/**************************************************************************/
/*  nav_mesh_generator_3d.cpp                                             */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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/* 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,    */
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/**************************************************************************/

#ifndef _3D_DISABLED

#include "nav_mesh_generator_3d.h"

#include "core/config/project_settings.h"
#include "core/math/convex_hull.h"
#include "core/os/thread.h"
#include "scene/3d/mesh_instance_3d.h"
#include "scene/3d/multimesh_instance_3d.h"
#include "scene/3d/physics_body_3d.h"
#include "scene/resources/box_shape_3d.h"
#include "scene/resources/capsule_shape_3d.h"
#include "scene/resources/concave_polygon_shape_3d.h"
#include "scene/resources/convex_polygon_shape_3d.h"
#include "scene/resources/cylinder_shape_3d.h"
#include "scene/resources/height_map_shape_3d.h"
#include "scene/resources/navigation_mesh.h"
#include "scene/resources/navigation_mesh_source_geometry_data_3d.h"
#include "scene/resources/primitive_meshes.h"
#include "scene/resources/shape_3d.h"
#include "scene/resources/sphere_shape_3d.h"
#include "scene/resources/world_boundary_shape_3d.h"

#include "modules/modules_enabled.gen.h" // For csg, gridmap.

#ifdef MODULE_CSG_ENABLED
#include "modules/csg/csg_shape.h"
#endif
#ifdef MODULE_GRIDMAP_ENABLED
#include "modules/gridmap/grid_map.h"
#endif

#include <Recast.h>

NavMeshGenerator3D *NavMeshGenerator3D::singleton = nullptr;
Mutex NavMeshGenerator3D::baking_navmesh_mutex;
Mutex NavMeshGenerator3D::generator_task_mutex;
bool NavMeshGenerator3D::use_threads = true;
bool NavMeshGenerator3D::baking_use_multiple_threads = true;
bool NavMeshGenerator3D::baking_use_high_priority_threads = true;
HashSet<Ref<NavigationMesh>> NavMeshGenerator3D::baking_navmeshes;
HashMap<WorkerThreadPool::TaskID, NavMeshGenerator3D::NavMeshGeneratorTask3D *> NavMeshGenerator3D::generator_tasks;

NavMeshGenerator3D *NavMeshGenerator3D::get_singleton() {
	return singleton;
}

NavMeshGenerator3D::NavMeshGenerator3D() {
	ERR_FAIL_COND(singleton != nullptr);
	singleton = this;

	baking_use_multiple_threads = GLOBAL_GET("navigation/baking/thread_model/baking_use_multiple_threads");
	baking_use_high_priority_threads = GLOBAL_GET("navigation/baking/thread_model/baking_use_high_priority_threads");

	// Using threads might cause problems on certain exports or with the Editor on certain devices.
	// This is the main switch to turn threaded navmesh baking off should the need arise.
	use_threads = baking_use_multiple_threads && !Engine::get_singleton()->is_editor_hint();
}

NavMeshGenerator3D::~NavMeshGenerator3D() {
	cleanup();
}

void NavMeshGenerator3D::sync() {
	if (generator_tasks.size() == 0) {
		return;
	}

	baking_navmesh_mutex.lock();
	generator_task_mutex.lock();

	LocalVector<WorkerThreadPool::TaskID> finished_task_ids;

	for (KeyValue<WorkerThreadPool::TaskID, NavMeshGeneratorTask3D *> &E : generator_tasks) {
		if (WorkerThreadPool::get_singleton()->is_task_completed(E.key)) {
			WorkerThreadPool::get_singleton()->wait_for_task_completion(E.key);
			finished_task_ids.push_back(E.key);

			NavMeshGeneratorTask3D *generator_task = E.value;
			DEV_ASSERT(generator_task->status == NavMeshGeneratorTask3D::TaskStatus::BAKING_FINISHED);

			baking_navmeshes.erase(generator_task->navigation_mesh);
			if (generator_task->callback.is_valid()) {
				generator_emit_callback(generator_task->callback);
			}
			memdelete(generator_task);
		}
	}

	for (WorkerThreadPool::TaskID finished_task_id : finished_task_ids) {
		generator_tasks.erase(finished_task_id);
	}

	generator_task_mutex.unlock();
	baking_navmesh_mutex.unlock();
}

void NavMeshGenerator3D::cleanup() {
	baking_navmesh_mutex.lock();
	generator_task_mutex.lock();

	baking_navmeshes.clear();

	for (KeyValue<WorkerThreadPool::TaskID, NavMeshGeneratorTask3D *> &E : generator_tasks) {
		WorkerThreadPool::get_singleton()->wait_for_task_completion(E.key);
		NavMeshGeneratorTask3D *generator_task = E.value;
		memdelete(generator_task);
	}
	generator_tasks.clear();

