/*************************************************************************/
/*  visual_server_scene.h                                                */
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#ifndef VISUALSERVERSCENE_H
#define VISUALSERVERSCENE_H

#include "servers/visual/rasterizer.h"

#include "core/math/bvh.h"
#include "core/math/geometry.h"
#include "core/math/octree.h"
#include "core/os/semaphore.h"
#include "core/os/thread.h"
#include "core/safe_refcount.h"
#include "core/self_list.h"
#include "servers/arvr/arvr_interface.h"

class VisualServerScene {
public:
	enum {

		MAX_INSTANCE_CULL = 65536,
		MAX_LIGHTS_CULLED = 4096,
		MAX_REFLECTION_PROBES_CULLED = 4096,
		MAX_ROOM_CULL = 32,
		MAX_EXTERIOR_PORTALS = 128,
	};

	uint64_t render_pass;
	bool _use_bvh;

	static VisualServerScene *singleton;

	/* CAMERA API */

	struct Camera : public RID_Data {

		enum Type {
			PERSPECTIVE,
			ORTHOGONAL,
			FRUSTUM
		};
		Type type;
		float fov;
		float znear, zfar;
		float size;
		Vector2 offset;
		uint32_t visible_layers;
		bool vaspect;
		RID env;

		Transform transform;

		Camera() {

			visible_layers = 0xFFFFFFFF;
			fov = 70;
			type = PERSPECTIVE;
			znear = 0.05;
			zfar = 100;
			size = 1.0;
			offset = Vector2();
			vaspect = false;
		}
	};

	mutable RID_Owner<Camera> camera_owner;

	virtual RID camera_create();
	virtual void camera_set_perspective(RID p_camera, float p_fovy_degrees, float p_z_near, float p_z_far);
	virtual void camera_set_orthogonal(RID p_camera, float p_size, float p_z_near, float p_z_far);
	virtual void camera_set_frustum(RID p_camera, float p_size, Vector2 p_offset, float p_z_near, float p_z_far);
	virtual void camera_set_transform(RID p_camera, const Transform &p_transform);
	virtual void camera_set_cull_mask(RID p_camera, uint32_t p_layers);
	virtual void camera_set_environment(RID p_camera, RID p_env);
	virtual void camera_set_use_vertical_aspect(RID p_camera, bool p_enable);

	/* SCENARIO API */

	struct Instance;

	// common interface for all spatial partitioning schemes
	// this is a bit excessive boilerplatewise but can be removed if we decide to stick with one method

	// note this is actually the BVH id +1, so that visual server can test against zero
	// for validity to maintain compatibility with octree (where 0 indicates invalid)
	typedef uint32_t SpatialPartitionID;

	class SpatialPartitioningScene {
	public:
		virtual SpatialPartitionID create(Instance *p_userdata, const AABB &p_aabb = AABB(), int p_subindex = 0, bool p_pairable = false, uint32_t p_pairable_type = 0, uint32_t pairable_mask = 1) = 0;
		virtual void erase(SpatialPartitionID p_handle) = 0;
		virtual void move(SpatialPartitionID p_handle, const AABB &p_aabb) = 0;
		virtual void activate(SpatialPartitionID p_handle, const AABB &p_aabb) {}
		virtual void deactivate(SpatialPartitionID p_handle) {}
		virtual void force_collision_check(SpatialPartitionID p_handle) {}
		virtual void update() {}
		virtual void update_collisions() {}
		virtual void set_pairable(SpatialPartitionID p_handle, bool p_pairable, uint32_t p_pairable_type, uint32_t p_pairable_mask) = 0;
		virtual int cull_convex(const Vector<Plane> &p_convex, Instance **p_result_array, int p_result_max, uint32_t p_mask = 0xFFFFFFFF) = 0;
		virtual int cull_aabb(const AABB &p_aabb, Instance **p_result_array, int p_result_max, int *p_subindex_array = nullptr, uint32_t p_mask = 0xFFFFFFFF) = 0;
		virtual int cull_segment(const Vector3 &p_from, const Vector3 &p_to, Instance **p_result_array, int p_result_max, int *p_subindex_array = nullptr, uint32_t p_mask = 0xFFFFFFFF) = 0;

		typedef void *(*PairCallback)(void *, uint32_t, Instance *, int, uint32_t, Instance *, int);
		typedef void (*UnpairCallback)(void *, uint32_t, Instance *, int, uint32_t, Instance *, int, void *);

		virtual void set_pair_callback(PairCallback p_callback, void *p_userdata) = 0;
		virtual void set_unpair_callback(UnpairCallback p_callback, void *p_userdata) = 0;

