/*************************************************************************/
/*  gi_probe.h                                                           */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
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/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/*************************************************************************/
#ifndef GIPROBE_H
#define GIPROBE_H

#include "multimesh_instance.h"
#include "scene/3d/visual_instance.h"

class GIProbeData : public Resource {

	GDCLASS(GIProbeData, Resource);

	RID probe;

protected:
	static void _bind_methods();

public:
	void set_bounds(const Rect3 &p_bounds);
	Rect3 get_bounds() const;

	void set_cell_size(float p_size);
	float get_cell_size() const;

	void set_to_cell_xform(const Transform &p_xform);
	Transform get_to_cell_xform() const;

	void set_dynamic_data(const PoolVector<int> &p_data);
	PoolVector<int> get_dynamic_data() const;

	void set_dynamic_range(int p_range);
	int get_dynamic_range() const;

	void set_propagation(float p_range);
	float get_propagation() const;

	void set_energy(float p_range);
	float get_energy() const;

	void set_bias(float p_range);
	float get_bias() const;

	void set_normal_bias(float p_range);
	float get_normal_bias() const;

	void set_interior(bool p_enable);
	bool is_interior() const;

	void set_compress(bool p_enable);
	bool is_compressed() const;

	virtual RID get_rid() const;

	GIProbeData();
	~GIProbeData();
};

class GIProbe : public VisualInstance {
	GDCLASS(GIProbe, VisualInstance);

public:
	enum Subdiv {
		SUBDIV_64,
		SUBDIV_128,
		SUBDIV_256,
		SUBDIV_512,
		SUBDIV_MAX

	};

	typedef void (*BakeBeginFunc)(int);
	typedef void (*BakeStepFunc)(int, const String &);
	typedef void (*BakeEndFunc)();

private:
	//stuff used for bake
	struct Baker {

		enum {
			CHILD_EMPTY = 0xFFFFFFFF
		};
		struct Cell {

			uint32_t childs[8];
			float albedo[3]; //albedo in RGB24
			float emission[3]; //accumulated light in 16:16 fixed point (needs to be integer for moving lights fast)
			float normal[3];
			uint32_t used_sides;
			float alpha; //used for upsampling
			int level;

			Cell() {
				for (int i = 0; i < 8; i++) {
					childs[i] = CHILD_EMPTY;
				}

				for (int i = 0; i < 3; i++) {
					emission[i] = 0;
					albedo[i] = 0;
					normal[i] = 0;
				}
				alpha = 0;
				used_sides = 0;
				level = 0;
			}
		};

		Vector<Cell> bake_cells;
		int cell_subdiv;

		struct MaterialCache {
			//128x128 textures
			Vector<Color> albedo;
			Vector<Color> emission;
		};

		Vector<Color> _get_bake_texture(Ref<Image> p_image, const Color &p_color);
		Map<Ref<Material>, MaterialCache> material_cache;
		MaterialCache _get_material_cache(Ref<Material> p_material);
		int leaf_voxel_count;

		Rect3 po2_bounds;
		int axis_cell_size[3];

		struct PlotMesh {
			Ref<Material> override_material;
			Vector<Ref<Material> > instance_materials;
			Ref<Mesh> mesh;
			Transform local_xform;
		};

		Transform to_cell_space;

		List<PlotMesh> mesh_list;
	};

	Ref<GIProbeData> probe_data;

	RID gi_probe;

	Subdiv subdiv;
	Vector3 extents;
	int dynamic_range;
	float energy;
	float bias;
	float normal_bias;
	float propagation;
	bool interior;
	bool compress;

	int color_scan_cell_width;
	int bake_texture_size;

	Vector<Color> _get_bake_texture(Ref<Image> p_image, const Color &p_color);
	Baker::MaterialCache _get_material_cache(Ref<Material> p_material, Baker *p_baker);
	void _plot_face(int p_idx, int p_level, int p_x, int p_y, int p_z, const Vector3 *p_vtx, const Vector2 *p_uv, const Baker::MaterialCache &p_material, const Rect3 &p_aabb, Baker *p_baker);
	void _plot_mesh(const Transform &p_xform, Ref<Mesh> &p_mesh, Baker *p_baker, const Vector<Ref<Material> > &p_materials, const Ref<Material> &p_override_material);
	void _find_meshes(Node *p_at_node, Baker *p_baker);
	void _fixup_plot(int p_idx, int p_level, int p_x, int p_y, int p_z, Baker *p_baker);

	void _debug_mesh(int p_idx, int p_level, const Rect3 &p_aabb, Ref<MultiMesh> &p_multimesh, int &idx, Baker *p_baker);
	void _create_debug_mesh(Baker *p_baker);

	void _debug_bake();

protected:
	static void _bind_methods();

public:
	static BakeBeginFunc bake_begin_function;
	static BakeStepFunc bake_step_function;
	static BakeEndFunc bake_end_function;

	void set_probe_data(const Ref<GIProbeData> &p_data);
	Ref<GIProbeData> get_probe_data() const;

	void set_subdiv(Subdiv p_subdiv);
	Subdiv get_subdiv() const;

	void set_extents(const Vector3 &p_extents);
	Vector3 get_extents() const;

	void set_dynamic_range(int p_dynamic_range);
	int get_dynamic_range() const;

	void set_energy(float p_energy);
	float get_energy() const;

	void set_bias(float p_bias);
	float get_bias() const;

	void set_normal_bias(float p_normal_bias);
	float get_normal_bias() const;

	void set_propagation(float p_propagation);
	float get_propagation() const;

	void set_interior(bool p_enable);
	bool is_interior() const;

	void set_compress(bool p_enable);
	bool is_compressed() const;

	void bake(Node *p_from_node = NULL, bool p_create_visual_debug = false);

	virtual Rect3 get_aabb() const;
	virtual PoolVector<Face3> get_faces(uint32_t p_usage_flags) const;

	GIProbe();
	~GIProbe();
};

VARIANT_ENUM_CAST(GIProbe::Subdiv)

#endif // GIPROBE_H
