From a9a868d3f0db09a5161d88f79e0855bca74c5be2 Mon Sep 17 00:00:00 2001
From: Karn Kaul <karnkaul@gmail.com>
Date: Wed, 5 Jun 2024 11:36:19 +0530
Subject: [PATCH 1/5] Add scene music, rename `Home` to `MenuScene`.

---
 src/spaced/spaced/scene.hpp                   |  2 ++
 src/spaced/spaced/scenes/game.cpp             | 35 +++++++++++--------
 src/spaced/spaced/scenes/game.hpp             |  6 ++--
 src/spaced/spaced/scenes/load_assets.cpp      |  8 ++---
 .../spaced/scenes/{home.cpp => menu.cpp}      | 10 +++---
 .../spaced/scenes/{home.hpp => menu.hpp}      |  6 ++--
 src/spaced/spaced/spaced.cpp                  | 10 +++++-
 src/spaced/spaced/spaced.hpp                  |  2 ++
 8 files changed, 50 insertions(+), 29 deletions(-)
 rename src/spaced/spaced/scenes/{home.cpp => menu.cpp} (76%)
 rename src/spaced/spaced/scenes/{home.hpp => menu.hpp} (50%)

diff --git a/src/spaced/spaced/scene.hpp b/src/spaced/spaced/scene.hpp
index 1f8a994..cbf320d 100644
--- a/src/spaced/spaced/scene.hpp
+++ b/src/spaced/spaced/scene.hpp
@@ -18,6 +18,8 @@ class Scene : public bave::PolyPinned {
 	void tick_frame(bave::Seconds dt);
 	void render_frame() const;
 
+	[[nodiscard]] virtual auto get_music_uri() const -> std::string_view { return {}; }
+
 	[[nodiscard]] auto get_app() const -> bave::App& { return m_app; }
 	[[nodiscard]] auto get_services() const -> Services const& { return m_services; }
 
diff --git a/src/spaced/spaced/scenes/game.cpp b/src/spaced/spaced/scenes/game.cpp
index 8eb7b65..142d639 100644
--- a/src/spaced/spaced/scenes/game.cpp
+++ b/src/spaced/spaced/scenes/game.cpp
@@ -2,7 +2,7 @@
 #include <bave/imgui/im_text.hpp>
 #include <spaced/assets/asset_list.hpp>
 #include <spaced/scenes/game.hpp>
-#include <spaced/scenes/home.hpp>
+#include <spaced/scenes/menu.hpp>
 #include <spaced/services/scene_switcher.hpp>
 #include <spaced/services/stats.hpp>
 #include <spaced/services/styles.hpp>
@@ -23,11 +23,13 @@ using bave::Ptr;
 using bave::Seconds;
 using bave::Shader;
 
-auto Game::get_manifest() -> AssetManifest {
+auto GameScene::get_manifest() -> AssetManifest {
 	return AssetManifest{
 		.audio_clips =
 			{
 				"sfx/bubble.wav",
+				"music/menu.mp3",
+				"music/game.mp3",
 			},
 		.particle_emitters =
 			{
@@ -38,7 +40,7 @@ auto Game::get_manifest() -> AssetManifest {
 	};
 }
 
-Game::Game(App& app, Services const& services) : Scene(app, services, "Game"), m_save(&app), m_world(&services, this) {
+GameScene::GameScene(App& app, Services const& services) : Scene(app, services, "Game"), m_save(&app), m_world(&services, this) {
 	clear_colour = services.get<Styles>().rgbas["mocha"];
 
 	auto hud = std::make_unique<Hud>(services);
@@ -49,19 +51,19 @@ Game::Game(App& app, Services const& services) : Scene(app, services, "Game"), m
 	++services.get<Stats>().game.play_count;
 }
 
-void Game::on_focus(FocusChange const& focus_change) { m_world.player.on_focus(focus_change); }
+void GameScene::on_focus(FocusChange const& focus_change) { m_world.player.on_focus(focus_change); }
 
-void Game::on_key(KeyInput const& key_input) {
+void GameScene::on_key(KeyInput const& key_input) {
 	if (key_input.key == Key::eEscape && key_input.action == Action::eRelease && key_input.mods == KeyMods{}) {
-		get_services().get<ISceneSwitcher>().switch_to<Home>();
+		get_services().get<ISceneSwitcher>().switch_to<MenuScene>();
 	}
 }
 
-void Game::on_move(PointerMove const& pointer_move) { m_world.player.on_move(pointer_move); }
+void GameScene::on_move(PointerMove const& pointer_move) { m_world.player.on_move(pointer_move); }
 
-void Game::on_tap(PointerTap const& pointer_tap) { m_world.player.on_tap(pointer_tap); }
+void GameScene::on_tap(PointerTap const& pointer_tap) { m_world.player.on_tap(pointer_tap); }
 
-void Game::tick(Seconds const dt) {
+void GameScene::tick(Seconds const dt) {
 	auto ft = bave::DeltaTime{};
 
 	m_world.tick(dt);
@@ -70,19 +72,19 @@ void Game::tick(Seconds const dt) {
 	if constexpr (bave::debug_v) { inspect(dt, ft.update()); }
 }
 
-void Game::render(Shader& shader) const { m_world.draw(shader); }
+void GameScene::render(Shader& shader) const { m_world.draw(shader); }
 
