implement settings

25 files changed, 334 insertions, 47 deletions

diff --git a/app/mac/view-controller.mm b/app/mac/view-controller.mm
index 8695634..e2e71f9 100644
--- a/app/mac/view-controller.mm
+++ b/app/mac/view-controller.mm
@@ -22,7 +22,6 @@
 {
 	auto view = [[SKView alloc] init];
 	[view setIgnoresSiblingOrder:YES];
-	[view setShowsFPS:YES];
 	[view presentScene:_scene];
 
 	[self setView:view];
diff --git a/lib/nes/app/CMakeLists.txt b/lib/nes/app/CMakeLists.txt
index c0d6909..df0769e 100644
--- a/lib/nes/app/CMakeLists.txt
+++ b/lib/nes/app/CMakeLists.txt
@@ -4,7 +4,8 @@ target_sources(
 		application.hh
 		application.cc
 		action.hh
-		file-browser.hh)
+		file-browser.hh
+		preferences.hh)
 
 add_subdirectory(input)
 add_subdirectory(graphics)
diff --git a/lib/nes/app/application.cc b/lib/nes/app/application.cc
index 01d3f0b..015e641 100644
--- a/lib/nes/app/application.cc
+++ b/lib/nes/app/application.cc
@@ -21,15 +21,25 @@ namespace nes::app
 			popup->render(r);
 		}
 
+		if (preferences_.get_fps_counter())
+		{
+			r.render_rect(30, 29, 2, 1, color::fixed_black);
+			auto const attrs = text_attributes{}
+				.set_max_width(2)
+				.set_alignment(text_alignment::right);
+			r.render_text_format(32, 29, color::fixed_white, attrs, "{}", fps_counter.get_fps());
+		}
+
 		base.switch_buffers();
 	}
 
 	application::application(display& display, input_device_keyboard& keyboard, file_browser& file_browser)
-		: display_{ display }
-		, input_manager_{ keyboard }
+		: input_manager_{ keyboard }
 		, file_browser_{ file_browser }
+		, display_{ preferences_, display }
 		, screen_title_{ keyboard }
 		, screen_browser_{ keyboard, file_browser }
+		, screen_settings_{ input_manager_, preferences_ }
 		, screen_error_{ keyboard }
 		, screen_confirm_quit_{ keyboard }
 	{
@@ -38,6 +48,8 @@ namespace nes::app
 
 	auto application::frame(std::chrono::microseconds const elapsed_time) -> void
 	{
+		display_.fps_counter.frame(elapsed_time);
+
 		if (display_.popup)
 		{
 			auto const a = display_.popup->process_events();
@@ -99,21 +111,18 @@ namespace nes::app
 			}
 			case action::type::go_to_title:
 			{
-				console_.clear();
-				display_.screen = &screen_title_;
-				display_.popup = nullptr;
+				go_to_screen(&screen_title_);
 				break;
 			}
 			case action::type::go_to_browser:
+			case action::type::confirm_quit:
 			{
-				console_.clear();
-				display_.screen = &screen_browser_;
-				display_.popup = nullptr;
+				go_to_screen(&screen_browser_);
 				break;
 			}
 			case action::type::go_to_settings:
 			{
-				// TODO
+				go_to_screen(&screen_settings_);
 				break;
 			}
 			case action::type::go_to_help:
@@ -132,13 +141,6 @@ namespace nes::app
 				display_.screen = nullptr;
 				break;
 			}
-			case action::type::confirm_quit:
-			{
-				display_.popup = nullptr;
-				display_.screen = &screen_browser_;
-				console_.clear();
-				break;
-			}
 			case action::type::launch_game:
 			{
 				u8 buffer[sys::cartridge::max_file_size];
@@ -176,4 +178,11 @@ namespace nes::app
 		screen_error_.set_action(action);
 		display_.popup = &screen_error_;
 	}
+
+	auto application::go_to_screen(screen* screen) -> void
+	{
+		console_.clear();
+		display_.screen = screen;
+		display_.popup = nullptr;
+	}
 } // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/app/application.hh b/lib/nes/app/application.hh
index 66b5206..c23f654 100644
--- a/lib/nes/app/application.hh
+++ b/lib/nes/app/application.hh
@@ -3,12 +3,15 @@
 #include "nes/app/input/input-manager.hh"
 #include "nes/app/ui/screen-title.hh"
 #include "nes/app/ui/screen-browser.hh"
+#include "nes/app/ui/screen-settings.hh"
 #include "nes/app/ui/screen-freeze.hh"
 #include "nes/app/ui/screen-error.hh"
 #include "nes/app/ui/screen-confirm-quit.hh"
+#include "nes/app/preferences.hh"
 #include "nes/sys/nes.hh"
 #include "nes/common/containers/box.hh"
 #include "nes/common/display.hh"
+#include "nes/common/fps-counter.hh"
 #include "nes/common/types.hh"
 #include <chrono>
 
