Game Pause

说明

根据上节游戏状态, 会有3个窗口部件

游戏状态	窗口部件
InProgress	WBP_PlayerHUDWidget
Pause	WBP_PauseHUDWidget	暂停, 可选择继续 - 本节内容
GameOver		游戏结束, 显示统计数据 - 下节内容

本节实现暂停窗口: 游戏中按下 P 显示暂停窗口, 可于暂停窗口选择回到游戏

概览

• 在STUGameHUD创建三种窗口部件
  
• 依据游戏状态, 设置窗口部件可见性
  
• 实现暂停窗口部件
  
• 实现键位绑定
  

API导航

TMap

关联容器

-
Add	添加元素
[]	键作为下标, 获取值
Contains	查询是否存在给定键

TPair

键值对

-
::Value	获得键值对的值

UserWidget

可见性

• UUserWidget::SetVisibility

  设置窗口组件可见性
  

  Copy1/** Sets the visibility of the widget. */
  2virtual void SetVisibility(ESlateVisibility InVisibility) override;

• ESlateVisibility

  可见选项
  

  -
  Visible	可见
  Hidden	隐藏

  Copy 1/** Is an entity visible? */
   2UENUM(BlueprintType)
   3enum class ESlateVisibility : uint8
   4{
   5    /** Visible and hit-testable (can interact with cursor). Default value. */
   6    Visible,
   7    /** Not visible and takes up no space in the layout (obviously not hit-testable). */
   8    Collapsed,
   9    /** Not visible but occupies layout space (obviously not hit-testable). */
  10    Hidden,
  11    /** Visible but not hit-testable (cannot interact with cursor) and children in the hierarchy (if any) are also not hit-testable. */
  12    HitTestInvisible UMETA(DisplayName = "Not Hit-Testable (Self & All Children)"),
  13    /** Visible but not hit-testable (cannot interact with cursor) and doesn't affect hit-testing on children (if any). */
  14    SelfHitTestInvisible UMETA(DisplayName = "Not Hit-Testable (Self Only)")
  15};

初始化

Copy1virtual bool Initialize();

PlayerController

键位绑定所在

Copy1/** Allows the PlayerController to set up custom input bindings. */
2virtual void SetupInputComponent();

成员InputComponent没在头文件中找到定义

鼠标受控

bShowMouseCursor
true	显示鼠标箭头
false	不显示鼠标箭头

Copy1/** Whether the mouse cursor should be displayed. */
2UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=MouseInterface)
3uint32 bShowMouseCursor:1;

设置

Copy1/** Setup an input mode. */
2virtual void SetInputMode(const FInputModeDataBase& InData);

FInputModeDataBase派生类
FInputModeUIOnly	只有UI可以响应用户输入
FInputModeGameOnly	只有玩家输入和PlayerController可以响应用户输入
FInputModeGameAndUI	UI优先响应用户输入, 如果UI未作出处理, 玩家输入和PlayerController可以响应用户输入

Copy 1/** Data structure used to setup an input mode that allows only the UI to respond to user input. */
 2struct ENGINE_API FInputModeUIOnly : public FInputModeDataBase
 3{
 4    // ...
 5};
 6
 7/** Data structure used to setup an input mode that allows only the player input / player controller to respond to user input. */
 8struct ENGINE_API FInputModeGameOnly : public FInputModeDataBase
 9{
10    // ...
11};
12
13
14/** Data structure used to setup an input mode that allows the UI to respond to user input, and if the UI doesn't handle it player input / player controller gets a chance. */
15struct ENGINE_API FInputModeGameAndUI : public FInputModeDataBase
16{
17    // ...
18};

GameModeBase

暂停游戏

-
PC	给出暂停行为的主导者, 用于权限检查
CanUnpauseDelegate	委托, 用于检查是否可以暂停

会暂停所有Actor的Tick

Copy1/**
2 * Adds the delegate to the list if the player Controller has the right to pause
3 * the game. The delegate is called to see if it is ok to unpause the game, e.g.
4 * the reason the game was paused has been cleared.
5 * @param PC the player Controller to check for admin privs
6 * @param CanUnpauseDelegate the delegate to query when checking for unpause
7 */
8virtual bool SetPause(APlayerController* PC, FCanUnpause CanUnpauseDelegate = FCanUnpause());