		// bvh specific
		virtual void params_set_node_expansion(real_t p_value) {}
		virtual void params_set_pairing_expansion(real_t p_value) {}

		// octree specific
		virtual void set_balance(float p_balance) {}

		virtual ~SpatialPartitioningScene() {}
	};

	class SpatialPartitioningScene_Octree : public SpatialPartitioningScene {
		Octree_CL<Instance, true> _octree;

	public:
		SpatialPartitionID create(Instance *p_userdata, const AABB &p_aabb = AABB(), int p_subindex = 0, bool p_pairable = false, uint32_t p_pairable_type = 0, uint32_t pairable_mask = 1);
		void erase(SpatialPartitionID p_handle);
		void move(SpatialPartitionID p_handle, const AABB &p_aabb);
		void set_pairable(SpatialPartitionID p_handle, bool p_pairable, uint32_t p_pairable_type, uint32_t p_pairable_mask);
		int cull_convex(const Vector<Plane> &p_convex, Instance **p_result_array, int p_result_max, uint32_t p_mask = 0xFFFFFFFF);
		int cull_aabb(const AABB &p_aabb, Instance **p_result_array, int p_result_max, int *p_subindex_array = nullptr, uint32_t p_mask = 0xFFFFFFFF);
		int cull_segment(const Vector3 &p_from, const Vector3 &p_to, Instance **p_result_array, int p_result_max, int *p_subindex_array = nullptr, uint32_t p_mask = 0xFFFFFFFF);
		void set_pair_callback(PairCallback p_callback, void *p_userdata);
		void set_unpair_callback(UnpairCallback p_callback, void *p_userdata);
		void set_balance(float p_balance);
	};

	class SpatialPartitioningScene_BVH : public SpatialPartitioningScene {
		// Note that SpatialPartitionIDs are +1 based when stored in visual server, to enable 0 to indicate invalid ID.
		BVH_Manager<Instance, true, 256> _bvh;

	public:
		SpatialPartitionID create(Instance *p_userdata, const AABB &p_aabb = AABB(), int p_subindex = 0, bool p_pairable = false, uint32_t p_pairable_type = 0, uint32_t p_pairable_mask = 1);
		void erase(SpatialPartitionID p_handle);
		void move(SpatialPartitionID p_handle, const AABB &p_aabb);
		void activate(SpatialPartitionID p_handle, const AABB &p_aabb);
		void deactivate(SpatialPartitionID p_handle);
		void force_collision_check(SpatialPartitionID p_handle);
		void update();
		void update_collisions();
		void set_pairable(SpatialPartitionID p_handle, bool p_pairable, uint32_t p_pairable_type, uint32_t p_pairable_mask);
		int cull_convex(const Vector<Plane> &p_convex, Instance **p_result_array, int p_result_max, uint32_t p_mask = 0xFFFFFFFF);
		int cull_aabb(const AABB &p_aabb, Instance **p_result_array, int p_result_max, int *p_subindex_array = nullptr, uint32_t p_mask = 0xFFFFFFFF);
		int cull_segment(const Vector3 &p_from, const Vector3 &p_to, Instance **p_result_array, int p_result_max, int *p_subindex_array = nullptr, uint32_t p_mask = 0xFFFFFFFF);
		void set_pair_callback(PairCallback p_callback, void *p_userdata);
		void set_unpair_callback(UnpairCallback p_callback, void *p_userdata);

		void params_set_node_expansion(real_t p_value) { _bvh.params_set_node_expansion(p_value); }
		void params_set_pairing_expansion(real_t p_value) { _bvh.params_set_pairing_expansion(p_value); }
	};

	struct Scenario : RID_Data {

		VS::ScenarioDebugMode debug;
		RID self;

		SpatialPartitioningScene *sps;

		List<Instance *> directional_lights;
		RID environment;
		RID fallback_environment;
		RID reflection_probe_shadow_atlas;
		RID reflection_atlas;

		SelfList<Instance>::List instances;

		Scenario();
		~Scenario() { memdelete(sps); }
	};

	mutable RID_Owner<Scenario> scenario_owner;

	static void *_instance_pair(void *p_self, SpatialPartitionID, Instance *p_A, int, SpatialPartitionID, Instance *p_B, int);
	static void _instance_unpair(void *p_self, SpatialPartitionID, Instance *p_A, int, SpatialPartitionID, Instance *p_B, int, void *);

	virtual RID scenario_create();

	virtual void scenario_set_debug(RID p_scenario, VS::ScenarioDebugMode p_debug_mode);
	virtual void scenario_set_environment(RID p_scenario, RID p_environment);
	virtual void scenario_set_fallback_environment(RID p_scenario, RID p_environment);
	virtual void scenario_set_reflection_atlas_size(RID p_scenario, int p_size, int p_subdiv);

