From 1fab6d64308a7abd940d49d03af329473f928526 Mon Sep 17 00:00:00 2001
From: Karn Kaul <karnkaul@gmail.com>
Date: Thu, 1 Feb 2024 23:07:00 +0530
Subject: [PATCH] Add `EnumFlags`, replace all raw bitsets.

---
 lib/docs/changelog.md                         |  4 +--
 lib/include/bave/app.hpp                      | 15 ++++-----
 lib/include/bave/core/enum_flags.hpp          | 33 +++++++++++++++++++
 lib/include/bave/core/make_bitset.hpp         | 31 -----------------
 .../bave/graphics/particle_emitter.hpp        |  6 ++--
 lib/include/bave/input/gamepad.hpp            |  6 ++--
 lib/include/bave/input/key_state.hpp          |  8 ++---
 lib/include/bave/input/mods.hpp               | 12 ++-----
 lib/platform/desktop/desktop_app.cpp          | 20 +++++------
 lib/src/app.cpp                               |  4 +--
 lib/src/graphics/particle_emitter.cpp         |  8 ++---
 tools/src/tools/runner.cpp                    |  2 +-
 12 files changed, 70 insertions(+), 79 deletions(-)
 create mode 100644 lib/include/bave/core/enum_flags.hpp
 delete mode 100644 lib/include/bave/core/make_bitset.hpp

diff --git a/lib/docs/changelog.md b/lib/docs/changelog.md
index fd9a4b4..dad3fe8 100644
--- a/lib/docs/changelog.md
+++ b/lib/docs/changelog.md
@@ -7,8 +7,8 @@
 - Added bave::Gamepad support, queried through bave::App::get_gamepad() and bave::App::get_gamepads().
   - Not yet supported on Android.
 - Added bave::KeyState and bave::App::get_key_state().
+- Added bave::EnumFlags.
 
 ### Changes
 
-- Replaced `bave::mod::*` with bave::Mod.
-- Refactored bave::ParticleEmitter::Modifier into an enum.
+- Unified all bit flags to be bave::EnumFlags.
diff --git a/lib/include/bave/app.hpp b/lib/include/bave/app.hpp
index 6946abe..3db822a 100644
--- a/lib/include/bave/app.hpp
+++ b/lib/include/bave/app.hpp
@@ -32,16 +32,15 @@ enum struct ErrCode : int { eSuccess = EXIT_SUCCESS, eFailure = EXIT_FAILURE };
 class App : public PolyPinned {
   public:
 	/// \brief Individual feature flags.
-	struct Feature {
-		static constexpr std::size_t resizeable{0};
-		static constexpr std::size_t has_title{1};
-		static constexpr std::size_t has_icon{2};
-		static constexpr std::size_t validation_layers{3};
-
-		static constexpr std::size_t count_v{8};
+	enum class Feature : int {
+		eResizeable,
+		eHasTitle,
+		eHasIcon,
+		eValidationLayers,
+		eCOUNT_,
 	};
 	/// \brief Bitset of feature flags.
-	using FeatureFlags = std::bitset<Feature::count_v>;
+	using FeatureFlags = EnumFlags<Feature>;
 