-void Game::add_score(std::int64_t const score) {
+void GameScene::add_score(std::int64_t const score) {
 	m_score += score;
 	m_hud->set_score(m_score);
 	update_hi_score();
 }
 
-void Game::on_game_over() {
+void GameScene::on_game_over() {
 	auto dci = ui::DialogCreateInfo{
 		.size = {600.0f, 200.0f},
 		.content_text = "GAME OVER",
-		.main_button = {.text = "RESTART", .callback = [this] { get_services().get<ISceneSwitcher>().switch_to<Game>(); }},
+		.main_button = {.text = "RESTART", .callback = [this] { get_services().get<ISceneSwitcher>().switch_to<GameScene>(); }},
 		.second_button = {.text = "QUIT", .callback = [this] { get_app().shutdown(); }},
 	};
 
@@ -91,13 +93,13 @@ void Game::on_game_over() {
 	push_view(std::move(dialog));
 }
 
-void Game::update_hi_score() {
+void GameScene::update_hi_score() {
 	if (m_score <= m_save.get_hi_score()) { return; }
 	m_save.set_hi_score(m_score);
 	m_hud->set_hi_score(m_save.get_hi_score());
 }
 
-void Game::inspect(Seconds const dt, Seconds const frame_time) {
+void GameScene::inspect(Seconds const dt, Seconds const frame_time) {
 	if constexpr (bave::imgui_v) {
 		m_debug.fps.tick(dt);
 
@@ -118,6 +120,9 @@ void Game::inspect(Seconds const dt, Seconds const frame_time) {
 			im_text("fps: {}", m_debug.fps.fps);
 			ImGui::SliderInt("fps limit", &m_debug.fps.limit, 5, 1000);
 			ImGui::Checkbox("fps lock", &m_debug.fps.lock);
+
+			ImGui::Separator();
+			if (ImGui::Button("reload scene")) { get_services().get<ISceneSwitcher>().switch_to<GameScene>(); }
 		}
 		ImGui::End();
 
diff --git a/src/spaced/spaced/scenes/game.hpp b/src/spaced/spaced/scenes/game.hpp
index 44419c9..3bd14d8 100644
--- a/src/spaced/spaced/scenes/game.hpp
+++ b/src/spaced/spaced/scenes/game.hpp
@@ -8,11 +8,11 @@
 #include <spaced/scene.hpp>
 
 namespace spaced {
-class Game : public Scene, public IScorer {
+class GameScene : public Scene, public IScorer {
   public:
 	static auto get_manifest() -> AssetManifest;
 
-	Game(bave::App& app, Services const& services);
+	GameScene(bave::App& app, Services const& services);
 
   private:
 	void on_focus(bave::FocusChange const& focus_change) final;
@@ -23,6 +23,8 @@ class Game : public Scene, public IScorer {
 	void tick(bave::Seconds dt) final;
 	void render(bave::Shader& shader) const final;
 
+	[[nodiscard]] auto get_music_uri() const -> std::string_view final { return "music/game.mp3"; }
+
 	[[nodiscard]] auto get_score() const -> std::int64_t final { return m_score; }
 	void add_score(std::int64_t score) final;
 	void on_game_over();
diff --git a/src/spaced/spaced/scenes/load_assets.cpp b/src/spaced/spaced/scenes/load_assets.cpp
index 8aef89a..ec6e481 100644
--- a/src/spaced/spaced/scenes/load_assets.cpp
+++ b/src/spaced/spaced/scenes/load_assets.cpp
@@ -1,7 +1,7 @@
 #include <spaced/assets/asset_list.hpp>
 #include <spaced/scenes/game.hpp>
-#include <spaced/scenes/home.hpp>
 #include <spaced/scenes/load_assets.hpp>
+#include <spaced/scenes/menu.hpp>
 #include <spaced/services/resources.hpp>
 #include <spaced/services/scene_switcher.hpp>
 #include <spaced/util.hpp>
@@ -15,11 +15,11 @@ using bave::Shader;
 namespace {
 auto make_load_stages(Loader loader, Services const& services) -> std::vector<AsyncExec::Stage> {
 	auto asset_list = AssetList{std::move(loader), services};
-	asset_list.add_manifest(Game::get_manifest());
+	asset_list.add_manifest(GameScene::get_manifest());
 	auto ret = asset_list.build_task_stages();
 	auto& stage = ret.emplace_back();
 	auto& resources = services.get<Resources>();
-	stage.push_back(util::create_font_atlas_task(resources.main_font, Home::get_text_heights()));
+	stage.push_back(util::create_font_atlas_task(resources.main_font, MenuScene::get_text_heights()));
 	return ret;
 }
 } // namespace
@@ -27,7 +27,7 @@ auto make_load_stages(Loader loader, Services const& services) -> std::vector<As
 LoadAssets::LoadAssets(App& app, Services const& services)
 	: Scene(app, services, "LoadAssets"), m_loading_screen(services), m_load(make_load_stages(make_loader(), services)) {}
 
