/*************************************************************************/
/*  gpu_particles_2d.h                                                   */
/*************************************************************************/
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
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#ifndef GPU_PARTICLES_2D_H
#define GPU_PARTICLES_2D_H

#include "scene/2d/node_2d.h"

class GPUParticles2D : public Node2D {
private:
	GDCLASS(GPUParticles2D, Node2D);

public:
	enum DrawOrder {
		DRAW_ORDER_INDEX,
		DRAW_ORDER_LIFETIME,
		DRAW_ORDER_REVERSE_LIFETIME,
	};

private:
	RID particles;

	bool one_shot = false;
	int amount = 0;
	double lifetime = 0.0;
	double pre_process_time = 0.0;
	real_t explosiveness_ratio = 0.0;
	real_t randomness_ratio = 0.0;
	double speed_scale = 0.0;
	Rect2 visibility_rect;
	bool local_coords = false;
	int fixed_fps = 0;
	bool fractional_delta = false;
	bool interpolate = true;
#ifdef TOOLS_ENABLED
	bool show_visibility_rect = false;
#endif
	Ref<Material> process_material;

	DrawOrder draw_order;

	Ref<Texture2D> texture;

	void _update_particle_emission_transform();

	NodePath sub_emitter;
	real_t collision_base_size = 1.0;

	bool trail_enabled = false;
	double trail_lifetime = 0.3;
	int trail_sections = 8;
	int trail_section_subdivisions = 4;

	RID mesh;

	void _attach_sub_emitter();

	void _texture_changed();

protected:
	static void _bind_methods();
	void _validate_property(PropertyInfo &p_property) const;
	void _notification(int p_what);
	void _update_collision_size();

public:
	void set_emitting(bool p_emitting);
	void set_amount(int p_amount);
	void set_lifetime(double p_lifetime);
	void set_one_shot(bool p_enable);
	void set_pre_process_time(double p_time);
	void set_explosiveness_ratio(real_t p_ratio);
	void set_randomness_ratio(real_t p_ratio);
	void set_visibility_rect(const Rect2 &p_visibility_rect);
	void set_use_local_coordinates(bool p_enable);
	void set_process_material(const Ref<Material> &p_material);
	void set_speed_scale(double p_scale);
	void set_collision_base_size(real_t p_ratio);
	void set_trail_enabled(bool p_enabled);
	void set_trail_lifetime(double p_seconds);
	void set_trail_sections(int p_sections);
	void set_trail_section_subdivisions(int p_subdivisions);

#ifdef TOOLS_ENABLED
	void set_show_visibility_rect(bool p_show_visibility_rect);
#endif

	bool is_emitting() const;
	int get_amount() const;
	double get_lifetime() const;
	bool get_one_shot() const;
	double get_pre_process_time() const;
	real_t get_explosiveness_ratio() const;
	real_t get_randomness_ratio() const;
	Rect2 get_visibility_rect() const;
	bool get_use_local_coordinates() const;
	Ref<Material> get_process_material() const;
	double get_speed_scale() const;

	real_t get_collision_base_size() const;
	bool is_trail_enabled() const;
	double get_trail_lifetime() const;
	int get_trail_sections() const;
	int get_trail_section_subdivisions() const;

	void set_fixed_fps(int p_count);
	int get_fixed_fps() const;

	void set_fractional_delta(bool p_enable);
	bool get_fractional_delta() const;

	void set_interpolate(bool p_enable);
	bool get_interpolate() const;

	void set_draw_order(DrawOrder p_order);
	DrawOrder get_draw_order() const;

	void set_texture(const Ref<Texture2D> &p_texture);
	Ref<Texture2D> get_texture() const;

	PackedStringArray get_configuration_warnings() const override;

	void set_sub_emitter(const NodePath &p_path);
	NodePath get_sub_emitter() const;

	enum EmitFlags {
		EMIT_FLAG_POSITION = RS::PARTICLES_EMIT_FLAG_POSITION,
		EMIT_FLAG_ROTATION_SCALE = RS::PARTICLES_EMIT_FLAG_ROTATION_SCALE,
		EMIT_FLAG_VELOCITY = RS::PARTICLES_EMIT_FLAG_VELOCITY,
		EMIT_FLAG_COLOR = RS::PARTICLES_EMIT_FLAG_COLOR,
		EMIT_FLAG_CUSTOM = RS::PARTICLES_EMIT_FLAG_CUSTOM
	};

	void emit_particle(const Transform2D &p_transform, const Vector2 &p_velocity, const Color &p_color, const Color &p_custom, uint32_t p_emit_flags);

	void restart();
	Rect2 capture_rect() const;
	GPUParticles2D();
	~GPUParticles2D();
};

VARIANT_ENUM_CAST(GPUParticles2D::DrawOrder)
VARIANT_ENUM_CAST(GPUParticles2D::EmitFlags)

#endif // GPU_PARTICLES_2D_H