 	/// \brief Driver Factory.
 	using Bootloader = std::function<std::unique_ptr<class Driver>(App&)>;
diff --git a/lib/include/bave/core/enum_flags.hpp b/lib/include/bave/core/enum_flags.hpp
new file mode 100644
index 0000000..b20f3c1
--- /dev/null
+++ b/lib/include/bave/core/enum_flags.hpp
@@ -0,0 +1,33 @@
+#pragma once
+#include <bave/core/enum_t.hpp>
+#include <bitset>
+
+namespace bave {
+/// \brief Enum-indexed wrapper around std::bitset.
+template <EnumT E, std::size_t Size = std::size_t(E::eCOUNT_)>
+class EnumFlags : public std::bitset<Size> {
+  public:
+	using std::bitset<Size>::bitset;
+
+	/// \brief Constructor taking multiple flags.
+	/// \param to_set flags to set.
+	template <std::same_as<E>... T>
+	EnumFlags(T const... to_set) {
+		(this->set(to_set), ...);
+	}
+
+	/// \brief Test if a flag is set.
+	/// \param e Flag to test for.
+	/// \returns true if set.
+	[[nodiscard]] auto test(E const e) const -> bool { return std::bitset<Size>::test(static_cast<std::size_t>(e)); }
+	/// \brief Set a flag.
+	/// \param e Flag to set.
+	void set(E const e) { std::bitset<Size>::set(static_cast<std::size_t>(e)); }
+	/// \brief Reset a flag.
+	/// \param e Flag to reset.
+	void reset(E const e) { std::bitset<Size>::reset(static_cast<std::size_t>(e)); }
+
+	[[nodiscard]] auto operator[](E const e) -> decltype(auto) { return std::bitset<Size>::operator[](static_cast<std::size_t>(e)); }
+	[[nodiscard]] auto operator[](E const e) const -> decltype(auto) { return std::bitset<Size>::operator[](static_cast<std::size_t>(e)); }
+};
+} // namespace bave
diff --git a/lib/include/bave/core/make_bitset.hpp b/lib/include/bave/core/make_bitset.hpp
deleted file mode 100644
index 59850c5..0000000
--- a/lib/include/bave/core/make_bitset.hpp
+++ /dev/null
@@ -1,31 +0,0 @@
-#pragma once
-#include <bave/core/enum_t.hpp>
-#include <bitset>
-
-namespace bave {
-/// \brief Create a std::bitset with bits set.
-/// \param bits bits to set.
-/// \returns std::bitset<Size> with bits set.
-template <std::size_t Size, std::convertible_to<std::size_t>... I>
-auto make_bitset(I const... bits) -> std::bitset<Size> {
-	auto ret = std::bitset<Size>{};
-	(ret.set(bits), ...);
-	return ret;
-}
-
-/// \brief Create a std::bitset with bits set.
-/// \param bits bits to set.
-/// \returns Ret with bits set.
-template <typename Ret, std::convertible_to<std::size_t>... I>
-auto make_bitset(I const... bits) -> Ret {
-	return make_bitset<Ret{}.size()>(bits...);
-}
-
-/// \brief Create a std::bitset with bits set.
-/// \param bits bits to set, as enum values.
-/// \returns Ret with bits set.
-template <typename Ret, EnumT... I>
-auto make_bitset(I const... bits) -> Ret {
-	return make_bitset<Ret>(static_cast<std::size_t>(bits)...);
-}
-} // namespace bave
diff --git a/lib/include/bave/graphics/particle_emitter.hpp b/lib/include/bave/graphics/particle_emitter.hpp
index c520fc9..bc8d826 100644
--- a/lib/include/bave/graphics/particle_emitter.hpp
+++ b/lib/include/bave/graphics/particle_emitter.hpp
@@ -1,6 +1,6 @@
 #pragma once
+#include <bave/core/enum_flags.hpp>
 #include <bave/core/inclusive_range.hpp>
-#include <bave/core/make_bitset.hpp>
 #include <bave/core/time.hpp>
 #include <bave/graphics/shape.hpp>
 
@@ -35,9 +35,9 @@ struct ParticleConfig {
 class ParticleEmitter : public QuadShape {
   public:
 	enum class Modifier : int { eTranslate, eRotate, eScale, eTint, eCOUNT_ };
-	using Modifiers = std::bitset<static_cast<std::size_t>(Modifier::eCOUNT_)>;
+	using Modifiers = EnumFlags<Modifier>;
 
-	inline static auto const all_modifiers_v = make_bitset<Modifiers>(Modifier::eTranslate, Modifier::eRotate, Modifier::eScale, Modifier::eTint);
+	inline static auto const all_modifiers_v = Modifiers{Modifier::eTranslate, Modifier::eRotate, Modifier::eScale, Modifier::eTint};
 
 	using Config = ParticleConfig;
 
diff --git a/lib/include/bave/input/gamepad.hpp b/lib/include/bave/input/gamepad.hpp
index 16295c8..809627e 100644
--- a/lib/include/bave/input/gamepad.hpp
+++ b/lib/include/bave/input/gamepad.hpp
@@ -1,8 +1,8 @@
 #pragma once
 #include <bave/core/c_string.hpp>
+#include <bave/core/enum_flags.hpp>
 #include <bave/input/action.hpp>
 #include <array>
-#include <bitset>
 
 namespace bave {
 /// \brief Set of gamepad IDs.
@@ -66,7 +66,7 @@ struct Gamepad {
 	/// \brief ID of gamepad.
 	Id id{};
 	/// \brief Button states.
-	std::bitset<buttons_v> button_states{};
+	EnumFlags<Button> button_states{};
 	/// \brief Axis values.
 	std::array<float, axes_v> axes{};
 	/// \brief Reported name of gamepad.
@@ -77,7 +77,7 @@ struct Gamepad {
 	/// \brief Check if a button is pressed.
 	/// \param button Button to test for.
 	/// \returns true if pressed.
-	[[nodiscard]] auto is_pressed(Button const button) const -> bool { return button_states.test(static_cast<std::size_t>(button)); }
+	[[nodiscard]] auto is_pressed(Button const button) const -> bool { return button_states.test(button); }
 