@@ -28,13 +31,17 @@ namespace nes::app
 		/// buffers.
 		class display_proxy final : public display
 		{
+			preferences& preferences_;
+
 		public:
+			fps_counter fps_counter;
 			display& base;
 			screen* popup{ nullptr };
 			screen* screen{ nullptr };
 
-			explicit display_proxy(display& base)
-				: base{ base }
+			explicit display_proxy(preferences& preferences, display& base)
+				: preferences_{ preferences }
+				, base{ base }
 			{
 			}
 
@@ -43,18 +50,20 @@ namespace nes::app
 			auto switch_buffers() -> void override;
 		};
 
-		display_proxy display_;
 		input_manager input_manager_;
+		preferences preferences_;
 		file_browser& file_browser_;
+		display_proxy display_;
 		box<sys::nes> console_{};
 		screen_title screen_title_;
 		screen_browser screen_browser_;
+		screen_settings screen_settings_;
 		screen_freeze screen_freeze_;
 		screen_error screen_error_;
 		screen_confirm_quit screen_confirm_quit_;
 
 	public:
-		explicit application(display&, input_device_keyboard&, file_browser& file_browser);
+		explicit application(display&, input_device_keyboard&, file_browser&);
 
 		application(application const&) = delete;
 		application(application&&) = delete;
@@ -70,5 +79,6 @@ namespace nes::app
 	private:
 		auto handle_action(action const&) -> void;
 		auto show_error(std::string_view message, status error, action const& action = action::close_popup()) -> void;
+		auto go_to_screen(screen*) -> void;
 	};
 } // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/app/graphics/renderer.cc b/lib/nes/app/graphics/renderer.cc
index 564125b..4f0d562 100644
--- a/lib/nes/app/graphics/renderer.cc
+++ b/lib/nes/app/graphics/renderer.cc
@@ -64,7 +64,7 @@ namespace nes::app
 	}
 
 	auto renderer::render_text(
-		i32 x, i32 const y, std::string_view const str, color const c, text_attributes const attributes) -> void
+		i32 x, i32 const y, std::string_view const str, color const c, text_attributes const attributes) -> u32
 	{
 		// Enforce max length
 		char buffer[width];
@@ -121,9 +121,10 @@ namespace nes::app
 		// Draw the text
 		for (auto i = u32{ 0 }; i < length; ++i)
 		{
-			auto const character = static_cast<u32>(buffer[i]);
-			render_mask_tile(x + static_cast<i32>(i), y, resolve_character(character), c);
+			render_mask_tile(x + static_cast<i32>(i), y, resolve_character(buffer[i]), c);
 		}
+
+		return length;
 	}
 
 	auto renderer::render_rect(i32 const x, i32 const y, u32 const width, u32 const height, color const c) -> void
@@ -217,7 +218,7 @@ namespace nes::app
 		return rgb::from_hex(0x000000);
 	}
 