	/* INSTANCING API */

	struct InstanceBaseData {

		virtual ~InstanceBaseData() {}
	};

	struct Instance : RasterizerScene::InstanceBase {

		RID self;
		//scenario stuff
		SpatialPartitionID spatial_partition_id;
		Scenario *scenario;
		SelfList<Instance> scenario_item;

		//aabb stuff
		bool update_aabb;
		bool update_materials;

		SelfList<Instance> update_item;

		AABB aabb;
		AABB transformed_aabb;
		AABB *custom_aabb; // <Zylann> would using aabb directly with a bool be better?
		float extra_margin;
		uint32_t object_id;

		float lod_begin;
		float lod_end;
		float lod_begin_hysteresis;
		float lod_end_hysteresis;
		RID lod_instance;

		uint64_t last_render_pass;
		uint64_t last_frame_pass;

		uint64_t version; // changes to this, and changes to base increase version

		InstanceBaseData *base_data;

		virtual void base_removed() {

			singleton->instance_set_base(self, RID());
		}

		virtual void base_changed(bool p_aabb, bool p_materials) {

			singleton->_instance_queue_update(this, p_aabb, p_materials);
		}

		Instance() :
				scenario_item(this),
				update_item(this) {

			spatial_partition_id = 0;
			scenario = NULL;

			update_aabb = false;
			update_materials = false;

			extra_margin = 0;

			object_id = 0;
			visible = true;

			lod_begin = 0;
			lod_end = 0;
			lod_begin_hysteresis = 0;
			lod_end_hysteresis = 0;

			last_render_pass = 0;
			last_frame_pass = 0;
			version = 1;
			base_data = NULL;

			custom_aabb = NULL;
		}

		~Instance() {

			if (base_data)
				memdelete(base_data);
			if (custom_aabb)
				memdelete(custom_aabb);
		}
	};

	SelfList<Instance>::List _instance_update_list;
	void _instance_queue_update(Instance *p_instance, bool p_update_aabb, bool p_update_materials = false);

	struct InstanceGeometryData : public InstanceBaseData {

		List<Instance *> lighting;
		bool lighting_dirty;
		bool can_cast_shadows;
		bool material_is_animated;

		List<Instance *> reflection_probes;
		bool reflection_dirty;

		List<Instance *> gi_probes;
		bool gi_probes_dirty;

		List<Instance *> lightmap_captures;

		InstanceGeometryData() {

			lighting_dirty = false;
			reflection_dirty = true;
			can_cast_shadows = true;
			material_is_animated = true;
			gi_probes_dirty = true;
		}
	};

	struct InstanceReflectionProbeData : public InstanceBaseData {

		Instance *owner;

		struct PairInfo {
			List<Instance *>::Element *L; //reflection iterator in geometry
			Instance *geometry;
		};
		List<PairInfo> geometries;

		RID instance;
		bool reflection_dirty;
		SelfList<InstanceReflectionProbeData> update_list;

		int render_step;

		InstanceReflectionProbeData() :
				update_list(this) {

			reflection_dirty = true;
			render_step = -1;
		}
	};

	SelfList<InstanceReflectionProbeData>::List reflection_probe_render_list;

	struct InstanceLightData : public InstanceBaseData {

		struct PairInfo {
			List<Instance *>::Element *L; //light iterator in geometry
			Instance *geometry;
		};

		RID instance;
		uint64_t last_version;
		List<Instance *>::Element *D; // directional light in scenario

		bool shadow_dirty;

		List<PairInfo> geometries;

		Instance *baked_light;

		InstanceLightData() {

			shadow_dirty = true;
			D = NULL;
			last_version = 0;
			baked_light = NULL;
		}
	};

	struct InstanceGIProbeData : public InstanceBaseData {

		Instance *owner;

		struct PairInfo {
			List<Instance *>::Element *L; //gi probe iterator in geometry
			Instance *geometry;
		};

		List<PairInfo> geometries;