	generator_task_mutex.unlock();
	baking_navmesh_mutex.unlock();
}

void NavMeshGenerator3D::finish() {
	cleanup();
}

void NavMeshGenerator3D::parse_source_geometry_data(Ref<NavigationMesh> p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_root_node, const Callable &p_callback) {
	ERR_FAIL_COND(!Thread::is_main_thread());
	ERR_FAIL_COND(!p_navigation_mesh.is_valid());
	ERR_FAIL_COND(p_root_node == nullptr);
	ERR_FAIL_COND(!p_root_node->is_inside_tree());
	ERR_FAIL_COND(!p_source_geometry_data.is_valid());

	generator_parse_source_geometry_data(p_navigation_mesh, p_source_geometry_data, p_root_node);

	if (p_callback.is_valid()) {
		generator_emit_callback(p_callback);
	}
}

void NavMeshGenerator3D::bake_from_source_geometry_data(Ref<NavigationMesh> p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, const Callable &p_callback) {
	ERR_FAIL_COND(!p_navigation_mesh.is_valid());
	ERR_FAIL_COND(!p_source_geometry_data.is_valid());

	if (!p_source_geometry_data->has_data()) {
		p_navigation_mesh->clear();
		if (p_callback.is_valid()) {
			generator_emit_callback(p_callback);
		}
		return;
	}

	baking_navmesh_mutex.lock();
	if (baking_navmeshes.has(p_navigation_mesh)) {
		baking_navmesh_mutex.unlock();
		ERR_FAIL_MSG("NavigationMesh is already baking. Wait for current bake to finish.");
	}
	baking_navmeshes.insert(p_navigation_mesh);
	baking_navmesh_mutex.unlock();

	generator_bake_from_source_geometry_data(p_navigation_mesh, p_source_geometry_data);

	baking_navmesh_mutex.lock();
	baking_navmeshes.erase(p_navigation_mesh);
	baking_navmesh_mutex.unlock();

	if (p_callback.is_valid()) {
		generator_emit_callback(p_callback);
	}
}

void NavMeshGenerator3D::bake_from_source_geometry_data_async(Ref<NavigationMesh> p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, const Callable &p_callback) {
	ERR_FAIL_COND(!p_navigation_mesh.is_valid());
	ERR_FAIL_COND(!p_source_geometry_data.is_valid());

	if (!p_source_geometry_data->has_data()) {
		p_navigation_mesh->clear();
		if (p_callback.is_valid()) {
			generator_emit_callback(p_callback);
		}
		return;
	}

	if (!use_threads) {
		bake_from_source_geometry_data(p_navigation_mesh, p_source_geometry_data, p_callback);
		return;
	}

	baking_navmesh_mutex.lock();
	if (baking_navmeshes.has(p_navigation_mesh)) {
		baking_navmesh_mutex.unlock();
		ERR_FAIL_MSG("NavigationMesh is already baking. Wait for current bake to finish.");
		return;
	}
	baking_navmeshes.insert(p_navigation_mesh);
	baking_navmesh_mutex.unlock();

	generator_task_mutex.lock();
	NavMeshGeneratorTask3D *generator_task = memnew(NavMeshGeneratorTask3D);
	generator_task->navigation_mesh = p_navigation_mesh;
	generator_task->source_geometry_data = p_source_geometry_data;
	generator_task->callback = p_callback;
	generator_task->status = NavMeshGeneratorTask3D::TaskStatus::BAKING_STARTED;
	generator_task->thread_task_id = WorkerThreadPool::get_singleton()->add_native_task(&NavMeshGenerator3D::generator_thread_bake, generator_task, NavMeshGenerator3D::baking_use_high_priority_threads, SNAME("NavMeshGeneratorBake3D"));
	generator_tasks.insert(generator_task->thread_task_id, generator_task);
	generator_task_mutex.unlock();
}

void NavMeshGenerator3D::generator_thread_bake(void *p_arg) {
	NavMeshGeneratorTask3D *generator_task = static_cast<NavMeshGeneratorTask3D *>(p_arg);

	generator_bake_from_source_geometry_data(generator_task->navigation_mesh, generator_task->source_geometry_data);

	generator_task->status = NavMeshGeneratorTask3D::TaskStatus::BAKING_FINISHED;
}

void NavMeshGenerator3D::generator_parse_geometry_node(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_node, bool p_recurse_children) {
	generator_parse_meshinstance3d_node(p_navigation_mesh, p_source_geometry_data, p_node);
	generator_parse_multimeshinstance3d_node(p_navigation_mesh, p_source_geometry_data, p_node);
	generator_parse_staticbody3d_node(p_navigation_mesh, p_source_geometry_data, p_node);
#ifdef MODULE_CSG_ENABLED
	generator_parse_csgshape3d_node(p_navigation_mesh, p_source_geometry_data, p_node);
#endif
#ifdef MODULE_GRIDMAP_ENABLED
	generator_parse_gridmap_node(p_navigation_mesh, p_source_geometry_data, p_node);
#endif

