[nostalgia] Collapse NostalgiaCore down to a single library and cleanup impl data access

src/nostalgia/core/event.hpp

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2016 - 2022 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#pragma once
+
+namespace nostalgia::core {
+
+class Context;
+
+using event_handler = int(*)(Context*);
+
+// Sets event handler that sleeps for the time given in the return value. The
+// sleep time is a minimum of ~16 milliseconds.
+void setEventHandler(Context *ctx, event_handler) noexcept;
+
+}