-void LoadAssets::on_loaded() { get_services().get<ISceneSwitcher>().switch_to<Home>(); }
+void LoadAssets::on_loaded() { get_services().get<ISceneSwitcher>().switch_to<MenuScene>(); }
 
 void LoadAssets::tick(Seconds const dt) {
 	auto const load_status = m_load.update();
diff --git a/src/spaced/spaced/scenes/home.cpp b/src/spaced/spaced/scenes/menu.cpp
similarity index 76%
rename from src/spaced/spaced/scenes/home.cpp
rename to src/spaced/spaced/scenes/menu.cpp
index 8c817c4..d65db83 100644
--- a/src/spaced/spaced/scenes/home.cpp
+++ b/src/spaced/spaced/scenes/menu.cpp
@@ -1,5 +1,5 @@
 #include <spaced/scenes/game.hpp>
-#include <spaced/scenes/home.hpp>
+#include <spaced/scenes/menu.hpp>
 #include <spaced/services/layout.hpp>
 #include <spaced/services/resources.hpp>
 #include <spaced/services/scene_switcher.hpp>
@@ -13,11 +13,11 @@ using bave::App;
 using bave::Seconds;
 using bave::TextHeight;
 
-auto Home::get_text_heights() -> std::vector<TextHeight> { return {TextHeight{100}, TextHeight{60}, ui::Dialog::text_height_v}; }
+auto MenuScene::get_text_heights() -> std::vector<TextHeight> { return {TextHeight{100}, TextHeight{60}, ui::Dialog::text_height_v}; }
 
-Home::Home(App& app, Services const& services) : Scene(app, services, "Home") { create_ui(); }
+MenuScene::MenuScene(App& app, Services const& services) : Scene(app, services, "Home") { create_ui(); }
 
-void Home::create_ui() {
+void MenuScene::create_ui() {
 	auto m_header = std::make_unique<ui::Text>(get_services());
 	m_header->text.set_height(TextHeight{100}).set_string("Home");
 	m_header->text.tint = bave::white_v;
@@ -25,7 +25,7 @@ void Home::create_ui() {
 	auto start = std::make_unique<ui::Button>(get_services());
 	start->set_text("start");
 	start->set_position({0.0f, -200.0f});
-	start->callback = [this]() { get_services().get<ISceneSwitcher>().switch_to<Game>(); };
+	start->callback = [this]() { get_services().get<ISceneSwitcher>().switch_to<GameScene>(); };
 
 	auto quit = std::make_unique<ui::Button>(get_services());
 	quit->set_text("quit");
diff --git a/src/spaced/spaced/scenes/home.hpp b/src/spaced/spaced/scenes/menu.hpp
similarity index 50%
rename from src/spaced/spaced/scenes/home.hpp
rename to src/spaced/spaced/scenes/menu.hpp
index be6028b..bfc7694 100644
--- a/src/spaced/spaced/scenes/home.hpp
+++ b/src/spaced/spaced/scenes/menu.hpp
@@ -2,13 +2,15 @@
 #include <spaced/scene.hpp>
 
 namespace spaced {
-class Home : public Scene {
+class MenuScene : public Scene {
   public:
 	static auto get_text_heights() -> std::vector<bave::TextHeight>;
 
-	explicit Home(bave::App& app, Services const& services);
+	explicit MenuScene(bave::App& app, Services const& services);
 
   private:
 	void create_ui();
+
+	[[nodiscard]] auto get_music_uri() const -> std::string_view final { return "music/menu.mp3"; }
 };
 } // namespace spaced
diff --git a/src/spaced/spaced/spaced.cpp b/src/spaced/spaced/spaced.cpp
index 1ef724d..3dc3661 100644
--- a/src/spaced/spaced/spaced.cpp
+++ b/src/spaced/spaced/spaced.cpp
@@ -161,7 +161,7 @@ void Spaced::tick() {
 	m_layout->set_framebuffer_size(get_app().get_framebuffer_size());
 
 	if (m_scene_switcher->next_scene) {
-		m_audio->stop_music();
+		switch_track(m_scene->get_music_uri(), m_scene_switcher->next_scene->get_music_uri());
 		m_scene = std::move(m_scene_switcher->next_scene);
 	}
 
@@ -234,4 +234,12 @@ void Spaced::set_scene() {
 	switcher->switch_to<LoadAssets>();
 	m_services.bind<ISceneSwitcher>(std::move(switcher));
 }
+
+void Spaced::switch_track(std::string_view const from, std::string_view const to) const {
+	if (to.empty()) {
+		m_audio->stop_music();
+	} else if (from != to) {
+		m_audio->play_music(to);
+	}
+}
 } // namespace spaced
diff --git a/src/spaced/spaced/spaced.hpp b/src/spaced/spaced/spaced.hpp
index c8ac94a..f2645ab 100644
--- a/src/spaced/spaced/spaced.hpp
+++ b/src/spaced/spaced/spaced.hpp
@@ -30,6 +30,8 @@ class Spaced : public bave::Driver {
 	void set_layout();
 	void set_scene();
 
+	void switch_track(std::string_view from, std::string_view to) const;
+
 	bave::Logger m_log{"Spaced"};
 	Services m_services{};
 	bave::Ptr<ILayout> m_layout{};

From 03703f9fc070995f29ba50ecb0d42d25a449bde4 Mon Sep 17 00:00:00 2001
From: Karn Kaul <karnkaul@gmail.com>
Date: Thu, 6 Jun 2024 16:53:11 +0530
Subject: [PATCH 2/5] Add `ui::Slider`.