-	auto renderer::resolve_character(u32 const c) const -> mask_tile
+	auto renderer::resolve_character(char const c) const -> mask_tile
 	{
 		switch (c)
 		{
@@ -260,6 +261,10 @@ namespace nes::app
 			case '9': return tiles::digit_9;
 			case '&': return tiles::symbol_ampersand;
 			case '\'': return tiles::symbol_apostrophe;
+			case '@': return tiles::symbol_at;
+			case '\\': return tiles::symbol_backslash;
+			case '{': return tiles::symbol_brace_open;
+			case '}': return tiles::symbol_brace_close;
 			case '[': return tiles::symbol_bracket_open;
 			case ']': return tiles::symbol_bracket_close;
 			case ':': return tiles::symbol_colon;
@@ -269,18 +274,21 @@ namespace nes::app
 			case '!': return tiles::symbol_exclamation_mark;
 			case '>': return tiles::symbol_greater;
 			case '#': return tiles::symbol_hashtag;
+			case '^': return tiles::symbol_hat;
 			case '<': return tiles::symbol_less;
 			case '-': return tiles::symbol_minus;
 			case '(': return tiles::symbol_paren_open;
 			case ')': return tiles::symbol_paren_close;
 			case '%': return tiles::symbol_percent;
 			case '.': return tiles::symbol_period;
+			case '|': return tiles::symbol_pipe;
 			case '+': return tiles::symbol_plus;
 			case '?': return tiles::symbol_question_mark;
 			case '"': return tiles::symbol_quotation_mark;
 			case ';': return tiles::symbol_semicolon;
 			case '/': return tiles::symbol_slash;
 			case '*': return tiles::symbol_star;
+			case '_': return tiles::symbol_underscore;
 			default: return tiles::symbol_unknown;
 		}
 	}
diff --git a/lib/nes/app/graphics/renderer.hh b/lib/nes/app/graphics/renderer.hh
index d4d7cc4..2e24ad3 100644
--- a/lib/nes/app/graphics/renderer.hh
+++ b/lib/nes/app/graphics/renderer.hh
@@ -46,7 +46,7 @@ namespace nes::app
 		/// Render an image at the given tile coordinates.
 		auto render_image(i32 x, i32 y, image_view) -> void;
 		/// Render a string of text at the given tile coordinates (one tile per character).
-		auto render_text(i32 x, i32 y, std::string_view, color, text_attributes = text_attributes{}) -> void;
+		auto render_text(i32 x, i32 y, std::string_view, color, text_attributes = text_attributes{}) -> u32;
 
 		template<typename... Args>
 		auto render_text_format(
@@ -55,8 +55,7 @@ namespace nes::app
 		{
 			string_buffer<width> buffer{};
 			buffer.append_format(fmt, args...);
-			render_text(x, y, buffer.get_result(), c, attrs);
-			return static_cast<u32>(buffer.get_result().length());
+			return render_text(x, y, buffer.get_result(), c, attrs);
 		}
 
 		template<typename... Args>
@@ -75,6 +74,6 @@ namespace nes::app
 
 	private:
 		auto resolve_color(color) const -> rgb;
-		auto resolve_character(u32) const -> mask_tile;
+		auto resolve_character(char) const -> mask_tile;
 	};
 } // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/app/graphics/tiles/CMakeLists.txt b/lib/nes/app/graphics/tiles/CMakeLists.txt
index eced5ca..5dced68 100644
--- a/lib/nes/app/graphics/tiles/CMakeLists.txt
+++ b/lib/nes/app/graphics/tiles/CMakeLists.txt
@@ -40,6 +40,10 @@ nes_generate_tiles(
 		digit_8.png
 		digit_9.png
 		symbol_ampersand.png
+		symbol_at.png
+		symbol_backslash.png
+		symbol_brace_open.png
+		symbol_brace_close.png
 		symbol_apostrophe.png
 		symbol_bracket_open.png
 		symbol_bracket_close.png
@@ -50,18 +54,21 @@ nes_generate_tiles(
 		symbol_exclamation_mark.png
 		symbol_greater.png
 		symbol_hashtag.png
+		symbol_hat.png
 		symbol_less.png
 		symbol_minus.png
 		symbol_paren_open.png
 		symbol_paren_close.png
 		symbol_percent.png
 		symbol_period.png
+		symbol_pipe.png
 		symbol_plus.png
 		symbol_question_mark.png
 		symbol_quotation_mark.png
 		symbol_semicolon.png
 		symbol_slash.png
 		symbol_star.png
+		symbol_underscore.png
 		symbol_unknown.png)
 
