constants.gd

extends Node

enum TERRAIN_SHAPE { NONE, FLAT, PEAK, DROP, SLANT }
const QUAD_UVS: = PoolVector2Array([Vector2(0, 0), Vector2(1, 0), Vector2(1, 1), Vector2(0, 1)])

island-preview.gd

extends Spatial

const MeshLibraryFactory = preload("res://island/mesh-library-factory.gd")

onready var grid: GridMap = get_node("grid")

func _ready():
	grid.mesh_library = MeshLibraryFactory.generate_terrain()
	grid.set_cell_item(0, 0, 0, CONSTANTS.TERRAIN_SHAPE.FLAT)

	print(grid.get_used_cells())
	# outputs: [(0, 0, 0)]
	print(grid.mesh_library.get_item_list())
	# outputs: [1, 2, 3, 4]

mesh-library-factory.gd

extends Resource

const terrain_mat = preload("res://island-scn/terrain-mat.material")

static func generate_terrain() -> MeshLibrary:
	var mesh_library: = MeshLibrary.new()
	_add_item(mesh_library, CONSTANTS.TERRAIN_SHAPE.FLAT, _flat_mesh())
	_add_item(mesh_library, CONSTANTS.TERRAIN_SHAPE.PEAK, _peak_mesh())
	_add_item(mesh_library, CONSTANTS.TERRAIN_SHAPE.DROP, _drop_mesh())
	_add_item(mesh_library, CONSTANTS.TERRAIN_SHAPE.SLANT, _slant_mesh())
	return mesh_library

static func _add_item(mesh_library: MeshLibrary, id: int, mesh: ArrayMesh):
	mesh_library.create_item(id)
	mesh_library.set_item_mesh(id, mesh)

const FLAT_MESH_VERTS = PoolVector3Array([
	Vector3(0, 1, 1),
	Vector3(1, 1, 1),
	Vector3(1, 1, 0),
	Vector3(0, 1, 0),
])
static func _flat_mesh() -> ArrayMesh:
	var mesh: = ArrayMesh.new()
	_add_surface(mesh, FLAT_MESH_VERTS, PoolIntArray([0, 1, 2]))
	_add_surface(mesh, FLAT_MESH_VERTS, PoolIntArray([0, 2, 3]))
	return mesh

const PEAK_MESH_VERTS: = PoolVector3Array([
	Vector3(0, 0, 1),
	Vector3(1, 1, 1),
	Vector3(1, 0, 0),
	Vector3(0, 0, 0),
])
static func _peak_mesh() -> ArrayMesh:
	var mesh: = ArrayMesh.new()
	_add_surface(mesh, PEAK_MESH_VERTS, PoolIntArray([0, 1, 2]))
	return mesh

const DROP_MESH_VERTS: = PoolVector3Array([
	Vector3(0, 1, 1),
	Vector3(1, 1, 1),
	Vector3(1, 1, 0),
	Vector3(0, 0, 0),
])
static func _drop_mesh() -> ArrayMesh:
	var mesh: = ArrayMesh.new()
	_add_surface(mesh, DROP_MESH_VERTS, PoolIntArray([0, 1, 2]))
	_add_surface(mesh, DROP_MESH_VERTS, PoolIntArray([0, 2, 3]))
	return mesh

const SLANT_MESH_VERTS: = PoolVector3Array([
	Vector3(0, 0, 1),
	Vector3(1, 1, 1),
	Vector3(1, 1, 0),
	Vector3(0, 0, 0),
])
static func _slant_mesh() -> ArrayMesh:
	var mesh: = ArrayMesh.new()
	_add_surface(mesh, SLANT_MESH_VERTS, PoolIntArray([0, 1, 2, 0, 2, 3]))
	return mesh

static func _add_surface(mesh: ArrayMesh, vertices: PoolVector3Array, indices: PoolIntArray):
	var arrays = []
	arrays.resize(ArrayMesh.ARRAY_MAX)
	arrays[ArrayMesh.ARRAY_VERTEX] = vertices
	arrays[ArrayMesh.ARRAY_TEX_UV] = CONSTANTS.QUAD_UVS
	arrays[ArrayMesh.ARRAY_INDEX] = indices
	mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arrays)
	mesh.surface_set_material(mesh.get_surface_count() - 1, terrain_mat)