---
 assets/styles.json                    |  7 ++
 src/spaced/spaced/game/enemy.cpp      |  3 +-
 src/spaced/spaced/services/styles.cpp |  2 +
 src/spaced/spaced/services/styles.hpp |  1 +
 src/spaced/spaced/ui/progress_bar.hpp |  6 +-
 src/spaced/spaced/ui/slider.cpp       | 99 +++++++++++++++++++++++++++
 src/spaced/spaced/ui/slider.hpp       | 46 +++++++++++++
 src/spaced/spaced/ui/style.hpp        |  6 ++
 src/spaced/spaced/util.cpp            | 14 ++++
 src/spaced/spaced/util.hpp            |  3 +
 10 files changed, 183 insertions(+), 4 deletions(-)
 create mode 100644 src/spaced/spaced/ui/slider.cpp
 create mode 100644 src/spaced/spaced/ui/slider.hpp

diff --git a/assets/styles.json b/assets/styles.json
index 67571fe..50dd488 100644
--- a/assets/styles.json
+++ b/assets/styles.json
@@ -55,6 +55,13 @@
       "content_text_tint": "#231d2aff"
     }
   },
+  "sliders": {
+    "default": {
+      "progress_bar": "default",
+      "knob_diameter": 30,
+      "knob_tint": "#9f2b68ff"
+    }
+  },
   "loading_screen": {
     "background_tint": "#231d2aff",
     "spinner": {
diff --git a/src/spaced/spaced/game/enemy.cpp b/src/spaced/spaced/game/enemy.cpp
index df89f08..e6e6a39 100644
--- a/src/spaced/spaced/game/enemy.cpp
+++ b/src/spaced/spaced/game/enemy.cpp
@@ -32,12 +32,11 @@ void Enemy::force_death() {
 	m_health_bar.set_progress(0.0f);
 }
 
-void Enemy::tick(Seconds const dt, bool const /*in_play*/) {
+void Enemy::tick(Seconds const /*dt*/, bool const /*in_play*/) {
 	m_health_bar.position = shape.transform.position;
 	m_health_bar.position.y += 0.5f * shape.get_shape().size.y + 20.0f;
 	m_health_bar.size = {shape.get_shape().size.x, 10.0f};
 	m_health_bar.set_progress(health.get_hit_points() / health.get_total_hit_points());
-	m_health_bar.tick(dt);
 }
 
 void Enemy::draw(Shader& shader) const {
diff --git a/src/spaced/spaced/services/styles.cpp b/src/spaced/spaced/services/styles.cpp
index bb86e6b..f2065d9 100644
--- a/src/spaced/spaced/services/styles.cpp
+++ b/src/spaced/spaced/services/styles.cpp
@@ -36,6 +36,7 @@ auto Styles::load(dj::Json const& json) -> Styles {
 	load_styles(ret.buttons, json["buttons"]);
 	load_styles(ret.progress_bars, json["progress_bars"]);
 	load_styles(ret.dialogs, json["dialogs"]);
+	load_styles(ret.sliders, json["sliders"]);
 	if (auto const& loading_screen = json["loading_screen"]) { from_json(loading_screen, ret.loading_screen); }
 	return ret;
 }
@@ -46,6 +47,7 @@ auto Styles::save() const -> dj::Json {
 	save_styles(buttons, ret, "buttons");
 	save_styles(progress_bars, ret, "progress_bars");
 	save_styles(dialogs, ret, "dialogs");
+	save_styles(sliders, ret, "sliders");
 	to_json(ret["loading_screen"], loading_screen);
 	return ret;
 }
diff --git a/src/spaced/spaced/services/styles.hpp b/src/spaced/spaced/services/styles.hpp
index 64c42ad..32a8d8a 100644
--- a/src/spaced/spaced/services/styles.hpp
+++ b/src/spaced/spaced/services/styles.hpp
@@ -13,6 +13,7 @@ struct Styles : IService {
 	StringMap<ui::ButtonStyle> buttons{};
 	StringMap<ui::ProgressBarStyle> progress_bars{};
 	StringMap<ui::DialogStyle> dialogs{};
+	StringMap<ui::SliderStyle> sliders{};
 	ui::LoadingScreenStyle loading_screen{};
 
 	static auto load(dj::Json const& json) -> Styles;
diff --git a/src/spaced/spaced/ui/progress_bar.hpp b/src/spaced/spaced/ui/progress_bar.hpp
index 02dd8a9..b86037f 100644
--- a/src/spaced/spaced/ui/progress_bar.hpp
+++ b/src/spaced/spaced/ui/progress_bar.hpp
@@ -1,11 +1,11 @@
 #pragma once
 #include <spaced/services/services.hpp>
+#include <spaced/ui/element.hpp>
 #include <spaced/ui/outline_quad.hpp>
 #include <spaced/ui/style.hpp>
-#include <spaced/ui/widget.hpp>
 
 namespace spaced::ui {
-class ProgressBar : public IWidget {
+class ProgressBar : public IElement {
   public:
 	using Style = ProgressBarStyle;
 
@@ -26,6 +26,8 @@ class ProgressBar : public IWidget {
 	[[nodiscard]] auto get_position() const -> glm::vec2 final { return position; }
 	void set_position(glm::vec2 position) final { this->position = position; }
 
