testbed: prepare input system

testbed/system/input_system.cpp

@@ -0,0 +1,22 @@
+#include <application/context.h>
+#include <entt/entity/registry.hpp>
+#include <system/input_system.h>
+
+namespace testbed {
+
+void input_system(entt::registry &registry, const SDL_Event &event, bool &quit) {
+    switch(event.type) {
+    case SDL_EVENT_QUIT:
+        quit = true;
+        break;
+    case SDL_EVENT_KEY_DOWN:
+        switch(event.key.key) {
+        case SDLK_ESCAPE:
+            quit = true;
+            break;
+        }
+        break;
+    }
+}
+
+} // namespace testbed