godot表面吸附插件

addons/surface_snap/plugin.gd

@@ -0,0 +1,60 @@
+@tool
+extends EditorPlugin
+
+## Snaps a 3D object against the surface of another collidable object.
+##
+## Usage: Select a single Node3D, hold Alt
+## and drag with the left mouse button over a collidable surface. Releasing
+## the button confirms the move (registered in the editor's Undo/Redo).
+##
+## Configuration: Project Settings -> "surface_snap/collision_mask" controls
+## which physics layers count as a valid snap surface.
+
+var _snap_tool: SurfaceSnapTool = SurfaceSnapTool.new()
+
+
+func _enter_tree() -> void:
+	_register_project_settings()
+
+
+func _exit_tree() -> void:
+	if _snap_tool.is_dragging():
+		_snap_tool.cancel_drag()
+
+
+func _handles(object: Object) -> bool:
+	return object is Node3D
+
+
+func _edit(object: Object) -> void:
+	pass
+
+
+func _forward_3d_gui_input(camera: Camera3D, event: InputEvent) -> int:
+	var selected_nodes: Array[Node] = EditorInterface.get_selection().get_selected_nodes()
+	var target: Node3D = null
+
+	if selected_nodes.size() == 1 and selected_nodes[0] is Node3D:
+		target = selected_nodes[0] as Node3D
+
+	var consumed: bool = _snap_tool.handle_input(camera, event, target, get_undo_redo())
+
+	if consumed:
+		return EditorPlugin.AFTER_GUI_INPUT_STOP
+
+	return EditorPlugin.AFTER_GUI_INPUT_PASS
+
+
+func _register_project_settings() -> void:
+	var setting_name: String = SurfaceSnapTool.SETTING_COLLISION_MASK
+	var default_value: int = SurfaceSnapTool.DEFAULT_COLLISION_MASK
+
+	if not ProjectSettings.has_setting(setting_name):
+		ProjectSettings.set_setting(setting_name, default_value)
+
+	ProjectSettings.set_initial_value(setting_name, default_value)
+	ProjectSettings.add_property_info({
+		"name": setting_name,
+		"type": TYPE_INT,
+		"hint": PROPERTY_HINT_LAYERS_3D_PHYSICS,
+	})