+	[[nodiscard]] auto get_bounds() const -> bave::Rect<> { return m_background.get_bounds(); }
+
   private:
 	Style m_style{};
 
diff --git a/src/spaced/spaced/ui/slider.cpp b/src/spaced/spaced/ui/slider.cpp
new file mode 100644
index 0000000..ff68b67
--- /dev/null
+++ b/src/spaced/spaced/ui/slider.cpp
@@ -0,0 +1,99 @@
+#include <spaced/services/styles.hpp>
+#include <spaced/ui/slider.hpp>
+#include <algorithm>
+
+namespace spaced::ui {
+using bave::Action;
+using bave::MouseButton;
+using bave::PointerId;
+using bave::PointerMove;
+using bave::PointerTap;
+using bave::Rect;
+using bave::Shader;
+
+Slider::Slider(Services const& services) : m_styles(&services.get<Styles>()), m_progress_bar(services) {
+	set_style(m_styles->sliders["default"]);
+	set_value(0.0f);
+}
+
+auto Slider::get_size() const -> glm::vec2 {
+	auto ret = m_progress_bar.get_size();
+	ret.y = m_knob.get_shape().diameter;
+	return ret;
+}
+
+void Slider::set_position(glm::vec2 const position) {
+	m_progress_bar.set_position(position);
+	set_value(m_value);
+}
+
+void Slider::set_value(float const value) {
+	update_value(std::clamp(value, 0.0f, 1.0f));
+	auto const origin = m_progress_bar.get_position();
+	auto const size = m_progress_bar.get_size();
+	auto const left_x = origin.x - 0.5f * size.x;
+	auto const delta = m_value * size.x;
+
+	m_knob.transform.position = glm::vec2{left_x + delta, origin.y};
+	m_progress_bar.set_progress(m_value);
+
+	if (on_change) { on_change(m_value); }
+}
+
+void Slider::set_style(Style style) {
+	m_style = std::move(style);
+	m_knob.tint = m_style.knob_tint;
+	auto shape = m_knob.get_shape();
+	shape.diameter = m_style.knob_diameter;
+	m_knob.set_shape(shape);
+	m_progress_bar.set_style(m_styles->progress_bars[m_style.progress_bar]);
+}
+
+void Slider::draw(Shader& shader) const {
+	m_progress_bar.draw(shader);
+	m_knob.draw(shader);
+}
+
+void Slider::on_tap(PointerTap const& pointer_tap) {
+	if (pointer_tap.pointer.id != PointerId::ePrimary || pointer_tap.button != MouseButton::eLeft) { return; }
+	switch (pointer_tap.action) {
+	case Action::ePress: m_pointer_down = hit_test(pointer_tap.pointer.position); break;
+	case Action::eRelease: m_pointer_down = false; break;
+	default: break;
+	}
+
+	if (m_pointer_down) { track(pointer_tap.pointer.position); }
+}
+
+void Slider::on_move(PointerMove const& pointer_move) {
+	if (pointer_move.pointer.id != PointerId::ePrimary) { return; }
+	if (!m_pointer_down) { return; }
+	track(pointer_move.pointer.position);
+}
+
+auto Slider::hit_test(glm::vec2 const position) const -> bool {
+	auto const bar_rect = Rect<>::from_size(m_progress_bar.get_size(), m_progress_bar.get_position());
+	if (bar_rect.contains(position)) { return true; }
+	if (m_knob.get_bounds().contains(position)) { return true; }
+	return false;
+}
+
+void Slider::track(glm::vec2 const pointer) {
+	auto const pointer_x = pointer.x;
+	auto const origin_x = m_progress_bar.get_position().x;
+	auto const size_x = m_progress_bar.get_size().x;
+	auto const left_x = origin_x - 0.5f * size_x;
+	auto const right_x = origin_x + 0.5f * size_x;
+	auto const knob_x = std::clamp(pointer_x, left_x, right_x);
+
+	m_knob.transform.position.x = knob_x;
+	update_value((knob_x - left_x) / size_x);
+	m_progress_bar.set_progress(m_value);
+}
+
+void Slider::update_value(float const value) {
+	if (std::abs(m_value - value) < 0.001f) { return; }
+	m_value = value;
+	if (on_change) { on_change(m_value); }
+}
+} // namespace spaced::ui
diff --git a/src/spaced/spaced/ui/slider.hpp b/src/spaced/spaced/ui/slider.hpp
new file mode 100644
index 0000000..dfda708
--- /dev/null
+++ b/src/spaced/spaced/ui/slider.hpp
@@ -0,0 +1,46 @@
+#pragma once
+#include <spaced/services/styles.hpp>
+#include <spaced/ui/progress_bar.hpp>
+#include <spaced/ui/style.hpp>
+#include <spaced/ui/widget.hpp>
+#include <functional>
+
+namespace spaced::ui {
+class Slider : public IWidget {
+  public:
+	using Style = SliderStyle;
+
+	explicit Slider(Services const& services);
+
+	[[nodiscard]] auto get_size() const -> glm::vec2 final;
+	[[nodiscard]] auto get_position() const -> glm::vec2 final { return m_progress_bar.get_position(); }
+	void set_position(glm::vec2 position) final;
+
+	[[nodiscard]] auto get_value() const -> float { return m_value; }
+	void set_value(float value);
+
+	[[nodiscard]] auto get_style() const -> Style { return m_style; }
+	void set_style(Style style);
+
+	std::function<void(float)> on_change{};
+
+  protected:
+	void draw(bave::Shader& shader) const final;
+	void on_move(bave::PointerMove const& pointer_move) final;
+	void on_tap(bave::PointerTap const& pointer_tap) final;
+
+	[[nodiscard]] auto hit_test(glm::vec2 position) const -> bool;
+	void track(glm::vec2 pointer);
+
+	void update_value(float value);
+
+	bave::NotNull<Styles const*> m_styles;
+	Style m_style{};
+
+	ui::ProgressBar m_progress_bar;
+	bave::CircleShape m_knob{};
+	float m_value{};
+
+	bool m_pointer_down{};
+};
+} // namespace spaced::ui
diff --git a/src/spaced/spaced/ui/style.hpp b/src/spaced/spaced/ui/style.hpp
index 014ef53..f7405b3 100644
--- a/src/spaced/spaced/ui/style.hpp
+++ b/src/spaced/spaced/ui/style.hpp
@@ -46,4 +46,10 @@ struct DialogStyle {
 	bave::Rgba outline_tint{bave::cyan_v};
 	bave::Rgba content_text_tint{bave::black_v};
 };
+
+struct SliderStyle {
+	std::string progress_bar{};
+	float knob_diameter{30.0f};
+	bave::Rgba knob_tint{bave::white_v};
+};
 } // namespace spaced::ui
diff --git a/src/spaced/spaced/util.cpp b/src/spaced/spaced/util.cpp
index ce46c37..9886888 100644
--- a/src/spaced/spaced/util.cpp
+++ b/src/spaced/spaced/util.cpp
@@ -89,6 +89,20 @@ void util::from_json(dj::Json const& json, ui::DialogStyle& out) {
 	from_json(json["content_text_tint"], out.content_text_tint);
 }
 