清除暂停

使所有Actor的Tick运行起来

Copy1/**
2 * Checks the list of delegates to determine if the pausing can be cleared. If
3 * the delegate says it's ok to unpause, that delegate is removed from the list
4 * and the rest are checked. The game is considered unpaused when the list is
5 * empty.
6 */
7virtual bool ClearPause();

Button

类似的委托还有OnPressed, OnReleased, OnHovered等等

Copy1DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnButtonClickedEvent);
2
3/** Called when the button is clicked */
4UPROPERTY(BlueprintAssignable, Category="Button|Event")
5FOnButtonClickedEvent OnClicked;

在STUGameHUD中管理窗口部件

添加属性: 保存暂停窗口部件类型

protected

ShootThemUp: UI/STUGameHUD.h

Copy1UPROPERTY(EditDefaultsOnly, BlueprintReadWrite)
2TSubclassOf<UUserWidget> PauseWidgetClass;

添加属性: 游戏状态-窗口部件对象键值对

使用UPROPERTY宏托管指针

private

ShootThemUp: UI/STUGameHUD.h

Copy1UPROPERTY()
2TMap<ESTUMatchState, UUserWidget *> GameWidgets;

添加美化接口: 创建窗口部件并添加到视口, 初始化键值对, 并设置窗口部件对象均不可见

private

ShootThemUp: UI/STUGameHUD.h

Copy1void InitGameWidgets();

1. 在BeginPlay中屏蔽PlayerHUDWidget初始化
   
   ShootThemUp: UI/STUGameHUD.cpp
   

   Copy1/*
   2auto PlayerHUDWidget = CreateWidget<UUserWidget>(GetWorld(), PlayerHUDWidgetClass);
   3if (PlayerHUDWidget)
   4{
   5    PlayerHUDWidget->AddToViewport();
   6}
   7*/

2. 在BeginPlay中调用
   
   ShootThemUp: UI/STUGameHUD.cpp
   
3. 实现
   
   ShootThemUp: UI/STUGameHUD.cpp
   

   Copy 1void ASTUGameHUD::InitGameWidgets()
    2{
    3    GameWidgets.Add(ESTUMatchState::InProgress, CreateWidget<UUserWidget>(GetWorld(), PlayerHUDWidgetClass));
    4    GameWidgets.Add(ESTUMatchState::Pause, CreateWidget<UUserWidget>(GetWorld(), PauseWidgetClass));
    5
    6    for (auto GameWidgetPair : GameWidgets)
    7    {
    8        const auto GameWidget = GameWidgetPair.Value;
    9        if (!GameWidget) continue;
   10
   11        GameWidget->AddToViewport();
   12        GameWidget->SetVisibility(ESlateVisibility::Hidden);
   13    }
   14}

添加属性: 指向当前可见窗口部件

1. 初始指向空
   
2. 当GameMode调用StartPlay时, 第一次进行设置
   
3. 使用UPROPERTY宏托管指针
   

private

ShootThemUp: UI/STUGameHUD.h

Copy1UPROPERTY()
2UUserWidget *CurrentWidget = nullptr;

游戏状态发生改变时, 修改窗口部件可见性

ShootThemUp: UI/STUGameHUD.cpp

Copy 1// OnMatchStateChanged
 2
 3if (CurrentWidget)
 4{
 5    CurrentWidget->SetVisibility(ESlateVisibility::Hidden);
 6}
 7
 8if (GameWidgets.Contains(NewState))
 9{
10    CurrentWidget = GameWidgets[NewState];
11}
12
13if (CurrentWidget)
14{
15    CurrentWidget->SetVisibility(ESlateVisibility::Visible);
16}