 nes_generate_tiles(
diff --git a/lib/nes/app/graphics/tiles/symbol_at.png b/lib/nes/app/graphics/tiles/symbol_at.png
new file mode 100644
index 0000000..e399054
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_at.png
diff --git a/lib/nes/app/graphics/tiles/symbol_backslash.png b/lib/nes/app/graphics/tiles/symbol_backslash.png
new file mode 100644
index 0000000..8d98ef0
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_backslash.png
diff --git a/lib/nes/app/graphics/tiles/symbol_brace_close.png b/lib/nes/app/graphics/tiles/symbol_brace_close.png
new file mode 100644
index 0000000..bb24228
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_brace_close.png
diff --git a/lib/nes/app/graphics/tiles/symbol_brace_open.png b/lib/nes/app/graphics/tiles/symbol_brace_open.png
new file mode 100644
index 0000000..32bdb99
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_brace_open.png
diff --git a/lib/nes/app/graphics/tiles/symbol_hat.png b/lib/nes/app/graphics/tiles/symbol_hat.png
new file mode 100644
index 0000000..ab21714
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_hat.png
diff --git a/lib/nes/app/graphics/tiles/symbol_pipe.png b/lib/nes/app/graphics/tiles/symbol_pipe.png
new file mode 100644
index 0000000..9db3443
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_pipe.png
diff --git a/lib/nes/app/graphics/tiles/symbol_underscore.png b/lib/nes/app/graphics/tiles/symbol_underscore.png
new file mode 100644
index 0000000..1823c95
--- /dev/null
+++ b/lib/nes/app/graphics/tiles/symbol_underscore.png
diff --git a/lib/nes/app/input/input-device-controller.hh b/lib/nes/app/input/input-device-controller.hh
index 69dd2a8..93147cd 100644
--- a/lib/nes/app/input/input-device-controller.hh
+++ b/lib/nes/app/input/input-device-controller.hh
@@ -2,7 +2,6 @@
 
 #include "nes/app/input/input-device.hh"
 #include "nes/common/containers/list.hh"
-#include <string_view>
 
 namespace nes::app
 {
@@ -23,9 +22,6 @@ namespace nes::app
 		/// controller already selected.
 		virtual auto is_reliable() const -> bool = 0;
 
-		/// Human-readable name for the controller.
-		virtual auto get_name() const -> std::string_view = 0;
-
 		/// Get the (persistent) player index for the controller, if already set before.
 		virtual auto get_index() const -> index = 0;
 
diff --git a/lib/nes/app/input/input-device-keyboard.hh b/lib/nes/app/input/input-device-keyboard.hh
index 23ee65c..ef89c59 100644
--- a/lib/nes/app/input/input-device-keyboard.hh
+++ b/lib/nes/app/input/input-device-keyboard.hh
@@ -43,6 +43,8 @@ namespace nes::app
 			return res;
 		}
 
+		auto get_name() const -> std::string_view final { return "Keyboard"; }
+
 	protected:
 		explicit input_device_keyboard() = default;
 	};
diff --git a/lib/nes/app/input/input-device.hh b/lib/nes/app/input/input-device.hh
index cc03057..008825d 100644
--- a/lib/nes/app/input/input-device.hh
+++ b/lib/nes/app/input/input-device.hh
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "nes/sys/types/button-mask.hh"
+#include <string_view>
 
 namespace nes::app
 {
@@ -15,8 +16,12 @@ namespace nes::app
 		auto operator=(input_device const&) -> input_device& = delete;
 		auto operator=(input_device&&) -> input_device& = delete;
 
+		/// Read the controller button state.
 		virtual auto read_buttons() -> sys::button_mask = 0;
 
+		/// Human-readable name for the device.
+		virtual auto get_name() const -> std::string_view = 0;
+
 	protected:
 		explicit input_device() = default;
 	};
diff --git a/lib/nes/app/input/input-manager.cc b/lib/nes/app/input/input-manager.cc
index ceb6690..e88ac84 100644
--- a/lib/nes/app/input/input-manager.cc
+++ b/lib/nes/app/input/input-manager.cc
@@ -15,6 +15,7 @@ namespace nes::app
 				return res;
 			}
 
+			auto get_name() const -> std::string_view override { return "(None)"; }
 			auto read_buttons() -> sys::button_mask override { return sys::button_mask{}; }
 		};
 	} // namespace
@@ -36,6 +37,10 @@ namespace nes::app
 				// This controller was previously used and assigned an index -> replace the current device with this
 				// (known) controller.
 				auto const i = static_cast<u32>(index);
+				if (keyboard_index_ == index)
+				{
+					keyboard_index_ = input_device_controller::index::unused;
+				}
 				if (inputs_[i].controller)
 				{
 					inputs_[i].controller->set_index(input_device_controller::index::unused);
@@ -56,6 +61,43 @@ namespace nes::app
 		fill_unassigned_inputs();
 	}
 
