1 files changed, 132 insertions, 0 deletions
diff --git a/src/crepe/system/InputSystem.h b/src/crepe/system/InputSystem.h
new file mode 100644
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+++ b/src/crepe/system/InputSystem.h
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+#pragma once
+
+#include "../api/Config.h"
+#include "../facade/EventData.h"
+
+#include "../api/Event.h"
+#include "../api/Metadata.h"
+#include "../types.h"
+#include "../util/OptionalRef.h"
+
+#include "System.h"
+
+namespace crepe {
+
+class Camera;
+class Button;
+class Transform;
+//! Event triggered when a button is clicked
+class ButtonPressEvent : public Event {
+public:
+	//! Metadata of the button.
+	const Metadata & metadata;
+	/**
+	 * \param metadata Metadata of the button pressed
+	 */
+	ButtonPressEvent(const Metadata & metadata) : metadata(metadata){};
+};
+//! Event triggered when the mouse enters a button
+class ButtonEnterEvent : public Event {
+public:
+	//! Metadata of the button.
+	const Metadata & metadata;
+	/**
+	 * \param metadata Metadata of the button pressed
+	 */
+	ButtonEnterEvent(const Metadata & metadata) : metadata(metadata){};
+};
+//! Event triggered when the mouse leaves a button
+class ButtonExitEvent : public Event {
+public:
+	//! Metadata of the button.
+	const Metadata & metadata;
+	/**
+	 * \param metadata Metadata of the button pressed
+	 */
+	ButtonExitEvent(const Metadata & metadata) : metadata(metadata){};
+};
+
+/**
+ * \brief Handles the processing of input events created by SDLContext
+ *
+ * This system processes events such as mouse clicks, mouse movement, and keyboard
+ * actions. It is responsible for detecting interactions with UI buttons and
+ * passing the corresponding events to the registered listeners.
+ */
+class InputSystem : public System {
+public:
+	using System::System;
+
+	/**
+	 * \brief Updates the system, processing all input events.
+	 * This method processes all events and triggers corresponding actions.
+	 */
+	void fixed_update() override;
+
+private:
+	//! Stores the last position of the mouse when the button was pressed.
+	vec2 last_mouse_down_position;
+	// TODO: specify world/hud space and make regular `vec2`
+
+	//! Stores the last mouse button pressed.
+	MouseButton last_mouse_button = MouseButton::NONE;
+	/**
+	 * \brief Handles mouse-related events.
+	 * \param event The event data for the mouse event.
+	 * \param camera_origin The origin position of the camera in world space.
+	 * \param current_cam The currently active camera.
+	 *
+	 * This method processes mouse events, adjusts the mouse position to world coordinates,
+	 * and triggers the appropriate mouse-specific event handling logic.
+	 */
+	void handle_mouse_event(const EventData & event, const vec2 & camera_origin,
+							const Camera & current_cam);
+	/**
+	 * \brief Handles non-mouse-related events.
+	 * \param event The event data for the non-mouse event.
+	 *
+	 * This method processes events that do not involve the mouse, such as keyboard events,
+	 * window events, and shutdown events, and triggers the corresponding event actions.
+	 */
+	void handle_non_mouse_event(const EventData & event);
+	/**
+	* \brief Handles the mouse click event.
+	* \param mouse_button The mouse button involved in the click.
+	* \param world_mouse_x The X coordinate of the mouse in world space.
+	* \param world_mouse_y The Y coordinate of the mouse in world space.
+	*
+	* This method processes the mouse click event and triggers the corresponding button action.
+	*/
+	void handle_click(const MouseButton & mouse_button, const vec2 & mouse_pos);
+
+	/**
+	* \brief Handles the mouse movement event.
+	* \param event_data The event data containing information about the mouse movement.
+	* \param world_mouse_x The X coordinate of the mouse in world space.
+	* \param world_mouse_y The Y coordinate of the mouse in world space.
+	*
+	* This method processes the mouse movement event and updates the button hover state.
+	*/
+	void handle_move(const EventData & event_data, const vec2 & mouse_pos);
+
+	/**
+	* \brief Checks if the mouse position is inside the bounds of the button.
+	* \param world_mouse_x The X coordinate of the mouse in world space.
+	* \param world_mouse_y The Y coordinate of the mouse in world space.
+	* \param button The button to check.
+	* \param transform The transform component of the button.
+	* \return True if the mouse is inside the button, false otherwise.
+	*/
+	bool is_mouse_inside_button(const vec2 & mouse_pos, const Button & button,
+								const Transform & transform);
+
+	/**
+	* \brief Handles the button press event, calling the on_click callback if necessary.
+	* \param button The button being pressed.
+	*
+	* This method triggers the on_click action for the button when it is pressed.
+	*/
+	void handle_button_press(Button & button);
+};
+
+} // namespace crepe