show display refresh rate in description

assets/config_menu/graphics.rml

@@ -283,7 +283,10 @@
                         Sets the game's output framerate. This option does not affect gameplay.
                         <br />
                         <br />
-                        Note: If you have issues with Display mode while using an external frame limiter, use Manual mode instead and configure it to that same frame limit.
+                        Note: If you have issues with <b>Display</b> mode while using an external frame limiter, use <b>Manual</b> mode instead and configure it to that same frame limit.
+                        <br />
+                        <br />
+                        <b>Detected display refresh rate: {{display_refresh_rate}}hz</b>
                     </p>
                     <p data-if="cur_config_index == 5">
                         Sets the multisample anti-aliasing (MSAA) quality level. This reduces jagged edges in the final image at the expense of rendering performance.

include/recomp_ui.h

@@ -72,6 +72,7 @@ namespace recomp {
 	void set_cursor_visible(bool visible);
 	void update_supported_options();
 	void toggle_fullscreen();
+	void update_rml_display_refresh_rate();
 
 	extern const std::unordered_map<ButtonVariant, std::string> button_variants;
 

src/ui/ui_config.cpp

@@ -377,6 +377,17 @@ struct DebugContext {
 	}
 };
 
+void recomp::update_rml_display_refresh_rate() {
+	static uint32_t lastRate = 0;
+	if (!graphics_model_handle) return;
+
+	uint32_t curRate = ultramodern::get_display_refresh_rate();
+	if (curRate != lastRate) {
+		graphics_model_handle.DirtyVariable("display_refresh_rate");
+	}
+	lastRate = curRate;
+}
+
 DebugContext debug_context;
 
 class ConfigMenu : public recomp::MenuController {
@@ -523,6 +534,11 @@ public:
 				graphics_model_handle.DirtyVariable("ds_info");
 			});
 
+		constructor.BindFunc("display_refresh_rate",
+			[](Rml::Variant& out) {
+				out = ultramodern::get_display_refresh_rate();
+			});
+
 		constructor.BindFunc("options_changed",
 			[](Rml::Variant& out) {
 				out = (ultramodern::get_graphics_config() != new_options);

src/ui/ui_renderer.cpp

@@ -956,6 +956,7 @@ struct UIContext {
         void update_config_menu_loop(bool menu_changed) {
             static int prevTab = -1;
             if (menu_changed) prevTab = -1;
+            recomp::update_rml_display_refresh_rate();
 
             Rml::ElementTabSet *tabset = (Rml::ElementTabSet *)current_document->GetElementById("config_tabset");
             if (tabset == nullptr) return;

ultramodern/events.cpp

@@ -292,6 +292,10 @@ uint32_t ultramodern::get_target_framerate(uint32_t original) {
     }
 }
 
+uint32_t ultramodern::get_display_refresh_rate() {
+    return display_refresh_rate.load();
+}
+
 void gfx_thread_func(uint8_t* rdram, std::atomic_flag* thread_ready, ultramodern::WindowHandle window_handle) {
     bool enabled_instant_present = false;
     using namespace std::chrono_literals;

ultramodern/ultramodern.hpp

@@ -96,6 +96,7 @@ std::chrono::high_resolution_clock::time_point get_start();
 std::chrono::high_resolution_clock::duration time_since_start();
 void get_window_size(uint32_t& width, uint32_t& height);
 uint32_t get_target_framerate(uint32_t original);
+uint32_t get_display_refresh_rate();
 void measure_input_latency();
 void sleep_milliseconds(uint32_t millis);
 void sleep_until(const std::chrono::high_resolution_clock::time_point& time_point);