	if (p_recurse_children) {
		for (int i = 0; i < p_node->get_child_count(); i++) {
			generator_parse_geometry_node(p_navigation_mesh, p_source_geometry_data, p_node->get_child(i), p_recurse_children);
		}
	}
}

void NavMeshGenerator3D::generator_parse_meshinstance3d_node(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_node) {
	MeshInstance3D *mesh_instance = Object::cast_to<MeshInstance3D>(p_node);

	if (mesh_instance) {
		NavigationMesh::ParsedGeometryType parsed_geometry_type = p_navigation_mesh->get_parsed_geometry_type();

		if (parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_MESH_INSTANCES || parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_BOTH) {
			Ref<Mesh> mesh = mesh_instance->get_mesh();
			if (mesh.is_valid()) {
				p_source_geometry_data->add_mesh(mesh, mesh_instance->get_global_transform());
			}
		}
	}
}

void NavMeshGenerator3D::generator_parse_multimeshinstance3d_node(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_node) {
	MultiMeshInstance3D *multimesh_instance = Object::cast_to<MultiMeshInstance3D>(p_node);

	if (multimesh_instance) {
		NavigationMesh::ParsedGeometryType parsed_geometry_type = p_navigation_mesh->get_parsed_geometry_type();

		if (parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_MESH_INSTANCES || parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_BOTH) {
			Ref<MultiMesh> multimesh = multimesh_instance->get_multimesh();
			if (multimesh.is_valid()) {
				Ref<Mesh> mesh = multimesh->get_mesh();
				if (mesh.is_valid()) {
					int n = multimesh->get_visible_instance_count();
					if (n == -1) {
						n = multimesh->get_instance_count();
					}
					for (int i = 0; i < n; i++) {
						p_source_geometry_data->add_mesh(mesh, multimesh_instance->get_global_transform() * multimesh->get_instance_transform(i));
					}
				}
			}
		}
	}
}

void NavMeshGenerator3D::generator_parse_staticbody3d_node(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_node) {
	StaticBody3D *static_body = Object::cast_to<StaticBody3D>(p_node);

	if (static_body) {
		NavigationMesh::ParsedGeometryType parsed_geometry_type = p_navigation_mesh->get_parsed_geometry_type();
		uint32_t parsed_collision_mask = p_navigation_mesh->get_collision_mask();

		if ((parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_STATIC_COLLIDERS || parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_BOTH) && (static_body->get_collision_layer() & parsed_collision_mask)) {
			List<uint32_t> shape_owners;
			static_body->get_shape_owners(&shape_owners);
			for (uint32_t shape_owner : shape_owners) {
				if (static_body->is_shape_owner_disabled(shape_owner)) {
					continue;
				}
				const int shape_count = static_body->shape_owner_get_shape_count(shape_owner);
				for (int shape_index = 0; shape_index < shape_count; shape_index++) {
					Ref<Shape3D> s = static_body->shape_owner_get_shape(shape_owner, shape_index);
					if (s.is_null()) {
						continue;
					}

					const Transform3D transform = static_body->get_global_transform() * static_body->shape_owner_get_transform(shape_owner);

					BoxShape3D *box = Object::cast_to<BoxShape3D>(*s);
					if (box) {
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						BoxMesh::create_mesh_array(arr, box->get_size());
						p_source_geometry_data->add_mesh_array(arr, transform);
					}

					CapsuleShape3D *capsule = Object::cast_to<CapsuleShape3D>(*s);
					if (capsule) {
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						CapsuleMesh::create_mesh_array(arr, capsule->get_radius(), capsule->get_height());
						p_source_geometry_data->add_mesh_array(arr, transform);
					}

					CylinderShape3D *cylinder = Object::cast_to<CylinderShape3D>(*s);
					if (cylinder) {
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						CylinderMesh::create_mesh_array(arr, cylinder->get_radius(), cylinder->get_radius(), cylinder->get_height());
						p_source_geometry_data->add_mesh_array(arr, transform);
					}

					SphereShape3D *sphere = Object::cast_to<SphereShape3D>(*s);
					if (sphere) {
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						SphereMesh::create_mesh_array(arr, sphere->get_radius(), sphere->get_radius() * 2.0);
						p_source_geometry_data->add_mesh_array(arr, transform);
					}

					ConcavePolygonShape3D *concave_polygon = Object::cast_to<ConcavePolygonShape3D>(*s);
					if (concave_polygon) {
						p_source_geometry_data->add_faces(concave_polygon->get_faces(), transform);
					}

					ConvexPolygonShape3D *convex_polygon = Object::cast_to<ConvexPolygonShape3D>(*s);
					if (convex_polygon) {
						Vector<Vector3> varr = Variant(convex_polygon->get_points());
						Geometry3D::MeshData md;

