rework input to be in line with rendering semantics

src/twn_engine_context_c.h

@@ -64,15 +64,15 @@ typedef struct EngineContext {
     int64_t delta_averager_residual;
     int64_t time_averager[4];
 
+    SDL_GLContext *gl_context;
+    SDL_Window *window;
+    uint32_t window_id;
+
     /* this should be a multiple of the current ticks per second */
     /* use it to simulate low framerate (e.g. at 60 tps, set to 2 for 30 fps) */
     /* it can be changed at runtime; any resulting logic anomalies are bugs */
     uint32_t update_multiplicity;
 
-    SDL_GLContext *gl_context;
-    SDL_Window *window;
-    uint32_t window_id;
-
     bool is_running;
     bool window_size_has_changed;
     bool resync_flag;