GizmoElementTorus.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "BaseGizmos/GizmoElementCircleBase.h"
#include "InputState.h"
#include "UObject/ObjectMacros.h"
#include "GizmoElementTorus.generated.h"
 
class FPrimitiveDrawInterface;
class FMaterialRenderProxy;
 
UCLASS(Transient, MinimalAPI)
class UGizmoElementTorus : public UGizmoElementCircleBase
{
    GENERATED_BODY()
 
public:
 
    //~ Begin UGizmoElementBase Interface.
    INTERACTIVETOOLSFRAMEWORK_API virtual void Render(IToolsContextRenderAPI* RenderAPI, const FRenderTraversalState& RenderState) override;
 
    // LineTrace approximates ray-torus intersection by intersecting the ray with the plane in which the torus 
    // lies, then determining a hit point closest to the linear circle defined by torus center and torus outer radius.
    // If the torus lies at a glancing angle, the ray-torus intersection is performed against cylinders approximating
    // the shape of the torus.
    INTERACTIVETOOLSFRAMEWORK_API virtual FInputRayHit LineTrace(const UGizmoViewContext* ViewContext, const FLineTraceTraversalState& LineTraceState, const FVector& RayOrigin, const FVector& RayDirection, FLineTraceOutput& OutLineTraceOutput) override;
    //~ End UGizmoElementBase Interface.
 
    // Inner circles radius.
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetInnerRadius(double InInnerRadius);
    INTERACTIVETOOLSFRAMEWORK_API virtual double GetInnerRadius() const;
 
    // Multiplier applied to the inner radius when hovering
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetHoverInnerRadiusMultiplier(double InHoverInnerRadiusMultiplier);
    INTERACTIVETOOLSFRAMEWORK_API virtual double GetHoverInnerRadiusMultiplier() const;
 
    // Multiplier applied to the inner radius when interacting
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetInteractInnerRadiusMultiplier(double InInteractInnerRadiusMultiplier);
    INTERACTIVETOOLSFRAMEWORK_API virtual double GetInteractInnerRadiusMultiplier() const;
 
    // Multiplier applied to the inner radius when selected
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetSelectInnerRadiusMultiplier(double InSelectInnerRadiusMultiplier);
    INTERACTIVETOOLSFRAMEWORK_API virtual double GetSelectInnerRadiusMultiplier() const;
 
    // Multiplier applied to the inner radius when subdued
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetSubdueInnerRadiusMultiplier(double InSubdueInnerRadiusMultiplier);
    INTERACTIVETOOLSFRAMEWORK_API virtual double GetSubdueInnerRadiusMultiplier() const;
 
    // Number of inner slices for rendering torus.
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetNumInnerSlices(int32 InNumInnerSlices);
    INTERACTIVETOOLSFRAMEWORK_API virtual int32 GetNumInnerSlices() const;
 
    // If partial, renders end caps when true.
    INTERACTIVETOOLSFRAMEWORK_API virtual void SetEndCaps(bool InEndCaps);
    INTERACTIVETOOLSFRAMEWORK_API virtual bool GetEndCaps() const;
 
protected:
 
    // Torus inner radius.
    UPROPERTY()
    double InnerRadius = 5.0;
 
    // Optional inner radius multipliers to apply when hovering, interacting, selected or subdued.
    UPROPERTY()
    FGizmoPerStateValueDouble InnerRadiusMultiplier;
 
    // Number of slices to render in each torus segment.
    UPROPERTY()
    int32 NumInnerSlices = 8;
 
    // Whether to render end caps on a partial torus.
    UPROPERTY()
    bool bEndCaps = false;
 
protected:
 
    // Returns the current inner radius based on the current interaction state.
    INTERACTIVETOOLSFRAMEWORK_API double GetCurrentInnerRadius() const;
 
    INTERACTIVETOOLSFRAMEWORK_API bool IsGlancingAngle(const UGizmoViewContext* View, const FVector& InWorldCenter, const FVector& InWorldNormal);
 
};