						Error err = ConvexHullComputer::convex_hull(varr, md);

						if (err == OK) {
							PackedVector3Array faces;

							for (const Geometry3D::MeshData::Face &face : md.faces) {
								for (uint32_t k = 2; k < face.indices.size(); ++k) {
									faces.push_back(md.vertices[face.indices[0]]);
									faces.push_back(md.vertices[face.indices[k - 1]]);
									faces.push_back(md.vertices[face.indices[k]]);
								}
							}

							p_source_geometry_data->add_faces(faces, transform);
						}
					}

					HeightMapShape3D *heightmap_shape = Object::cast_to<HeightMapShape3D>(*s);
					if (heightmap_shape) {
						int heightmap_depth = heightmap_shape->get_map_depth();
						int heightmap_width = heightmap_shape->get_map_width();

						if (heightmap_depth >= 2 && heightmap_width >= 2) {
							const Vector<real_t> &map_data = heightmap_shape->get_map_data();

							Vector2 heightmap_gridsize(heightmap_width - 1, heightmap_depth - 1);
							Vector2 start = heightmap_gridsize * -0.5;

							Vector<Vector3> vertex_array;
							vertex_array.resize((heightmap_depth - 1) * (heightmap_width - 1) * 6);
							int map_data_current_index = 0;

							for (int d = 0; d < heightmap_depth; d++) {
								for (int w = 0; w < heightmap_width; w++) {
									if (map_data_current_index + 1 + heightmap_depth < map_data.size()) {
										float top_left_height = map_data[map_data_current_index];
										float top_right_height = map_data[map_data_current_index + 1];
										float bottom_left_height = map_data[map_data_current_index + heightmap_depth];
										float bottom_right_height = map_data[map_data_current_index + 1 + heightmap_depth];

										Vector3 top_left = Vector3(start.x + w, top_left_height, start.y + d);
										Vector3 top_right = Vector3(start.x + w + 1.0, top_right_height, start.y + d);
										Vector3 bottom_left = Vector3(start.x + w, bottom_left_height, start.y + d + 1.0);
										Vector3 bottom_right = Vector3(start.x + w + 1.0, bottom_right_height, start.y + d + 1.0);

										vertex_array.push_back(top_right);
										vertex_array.push_back(bottom_left);
										vertex_array.push_back(top_left);
										vertex_array.push_back(top_right);
										vertex_array.push_back(bottom_right);
										vertex_array.push_back(bottom_left);
									}
									map_data_current_index += 1;
								}
							}
							if (vertex_array.size() > 0) {
								p_source_geometry_data->add_faces(vertex_array, transform);
							}
						}
					}
				}
			}
		}
	}
}

#ifdef MODULE_CSG_ENABLED
void NavMeshGenerator3D::generator_parse_csgshape3d_node(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_node) {
	CSGShape3D *csgshape3d = Object::cast_to<CSGShape3D>(p_node);

	if (csgshape3d) {
		NavigationMesh::ParsedGeometryType parsed_geometry_type = p_navigation_mesh->get_parsed_geometry_type();
		uint32_t parsed_collision_mask = p_navigation_mesh->get_collision_mask();

		if (parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_MESH_INSTANCES || (parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_STATIC_COLLIDERS && csgshape3d->is_using_collision() && (csgshape3d->get_collision_layer() & parsed_collision_mask)) || parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_BOTH) {
			CSGShape3D *csg_shape = Object::cast_to<CSGShape3D>(p_node);
			Array meshes = csg_shape->get_meshes();
			if (!meshes.is_empty()) {
				Ref<Mesh> mesh = meshes[1];
				if (mesh.is_valid()) {
					p_source_geometry_data->add_mesh(mesh, csg_shape->get_global_transform());
				}
			}
		}
	}
}
#endif // MODULE_CSG_ENABLED

#ifdef MODULE_GRIDMAP_ENABLED
void NavMeshGenerator3D::generator_parse_gridmap_node(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_node) {
	GridMap *gridmap = Object::cast_to<GridMap>(p_node);

	if (gridmap) {
		NavigationMesh::ParsedGeometryType parsed_geometry_type = p_navigation_mesh->get_parsed_geometry_type();
		uint32_t parsed_collision_mask = p_navigation_mesh->get_collision_mask();

		if (parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_MESH_INSTANCES || parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_BOTH) {
			Array meshes = gridmap->get_meshes();
			Transform3D xform = gridmap->get_global_transform();
			for (int i = 0; i < meshes.size(); i += 2) {
				Ref<Mesh> mesh = meshes[i + 1];
				if (mesh.is_valid()) {
					p_source_geometry_data->add_mesh(mesh, xform * (Transform3D)meshes[i]);
				}
			}
		}

