text: /*************************************************************************/
  /*  voxelizer.h                                                          */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2020 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:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
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  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
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  /*************************************************************************/
  
  #ifndef VOXEL_LIGHT_BAKER_H
  #define VOXEL_LIGHT_BAKER_H
  
  #include "core/math/vector3i.h"
  #include "scene/3d/mesh_instance_3d.h"
  #include "scene/resources/multimesh.h"
  
  class Voxelizer {
  private:
  	enum {
  		CHILD_EMPTY = 0xFFFFFFFF
  
  	};
  
  	struct Cell {
  		uint32_t children[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
  		uint16_t x;
  		uint16_t y;
  		uint16_t z;
  		uint16_t level;
  
  		Cell() {
  			for (int i = 0; i < 8; i++) {
  				children[i] = CHILD_EMPTY;
  			}
  
  			for (int i = 0; i < 3; i++) {
  				emission[i] = 0;
  				albedo[i] = 0;
  				normal[i] = 0;
  			}
  			alpha = 0;
  			used_sides = 0;
  			x = y = z = 0;
  			level = 0;
  		}
  	};
  
  	Vector<Cell> bake_cells;
  	int cell_subdiv;
  
  	struct CellSort {
  		union {
  			struct {
  				uint64_t z : 16;
  				uint64_t y : 16;
  				uint64_t x : 16;
  				uint64_t level : 16;
  			};
  			uint64_t key;
  		};
  
  		int32_t index;
  
  		_FORCE_INLINE_ bool operator<(const CellSort &p_cell_sort) const {
  			return key < p_cell_sort.key;
  		}
  	};
  
  	struct MaterialCache {
  		//128x128 textures
  		Vector<Color> albedo;
  		Vector<Color> emission;
  	};
  
  	Map<Ref<Material>, MaterialCache> material_cache;
  	AABB original_bounds;
  	AABB po2_bounds;
  	int axis_cell_size[3];
  
  	Transform to_cell_space;
  
  	int color_scan_cell_width;
  	int bake_texture_size;
  	float cell_size;
  
  	int max_original_cells;
  	int leaf_voxel_count;
  
  	Vector<Color> _get_bake_texture(Ref<Image> p_image, const Color &p_color_mul, const Color &p_color_add);
  	MaterialCache _get_material_cache(Ref<Material> p_material);
  
  	void _plot_face(int p_idx, int p_level, int p_x, int p_y, int p_z, const Vector3 *p_vtx, const Vector3 *p_normal, const Vector2 *p_uv, const MaterialCache &p_material, const AABB &p_aabb);
  	void _fixup_plot(int p_idx, int p_level);
  	void _debug_mesh(int p_idx, int p_level, const AABB &p_aabb, Ref<MultiMesh> &p_multimesh, int &idx);
  
  	bool sorted;
  	void _sort();
  
  public:
  	void begin_bake(int p_subdiv, const AABB &p_bounds);
  	void plot_mesh(const Transform &p_xform, Ref<Mesh> &p_mesh, const Vector<Ref<Material>> &p_materials, const Ref<Material> &p_override_material);
  	void end_bake();
  
  	int get_gi_probe_octree_depth() const;
  	Vector3i get_giprobe_octree_size() const;
  	int get_giprobe_cell_count() const;
  	Vector<uint8_t> get_giprobe_octree_cells() const;
  	Vector<uint8_t> get_giprobe_data_cells() const;
  	Vector<int> get_giprobe_level_cell_count() const;
  	Vector<uint8_t> get_sdf_3d_image() const;
  
  	Ref<MultiMesh> create_debug_multimesh();
  
  	Transform get_to_cell_space_xform() const;
  	Voxelizer();
  };
  
  #endif // VOXEL_LIGHT_BAKER_H
  