 };
 
+struct TogglerCounter : Toggler {
+	void register_state(unsigned newstate) {
+		if (newstate == is_high_) {
+			steady_state_ctr++;
+			return;
+		}
+
+		is_high_ = newstate;
+		steady_state_ctr = 0;
+
+		if (newstate)
+			got_rising_edge_ = true;
+		else
+			got_falling_edge_ = true;
+	}
+
+	unsigned steady_state_count() const {
+		return steady_state_ctr;
+	}
+
+	void reset_count() {
+		steady_state_ctr = 0;
+	}
+
+	void process(unsigned new_state) {
+		register_state(new_state);
+	}
+
+private:
+	unsigned steady_state_ctr = 0;
+};
+
 template<unsigned RisingEdgePattern = 0x00000001,
 		 unsigned FallingEdgePattern = 0xFFFFFFFE,
 		 unsigned StateMask = 0x00000FFF>