暂停游戏与处理模式

前言

在大多数游戏中，或多或少都会希望能够中断游戏去干些别的，例如休息一下或者修改选项。要非常细致地控制哪些可以暂停（哪些不可以）实现起来非常麻烦，所以 Godot 提供了一个简单的暂停框架。

如何暂停工作

要将游戏暂停，就必须设置暂停状态。将 SceneTree.paused 属性赋值为 true 即可：

GDScriptC#

get_tree().paused = true

GetTree().Paused = true;

这样做会导致两件事。首先，所有节点的 2D 和 3D 物理都会停止。其次，根据处理模式的不同，某些节点的行为会停止或者开始。

备注

游戏暂停时，可以通过 set_active 方法激活物理服务器。

处理模式

Each node in Godot has a “Process Mode” that defines when it processes. It can be found and changed under a node’s Node properties in the inspector.

你也可以通过代码来修改该属性：

GDScriptC#

func _ready():
    process_mode = Node.PROCESS_MODE_PAUSABLE

public override void _Ready()
{
    ProcessMode = Node.ProcessModeEnum.Pausable;
}

各个模式对节点的要求是这样的：

• Inherit（继承） ：处理与否取决于父、祖父等等节点中第一个具有非 Inherit 状态的节点。

• Pausable: Process the node (and its children in Inherit mode) only when the game is not paused.

• WhenPaused: Process the node (and its children in Inherit mode) only when the game is paused.

• Always: Process the node (and its children in Inherit mode) no matter what. Paused or not, this node will process.

• Disabled: The node (and its children in Inherit mode) will not process at all.

默认情况下，所有节点的这个属性都是“Inherit”状态。如果父节点也是“Inherit”，那么就会去检查祖父节点，以此类推。如果祖宗们都没有更改过状态，那么就会使用 SceneTree 的暂停状态。也就是说，在游戏暂停时默认所有节点都会被暂停下来。节点停止处理时会发生不少事情。

The _process, _physics_process, _input, and _input_event functions will not be called. However signals still work and cause their connected function to run, even if that function’s script is attached to a node that is not currently being processed.

动画节点会暂停它们的当前动画，音频节点会暂停它们的当前音频流，粒子也会暂停。游戏不再暂停时，它们都会自动继续运行。

请注意有一点非常重要，即便游戏暂停时节点仍在进行处理，但物理默认是无法正常工作的。如前文所述，这是因为物理服务器会被关闭。游戏暂停时，可以通过 set_active 方法激活物理服务器。

暂停菜单示例

Start by creating a button that will be used to pause the game.

Create a menu containing a close button, set the Process Mode of the menu’s root node to When Paused, then hide the menu. Since the process mode is set to When Paused on the root node, all its children and grandchildren will inherit that process mode. This way, all the nodes in the menu will start processing when the game is paused.

Attach a script to the menu’s root node, connect the pause button created earlier to a new method in the script, and inside that method pause the game and show the pause menu.

GDScriptC#

func _on_pause_button_pressed():
    get_tree().paused = true
    show()

private void OnPauseButtonPressed()
{
    GetTree().Paused = true;
    Show();
}

Finally, connect the menu’s close button to a new method in the script. Inside that method, unpause the game and hide the pause menu.

GDScriptC#

func _on_close_button_pressed():
    hide()
    get_tree().paused = false

private void OnCloseButtonPressed()
{
    Hide();
    GetTree().Paused = false;
}

You should now have a working pause menu.