+	auto input_manager::toggle_input(u32 const i) -> void
+	{
+		// If currently none/keyboard, use the first available controller.
+		auto curr_was_prev = inputs_[i].controller == nullptr;
+		if (curr_was_prev && keyboard_index_ == input_device_controller::index::unused)
+		{
+			// If currently none and keyboard is available, switch to keyboard.
+			keyboard_index_ = static_cast<input_device_controller::index>(i);
+			inputs_[i].controller = nullptr;
+			inputs_[i].device = keyboard_;
+			return;
+		}
+
+		// Reset old controller index
+		if (inputs_[i].controller) { inputs_[i].controller->set_index(input_device_controller::index::unused); }
+		if (keyboard_index_ == static_cast<input_device_controller::index>(i)) { keyboard_index_ = input_device_controller::index::unused; }
+
+		for (auto& controller : controllers_)
+		{
+			if (&controller == inputs_[i].controller)
+			{
+				curr_was_prev = true;
+			}
+			else if (curr_was_prev && controller.get_index() == input_device_controller::index::unused)
+			{
+				inputs_[i].controller = &controller;
+				inputs_[i].controller->set_index(static_cast<input_device_controller::index>(i));
+				inputs_[i].device = &controller;
+				return;
+			}
+		}
+
+		// No successor found, switch to none.
+		inputs_[i].controller = nullptr;
+		inputs_[i].device = &input_device_dummy::get_instance();
+	}
+
 	auto input_manager::fill_unassigned_inputs() -> void
 	{
 		auto it = controllers_.begin();
@@ -87,6 +129,7 @@ namespace nes::app
 				// We're all out of controllers -> fall back to the keyboard (if this is the first missing controller)
 				// or nothing.
 				inputs_[i].device = fallback;
+				if (fallback == keyboard_) { keyboard_index_ = static_cast<input_device_controller::index>(i); }
 				fallback = &input_device_dummy::get_instance(); // Only use the keyboard as a fallback once.
 			}
 		}
diff --git a/lib/nes/app/input/input-manager.hh b/lib/nes/app/input/input-manager.hh
index b0b60e8..7a63326 100644
--- a/lib/nes/app/input/input-manager.hh
+++ b/lib/nes/app/input/input-manager.hh
@@ -16,6 +16,7 @@ namespace nes::app
 		static constexpr auto input_count = u32{ 2 };
 
 		input_device_keyboard* keyboard_;
+		input_device_controller::index keyboard_index_{ input_device_controller::index::unused };
 		list<input_device_controller> controllers_;
 		struct
 		{
@@ -34,6 +35,9 @@ namespace nes::app
 		auto get_input_1() const -> input_device& { return *inputs_[0].device; }
 		auto get_input_2() const -> input_device& { return *inputs_[1].device; }
 
+		auto toggle_input_1() -> void { toggle_input(0); }
+		auto toggle_input_2() -> void { toggle_input(1); }
+
 		auto get_keyboard() const -> input_device_keyboard& { return *keyboard_; }
 		auto get_controllers() const -> list<input_device_controller> const& { return controllers_; }
 
@@ -41,6 +45,7 @@ namespace nes::app
 		auto remove_controller(input_device_controller&) -> void;
 
 	private:
+		auto toggle_input(u32) -> void;
 		auto fill_unassigned_inputs() -> void;
 	};
 } // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/app/preferences.hh b/lib/nes/app/preferences.hh
new file mode 100644
index 0000000..0c13755
--- /dev/null
+++ b/lib/nes/app/preferences.hh
@@ -0,0 +1,21 @@
+#pragma once
+
+namespace nes::app
+{
+	/// Manages application preferences.
+	class preferences
+	{
+		bool fps_counter_{ false };
+
+	public:
+		explicit preferences() = default;
+
+		preferences(preferences const&) = delete;
+		preferences(preferences&&) = delete;
+		auto operator=(preferences const&) -> preferences& = delete;
+		auto operator=(preferences&&) -> preferences& = delete;
+
+		auto get_fps_counter() const -> bool { return fps_counter_; }
+		auto set_fps_counter(bool const v) -> void { fps_counter_ = v; }
+	};
+} // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/app/ui/screen-settings.cc b/lib/nes/app/ui/screen-settings.cc
index 4d32662..98070d7 100644
--- a/lib/nes/app/ui/screen-settings.cc
+++ b/lib/nes/app/ui/screen-settings.cc
@@ -1,5 +1,98 @@
-//
-// Created by Hannes Schulze on 06.02.25.
-//
+#include "nes/app/ui/screen-settings.hh"
+#include "nes/app/input/input-manager.hh"
+#include "nes/app/preferences.hh"
 