		else if ((parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_STATIC_COLLIDERS || parsed_geometry_type == NavigationMesh::PARSED_GEOMETRY_BOTH) && (gridmap->get_collision_layer() & parsed_collision_mask)) {
			Array shapes = gridmap->get_collision_shapes();
			for (int i = 0; i < shapes.size(); i += 2) {
				RID shape = shapes[i + 1];
				PhysicsServer3D::ShapeType type = PhysicsServer3D::get_singleton()->shape_get_type(shape);
				Variant data = PhysicsServer3D::get_singleton()->shape_get_data(shape);

				switch (type) {
					case PhysicsServer3D::SHAPE_SPHERE: {
						real_t radius = data;
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						SphereMesh::create_mesh_array(arr, radius, radius * 2.0);
						p_source_geometry_data->add_mesh_array(arr, shapes[i]);
					} break;
					case PhysicsServer3D::SHAPE_BOX: {
						Vector3 extents = data;
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						BoxMesh::create_mesh_array(arr, extents * 2.0);
						p_source_geometry_data->add_mesh_array(arr, shapes[i]);
					} break;
					case PhysicsServer3D::SHAPE_CAPSULE: {
						Dictionary dict = data;
						real_t radius = dict["radius"];
						real_t height = dict["height"];
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						CapsuleMesh::create_mesh_array(arr, radius, height);
						p_source_geometry_data->add_mesh_array(arr, shapes[i]);
					} break;
					case PhysicsServer3D::SHAPE_CYLINDER: {
						Dictionary dict = data;
						real_t radius = dict["radius"];
						real_t height = dict["height"];
						Array arr;
						arr.resize(RS::ARRAY_MAX);
						CylinderMesh::create_mesh_array(arr, radius, radius, height);
						p_source_geometry_data->add_mesh_array(arr, shapes[i]);
					} break;
					case PhysicsServer3D::SHAPE_CONVEX_POLYGON: {
						PackedVector3Array vertices = data;
						Geometry3D::MeshData md;

						Error err = ConvexHullComputer::convex_hull(vertices, md);

						if (err == OK) {
							PackedVector3Array faces;

							for (const Geometry3D::MeshData::Face &face : md.faces) {
								for (uint32_t k = 2; k < face.indices.size(); ++k) {
									faces.push_back(md.vertices[face.indices[0]]);
									faces.push_back(md.vertices[face.indices[k - 1]]);
									faces.push_back(md.vertices[face.indices[k]]);
								}
							}

							p_source_geometry_data->add_faces(faces, shapes[i]);
						}
					} break;
					case PhysicsServer3D::SHAPE_CONCAVE_POLYGON: {
						Dictionary dict = data;
						PackedVector3Array faces = Variant(dict["faces"]);
						p_source_geometry_data->add_faces(faces, shapes[i]);
					} break;
					case PhysicsServer3D::SHAPE_HEIGHTMAP: {
						Dictionary dict = data;
						///< dict( int:"width", int:"depth",float:"cell_size", float_array:"heights"
						int heightmap_depth = dict["depth"];
						int heightmap_width = dict["width"];

						if (heightmap_depth >= 2 && heightmap_width >= 2) {
							const Vector<real_t> &map_data = dict["heights"];

							Vector2 heightmap_gridsize(heightmap_width - 1, heightmap_depth - 1);
							Vector2 start = heightmap_gridsize * -0.5;

							Vector<Vector3> vertex_array;
							vertex_array.resize((heightmap_depth - 1) * (heightmap_width - 1) * 6);
							int map_data_current_index = 0;

							for (int d = 0; d < heightmap_depth; d++) {
								for (int w = 0; w < heightmap_width; w++) {
									if (map_data_current_index + 1 + heightmap_depth < map_data.size()) {
										float top_left_height = map_data[map_data_current_index];
										float top_right_height = map_data[map_data_current_index + 1];
										float bottom_left_height = map_data[map_data_current_index + heightmap_depth];
										float bottom_right_height = map_data[map_data_current_index + 1 + heightmap_depth];

										Vector3 top_left = Vector3(start.x + w, top_left_height, start.y + d);
										Vector3 top_right = Vector3(start.x + w + 1.0, top_right_height, start.y + d);
										Vector3 bottom_left = Vector3(start.x + w, bottom_left_height, start.y + d + 1.0);
										Vector3 bottom_right = Vector3(start.x + w + 1.0, bottom_right_height, start.y + d + 1.0);

										vertex_array.push_back(top_right);
										vertex_array.push_back(bottom_left);
										vertex_array.push_back(top_left);
										vertex_array.push_back(top_right);
										vertex_array.push_back(bottom_right);
										vertex_array.push_back(bottom_left);
									}
									map_data_current_index += 1;
								}
							}
							if (vertex_array.size() > 0) {
								p_source_geometry_data->add_faces(vertex_array, shapes[i]);
							}
						}
					} break;
					default: {
						WARN_PRINT("Unsupported collision shape type.");
					} break;
				}
			}
		}
	}
}
#endif // MODULE_GRIDMAP_ENABLED

