Frame Interp: Game Clock Refactor & Ring Item Selection

include/d/d_menu_ring.h

@@ -204,6 +204,9 @@ private:
     /* 0x6D1 */ u8 field_0x6d1;
     /* 0x6D2 */ u8 field_0x6d2;
     /* 0x6D3 */ u8 field_0x6d3;
+#if TARGET_PC
+    f32 mSelectItemSlideElapsed[4];
+#endif
 };
 
 #endif /* D_MENU_D_MENU_RING_H */

include/dusk/frame_interpolation.h

@@ -22,6 +22,7 @@ float get_interpolation_step();
 void request_presentation_sync();
 bool presentation_sync_active();
 
+// TODO: These should be phased out as UI is progressively updated to use game_clock
 void set_ui_tick_pending(bool value);
 bool get_ui_tick_pending();
 

include/dusk/game_clock.h

@@ -0,0 +1,32 @@
+#ifndef DUSK_GAME_CLOCK_H
+#define DUSK_GAME_CLOCK_H
+
+#include <stddef.h>
+
+namespace dusk {
+namespace game_clock {
+
+void ensure_initialized();
+void reset_accumulator();
+
+constexpr float sim_pace() { return 1.0f / 30.0f; }
+constexpr float period_for_original_frames(float frame_count) { return frame_count * sim_pace(); }
+constexpr float ui_maximum_dt() { return 0.05f; }
+constexpr float ui_initial_dt() { return 1.0f / 60.0f; }
+
+struct MainLoopPacer {
+    float presentation_dt_seconds;
+    bool is_interpolating;
+    bool do_sim_tick;
+    float interpolation_step;
+    float sim_pace;
+};
+
+MainLoopPacer advance_main_loop();
+
+float consume_interval(const void* consumer);
+
+}  // namespace game_clock
+}  // namespace dusk
+
+#endif  // DUSK_GAME_CLOCK_H