+void util::to_json(dj::Json& out, ui::SliderStyle const& slider_style) {
+	using bave::to_json;
+	to_json(out["progress_bar"], slider_style.progress_bar);
+	to_json(out["knob_diameter"], slider_style.knob_diameter);
+	to_json(out["knob_tint"], slider_style.knob_tint);
+}
+
+void util::from_json(dj::Json const& json, ui::SliderStyle& out) {
+	using bave::from_json;
+	from_json(json["progress_bar"], out.progress_bar);
+	from_json(json["knob_diameter"], out.knob_diameter);
+	from_json(json["knob_tint"], out.knob_tint);
+}
+
 auto util::create_font_atlas_task(std::shared_ptr<bave::Font> font, std::vector<bave::TextHeight> heights) -> std::function<void()> {
 	if (!font || heights.empty()) { return {}; }
 	return [font = std::move(font), heights = std::move(heights)] {
diff --git a/src/spaced/spaced/util.hpp b/src/spaced/spaced/util.hpp
index be29deb..89bbbb4 100644
--- a/src/spaced/spaced/util.hpp
+++ b/src/spaced/spaced/util.hpp
@@ -20,5 +20,8 @@ void from_json(dj::Json const& json, ui::ProgressBarStyle& out);
 void to_json(dj::Json& out, ui::DialogStyle const& dialog_style);
 void from_json(dj::Json const& json, ui::DialogStyle& out);
 
+void to_json(dj::Json& out, ui::SliderStyle const& slider_style);
+void from_json(dj::Json const& json, ui::SliderStyle& out);
+
 auto create_font_atlas_task(std::shared_ptr<bave::Font> font, std::vector<bave::TextHeight> heights) -> std::function<void()>;
 } // namespace spaced::util

From 521abc4d08c14633b60aa17aa0b381a8a09c04ad Mon Sep 17 00:00:00 2001
From: Karn Kaul <karnkaul@gmail.com>
Date: Thu, 13 Jun 2024 14:06:57 +0530
Subject: [PATCH 3/5] Fix mutable `ui::View` iteration: use cached views.

---
 src/spaced/spaced/scene.cpp | 12 ++++++++++--
 src/spaced/spaced/scene.hpp |  3 +++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/spaced/spaced/scene.cpp b/src/spaced/spaced/scene.cpp
index 5628373..a339c55 100644
--- a/src/spaced/spaced/scene.cpp
+++ b/src/spaced/spaced/scene.cpp
@@ -38,7 +38,7 @@ void Scene::push_view(std::unique_ptr<ui::View> view) {
 
 void Scene::tick_frame(Seconds const dt) {
 	tick(dt);
-	for (auto const& view : m_views) { view->tick(dt); }
+	for (auto const& view : cache_views()) { view->tick(dt); }
 	std::erase_if(m_views, [](auto const& view) { return view->is_destroyed(); });
 }
 
@@ -51,11 +51,19 @@ void Scene::render_frame() const {
 
 template <typename F>
 auto Scene::on_ui_event(F per_view) -> bool {
-	for (auto it = m_views.rbegin(); it != m_views.rend(); ++it) {
+	auto const cached_views = cache_views();
+	for (auto it = cached_views.rbegin(); it != cached_views.rend(); ++it) {
 		auto const& view = *it;
 		per_view(*view);
 		if (view->block_input_events) { return true; }
 	}
 	return false;
 }
+
+auto Scene::cache_views() -> std::span<bave::Ptr<ui::View> const> {
+	m_cached_views.clear();
+	m_cached_views.reserve(m_views.size());
+	for (auto const& view : m_views) { m_cached_views.push_back(view.get()); }
+	return m_cached_views;
+}
 } // namespace spaced
diff --git a/src/spaced/spaced/scene.hpp b/src/spaced/spaced/scene.hpp
index cbf320d..77acfcd 100644
--- a/src/spaced/spaced/scene.hpp
+++ b/src/spaced/spaced/scene.hpp
@@ -51,8 +51,11 @@ class Scene : public bave::PolyPinned {
 	template <typename F>
 	auto on_ui_event(F per_view) -> bool;
 
+	auto cache_views() -> std::span<bave::Ptr<ui::View> const>;
+
 	bave::App& m_app;
 	Services const& m_services;
 	std::vector<std::unique_ptr<ui::View>> m_views{};
+	std::vector<bave::Ptr<ui::View>> m_cached_views{};
 };
 } // namespace spaced

From 0d6a85cdcfadfe98d72379916cad5f154f0ca5c6 Mon Sep 17 00:00:00 2001
From: Karn Kaul <karnkaul@gmail.com>
Date: Thu, 13 Jun 2024 14:07:39 +0530
Subject: [PATCH 4/5] Fix redundant on change callbacks in `ui::Slider`.

