gosu_Gosu中的鼠标和键盘输入

末蓝、 2022-12-07 12:08 154阅读 0赞

gosu

Games are, by definition, interactive. Gosu makes this interaction straightforward with a simple interface for detecting and reacting to key and mouse button presses.

根据定义，游戏是交互式的。 Gosu通过用于检测按键和鼠标按键按下并做出React的简单界面，使交互变得简单明了。

There are two primary ways to handle input in your program. The first is an event-oriented approach. When buttons are pressed, your programs receives an event and you can react accordingly. The second is to check if, at the time of an update, a certain button is pressed. Both techniques are perfectly valid, use whichever one suits you best.

有两种主要方法可以处理程序中的输入。 第一种是面向事件的方法。 当按下按钮时，您的程序会收到一个事件，您可以做出相应的React。 第二个是检查更新时是否按下了某个按钮。 两种技术都非常有效，请使用最适合您的一种。

## 键和按钮常数 **(** Key and Button Constants **)** ##

Behind the scenes, buttons are represented by integers. These integer codes are platform-dependent and probably shouldn't find their way into your game code. To abstract this away, Gosu provides a number of constants to use.

在幕后，按钮由整数表示。 这些整数代码取决于平台，并且可能不应该在您的游戏代码中找到它们。 为了对此进行抽象，Gosu提供了许多要使用的常量。

For every keyboard key, there is a **Gosu::Kb\*** constant. For most of the keys, the names of these constants are easily guessed. For example, the arrow keys are **Gosu::KbLeft**, **Gosu::KbRight**, **Gosu::KbUp** and **Gosu::KbDown**. For a complete list, see the [documentation for the Gosu module][].

对于每个键盘按键，都有一个**Gosu :: Kb \***常量。 对于大多数键，这些常数的名称很容易猜到。 例如，箭头键是**Gosu :: KbLeft** ， **Gosu :: KbRight** ， **Gosu :: KbUp**和**Gosu :: KbDown** 。 有关完整列表，请参阅[Gosu模块][documentation for the Gosu module]的[文档][documentation for the Gosu module] 。

There are also similar constants for mouse buttons. You'll mainly be using the **Gosu::MsLeft** and **Gosu::MsRight** for left and right click. There is also support for gamepads via the **Gosu::Gp\*** constants.

鼠标按钮也有类似的常数。 您将主要使用**Gosu :: MsLeft**和**Gosu :: MsRight**进行左键和右键单击。 还可以通过**Gosu :: Gp \***常量支持游戏手柄。

*This article is part of a series. Read more articles about Rapid Game Prototyping in Ruby*

*本文是系列文章的一部分。* *阅读有关Ruby中快速游戏原型的更多文章*

## 面向事件的输入 **(** Event-Oriented Input **)** ##

Input events are delivered to the **Gosu::Window** instance. In the main loop, before **update** is called, Gosu will deliver events for all buttons that have either been pressed or released. It does this by calling the **button\_down** and **button\_up** methods, passing the id of the key or button pressed.

输入事件将传递到**Gosu :: Window**实例。 在主循环中，在调用**更新**之前，Gosu将为所有按下或释放的按钮传递事件。 它通过调用**button\_down**和**button\_up**方法，传递按下的键或按钮的ID来完成此操作。

In the **button\_down** and **button\_up** methods, you often find a *case* statement. This, beside being very function, provides a very elegant and expressive way to decide what to do depending on which button was pressed or released. The following is a short example of what a **button\_down** method can look like. It should be placed in your **Gosu::Window** subclass, and will close the window (ending the program) when the **escape** key is pressed.

