/*************************************************************************/
/*  soft_body.h                                                          */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifndef SOFT_PHYSICS_BODY_H
#define SOFT_PHYSICS_BODY_H

#include "scene/3d/mesh_instance.h"

class SoftBody;

class SoftBodyVisualServerHandler {
	friend class SoftBody;

	RID mesh;
	int surface;
	PoolVector<uint8_t> buffer;
	uint32_t stride;
	uint32_t offset_vertices;
	uint32_t offset_normal;

	PoolVector<uint8_t>::Write write_buffer;

private:
	SoftBodyVisualServerHandler();
	bool is_ready(RID p_mesh_rid) const { return mesh.is_valid() && mesh == p_mesh_rid; }
	void prepare(RID p_mesh_rid, int p_surface);
	void clear();
	void open();
	void close();
	void commit_changes();

public:
	void set_vertex(int p_vertex_id, const void *p_vector3);
	void set_normal(int p_vertex_id, const void *p_vector3);
	void set_aabb(const AABB &p_aabb);
};

class SoftBody : public MeshInstance {
	GDCLASS(SoftBody, MeshInstance);

public:
	struct PinnedPoint {
		int point_index;
		NodePath spatial_attachment_path;
		Spatial *spatial_attachment; // Cache
		Vector3 offset;

		PinnedPoint();
		PinnedPoint(const PinnedPoint &obj_tocopy);
		PinnedPoint operator=(const PinnedPoint &obj);
	};

private:
	SoftBodyVisualServerHandler visual_server_handler;

	RID physics_rid;

	bool physics_enabled = true;

	RID owned_mesh;
	uint32_t collision_mask;
	uint32_t collision_layer;
	NodePath parent_collision_ignore;
	PoolVector<PinnedPoint> pinned_points;
	bool simulation_started;
	bool pinned_points_cache_dirty;

	Ref<ArrayMesh> debug_mesh_cache;
	class MeshInstance *debug_mesh;

	bool capture_input_on_drag;
	bool ray_pickable;

	void _update_pickable();

	void _update_physics_server();
	void _draw_soft_mesh();

	void _prepare_physics_server();
	void _become_mesh_owner();

protected:
	bool _set(const StringName &p_name, const Variant &p_value);
	bool _get(const StringName &p_name, Variant &r_ret) const;
	void _get_property_list(List<PropertyInfo> *p_list) const;

	bool _set_property_pinned_points_indices(const Array &p_indices);
	bool _set_property_pinned_points_attachment(int p_item, const String &p_what, const Variant &p_value);
	bool _get_property_pinned_points(int p_item, const String &p_what, Variant &r_ret) const;

	virtual void _changed_callback(Object *p_changed, const char *p_prop);

	void _notification(int p_what);
	static void _bind_methods();

	virtual String get_configuration_warning() const;

public:
	void set_collision_mask(uint32_t p_mask);
	uint32_t get_collision_mask() const;

	void set_collision_layer(uint32_t p_layer);
	uint32_t get_collision_layer() const;

	void set_collision_mask_bit(int p_bit, bool p_value);
	bool get_collision_mask_bit(int p_bit) const;

	void set_collision_layer_bit(int p_bit, bool p_value);
	bool get_collision_layer_bit(int p_bit) const;

	void set_parent_collision_ignore(const NodePath &p_parent_collision_ignore);
	const NodePath &get_parent_collision_ignore() const;

	void set_physics_enabled(bool p_enabled);
	bool is_physics_enabled() const;

	void set_pinned_points_indices(PoolVector<PinnedPoint> p_pinned_points_indices);
	PoolVector<PinnedPoint> get_pinned_points_indices();

	void set_simulation_precision(int p_simulation_precision);
	int get_simulation_precision();

	void set_total_mass(real_t p_total_mass);
	real_t get_total_mass();

	void set_linear_stiffness(real_t p_linear_stiffness);
	real_t get_linear_stiffness();

	void set_areaAngular_stiffness(real_t p_areaAngular_stiffness);
	real_t get_areaAngular_stiffness();

	void set_volume_stiffness(real_t p_volume_stiffness);
	real_t get_volume_stiffness();

	void set_pressure_coefficient(real_t p_pressure_coefficient);
	real_t get_pressure_coefficient();

	void set_pose_matching_coefficient(real_t p_pose_matching_coefficient);
	real_t get_pose_matching_coefficient();

	void set_damping_coefficient(real_t p_damping_coefficient);
	real_t get_damping_coefficient();

	void set_drag_coefficient(real_t p_drag_coefficient);
	real_t get_drag_coefficient();

	Array get_collision_exceptions();
	void add_collision_exception_with(Node *p_node);
	void remove_collision_exception_with(Node *p_node);

	Vector3 get_point_transform(int p_point_index);

	void pin_point_toggle(int p_point_index);
	void pin_point(int p_point_index, bool pin, const NodePath &p_spatial_attachment_path = NodePath());
	bool is_point_pinned(int p_point_index) const;

	void set_ray_pickable(bool p_ray_pickable);
	bool is_ray_pickable() const;

	SoftBody();
	~SoftBody();

private:
	void reset_softbody_pin();

	void _make_cache_dirty();
	void _update_cache_pin_points_datas();

	void _pin_point_on_physics_server(int p_point_index, bool pin);
	void _add_pinned_point(int p_point_index, const NodePath &p_spatial_attachment_path);
	void _reset_points_offsets();

	void _remove_pinned_point(int p_point_index);
	int _get_pinned_point(int p_point_index, PinnedPoint *&r_point) const;
	int _has_pinned_point(int p_point_index) const;
};

#endif // SOFT_PHYSICS_BODY_H