--- a/qmlfrontend/engine_interface.h	Fri Mar 22 21:06:12 2019 +0100
+++ b/qmlfrontend/engine_interface.h	Fri Mar 22 21:29:10 2019 +0100
@@ -37,6 +37,9 @@
 
 typedef bool advance_simulation_t(EngineInstance* engine_state, uint32_t ticks);
 
+typedef void move_camera_t(EngineInstance* engine_state, int32_t delta_x,
+                           int32_t delta_y);
+
 #ifdef __cplusplus
 }
 };