-#include "screen-settings.hh"
+namespace nes::app
+{
+	auto screen_settings::selection_impl::render_item(
+		renderer& renderer, item const& item, i32 const x, i32 const y, u32 const width, color const c) const -> void
+	{
+		auto const render = [&](std::string_view const label, std::string_view const value)
+		{
+			auto const label_length = renderer.render_text(x, y, label, c);
+			auto const value_attrs = text_attributes{}
+				.set_alignment(text_alignment::right)
+				.set_ellipsize_mode(ellipsize_mode::end)
+				.set_max_width(width - label_length - 2);
+			renderer.render_text(x + static_cast<i32>(width), y, value, color::foreground_secondary, value_attrs);
+		};
+		switch (item)
+		{
+			case item::controller_1:
+				render("Controller 1:", input_manager_.get_input_1().get_name());
+				break;
+			case item::controller_2:
+				render("Controller 2:", input_manager_.get_input_2().get_name());
+				break;
+			case item::fps_counter:
+				render("FPS Counter:", preferences_.get_fps_counter() ? "Yes" : "No");
+				break;
+		}
+	}
+
+	auto screen_settings::selection_impl::load_page(item (&items)[page_size], u32) -> u32
+	{
+		items[0] = item::controller_1;
+		items[1] = item::controller_2;
+		items[2] = item::fps_counter;
+		return 3;
+	}
+
+	screen_settings::screen_settings(input_manager& input_manager, preferences& preferences)
+		: input_manager_{ input_manager }
+		, preferences_{ preferences }
+		, selection_{ input_manager, preferences }
+	{
+		selection_.set_page_count(1);
+	}
+
+	auto screen_settings::render(renderer& renderer) -> void
+	{
+		renderer.render_fill(color::background_primary);
+		renderer.render_rect(0, 0, 32, 3, color::background_secondary);
+
+		auto const page_length = renderer.render_text_format(
+			30, 1, color::foreground_secondary, text_attributes{}.set_alignment(text_alignment::right),
+			"Page {}/{}", selection_.get_current_page() + 1, selection_.get_page_count());
+
+		renderer.render_text(
+			2, 1, "Settings", color::foreground_primary,
+			text_attributes{}.set_max_width(26 - page_length).set_ellipsize_mode(ellipsize_mode::middle));
+
+		selection_.render(renderer);
+	}
+
+	auto screen_settings::process_events() -> action
+	{
+		while (auto const event = input_manager_.get_keyboard().poll_event())
+		{
+			if (event == input_event::key_down(key::space))
+			{
+				selection_.go_next();
+			}
+			else if (event == input_event::key_down(key::arrow_up))
+			{
+				selection_.go_up();
+			}
+			else if (event == input_event::key_down(key::arrow_down))
+			{
+				selection_.go_down();
+			}
+			else if (event == input_event::key_down(key::backspace))
+			{
+				return action::go_to_title();
+			}
+			else if (event == input_event::key_down(key::enter))
+			{
+				switch (*selection_.get_selected())
+				{
+					case item::controller_1: input_manager_.toggle_input_1(); break;
+					case item::controller_2: input_manager_.toggle_input_2(); break;
+					case item::fps_counter: preferences_.set_fps_counter(!preferences_.get_fps_counter()); break;
+				}
+			}
+		}
+
+		return action{};
+	}
+} // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/app/ui/screen-settings.hh b/lib/nes/app/ui/screen-settings.hh
index 8f510ca..8910c5c 100644
--- a/lib/nes/app/ui/screen-settings.hh
+++ b/lib/nes/app/ui/screen-settings.hh
@@ -1,16 +1,51 @@
-//
-// Created by Hannes Schulze on 06.02.25.
-//
+#pragma once
 
