1 files changed, 121 insertions, 0 deletions
diff --git a/game/addons/zylann.hterrain/tools/brush/decal.gd b/game/addons/zylann.hterrain/tools/brush/decal.gd
new file mode 100644
index 0000000..13433ed
--- /dev/null
+++ b/game/addons/zylann.hterrain/tools/brush/decal.gd
@@ -0,0 +1,121 @@
+@tool
+# Shows a cursor on top of the terrain to preview where the brush will paint
+
+# TODO Use an actual decal node, it wasn't available in Godot 3
+
+const HT_DirectMeshInstance = preload("../../util/direct_mesh_instance.gd")
+const HTerrain = preload("../../hterrain.gd")
+const HTerrainData = preload("../../hterrain_data.gd")
+const HT_Util = preload("../../util/util.gd")
+
+var _mesh_instance : HT_DirectMeshInstance
+var _mesh : PlaneMesh
+var _material = ShaderMaterial.new()
+#var _debug_mesh = CubeMesh.new()
+#var _debug_mesh_instance = null
+
+var _terrain : HTerrain = null
+
+
+func _init():
+	_material.shader = load("res://addons/zylann.hterrain/tools/brush/decal.gdshader")
+	_mesh_instance = HT_DirectMeshInstance.new()
+	_mesh_instance.set_material(_material)
+	
+	_mesh = PlaneMesh.new()
+	_mesh_instance.set_mesh(_mesh)
+	
+	#_debug_mesh_instance = DirectMeshInstance.new()
+	#_debug_mesh_instance.set_mesh(_debug_mesh)
+
+
+func set_size(size: float):
+	_mesh.size = Vector2(size, size)
+	# Must line up to terrain vertex policy, so must apply an off-by-one.
+	# If I don't do that, the brush will appear to wobble above the ground
+	var ss := size - 1
+	# Don't subdivide too much
+	while ss > 50:
+		ss /= 2
+	_mesh.subdivide_width = ss
+	_mesh.subdivide_depth = ss
+
+
+#func set_shape(shape_image):
+#	set_size(shape_image.get_width())
+
+
+func _on_terrain_transform_changed(terrain_global_trans: Transform3D):
+	var inv = terrain_global_trans.affine_inverse()
+	_material.set_shader_parameter("u_terrain_inverse_transform", inv)
+
+	var normal_basis = terrain_global_trans.basis.inverse().transposed()
+	_material.set_shader_parameter("u_terrain_normal_basis", normal_basis)
+
+
+func set_terrain(terrain: HTerrain):
+	if _terrain == terrain:
+		return
+
+	if _terrain != null:
+		_terrain.transform_changed.disconnect(_on_terrain_transform_changed)
+		_mesh_instance.exit_world()
+		#_debug_mesh_instance.exit_world()
+
+	_terrain = terrain
+
+	if _terrain != null:
+		_terrain.transform_changed.connect(_on_terrain_transform_changed)
+		_on_terrain_transform_changed(_terrain.get_internal_transform())
+		_mesh_instance.enter_world(terrain.get_world_3d())
+		#_debug_mesh_instance.enter_world(terrain.get_world())
+
+	update_visibility()
+
+
+func set_position(p_local_pos: Vector3):
+	assert(_terrain != null)
+	assert(typeof(p_local_pos) == TYPE_VECTOR3)
+	
+	# Set custom AABB (in local cells) because the decal is displaced by shader
+	var data = _terrain.get_data()
+	if data != null:
+		var r = _mesh.size / 2
+		var aabb = data.get_region_aabb( \
+			int(p_local_pos.x - r.x), \
+			int(p_local_pos.z - r.y), \
+			int(2 * r.x), \
+			int(2 * r.y))
+		aabb.position = Vector3(-r.x, aabb.position.y, -r.y)
+		_mesh.custom_aabb = aabb
+		#_debug_mesh.size = aabb.size
+	
+	var trans = Transform3D(Basis(), p_local_pos)
+	var terrain_gt = _terrain.get_internal_transform()
+	trans = terrain_gt * trans
+	_mesh_instance.set_transform(trans)
+	#_debug_mesh_instance.set_transform(trans)
+
+
+# This is called very often so it should be cheap
+func update_visibility():
+	var heightmap = _get_heightmap(_terrain)
+	if heightmap == null:
+		# I do this for refcounting because heightmaps are large resources
+		_material.set_shader_parameter("u_terrain_heightmap", null)
+		_mesh_instance.set_visible(false)
+		#_debug_mesh_instance.set_visible(false)
+	else:
+		_material.set_shader_parameter("u_terrain_heightmap", heightmap)
+		_mesh_instance.set_visible(true)
+		#_debug_mesh_instance.set_visible(true)
+
+
+func _get_heightmap(terrain):
+	if terrain == null:
+		return null
+	var data = terrain.get_data()
+	if data == null:
+		return null
+	return data.get_texture(HTerrainData.CHANNEL_HEIGHT)
+