void NavMeshGenerator3D::generator_parse_source_geometry_data(const Ref<NavigationMesh> &p_navigation_mesh, Ref<NavigationMeshSourceGeometryData3D> p_source_geometry_data, Node *p_root_node) {
	List<Node *> parse_nodes;

	if (p_navigation_mesh->get_source_geometry_mode() == NavigationMesh::SOURCE_GEOMETRY_ROOT_NODE_CHILDREN) {
		parse_nodes.push_back(p_root_node);
	} else {
		p_root_node->get_tree()->get_nodes_in_group(p_navigation_mesh->get_source_group_name(), &parse_nodes);
	}

	Transform3D root_node_transform = Transform3D();
	if (Object::cast_to<Node3D>(p_root_node)) {
		root_node_transform = Object::cast_to<Node3D>(p_root_node)->get_global_transform().affine_inverse();
	}

	p_source_geometry_data->clear();
	p_source_geometry_data->root_node_transform = root_node_transform;

	bool recurse_children = p_navigation_mesh->get_source_geometry_mode() != NavigationMesh::SOURCE_GEOMETRY_GROUPS_EXPLICIT;

	for (Node *parse_node : parse_nodes) {
		generator_parse_geometry_node(p_navigation_mesh, p_source_geometry_data, parse_node, recurse_children);
	}
};

void NavMeshGenerator3D::generator_bake_from_source_geometry_data(Ref<NavigationMesh> p_navigation_mesh, const Ref<NavigationMeshSourceGeometryData3D> &p_source_geometry_data) {
	if (p_navigation_mesh.is_null() || p_source_geometry_data.is_null()) {
		return;
	}

	const Vector<float> &vertices = p_source_geometry_data->get_vertices();
	const Vector<int> &indices = p_source_geometry_data->get_indices();

	if (vertices.size() < 3 || indices.size() < 3) {
		return;
	}

	rcHeightfield *hf = nullptr;
	rcCompactHeightfield *chf = nullptr;
	rcContourSet *cset = nullptr;
	rcPolyMesh *poly_mesh = nullptr;
	rcPolyMeshDetail *detail_mesh = nullptr;
	rcContext ctx;

	// added to keep track of steps, no functionality right now
	String bake_state = "";

	bake_state = "Setting up Configuration..."; // step #1

	const float *verts = vertices.ptr();
	const int nverts = vertices.size() / 3;
	const int *tris = indices.ptr();
	const int ntris = indices.size() / 3;

	float bmin[3], bmax[3];
	rcCalcBounds(verts, nverts, bmin, bmax);

	rcConfig cfg;
	memset(&cfg, 0, sizeof(cfg));

	cfg.cs = p_navigation_mesh->get_cell_size();
	cfg.ch = p_navigation_mesh->get_cell_height();
	cfg.walkableSlopeAngle = p_navigation_mesh->get_agent_max_slope();
	cfg.walkableHeight = (int)Math::ceil(p_navigation_mesh->get_agent_height() / cfg.ch);
	cfg.walkableClimb = (int)Math::floor(p_navigation_mesh->get_agent_max_climb() / cfg.ch);
	cfg.walkableRadius = (int)Math::ceil(p_navigation_mesh->get_agent_radius() / cfg.cs);
	cfg.maxEdgeLen = (int)(p_navigation_mesh->get_edge_max_length() / p_navigation_mesh->get_cell_size());
	cfg.maxSimplificationError = p_navigation_mesh->get_edge_max_error();
	cfg.minRegionArea = (int)(p_navigation_mesh->get_region_min_size() * p_navigation_mesh->get_region_min_size());
	cfg.mergeRegionArea = (int)(p_navigation_mesh->get_region_merge_size() * p_navigation_mesh->get_region_merge_size());
	cfg.maxVertsPerPoly = (int)p_navigation_mesh->get_vertices_per_polygon();
	cfg.detailSampleDist = MAX(p_navigation_mesh->get_cell_size() * p_navigation_mesh->get_detail_sample_distance(), 0.1f);
	cfg.detailSampleMaxError = p_navigation_mesh->get_cell_height() * p_navigation_mesh->get_detail_sample_max_error();

