// Fill out your copyright notice in the Description page of Project Settings.


#include "SVolumeMeterBar.h"

#include "Dsp.h"
#include "UI/Style/AronaStyle.h"
#include "SlateOptMacros.h"

BEGIN_SLATE_FUNCTION_BUILD_OPTIMIZATION

void SVolumeMeterBar::Construct(const FArguments& InArgs)
{
	Width = InArgs._Width;
	MeterValue = InArgs._MeterValue;
	Mode = InArgs._Mode;
	MinValue = InArgs._MinValue;
	MaxValue = InArgs._MaxValue;
}

int32 SVolumeMeterBar::OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect,
	FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle,
	bool bParentEnabled) const
{
	const float BarSpace = FAronaStyle::GetValue<float>(VolumeMeterBarSpace);
	
	const TArray<float>& CurrentValue = MeterValue.Get();
	if (CurrentValue.Num() == 0)
	{
		return LayerId;
	}
	
	float CursorX = 0;
	for (int i = 0; i < CurrentValue.Num(); ++i)
	{
		float Value;
		switch (Mode)
		{
			case EVolumeMeterMode::Linear:
				Value = CurrentValue[i];
			break;
			case EVolumeMeterMode::Decibel:
				Value = Audio::ConvertToDecibels(CurrentValue[i]);
			break;
			default:
				Value = 0;
		}
		Value = FMath::Clamp(Value, MinValue, MaxValue);
		const float Height = (Value - MinValue) / (MaxValue - MinValue) * AllottedGeometry.Size.Y;
		
		FSlateDrawElement::MakeBox(
			OutDrawElements,
			++LayerId,
			AllottedGeometry.ToPaintGeometry(FVector2D(Width, Height), FSlateLayoutTransform(1.f, TransformPoint(1.f, FVector2f(CursorX, AllottedGeometry.Size.Y - Height)))),
			FAronaStyle::GetSlateBrush(VolumeMeterBar),
			ESlateDrawEffect::None,
			FLinearColor::Red
		);

		CursorX += Width + BarSpace;
	}
	return LayerId;
}

FVector2D SVolumeMeterBar::ComputeDesiredSize(float LayoutScaleMultiplier) const
{
	return FVector2D(Width, 0);
}

END_SLATE_FUNCTION_BUILD_OPTIMIZATION