1 files changed, 56 insertions, 0 deletions
diff --git a/lib/nes/app/input/input-buffer.cc b/lib/nes/app/input/input-buffer.cc
new file mode 100644
index 0000000..e8da51c
--- /dev/null
+++ b/lib/nes/app/input/input-buffer.cc
@@ -0,0 +1,56 @@
+#include "nes/app/input/input-buffer.hh"
+#include "nes/app/input/input-event.hh"
+
+namespace nes::app
+{
+	auto input_buffer::key_down(key const k) -> void
+	{
+		set_pressed(k, true);
+	}
+
+	auto input_buffer::key_up(key const k) -> void
+	{
+		set_pressed(k, false);
+	}
+
+	auto input_buffer::read_key(key const k) -> bool
+	{
+		return get_event(k).pressed;
+	}
+
+	auto input_buffer::poll_event() -> input_event
+	{
+		auto it = event_queue_.begin();
+		if (it == event_queue_.end()) { return input_event{}; }
+
+		auto const event = *it;
+		auto const k = get_key(*event);
+		auto const pressed = event->pressed;
+		event_queue_.remove(it);
+
+		return pressed ? input_event::key_down(k) : input_event::key_up(k);
+	}
+
+	auto input_buffer::get_event(key const k) -> event&
+	{
+		return key_events_[static_cast<u32>(k)];
+	}
+
+	auto input_buffer::get_key(event const& ev) -> key
+	{
+		return static_cast<key>(&ev - key_events_);
+	}
+
+	auto input_buffer::set_pressed(key const k, bool const pressed) -> void
+	{
+		auto& event = get_event(k);
+		if (event.pressed == pressed) { return; }
+		event.pressed = pressed;
+
+		// Remove the event if it was not previously fetched (skipping it entirely), otherwise add a new event.
+		if (!event_queue_.remove(event))
+		{
+			event_queue_.append(event);
+		}
+	}
+} // namespace nes::app
+\ No newline at end of file