---
 src/spaced/spaced/ui/slider.cpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/spaced/spaced/ui/slider.cpp b/src/spaced/spaced/ui/slider.cpp
index ff68b67..390fab0 100644
--- a/src/spaced/spaced/ui/slider.cpp
+++ b/src/spaced/spaced/ui/slider.cpp
@@ -36,8 +36,6 @@ void Slider::set_value(float const value) {
 
 	m_knob.transform.position = glm::vec2{left_x + delta, origin.y};
 	m_progress_bar.set_progress(m_value);
-
-	if (on_change) { on_change(m_value); }
 }
 
 void Slider::set_style(Style style) {

From 041fda138179dafe3f47ccc06faf71a464f1608a Mon Sep 17 00:00:00 2001
From: Karn Kaul <karnkaul@gmail.com>
Date: Thu, 13 Jun 2024 14:39:06 +0530
Subject: [PATCH 5/5] Add `Prefs` and its UI.

---
 src/spaced/spaced/prefs.cpp       | 85 +++++++++++++++++++++++++++++++
 src/spaced/spaced/prefs.hpp       | 33 ++++++++++++
 src/spaced/spaced/scenes/menu.cpp | 10 +++-
 src/spaced/spaced/spaced.cpp      |  8 +++
 src/spaced/spaced/spaced.hpp      |  1 +
 5 files changed, 136 insertions(+), 1 deletion(-)
 create mode 100644 src/spaced/spaced/prefs.cpp
 create mode 100644 src/spaced/spaced/prefs.hpp

diff --git a/src/spaced/spaced/prefs.cpp b/src/spaced/spaced/prefs.cpp
new file mode 100644
index 0000000..da68d6d
--- /dev/null
+++ b/src/spaced/spaced/prefs.cpp
@@ -0,0 +1,85 @@
+#include <bave/persistor.hpp>
+#include <djson/json.hpp>
+#include <spaced/prefs.hpp>
+#include <spaced/services/audio.hpp>
+#include <spaced/services/styles.hpp>
+#include <spaced/ui/button.hpp>
+#include <spaced/ui/slider.hpp>
+#include <spaced/ui/text.hpp>
+
+namespace spaced {
+using bave::App;
+using bave::NotNull;
+using bave::Persistor;
+
+namespace {
+constexpr std::string_view uri_v{"spaced/prefs.json"};
+} // namespace
+
+auto Prefs::load(App const& app) -> Prefs {
+	auto ret = Prefs{};
+	auto const persistor = Persistor{app};
+	if (persistor.exists(uri_v)) {
+		auto const json = persistor.read_json(uri_v);
+		from_json(json["music_gain"], ret.music_gain);
+		from_json(json["sfx_gain"], ret.sfx_gain);
+	}
+	return ret;
+}
+
+void Prefs::save(App const& app) const {
+	auto json = dj::Json{};
+	to_json(json["music_gain"], music_gain);
+	to_json(json["sfx_gain"], sfx_gain);
+	auto const persistor = Persistor{app};
+	persistor.write_json(uri_v, json);
+}
+
+Prefs::View::View(NotNull<App const*> app, Services const& services)
+	: ui::View(services), m_app(app), m_audio(&services.get<IAudio>()), m_prefs(Prefs::load(*app)) {
+	auto const& styles = services.get<Styles>();
+
+	auto bg = std::make_unique<ui::OutlineQuad>();
+	bg->set_size({400.0f, 400.0f});
+	bg->set_outline_width(5.0f);
+	bg->set_corner_ratio(0.1f);
+	bg->set_tint(styles.rgbas["milk"]);
+	push(std::move(bg));
+
+	auto text = std::make_unique<ui::Text>(services);
+	text->text.set_string("music");
+	text->set_position({0.0f, 130.0f});
+	push(std::move(text));
+
+	auto slider = std::make_unique<ui::Slider>(services);
+	slider->set_value(m_prefs.music_gain);
+	slider->on_change = [this](float const val) {
+		m_prefs.music_gain = val;
+		m_audio->set_music_gain(val);
+	};
+	slider->set_position({0.0f, 100.0f});
+	push(std::move(slider));
+
+	text = std::make_unique<ui::Text>(services);
+	text->text.set_string("sfx");
+	text->set_position({0.0f, 30.0f});
+	push(std::move(text));
+
+	slider = std::make_unique<ui::Slider>(services);
+	slider->set_value(m_prefs.sfx_gain);
+	slider->on_change = [this](float const val) {
+		m_prefs.sfx_gain = val;
+		m_audio->set_sfx_gain(val);
+	};
+	slider->set_position({0.0f, 0.0f});
+	push(std::move(slider));
+
+	auto button = std::make_unique<ui::Button>(services);
+	button->set_text("close");
+	button->callback = [this] { set_destroyed(); };
+	button->set_position({0.0f, -100.0f});
+	push(std::move(button));
+}
+
+Prefs::View::~View() { m_prefs.save(*m_app); }
+} // namespace spaced
diff --git a/src/spaced/spaced/prefs.hpp b/src/spaced/spaced/prefs.hpp
new file mode 100644
index 0000000..be0863d
--- /dev/null
+++ b/src/spaced/spaced/prefs.hpp
@@ -0,0 +1,33 @@
+#pragma once
+#include <bave/app.hpp>
+#include <spaced/ui/view.hpp>
+
+namespace spaced {
+class IAudio;
+
+struct Prefs {
+	class View;
+
+	float music_gain{1.0f};
+	float sfx_gain{1.0f};
+
+	static auto load(bave::App const& app) -> Prefs;
+	void save(bave::App const& app) const;
+};
+
+class Prefs::View : public ui::View {
+  public:
+	View(View const&) = delete;
+	View(View&&) = delete;
+	auto operator=(View const&) = delete;
+	auto operator=(View&&) = delete;
+
+	explicit View(bave::NotNull<bave::App const*> app, Services const& services);
+	~View() override;
+
+  private:
+	bave::NotNull<bave::App const*> m_app;
+	bave::NotNull<IAudio*> m_audio;
+	Prefs m_prefs;
+};
+} // namespace spaced
diff --git a/src/spaced/spaced/scenes/menu.cpp b/src/spaced/spaced/scenes/menu.cpp
index d65db83..650c229 100644
--- a/src/spaced/spaced/scenes/menu.cpp
+++ b/src/spaced/spaced/scenes/menu.cpp
@@ -1,3 +1,4 @@
+#include <spaced/prefs.hpp>
 #include <spaced/scenes/game.hpp>
 #include <spaced/scenes/menu.hpp>
 #include <spaced/services/layout.hpp>
@@ -20,13 +21,19 @@ MenuScene::MenuScene(App& app, Services const& services) : Scene(app, services,
 void MenuScene::create_ui() {
 	auto m_header = std::make_unique<ui::Text>(get_services());
 	m_header->text.set_height(TextHeight{100}).set_string("Home");
+	m_header->set_position({0.0f, 100.0f});
 	m_header->text.tint = bave::white_v;
 