	if (!Math::is_equal_approx((float)cfg.walkableHeight * cfg.ch, p_navigation_mesh->get_agent_height())) {
		WARN_PRINT("Property agent_height is ceiled to cell_height voxel units and loses precision.");
	}
	if (!Math::is_equal_approx((float)cfg.walkableClimb * cfg.ch, p_navigation_mesh->get_agent_max_climb())) {
		WARN_PRINT("Property agent_max_climb is floored to cell_height voxel units and loses precision.");
	}
	if (!Math::is_equal_approx((float)cfg.walkableRadius * cfg.cs, p_navigation_mesh->get_agent_radius())) {
		WARN_PRINT("Property agent_radius is ceiled to cell_size voxel units and loses precision.");
	}
	if (!Math::is_equal_approx((float)cfg.maxEdgeLen * cfg.cs, p_navigation_mesh->get_edge_max_length())) {
		WARN_PRINT("Property edge_max_length is rounded to cell_size voxel units and loses precision.");
	}
	if (!Math::is_equal_approx((float)cfg.minRegionArea, p_navigation_mesh->get_region_min_size() * p_navigation_mesh->get_region_min_size())) {
		WARN_PRINT("Property region_min_size is converted to int and loses precision.");
	}
	if (!Math::is_equal_approx((float)cfg.mergeRegionArea, p_navigation_mesh->get_region_merge_size() * p_navigation_mesh->get_region_merge_size())) {
		WARN_PRINT("Property region_merge_size is converted to int and loses precision.");
	}
	if (!Math::is_equal_approx((float)cfg.maxVertsPerPoly, p_navigation_mesh->get_vertices_per_polygon())) {
		WARN_PRINT("Property vertices_per_polygon is converted to int and loses precision.");
	}
	if (p_navigation_mesh->get_cell_size() * p_navigation_mesh->get_detail_sample_distance() < 0.1f) {
		WARN_PRINT("Property detail_sample_distance is clamped to 0.1 world units as the resulting value from multiplying with cell_size is too low.");
	}

	cfg.bmin[0] = bmin[0];
	cfg.bmin[1] = bmin[1];
	cfg.bmin[2] = bmin[2];
	cfg.bmax[0] = bmax[0];
	cfg.bmax[1] = bmax[1];
	cfg.bmax[2] = bmax[2];

	AABB baking_aabb = p_navigation_mesh->get_filter_baking_aabb();
	if (baking_aabb.has_volume()) {
		Vector3 baking_aabb_offset = p_navigation_mesh->get_filter_baking_aabb_offset();
		cfg.bmin[0] = baking_aabb.position[0] + baking_aabb_offset.x;
		cfg.bmin[1] = baking_aabb.position[1] + baking_aabb_offset.y;
		cfg.bmin[2] = baking_aabb.position[2] + baking_aabb_offset.z;
		cfg.bmax[0] = cfg.bmin[0] + baking_aabb.size[0];
		cfg.bmax[1] = cfg.bmin[1] + baking_aabb.size[1];
		cfg.bmax[2] = cfg.bmin[2] + baking_aabb.size[2];
	}

	bake_state = "Calculating grid size..."; // step #2
	rcCalcGridSize(cfg.bmin, cfg.bmax, cfg.cs, &cfg.width, &cfg.height);

	// ~30000000 seems to be around sweetspot where Editor baking breaks
	if ((cfg.width * cfg.height) > 30000000) {
		WARN_PRINT("NavigationMesh baking process will likely fail."
				   "\nSource geometry is suspiciously big for the current Cell Size and Cell Height in the NavMesh Resource bake settings."
				   "\nIf baking does not fail, the resulting NavigationMesh will create serious pathfinding performance issues."
				   "\nIt is advised to increase Cell Size and/or Cell Height in the NavMesh Resource bake settings or reduce the size / scale of the source geometry.");
	}

	bake_state = "Creating heightfield..."; // step #3
	hf = rcAllocHeightfield();

	ERR_FAIL_COND(!hf);
	ERR_FAIL_COND(!rcCreateHeightfield(&ctx, *hf, cfg.width, cfg.height, cfg.bmin, cfg.bmax, cfg.cs, cfg.ch));

	bake_state = "Marking walkable triangles..."; // step #4
	{
		Vector<unsigned char> tri_areas;
		tri_areas.resize(ntris);

		ERR_FAIL_COND(tri_areas.size() == 0);

		memset(tri_areas.ptrw(), 0, ntris * sizeof(unsigned char));
		rcMarkWalkableTriangles(&ctx, cfg.walkableSlopeAngle, verts, nverts, tris, ntris, tri_areas.ptrw());

		ERR_FAIL_COND(!rcRasterizeTriangles(&ctx, verts, nverts, tris, tri_areas.ptr(), ntris, *hf, cfg.walkableClimb));
	}

	if (p_navigation_mesh->get_filter_low_hanging_obstacles()) {
		rcFilterLowHangingWalkableObstacles(&ctx, cfg.walkableClimb, *hf);
	}
	if (p_navigation_mesh->get_filter_ledge_spans()) {
		rcFilterLedgeSpans(&ctx, cfg.walkableHeight, cfg.walkableClimb, *hf);
	}
	if (p_navigation_mesh->get_filter_walkable_low_height_spans()) {
		rcFilterWalkableLowHeightSpans(&ctx, cfg.walkableHeight, *hf);
	}

	bake_state = "Constructing compact heightfield..."; // step #5

	chf = rcAllocCompactHeightfield();