在**button\_down**和**button\_up**方法中，通常会找到一个*case*语句。 除了非常有用的功能外，它还提供了一种非常优雅且富有表现力的方式，可以根据按下或释放的按钮来决定要做什么。 以下是**button\_down**方法的外观的简短示例。 应该放置在你的**古薮::窗口**的子类，并且会关闭窗口(结束程序)按下**ESC**键时。

def button_down(id)
    case id
    when Gosu::KbEscape
    close
    end
    end

Easy, right? Let's expand this. Here is a **Player** class. It can move left and right if the left and right keys are pressed. Note that this class also has **button\_down** and **button\_up** methods. They work just like the methods from a **Gosu::Window** subclass. Gosu doesn't know anything about **Player** though, we'll be calling the **Player**'s methods manually from the **Gosu::Window**'s methods. A full, runnable example can be found [here][].

容易吧？ 让我们扩展一下。 这是一个**播放器**类。 如果按下左右键，它可以左右移动。 请注意，此类也具有**button\_down**和**button\_up**方法。 它们的工作方式就像**Gosu :: Window**子类中的方法一样。 Gosu对**Player**一无所知，我们将从**Gosu :: Window**的方法中手动调用**Player**的方法。 可以在[此处][here]找到完整的可运行示例。

class Player
    # In pixels/second
    SPEED = 200
    def self.load(window)
    with_data('player.png') do|f|
    @@image = Gosu::Image.new(window, f, false)
    end
    end
    def initialize(window)
    @window = window
    @x = (@window.width / 2) - (@@image.width / 2)
    @y = @window.height - @@image.height
    @direction = 0
    end
    def update(delta)
    @x += @direction * SPEED * delta
    @x = 0 if @x @window.width - @@image.width
    @x = @window.width - @@image.width
    end
    end
    def draw
    @@image.draw(@x, @y, Z::Player)
    end
    def button_down(id)
    case id
    when Gosu::KbLeft
    @direction -= 1
    when Gosu::KbRight
    @direction += 1
    end
    end
    def button_up(id)
    case id
    when Gosu::KbLeft
    @direction += 1
    when Gosu::KbRight
    @direction -= 1
    end
    end
    end

*This article is part of a series. Read more articles about Rapid Game Prototyping in Ruby*

*本文是系列文章的一部分。* *阅读有关Ruby中快速游戏原型的更多文章*

## 查询输入 **(** Querying Input **)** ##

If event-based input is not your style, you can query any **Gosu::Window** to see if any button or key is pressed, at any time. You can ignore the **button\_down** and **button\_up** callbacks entirely.

如果基于事件的输入不是您的样式，则可以随时查询任何**Gosu :: Window**以查看是否按下了任何按钮或键。 您可以完全忽略**button\_down**和**button\_up**回调。

To query the **Gosu::Window** to see if a key is pressed, call the **button\_down?** method with the id of the button you'd like to check. Don't forget the question mark in this call! If you call **button\_down(Gosu::KbLeft)**, you'll be *reporting* a button press to the **Gosu::Window** subclass. Even if you don't have any callback methods defined, the parent class, **Gosu::Window** will. There will be no error, it just won't work as you expect. Just don't forget that question mark!

要查询**Gosu :: Window**以查看是否按下了某个键，请调用**button\_down？** 方法，其中包含您要检查的按钮的ID。 不要忘了这个电话中的问号！ 如果调用**button\_down(Gosu :: KbLeft)** ， **则将**向**Gosu :: Window**子类*报告*按钮按下。 即使您没有定义任何回调方法，父类**Gosu :: Window**也可以。 不会有错误，只是无法按预期工作。 只是不要忘记那个问号！

Here is the **Player** class re-written to use **button\_down?** instead of events. A full, runnable example is available [here][here 1]. This time, input is checked for at the beginning of the **update** method. You'll also notice that this example is shorter but, in my opinion, less elegant.