 	/// \brief Obtain an axis value.
 	/// \param axis Axis to obtain value of.
diff --git a/lib/include/bave/input/key_state.hpp b/lib/include/bave/input/key_state.hpp
index fe4f52d..aee909b 100644
--- a/lib/include/bave/input/key_state.hpp
+++ b/lib/include/bave/input/key_state.hpp
@@ -1,18 +1,18 @@
 #pragma once
+#include <bave/core/enum_flags.hpp>
 #include <bave/input/key.hpp>
-#include <bitset>
 
 namespace bave {
 /// \brief Stateful wrapper for keys held down over multiple frames.
 struct KeyState {
 	static constexpr auto max_keys_v = static_cast<std::size_t>(Key::eCOUNT_);
 
-	std::bitset<max_keys_v> held_keys{};
+	EnumFlags<Key> held_keys{};
 
-	/// \brief Check if a key is held down (pressed).
+	/// \brief Check if a key is pressed (held down).
 	/// \param key The key to check for.
 	/// \returns true if key has been pressed but not yet released.
 	/// \pre key must be non-negative and less than Key::eCOUNT_.
-	[[nodiscard]] auto is_held(Key const key) const -> bool { return held_keys.test(static_cast<std::size_t>(key)); }
+	[[nodiscard]] auto is_pressed(Key const key) const -> bool { return held_keys.test(key); }
 };
 } // namespace bave
diff --git a/lib/include/bave/input/mods.hpp b/lib/include/bave/input/mods.hpp
index c4775a3..b1bc137 100644
--- a/lib/include/bave/input/mods.hpp
+++ b/lib/include/bave/input/mods.hpp
@@ -1,17 +1,9 @@
 #pragma once
-#include <bave/core/make_bitset.hpp>
+#include <bave/core/enum_flags.hpp>
 
 namespace bave {
 enum class Mod : int { eShift, eCtrl, eAlt, eSuper, eCapsLock, eNumLock, eCOUNT_ };
 
 /// \brief Bit flags for modifier keys.
-using KeyMods = std::bitset<static_cast<std::size_t>(Mod::eCOUNT_)>;
-
-/// \brief Create KeyMods with mods set.
-/// \param mods mods to set.
-/// \returns KeyMods with mods set.
-template <std::same_as<Mod>... I>
-auto make_key_mods(I const... mods) -> KeyMods {
-	return make_bitset<KeyMods>(mods...);
-}
+using KeyMods = EnumFlags<Mod>;
 } // namespace bave
diff --git a/lib/platform/desktop/desktop_app.cpp b/lib/platform/desktop/desktop_app.cpp
index 0a0bdc0..bc92564 100644
--- a/lib/platform/desktop/desktop_app.cpp
+++ b/lib/platform/desktop/desktop_app.cpp
@@ -111,13 +111,13 @@ constexpr auto to_action(int const glfw_action) {
 
 constexpr auto to_mods(int const glfw_mods) {
 	auto ret = KeyMods{};
-	if ((glfw_mods & GLFW_MOD_SHIFT) != 0) { ret.set(static_cast<std::size_t>(Mod::eShift)); }
-	if ((glfw_mods & GLFW_MOD_CONTROL) != 0) { ret.set(static_cast<std::size_t>(Mod::eCtrl)); }
-	if ((glfw_mods & GLFW_MOD_CONTROL) != 0) { ret.set(static_cast<std::size_t>(Mod::eCtrl)); }
-	if ((glfw_mods & GLFW_MOD_ALT) != 0) { ret.set(static_cast<std::size_t>(Mod::eAlt)); }
-	if ((glfw_mods & GLFW_MOD_SUPER) != 0) { ret.set(static_cast<std::size_t>(Mod::eSuper)); }
-	if ((glfw_mods & GLFW_MOD_CAPS_LOCK) != 0) { ret.set(static_cast<std::size_t>(Mod::eCapsLock)); }
-	if ((glfw_mods & GLFW_MOD_NUM_LOCK) != 0) { ret.set(static_cast<std::size_t>(Mod::eNumLock)); }
+	if ((glfw_mods & GLFW_MOD_SHIFT) != 0) { ret.set(Mod::eShift); }
+	if ((glfw_mods & GLFW_MOD_CONTROL) != 0) { ret.set(Mod::eCtrl); }
+	if ((glfw_mods & GLFW_MOD_CONTROL) != 0) { ret.set(Mod::eCtrl); }
+	if ((glfw_mods & GLFW_MOD_ALT) != 0) { ret.set(Mod::eAlt); }
+	if ((glfw_mods & GLFW_MOD_SUPER) != 0) { ret.set(Mod::eSuper); }
+	if ((glfw_mods & GLFW_MOD_CAPS_LOCK) != 0) { ret.set(Mod::eCapsLock); }
+	if ((glfw_mods & GLFW_MOD_NUM_LOCK) != 0) { ret.set(Mod::eNumLock); }
 	return ret;
 }
 } // namespace
@@ -184,9 +184,7 @@ void DesktopApp::render() {
 
 void DesktopApp::do_shutdown() { glfwSetWindowShouldClose(m_window.get(), GLFW_TRUE); }
 