		Set<Instance *> lights;

		struct LightCache {

			VS::LightType type;
			Transform transform;
			Color color;
			float energy;
			float radius;
			float attenuation;
			float spot_angle;
			float spot_attenuation;
			bool visible;

			bool operator==(const LightCache &p_cache) {

				return (type == p_cache.type &&
						transform == p_cache.transform &&
						color == p_cache.color &&
						energy == p_cache.energy &&
						radius == p_cache.radius &&
						attenuation == p_cache.attenuation &&
						spot_angle == p_cache.spot_angle &&
						spot_attenuation == p_cache.spot_attenuation &&
						visible == p_cache.visible);
			}

			bool operator!=(const LightCache &p_cache) {

				return !operator==(p_cache);
			}

			LightCache() {

				type = VS::LIGHT_DIRECTIONAL;
				energy = 1.0;
				radius = 1.0;
				attenuation = 1.0;
				spot_angle = 1.0;
				spot_attenuation = 1.0;
				visible = true;
			}
		};

		struct LocalData {
			uint16_t pos[3];
			uint16_t energy[3]; //using 0..1024 for float range 0..1. integer is needed for deterministic add/remove of lights
		};

		struct CompBlockS3TC {
			uint32_t offset; //offset in mipmap
			uint32_t source_count; //sources
			uint32_t sources[16]; //id for each source
			uint8_t alpha[8]; //alpha block is pre-computed
		};

		struct Dynamic {

			Map<RID, LightCache> light_cache;
			Map<RID, LightCache> light_cache_changes;
			PoolVector<int> light_data;
			PoolVector<LocalData> local_data;
			Vector<Vector<uint32_t> > level_cell_lists;
			RID probe_data;
			bool enabled;
			int bake_dynamic_range;
			RasterizerStorage::GIProbeCompression compression;

			Vector<PoolVector<uint8_t> > mipmaps_3d;
			Vector<PoolVector<CompBlockS3TC> > mipmaps_s3tc; //for s3tc

			int updating_stage;
			float propagate;

			int grid_size[3];

			Transform light_to_cell_xform;

		} dynamic;

		RID probe_instance;

		bool invalid;
		uint32_t base_version;

		SelfList<InstanceGIProbeData> update_element;

		InstanceGIProbeData() :
				update_element(this) {
			invalid = true;
			base_version = 0;
			dynamic.updating_stage = GI_UPDATE_STAGE_CHECK;
		}
	};

	SelfList<InstanceGIProbeData>::List gi_probe_update_list;

	struct InstanceLightmapCaptureData : public InstanceBaseData {

		struct PairInfo {
			List<Instance *>::Element *L; //iterator in geometry
			Instance *geometry;
		};
		List<PairInfo> geometries;

		Set<Instance *> users;

		InstanceLightmapCaptureData() {
		}
	};

	int instance_cull_count;
	Instance *instance_cull_result[MAX_INSTANCE_CULL];
	Instance *instance_shadow_cull_result[MAX_INSTANCE_CULL]; //used for generating shadowmaps
	Instance *light_cull_result[MAX_LIGHTS_CULLED];
	RID light_instance_cull_result[MAX_LIGHTS_CULLED];
	int light_cull_count;
	int directional_light_count;
	RID reflection_probe_instance_cull_result[MAX_REFLECTION_PROBES_CULLED];
	int reflection_probe_cull_count;

	RID_Owner<Instance> instance_owner;

	virtual RID instance_create();

	virtual void instance_set_base(RID p_instance, RID p_base);
	virtual void instance_set_scenario(RID p_instance, RID p_scenario);
	virtual void instance_set_layer_mask(RID p_instance, uint32_t p_mask);
	virtual void instance_set_transform(RID p_instance, const Transform &p_transform);
	virtual void instance_attach_object_instance_id(RID p_instance, ObjectID p_id);
	virtual void instance_set_blend_shape_weight(RID p_instance, int p_shape, float p_weight);
	virtual void instance_set_surface_material(RID p_instance, int p_surface, RID p_material);
	virtual void instance_set_visible(RID p_instance, bool p_visible);
	virtual void instance_set_use_lightmap(RID p_instance, RID p_lightmap_instance, RID p_lightmap, int p_lightmap_slice, const Rect2 &p_lightmap_uv_rect);

	virtual void instance_set_custom_aabb(RID p_instance, AABB p_aabb);

	virtual void instance_attach_skeleton(RID p_instance, RID p_skeleton);
	virtual void instance_set_exterior(RID p_instance, bool p_enabled);

	virtual void instance_set_extra_visibility_margin(RID p_instance, real_t p_margin);