这是**Player**类重写为使用**button\_down吗？** 而不是事件。 [此处][here 1]提供[了][here 1]完整的可运行示例。 这次，在**更新**方法的开头检查输入。 您还将注意到该示例较短，但我认为它不太优雅。

class Player
    attr_reader :x, :y
    # In pixels/second
    SPEED = 200
    def self.load(window)
    with_data('player.png') do|f|
    @@image = Gosu::Image.new(window, f, false)
    end
    end
    def initialize(window)
    @window = window
    @x = (@window.width / 2) - (@@image.width / 2)
    @y = @window.height - @@image.height
    @direction = 0
    end
    def update(delta)
    @direction = 0
    if @window.button_down?(Gosu::KbLeft)
    @direction -= 1
    end
    if @window.button_down?(Gosu::KbRight)
    @direction += 1
    end
    @x += @direction * SPEED * delta
    @x = 0 if @x @window.width - @@image.width
    @x = @window.width - @@image.width
    end
    end
    def draw
    @@image.draw(@x, @y, Z::Player)
    end
    end

*This article is part of a series. Read more articles about Rapid Game Prototyping in Ruby*

*本文是系列文章的一部分。* *阅读有关Ruby中快速游戏原型的更多文章*

## 鼠标输入 **(** Mouse Input **)** ##

![776a560843cf67e286cf92cd73b57985.png][]

The mouse buttons are handled in the same way as keyboard and gamepad buttons. You can both query them with **button\_down?** and events with **button\_down** and **button\_up**. However, mouse movement may only be queried, there are no events for mouse movement. **Gosu::Window**'s **mouse\_x** and **mouse\_y** methods provide the X and Y coordinates of the mouse pointer.

鼠标按钮的处理方式与键盘和游戏板按钮相同。 您都可以通过**button\_down**查询它们**吗？** 以及具有**button\_down**和**button\_up的**事件。 但是，只能查询鼠标的移动，没有鼠标移动的事件。 **Gosu :: Window**的**mouse\_x**和**mouse\_y**方法提供鼠标指针的X和Y坐标。

Note that the X and Y coordinates are relative to the game window. So, for example, if the mouse is at the top left corner, it will be near the coordinate *(0,0)*. Also, if the mouse pointer is *outside* of the game window entirely, it will still report where the pointer is relative to the window. So both **mouse\_x** and **mouse\_y** can be less than zero and more than the width or height of the window.

请注意，X和Y坐标是相对于游戏窗口的。 因此，例如，如果鼠标在左上角，它将靠近坐标*(0,0)* 。 同样，如果鼠标指针完全位于游戏窗口*之外* ，它仍将报告指针相对于窗口的位置。 因此， **mouse\_x**和**mouse\_y**都可以小于零且大于窗口的宽度或高度。

The following program will display a new sprite wherever you click the mouse. Note that it uses both event-driven input (for the clicks), and query-driven input (to get the position of the mouse). A full, runnable file is available [here][here 2].

无论您在哪里单击鼠标，以下程序都将显示一个新的精灵。 请注意，它同时使用了事件驱动的输入(用于单击)和查询驱动的输入(用于获取鼠标的位置)。 完整的可运行文件[在此处提供][here 2] 。

class MyWindow

> 翻译自: [https://www.thoughtco.com/mouse-and-keyboard-input-in-gosu-2908025][https_www.thoughtco.com_mouse-and-keyboard-input-in-gosu-2908025]

gosu

[documentation for the Gosu module]: http://www.libgosu.org/rdoc/classes/Gosu.html
[here]: http://github.com/mmorin/Examples/blob/master/gosu/input/input1.rb
[here 1]: http://github.com/mmorin/Examples/blob/master/gosu/input/input2.rb
[776a560843cf67e286cf92cd73b57985.png]: /images/20221123/4180bcc8e2f1428ba0ea219c9ce7c8e7.png
[here 2]: http://github.com/mmorin/Examples/blob/master/gosu/input/input3.rb
[https_www.thoughtco.com_mouse-and-keyboard-input-in-gosu-2908025]: https://www.thoughtco.com/mouse-and-keyboard-input-in-gosu-2908025