设计暂停窗口部件

创建C++类

-
基类	UUserWidget
路径	UI
名称	STUPauseWidget
属性	Public

创建蓝图窗口部件

去到 Content/UI , 创建蓝图窗口部件, 基类STUPauseWidget, 命名为WBP_PauseWidget

设置WBP_PauseWidget

1. 添加 Canvas Panel
   

2. 添加 Background Blur
   
   模糊背景, 后期处理特效
   

   -
   Anchors	平铺
   Offset	均为0
   BlurStrength	模糊强度: 4

   

   
   

   

   
   

3. 添加垂直对齐盒
   

   -
   Anchors	居中
   Position X	0
   Position Y	0
   Alignment	X = Y = 0.5
   Size To Content	勾选

   

   
   

   

   
   

4. 添加文本
   

   -
   Text	GAME PAUSE
   Font > Size	100

   

   
   

5. 添加分隔符
   

   -
   Size > Y	纵向间距: 40

   

   
   

6. 添加按钮
   

   默认为变量, 重命名为 ClearPauseButton
   

   

   
   

   -
   Horizontal Alignment	居中
   Vertical Alignment	居中

   

   
   

7. 为按钮添加上级: 大小盒
   

   

   
   

   -
   Width	300
   Height	100

   

   
   

8. 设置ClearPauseButton
   

   -	Hex Linear
   Normal	FF0010FF	常规
   Hover	000000FF	鼠标悬浮
   Pressed	FF0010FF	点击时

   

   
   

9. 添加文本
   

   

   
   

添加键位绑定

Edit > Project Settings.. > Engine > Input

-
键位	P
绑定类型	动作映射 Action Mapping
键位描述	PauseGame

STUGameModeBase实现设置/取消暂停功能

• 在基类函数基础上, 更新游戏状态
  
• 注意到, 返回类型为布尔, 即存在设置不成功的情况
  

public

ShootThemUp: STUGameModeBase.h

Copy1virtual bool SetPause(APlayerController* PC, FCanUnpause CanUnpauseDelegate = FCanUnpause()) override;
2virtual bool ClearPause() override;

ShootThemUp: STUGameModeBase.cpp

Copy 1bool ASTUGameModeBase::SetPause(APlayerController* PC, FCanUnpause CanUnpauseDelegate)
 2{
 3    const auto PauseSet = Super::SetPause(PC, CanUnpauseDelegate);
 4
 5    if (PauseSet)
 6    {
 7        SetMatchState(ESTUMatchState::Pause);
 8    }
 9
10    return PauseSet;
11}
12
13bool ASTUGameModeBase::ClearPause()
14{
15    const auto PauseCleared = Super::ClearPause();
16
17    if (PauseCleared)
18    {
19        SetMatchState(ESTUMatchState::InProgress);
20    }
21
22    return PauseCleared;
23}

绑定键位描述

考虑到游戏角色会死亡, 而复活冷却也可以使用暂停功能: 为PlayerController添加键位绑定

1. 添加回调函数
   
   private

ShootThemUp: Player/STUPlayerController.h
   

   Copy1void OnPauseGame();

2. 覆写SetupInputComponent: 绑定键位
   
   protected

ShootThemUp: Player/STUPlayerController.h
   

   Copy1virtual void SetupInputComponent() override;

   ShootThemUp: Player/STUPlayerController.cpp
   

   Copy1void ASTUPlayerController::SetupInputComponent()
   2{
   3    Super::SetupInputComponent();
   4    if (!InputComponent) return;
   5    InputComponent->BindAction("PauseGame", IE_Pressed, this, &ASTUPlayerController::OnPauseGame);
   6}

3. 实现回调函数
   
   ShootThemUp: Player/STUPlayerController.cpp
   

   Copy1#include "GameFrameWork/GameModeBase.h"
   2#include "Engine/World.h"
   3
   4void ASTUPlayerController::OnPauseGame()
   5{
   6    if (!GetWorld() || !GetWorld()->GetAuthGameMode()) return;
   7
   8    GetWorld()->GetAuthGameMode()->SetPause(this);
   9}