	ERR_FAIL_COND(!chf);
	ERR_FAIL_COND(!rcBuildCompactHeightfield(&ctx, cfg.walkableHeight, cfg.walkableClimb, *hf, *chf));

	rcFreeHeightField(hf);
	hf = nullptr;

	bake_state = "Eroding walkable area..."; // step #6

	ERR_FAIL_COND(!rcErodeWalkableArea(&ctx, cfg.walkableRadius, *chf));

	bake_state = "Partitioning..."; // step #7

	if (p_navigation_mesh->get_sample_partition_type() == NavigationMesh::SAMPLE_PARTITION_WATERSHED) {
		ERR_FAIL_COND(!rcBuildDistanceField(&ctx, *chf));
		ERR_FAIL_COND(!rcBuildRegions(&ctx, *chf, 0, cfg.minRegionArea, cfg.mergeRegionArea));
	} else if (p_navigation_mesh->get_sample_partition_type() == NavigationMesh::SAMPLE_PARTITION_MONOTONE) {
		ERR_FAIL_COND(!rcBuildRegionsMonotone(&ctx, *chf, 0, cfg.minRegionArea, cfg.mergeRegionArea));
	} else {
		ERR_FAIL_COND(!rcBuildLayerRegions(&ctx, *chf, 0, cfg.minRegionArea));
	}

	bake_state = "Creating contours..."; // step #8

	cset = rcAllocContourSet();

	ERR_FAIL_COND(!cset);
	ERR_FAIL_COND(!rcBuildContours(&ctx, *chf, cfg.maxSimplificationError, cfg.maxEdgeLen, *cset));

	bake_state = "Creating polymesh..."; // step #9

	poly_mesh = rcAllocPolyMesh();
	ERR_FAIL_COND(!poly_mesh);
	ERR_FAIL_COND(!rcBuildPolyMesh(&ctx, *cset, cfg.maxVertsPerPoly, *poly_mesh));

	detail_mesh = rcAllocPolyMeshDetail();
	ERR_FAIL_COND(!detail_mesh);
	ERR_FAIL_COND(!rcBuildPolyMeshDetail(&ctx, *poly_mesh, *chf, cfg.detailSampleDist, cfg.detailSampleMaxError, *detail_mesh));

	rcFreeCompactHeightfield(chf);
	chf = nullptr;
	rcFreeContourSet(cset);
	cset = nullptr;

	bake_state = "Converting to native navigation mesh..."; // step #10

	Vector<Vector3> nav_vertices;

	for (int i = 0; i < detail_mesh->nverts; i++) {
		const float *v = &detail_mesh->verts[i * 3];
		nav_vertices.push_back(Vector3(v[0], v[1], v[2]));
	}
	p_navigation_mesh->set_vertices(nav_vertices);
	p_navigation_mesh->clear_polygons();

	for (int i = 0; i < detail_mesh->nmeshes; i++) {
		const unsigned int *detail_mesh_m = &detail_mesh->meshes[i * 4];
		const unsigned int detail_mesh_bverts = detail_mesh_m[0];
		const unsigned int detail_mesh_m_btris = detail_mesh_m[2];
		const unsigned int detail_mesh_ntris = detail_mesh_m[3];
		const unsigned char *detail_mesh_tris = &detail_mesh->tris[detail_mesh_m_btris * 4];
		for (unsigned int j = 0; j < detail_mesh_ntris; j++) {
			Vector<int> nav_indices;
			nav_indices.resize(3);
			// Polygon order in recast is opposite than godot's
			nav_indices.write[0] = ((int)(detail_mesh_bverts + detail_mesh_tris[j * 4 + 0]));
			nav_indices.write[1] = ((int)(detail_mesh_bverts + detail_mesh_tris[j * 4 + 2]));
			nav_indices.write[2] = ((int)(detail_mesh_bverts + detail_mesh_tris[j * 4 + 1]));
			p_navigation_mesh->add_polygon(nav_indices);
		}
	}

	bake_state = "Cleanup..."; // step #11

	rcFreePolyMesh(poly_mesh);
	poly_mesh = nullptr;
	rcFreePolyMeshDetail(detail_mesh);
	detail_mesh = nullptr;

	bake_state = "Baking finished."; // step #12
}

bool NavMeshGenerator3D::generator_emit_callback(const Callable &p_callback) {
	ERR_FAIL_COND_V(!p_callback.is_valid(), false);

	Callable::CallError ce;
	Variant result;
	p_callback.callp(nullptr, 0, result, ce);

	return ce.error == Callable::CallError::CALL_OK;
}

#endif // _3D_DISABLED
