extends SpaceEntity

class_name SpaceRegion


@export var elevation: float = 0.0
@export var height: float = 100.0


func generate_geometry(space: Space) -> Node3D:
	var geometry := MeshInstance3D.new()
	geometry.name = name

	var polygon = self.polygon
	var polygon_pairs = Array()
	for i in range(-1, polygon.size() - 1):
		polygon_pairs.append([polygon[i], polygon[i+1]])

	var vertices = PackedVector3Array()
	var uvs = PackedVector2Array()
	for line in polygon_pairs:
		vertices.append(Vector3(
			line[0][0] * space.unit_scale, elevation * space.unit_scale,
			line[0][1] * space.unit_scale
		))
		vertices.append(Vector3(
			line[1][0] * space.unit_scale, (elevation + height) * space.unit_scale,
			line[1][1] * space.unit_scale,
		))
		vertices.append(Vector3(
			line[1][0] * space.unit_scale, elevation * space.unit_scale,
			line[1][1] * space.unit_scale,
		))
		vertices.append(Vector3(
			line[1][0] * space.unit_scale, (elevation + height) * space.unit_scale,
			line[1][1] * space.unit_scale,
		))
		vertices.append(Vector3(
			line[0][0] * space.unit_scale, elevation * space.unit_scale,
			line[0][1] * space.unit_scale,
		))
		vertices.append(Vector3(
			line[0][0] * space.unit_scale, (elevation + height) * space.unit_scale,
			line[0][1] * space.unit_scale,
		))
		uvs.append(Vector2(0, 1))
		uvs.append(Vector2(1, 0))
		uvs.append(Vector2(1, 1))
		uvs.append(Vector2(1, 0))
		uvs.append(Vector2(0, 1))
		uvs.append(Vector2(0, 0))

	var arrays = Array()
	arrays.resize(Mesh.ARRAY_MAX)
	arrays[Mesh.ARRAY_VERTEX] = vertices
	arrays[Mesh.ARRAY_TEX_UV] = uvs

	var mesh = ArrayMesh.new()
	mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arrays)
	mesh.surface_set_material(0, preload("res://Scenes/Material.tres"))

	geometry.mesh = mesh

	return geometry