/*************************************************************************/
/*  godot_area_2d.h                                                      */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifndef GODOT_AREA_2D_H
#define GODOT_AREA_2D_H

#include "godot_collision_object_2d.h"

#include "core/templates/self_list.h"
#include "servers/physics_server_2d.h"

class GodotSpace2D;
class GodotBody2D;
class GodotConstraint2D;

class GodotArea2D : public GodotCollisionObject2D {
	PhysicsServer2D::AreaSpaceOverrideMode space_override_mode = PhysicsServer2D::AREA_SPACE_OVERRIDE_DISABLED;
	real_t gravity = 9.80665;
	Vector2 gravity_vector = Vector2(0, -1);
	bool gravity_is_point = false;
	real_t gravity_distance_scale = 0.0;
	real_t point_attenuation = 1.0;
	real_t linear_damp = 0.1;
	real_t angular_damp = 1.0;
	int priority = 0;
	bool monitorable = false;

	ObjectID monitor_callback_id;
	StringName monitor_callback_method;

	ObjectID area_monitor_callback_id;
	StringName area_monitor_callback_method;

	SelfList<GodotArea2D> monitor_query_list;
	SelfList<GodotArea2D> moved_list;

	struct BodyKey {
		RID rid;
		ObjectID instance_id;
		uint32_t body_shape = 0;
		uint32_t area_shape = 0;

		_FORCE_INLINE_ bool operator<(const BodyKey &p_key) const {
			if (rid == p_key.rid) {
				if (body_shape == p_key.body_shape) {
					return area_shape < p_key.area_shape;
				} else {
					return body_shape < p_key.body_shape;
				}
			} else {
				return rid < p_key.rid;
			}
		}

		_FORCE_INLINE_ BodyKey() {}
		BodyKey(GodotBody2D *p_body, uint32_t p_body_shape, uint32_t p_area_shape);
		BodyKey(GodotArea2D *p_body, uint32_t p_body_shape, uint32_t p_area_shape);
	};

	struct BodyState {
		int state = 0;
		_FORCE_INLINE_ void inc() { state++; }
		_FORCE_INLINE_ void dec() { state--; }
	};

	Map<BodyKey, BodyState> monitored_bodies;
	Map<BodyKey, BodyState> monitored_areas;

	Set<GodotConstraint2D *> constraints;

	virtual void _shapes_changed();
	void _queue_monitor_update();

public:
	void set_monitor_callback(ObjectID p_id, const StringName &p_method);
	_FORCE_INLINE_ bool has_monitor_callback() const { return monitor_callback_id.is_valid(); }

	void set_area_monitor_callback(ObjectID p_id, const StringName &p_method);
	_FORCE_INLINE_ bool has_area_monitor_callback() const { return area_monitor_callback_id.is_valid(); }

	_FORCE_INLINE_ void add_body_to_query(GodotBody2D *p_body, uint32_t p_body_shape, uint32_t p_area_shape);
	_FORCE_INLINE_ void remove_body_from_query(GodotBody2D *p_body, uint32_t p_body_shape, uint32_t p_area_shape);

	_FORCE_INLINE_ void add_area_to_query(GodotArea2D *p_area, uint32_t p_area_shape, uint32_t p_self_shape);
	_FORCE_INLINE_ void remove_area_from_query(GodotArea2D *p_area, uint32_t p_area_shape, uint32_t p_self_shape);

	void set_param(PhysicsServer2D::AreaParameter p_param, const Variant &p_value);
	Variant get_param(PhysicsServer2D::AreaParameter p_param) const;

	void set_space_override_mode(PhysicsServer2D::AreaSpaceOverrideMode p_mode);
	PhysicsServer2D::AreaSpaceOverrideMode get_space_override_mode() const { return space_override_mode; }

	_FORCE_INLINE_ void set_gravity(real_t p_gravity) { gravity = p_gravity; }
	_FORCE_INLINE_ real_t get_gravity() const { return gravity; }

	_FORCE_INLINE_ void set_gravity_vector(const Vector2 &p_gravity) { gravity_vector = p_gravity; }
	_FORCE_INLINE_ Vector2 get_gravity_vector() const { return gravity_vector; }

	_FORCE_INLINE_ void set_gravity_as_point(bool p_enable) { gravity_is_point = p_enable; }
	_FORCE_INLINE_ bool is_gravity_point() const { return gravity_is_point; }

	_FORCE_INLINE_ void set_gravity_distance_scale(real_t scale) { gravity_distance_scale = scale; }
	_FORCE_INLINE_ real_t get_gravity_distance_scale() const { return gravity_distance_scale; }

	_FORCE_INLINE_ void set_point_attenuation(real_t p_point_attenuation) { point_attenuation = p_point_attenuation; }
	_FORCE_INLINE_ real_t get_point_attenuation() const { return point_attenuation; }

	_FORCE_INLINE_ void set_linear_damp(real_t p_linear_damp) { linear_damp = p_linear_damp; }
	_FORCE_INLINE_ real_t get_linear_damp() const { return linear_damp; }

	_FORCE_INLINE_ void set_angular_damp(real_t p_angular_damp) { angular_damp = p_angular_damp; }
	_FORCE_INLINE_ real_t get_angular_damp() const { return angular_damp; }

	_FORCE_INLINE_ void set_priority(int p_priority) { priority = p_priority; }
	_FORCE_INLINE_ int get_priority() const { return priority; }

	_FORCE_INLINE_ void add_constraint(GodotConstraint2D *p_constraint) { constraints.insert(p_constraint); }
	_FORCE_INLINE_ void remove_constraint(GodotConstraint2D *p_constraint) { constraints.erase(p_constraint); }
	_FORCE_INLINE_ const Set<GodotConstraint2D *> &get_constraints() const { return constraints; }
	_FORCE_INLINE_ void clear_constraints() { constraints.clear(); }

	void set_monitorable(bool p_monitorable);
	_FORCE_INLINE_ bool is_monitorable() const { return monitorable; }

	void set_transform(const Transform2D &p_transform);

	void set_space(GodotSpace2D *p_space);

	void call_queries();

	void compute_gravity(const Vector2 &p_position, Vector2 &r_gravity) const;

	GodotArea2D();
	~GodotArea2D();
};

void GodotArea2D::add_body_to_query(GodotBody2D *p_body, uint32_t p_body_shape, uint32_t p_area_shape) {
	BodyKey bk(p_body, p_body_shape, p_area_shape);
	monitored_bodies[bk].inc();
	if (!monitor_query_list.in_list()) {
		_queue_monitor_update();
	}
}

void GodotArea2D::remove_body_from_query(GodotBody2D *p_body, uint32_t p_body_shape, uint32_t p_area_shape) {
	BodyKey bk(p_body, p_body_shape, p_area_shape);
	monitored_bodies[bk].dec();
	if (!monitor_query_list.in_list()) {
		_queue_monitor_update();
	}
}

void GodotArea2D::add_area_to_query(GodotArea2D *p_area, uint32_t p_area_shape, uint32_t p_self_shape) {
	BodyKey bk(p_area, p_area_shape, p_self_shape);
	monitored_areas[bk].inc();
	if (!monitor_query_list.in_list()) {
		_queue_monitor_update();
	}
}

void GodotArea2D::remove_area_from_query(GodotArea2D *p_area, uint32_t p_area_shape, uint32_t p_self_shape) {
	BodyKey bk(p_area, p_area_shape, p_self_shape);
	monitored_areas[bk].dec();
	if (!monitor_query_list.in_list()) {
		_queue_monitor_update();
	}
}

#endif // GODOT_AREA_2D_H