SVirtualJoystick.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "InputCoreTypes.h"
#include "Input/Reply.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SLeafWidget.h"
 
class FPaintArgs;
class FSlateWindowElementList;
class ISlateBrushSource;
 
class SVirtualJoystick : public SLeafWidget
{
 
public:
    struct FControlInfo
    {
        // Set by the game
 
        bool bTreatAsButton = false;
 
        TSharedPtr< ISlateBrushSource > Image1;
 
        TSharedPtr< ISlateBrushSource > Image2;
 
        FVector2D Center = FVector2D::ZeroVector;
 
        FVector2D VisualSize = FVector2D::ZeroVector;
 
        FVector2D ThumbSize = FVector2D::ZeroVector;
 
        FVector2D InteractionSize = FVector2D::ZeroVector;
 
        FVector2D InputScale = FVector2D(1.f, 1.f);
 
        FKey MainInputKey;
 
        FKey AltInputKey;
    };
 
    struct FControlData
    {
        FControlInfo Info;
        
        SLATE_API void Reset();
 
        // Current state
 
        FVector2D ThumbPosition = FVector2D::ZeroVector;
 
        FVector2D VisualCenter = FVector2D::ZeroVector;
 
        FVector2D CorrectedCenter = FVector2D::ZeroVector;
 
        FVector2D CorrectedVisualSize = FVector2D::ZeroVector;
 
        FVector2D CorrectedThumbSize = FVector2D::ZeroVector;
 
        FVector2D CorrectedInteractionSize = FVector2D::ZeroVector;
 
        FVector2D CorrectedInputScale = FVector2D::ZeroVector;
 
        int32 CapturedPointerIndex = -1;
 
        float ElapsedTime = 0.0f;
 
        FVector2D NextCenter = FVector2D::ZeroVector;
 
        bool bSendOneMoreEvent = false;
 
        bool bHasBeenPositioned = false;
 
        bool bNeedUpdatedCenter = false;
    };
 
    SLATE_BEGIN_ARGS(SVirtualJoystick)
        {}
    SLATE_END_ARGS()
 
    SLATE_API void Construct(const FArguments& InArgs);
 
    static SLATE_API bool ShouldDisplayTouchInterface();
 
    SLATE_API void SetJoystickVisibility(const bool bVisible, const bool bFade);
 
    SLATE_API void AddControl(const FControlInfo& Control);
    SLATE_API void ClearControls();
    SLATE_API void SetControls(const TArray<FControlInfo>& InControls);
 
    SLATE_API void SetGlobalParameters(float InActiveOpacity, float InInactiveOpacity, float InTimeUntilDeactive, float InTimeUntilReset, float InActivationDelay, bool InbPreventReCenter, float InStartupDelay);
 
    SLATE_API virtual int32 OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const override;
    
    SLATE_API virtual FVector2D ComputeDesiredSize(float) const override;
 
    SLATE_API virtual FReply OnTouchStarted(const FGeometry& MyGeometry, const FPointerEvent& Event) override;
    SLATE_API virtual FReply OnTouchMoved(const FGeometry& MyGeometry, const FPointerEvent& Event) override;
    SLATE_API virtual FReply OnTouchEnded(const FGeometry& MyGeometry, const FPointerEvent& Event) override;
 
    SLATE_API virtual void Tick(const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime) override;
 
    SLATE_API virtual bool SupportsKeyboardFocus() const override;
 
protected:
    SLATE_API virtual void HandleDisplayMetricsChanged(const FDisplayMetrics& NewDisplayMetric);
 
    static SLATE_API void AlignBoxIntoScreen(FVector2D& Position, const FVector2D& Size, const FVector2D& ScreenSize);
    SLATE_API FVector2D ComputeThumbPosition(int32 ControlIndex, const FVector2D& LocalCoord, float* OutDistanceToTouchSqr = nullptr, float* OutDistanceToEdgeSqr = nullptr);
 
    SLATE_API virtual bool HandleTouch(int32 ControlIndex, const FVector2D& LocalCoord, const FVector2D& ScreenSize);
 
    inline float GetBaseOpacity();
 
    template <typename T>
    using TControlArray = TArray<T, TInlineAllocator<2>>;
    
    TControlArray<FControlData> Controls;
 
    float ActiveOpacity = 1.0f;
    float InactiveOpacity = 0.1f;
    float TimeUntilDeactive = 0.5f;
    float TimeUntilReset = 2.0f;
    float ActivationDelay = 0.0f;
    float StartupDelay = 0.0f;
 
    enum EVirtualJoystickState
    {
        State_Active,
        State_CountingDownToInactive,
        State_CountingDownToReset,
        State_Inactive,
        State_WaitForStart,
        State_CountingDownToStart,
    };
 
    EVirtualJoystickState State = State_Inactive;
 
    uint32 bVisible:1;
 
    uint32 bCenterOnEvent:1;
 
    uint32 bPreventReCenter:1;
 
    float CurrentOpacity = InactiveOpacity;
 
    /* Countdown until next state change */
    float Countdown;
 
    float PreviousScalingFactor = 0.0f;
};