-#ifndef SCREEN_SETTINGS_HH
-#define SCREEN_SETTINGS_HH
+#include "nes/app/ui/screen.hh"
+#include "nes/app/ui/selection.hh"
 
+namespace nes::app
+{
+	class input_manager;
+	class preferences;
 
+	/// Screen used to configure various emulator options.
+	class screen_settings final : public screen
+	{
+		static constexpr auto page_size = u32{ 8 };
 
-class screen_settings {
+		enum class item
+		{
+			controller_1,
+			controller_2,
+			fps_counter,
+		};
 
-};
+		class selection_impl final : public selection<item, page_size>
+		{
+			input_manager& input_manager_;
+			preferences& preferences_;
 
+		public:
+			explicit selection_impl(input_manager& input_manager, preferences& preferences)
+				: selection{ 2, 5, 28 }
+				, input_manager_{ input_manager }
+				, preferences_{ preferences }
+			{
+			}
 
+		protected:
+			auto render_item(renderer&, item const&, i32 x, i32 y, u32 width, color) const -> void override;
+			auto load_page(item(&)[page_size], u32 page) -> u32 override;
+		};
 
-#endif //SCREEN_SETTINGS_HH
+		input_manager& input_manager_;
+		preferences& preferences_;
+		selection_impl selection_;
+
+	public:
+		explicit screen_settings(input_manager&, preferences&);
+
+		auto render(renderer&) -> void override;
+		auto process_events() -> action override;
+	};
+} // namespace nes::app
\ No newline at end of file
diff --git a/lib/nes/common/CMakeLists.txt b/lib/nes/common/CMakeLists.txt
index 3920d36..9a7cc6b 100644
--- a/lib/nes/common/CMakeLists.txt
+++ b/lib/nes/common/CMakeLists.txt
@@ -5,6 +5,8 @@ target_sources(
 		debug.hh
 		rgb.hh
 		display.hh
-		status.hh)
+		status.hh
+		fps-counter.hh
+		fps-counter.cc)
 
 add_subdirectory(containers)
\ No newline at end of file
diff --git a/lib/nes/common/fps-counter.cc b/lib/nes/common/fps-counter.cc
new file mode 100644
index 0000000..ef6169b
--- /dev/null
+++ b/lib/nes/common/fps-counter.cc
@@ -0,0 +1,29 @@
+#include "nes/common/fps-counter.hh"
+
+namespace nes
+{
+	auto fps_counter::frame(std::chrono::microseconds const elapsed_time) -> void
+	{
+		if (elapsed_time.count() <= 0) { return; }
+
+		if (buffer_position_ == 0)
+		{
+			// Update fps count.
+			auto sum = u32{ 0 };
+			for (auto i = u32{ 0 }; i < buffer_size; ++i) { sum += frame_times_[i]; }
+			if (sum > 0)
+			{
+				buffered_fps_ = (buffer_size * 1000000) / sum;
+			}
+			else
+			{
+				buffered_fps_ = 0;
+			}
+		}
+
+		// Add the frame time to the buffer, replacing any existing content in the ring buffer.
+		auto const frame_time = static_cast<u32>(elapsed_time.count());
+		frame_times_[buffer_position_] = frame_time;
+		buffer_position_ = (buffer_position_ + 1) % buffer_size;
+	}
+} // namespace nes
\ No newline at end of file
diff --git a/lib/nes/common/fps-counter.hh b/lib/nes/common/fps-counter.hh
new file mode 100644
index 0000000..96db98c
--- /dev/null
+++ b/lib/nes/common/fps-counter.hh
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "nes/common/types.hh"
+#include <chrono>
+
+namespace nes
+{
+	/// Counts frames.
+	class fps_counter
+	{
+		static constexpr auto buffer_size = u32{ 20 };
+
+		u32 frame_times_[buffer_size]{}; // The time until the next frame for the last <buffer_size> frames.
+		u32 buffer_position_{ 0 }; // Position in the ring buffer.
+		u32 buffered_fps_{ 0 }; // Delay updates to FPS to one update per round in the ring buffer.
+
+	public:
+		explicit fps_counter() = default;
+
+		auto frame(std::chrono::microseconds elapsed_time) -> void;
+		auto get_fps() const -> u32 { return buffered_fps_; }
+	};
+} // namespace nes
\ No newline at end of file