实现STUPauseWidget

获取按钮

和蓝图窗口部件中按钮的变量名一致

protected

ShootThemUp: UI/STUPauseWidget.h

Copy1class UButton;
2
3UPROPERTY(meta = (BindWidget))
4UButton *ClearPauseButton;

添加点击按钮的回调函数

private

ShootThemUp: UI/STUPauseWidget.h

Copy1UFUNCTION()
2void OnClearPause();

ShootThemUp: UI/STUPauseWidget.cpp

Copy1#include "GameFramework/GameModeBase.h"
2
3void USTUPauseWidget::OnClearPause()
4{
5    if (!GetWorld() || !GetWorld()->GetAuthGameMode()) return;
6
7    GetWorld()->GetAuthGameMode()->ClearPause();
8}

为按钮点击事件绑定回调函数

覆写Initialize

public

ShootThemUp: UI/STUPauseWidget.h

Copy1virtual bool Initialize() override;

注意: 未调用基类Initialize, ClearPauseButton为空

ShootThemUp: UI/STUPauseWidget.cpp

Copy 1#include "Components/Button.h"
 2
 3bool USTUPauseWidget::Initialize()
 4{
 5    bool InitStatus = Super::Initialize();
 6
 7    if (ClearPauseButton)
 8    {
 9        ClearPauseButton->OnClicked.AddDynamic(this, &USTUPauseWidget::OnClearPause);
10    }
11
12    return InitStatus;
13}

查看

1. 设置 BP_STUGameHUD
   

   -
   Pause Widget Class	WBP_PauseWidget

   

   
   

2. 设置 BP_STUGameModeBase
   

   -
   Round Time	30

3. 鼠标不在按钮上
   

   

   
   

4. 鼠标在 Continue 上
   

   

   
   

当前

• 运行游戏后, 需要鼠标点击一下才能进入游戏
  
• 按下 P 后, 需要按下 Shift-F1 使鼠标脱离控制
  
• 点击 Continue 后, 还需鼠标点击一下
  

STUPlayerController设置鼠标受控

private

ShootThemUp: Player/STUPlayerController.h

Copy1#include "STUCoreTypes.h"
2
3void OnMatchStateChanged(ESTUMatchState NewState);

ShootThemUp: UI/STUPauseWidget.cpp

Copy 1void ASTUPlayerController::OnMatchStateChanged(ESTUMatchState NewState)
 2{
 3    if (NewState == ESTUMatchState::InProgress)
 4    {
 5        bShowMouseCursor = false;
 6        SetInputMode(FInputModeGameOnly());
 7    }
 8    else
 9    {
10        bShowMouseCursor = true;
11        SetInputMode(FInputModeUIOnly());
12    }
13}

添加BeginPlay函数, 在其中注册游戏状态改变服务

protected

ShootThemUp: Player/STUPlayerController.h

Copy1virtual void BeginPlay() override;

ShootThemUp: Player/STUPlayerController.cpp

Copy 1// #include "GameFrameWork/GameModeBase.h"
 2#include "Engine/World.h"
 3#include "STUGameModeBase.h"
 4
 5void ASTUPlayerController::BeginPlay()
 6{
 7    Super::BeginPlay();
 8
 9    if (GetWorld())
10    {
11        const auto GameMode = Cast<ASTUGameModeBase>(GetWorld()->GetAuthGameMode());
12        if (GameMode)
13        {
14            GameMode->OnMatchStateChanged.AddUObject(this, &ASTUPlayerController::OnMatchStateChanged);
15        }
16    }
17}

说明

如果只设置bShowMouseCursor

• 游戏开始时, 仍需鼠标点击一下
  
• 按下 P 之后, 鼠标箭头出现, 但活动区域仅限视口, 且鼠标悬浮在按钮之上时, 按钮未变成黑色
  
  Selected Viewport
  
• 鼠标尝试点击按钮, 这才和之前 Shift-F1 效果一样, 鼠标脱离控制
  

修改

之前误把Initialize声明在 private 区域, 移动到 public

ShootThemUp: UI/STUPlayerHUDWidget.h