//
// This class implements the layout calculatations for a radial
// menu.
//

#pragma once

#include "CoreMinimal.h"
#include "RadialMenu.generated.h"


USTRUCT(BlueprintType)
struct FRadialMenuItem
{
    GENERATED_BODY()

    FVector2D Point1 = {0,0};
    FVector2D Point2 = {0,0};
    FVector2D Point3 = {0,0};
    bool RightSide = false;
};

UCLASS(BlueprintType)
class URadialMenu : public UObject
{
    GENERATED_BODY()

public:
    UFUNCTION(BlueprintCallable)
    void Configure(int32 NItems, float ItemHeight, float InnerRadius, float MinSpoke, float Spread);

    UFUNCTION(BlueprintCallable)
    int32 NumItems() const { return Items.Num(); }

    UFUNCTION(BlueprintCallable)
    const TArray<FRadialMenuItem> GetItems() const { return Items; }

    TArray<FRadialMenuItem> Items;

private:
    using View = TArrayView<FRadialMenuItem>;

    void CalculateSide(View V);
    void FlipHorizontal(View V);

    // The half-circle is divided into pie slices.  Returns a direction vector
    // which aims directly down the center of the pie slice.
    FVector2D PieSliceToVector(double Slice, double Slices);
    
    int32 CNItems = 0;
    float CItemHeight = 0;
    float CInnerRadius = 0;
    float CMinSpoke = 0;
    float CSpread = 0;
    int32 CNumLeft = 0;
    int32 CNumRight = 0;
    View LeftItems;
    View RightItems;
};