-auto DesktopApp::do_get_native_features() const -> FeatureFlags {
-	return make_bitset<FeatureFlags>(Feature::resizeable, Feature::has_title, Feature::has_icon);
-}
+auto DesktopApp::do_get_native_features() const -> FeatureFlags { return FeatureFlags{Feature::eResizeable, Feature::eHasTitle, Feature::eHasIcon}; }
 
 auto DesktopApp::do_get_window_size() const -> glm::ivec2 {
 	auto ret = glm::ivec2{};
@@ -357,7 +355,7 @@ void DesktopApp::update_gamepads() {
 		project_trigger(gamepad.axes.at(static_cast<std::size_t>(GamepadAxis::eRightTrigger)));
 		gamepad.button_states = {};
 		for (std::size_t b = 0; b < buttons.size(); ++b) {
-			if (buttons[b] == 0x1) { gamepad.button_states.set(b); }
+			if (buttons[b] == 0x1) { gamepad.button_states.set(static_cast<GamepadButton>(b)); }
 		}
 
 		static constexpr auto active_axis = [](float const value) { return value > 0.2f; };
diff --git a/lib/src/app.cpp b/lib/src/app.cpp
index 6a42cf1..20ca4b6 100644
--- a/lib/src/app.cpp
+++ b/lib/src/app.cpp
@@ -90,7 +90,7 @@ auto App::change_mount_point(std::string_view const directory) -> bool {
 
 auto App::get_features() const -> FeatureFlags {
 	auto ret = do_get_native_features();
-	if (get_render_device().validation_layers_enabled()) { ret.set(Feature::validation_layers); }
+	if (get_render_device().validation_layers_enabled()) { ret.set(Feature::eValidationLayers); }
 	return ret;
 }
 
@@ -118,7 +118,7 @@ void App::push_event(Event event) {
 	if (auto const* pointer_tap = std::get_if<PointerTap>(&event)) {
 		m_gesture_recognizer.on_tap(*pointer_tap);
 	} else if (auto const* key_input = std::get_if<KeyInput>(&event)) {
-		auto key_state = m_key_state.held_keys[static_cast<std::size_t>(key_input->key)];
+		auto key_state = m_key_state.held_keys[key_input->key];
 		switch (key_input->action) {
 		case Action::ePress: key_state = true; break;
 		case Action::eRelease: key_state = false; break;
diff --git a/lib/src/graphics/particle_emitter.cpp b/lib/src/graphics/particle_emitter.cpp
index 4e196e9..251ca0f 100644
--- a/lib/src/graphics/particle_emitter.cpp
+++ b/lib/src/graphics/particle_emitter.cpp
@@ -56,10 +56,10 @@ void ParticleEmitter::tick(Seconds dt) {
 		while (m_particles.size() < config.count) { m_particles.push_back(make_particle()); }
 	}
 
-	auto const do_translate = modifiers.test(static_cast<std::size_t>(Modifier::eTranslate));
-	auto const do_rotate = modifiers.test(static_cast<std::size_t>(Modifier::eRotate));
-	auto const do_scale = modifiers.test(static_cast<std::size_t>(Modifier::eScale));
-	auto const do_tint = modifiers.test(static_cast<std::size_t>(Modifier::eTint));
+	auto const do_translate = modifiers.test(Modifier::eTranslate);
+	auto const do_rotate = modifiers.test(Modifier::eRotate);
+	auto const do_scale = modifiers.test(Modifier::eScale);
+	auto const do_tint = modifiers.test(Modifier::eTint);
 
 	instances.resize(m_particles.size());
 	for (std::size_t index = 0; index < m_particles.size(); ++index) {
diff --git a/tools/src/tools/runner.cpp b/tools/src/tools/runner.cpp
index 3f6beed..ee0eead 100644
--- a/tools/src/tools/runner.cpp
+++ b/tools/src/tools/runner.cpp
@@ -43,7 +43,7 @@ void Runner::tick() {
 void Runner::render() const { m_active->render(); }
 
 void Runner::on_key(KeyInput const& key_input) {
-	if (key_input.action == Action::ePress && key_input.key == Key::eW && key_input.mods == make_key_mods(Mod::eCtrl)) { get_app().shutdown(); }
+	if (key_input.action == Action::ePress && key_input.key == Key::eW && key_input.mods == KeyMods(Mod::eCtrl)) { get_app().shutdown(); }
 	m_active->on_key(key_input);
 }