 	auto start = std::make_unique<ui::Button>(get_services());
 	start->set_text("start");
-	start->set_position({0.0f, -200.0f});
+	start->set_position({0.0f, -100.0f});
 	start->callback = [this]() { get_services().get<ISceneSwitcher>().switch_to<GameScene>(); };
 
+	auto options = std::make_unique<ui::Button>(get_services());
+	options->set_text("options");
+	options->set_position({0.0f, -250.0f});
+	options->callback = [this] { push_view(std::make_unique<Prefs::View>(&get_app(), get_services())); };
+
 	auto quit = std::make_unique<ui::Button>(get_services());
 	quit->set_text("quit");
 	quit->set_position({0.0f, -400.0f});
@@ -35,6 +42,7 @@ void MenuScene::create_ui() {
 	auto view = std::make_unique<ui::View>(get_services());
 	view->push(std::move(m_header));
 	view->push(std::move(start));
+	view->push(std::move(options));
 	view->push(std::move(quit));
 	push_view(std::move(view));
 }
diff --git a/src/spaced/spaced/spaced.cpp b/src/spaced/spaced/spaced.cpp
index 3dc3661..21ddd17 100644
--- a/src/spaced/spaced/spaced.cpp
+++ b/src/spaced/spaced/spaced.cpp
@@ -2,6 +2,7 @@
 #include <bave/io/json_io.hpp>
 #include <bave/loader.hpp>
 #include <bave/persistor.hpp>
+#include <spaced/prefs.hpp>
 #include <spaced/scenes/load_assets.hpp>
 #include <spaced/services/audio.hpp>
 #include <spaced/services/gamepad_provider.hpp>
@@ -143,6 +144,7 @@ Spaced::Spaced(App& app) : Driver(app), m_scene(std::make_unique<Scene>(app, m_s
 	load_resources();
 	set_layout();
 	create_services();
+	set_prefs();
 	set_scene();
 }
 
@@ -228,6 +230,12 @@ void Spaced::create_services() {
 	m_services.bind<Stats>(std::move(stats));
 }
 
+void Spaced::set_prefs() {
+	auto const prefs = Prefs::load(get_app());
+	m_audio->set_music_gain(prefs.music_gain);
+	m_audio->set_sfx_gain(prefs.sfx_gain);
+}
+
 void Spaced::set_scene() {
 	auto switcher = std::make_unique<SceneSwitcher>(get_app(), m_services);
 	m_scene_switcher = switcher.get();
diff --git a/src/spaced/spaced/spaced.hpp b/src/spaced/spaced/spaced.hpp
index f2645ab..42de8b9 100644
--- a/src/spaced/spaced/spaced.hpp
+++ b/src/spaced/spaced/spaced.hpp
@@ -28,6 +28,7 @@ class Spaced : public bave::Driver {
 	void load_resources();
 	void create_services();
 	void set_layout();
+	void set_prefs();
 	void set_scene();
 
 	void switch_track(std::string_view from, std::string_view to) const;