	// don't use these in a game!
	virtual Vector<ObjectID> instances_cull_aabb(const AABB &p_aabb, RID p_scenario = RID()) const;
	virtual Vector<ObjectID> instances_cull_ray(const Vector3 &p_from, const Vector3 &p_to, RID p_scenario = RID()) const;
	virtual Vector<ObjectID> instances_cull_convex(const Vector<Plane> &p_convex, RID p_scenario = RID()) const;

	virtual void instance_geometry_set_flag(RID p_instance, VS::InstanceFlags p_flags, bool p_enabled);
	virtual void instance_geometry_set_cast_shadows_setting(RID p_instance, VS::ShadowCastingSetting p_shadow_casting_setting);
	virtual void instance_geometry_set_material_override(RID p_instance, RID p_material);

	virtual void instance_geometry_set_draw_range(RID p_instance, float p_min, float p_max, float p_min_margin, float p_max_margin);
	virtual void instance_geometry_set_as_instance_lod(RID p_instance, RID p_as_lod_of_instance);

	_FORCE_INLINE_ void _update_instance(Instance *p_instance);
	_FORCE_INLINE_ void _update_instance_aabb(Instance *p_instance);
	_FORCE_INLINE_ void _update_dirty_instance(Instance *p_instance);
	_FORCE_INLINE_ void _update_instance_lightmap_captures(Instance *p_instance);

	_FORCE_INLINE_ bool _light_instance_update_shadow(Instance *p_instance, const Transform p_cam_transform, const CameraMatrix &p_cam_projection, bool p_cam_orthogonal, RID p_shadow_atlas, Scenario *p_scenario);

	void _prepare_scene(const Transform p_cam_transform, const CameraMatrix &p_cam_projection, bool p_cam_orthogonal, RID p_force_environment, uint32_t p_visible_layers, RID p_scenario, RID p_shadow_atlas, RID p_reflection_probe);
	void _render_scene(const Transform p_cam_transform, const CameraMatrix &p_cam_projection, bool p_cam_orthogonal, RID p_force_environment, RID p_scenario, RID p_shadow_atlas, RID p_reflection_probe, int p_reflection_probe_pass);
	void render_empty_scene(RID p_scenario, RID p_shadow_atlas);

	void render_camera(RID p_camera, RID p_scenario, Size2 p_viewport_size, RID p_shadow_atlas);
	void render_camera(Ref<ARVRInterface> &p_interface, ARVRInterface::Eyes p_eye, RID p_camera, RID p_scenario, Size2 p_viewport_size, RID p_shadow_atlas);
	void update_dirty_instances();

	//probes
	struct GIProbeDataHeader {

		uint32_t version;
		uint32_t cell_subdiv;
		uint32_t width;
		uint32_t height;
		uint32_t depth;
		uint32_t cell_count;
		uint32_t leaf_cell_count;
	};

	struct GIProbeDataCell {

		uint32_t children[8];
		uint32_t albedo;
		uint32_t emission;
		uint32_t normal;
		uint32_t level_alpha;
	};

	enum {
		GI_UPDATE_STAGE_CHECK,
		GI_UPDATE_STAGE_LIGHTING,
		GI_UPDATE_STAGE_UPLOADING,
	};

	void _gi_probe_bake_thread();
	static void _gi_probe_bake_threads(void *);

	bool probe_bake_thread_exit;
	Thread probe_bake_thread;
	Semaphore probe_bake_sem;
	Mutex probe_bake_mutex;
	List<Instance *> probe_bake_list;

	bool _render_reflection_probe_step(Instance *p_instance, int p_step);
	void _gi_probe_fill_local_data(int p_idx, int p_level, int p_x, int p_y, int p_z, const GIProbeDataCell *p_cell, const GIProbeDataHeader *p_header, InstanceGIProbeData::LocalData *p_local_data, Vector<uint32_t> *prev_cell);

	_FORCE_INLINE_ uint32_t _gi_bake_find_cell(const GIProbeDataCell *cells, int x, int y, int z, int p_cell_subdiv);
	void _bake_gi_downscale_light(int p_idx, int p_level, const GIProbeDataCell *p_cells, const GIProbeDataHeader *p_header, InstanceGIProbeData::LocalData *p_local_data, float p_propagate);
	void _bake_gi_probe_light(const GIProbeDataHeader *header, const GIProbeDataCell *cells, InstanceGIProbeData::LocalData *local_data, const uint32_t *leaves, int p_leaf_count, const InstanceGIProbeData::LightCache &light_cache, int p_sign);
	void _bake_gi_probe(Instance *p_gi_probe);
	bool _check_gi_probe(Instance *p_gi_probe);
	void _setup_gi_probe(Instance *p_instance);

	void render_probes();

	bool free(RID p_rid);

	VisualServerScene();
	virtual ~VisualServerScene();
};

#endif // VISUALSERVERSCENE_H
