// Copyright Epic Games, Inc. All Rights Reserved.

#include "Factories/VolumeTextureFactory.h"
#include "Styling/SlateBrush.h"
#include "Brushes/SlateDynamicImageBrush.h"
#include "Engine/VolumeTexture.h"

#define LOCTEXT_NAMESPACE "VolumeTextureFactory"

UVolumeTextureFactory::UVolumeTextureFactory(const FObjectInitializer& ObjectInitializer)
    : Super(ObjectInitializer)
{
    bCreateNew     = true;
    bEditAfterNew  = true;
    SupportedClass = UVolumeTexture::StaticClass();
}

FText UVolumeTextureFactory::GetDisplayName() const
{
    return LOCTEXT("VolumeTextureFactoryDescription", "Volume Texture");
}

bool UVolumeTextureFactory::ConfigureProperties()
{
    return true;
}

UObject* UVolumeTextureFactory::FactoryCreateNew(UClass* Class, UObject* InParent, FName Name, EObjectFlags Flags, UObject* Context, FFeedbackContext* Warn)
{
    UVolumeTexture* NewVolumeTexture  = NewObject<UVolumeTexture>(InParent, Name, Flags);
    NewVolumeTexture->MipGenSettings  = TMGS_FromTextureGroup;
    NewVolumeTexture->NeverStream     = true;
    NewVolumeTexture->CompressionNone = false;

    if (InitialTexture)
    {
        NewVolumeTexture->SRGB       = InitialTexture->SRGB;

        const FTextureSource& Source = InitialTexture->Source;
        const int32 NumPixels        = Source.GetSizeX() * Source.GetSizeY();

        if (NumPixels > 0)
        {
            // By default, assume that the 2d texture holds a square images.
            int32 TileSize = FMath::RoundToInt(FMath::Pow((float)NumPixels, 1.f / 3.f));

            // Remap the tiles as if there were streached accross the texture length.
            int32 NumTilesBySide = FMath::RoundToInt(FMath::Sqrt((float)(Source.GetSizeX() / TileSize) * (Source.GetSizeY() / TileSize)));

            if (NumTilesBySide > 0)
            {
                NewVolumeTexture->Source2DTexture   = InitialTexture;
                NewVolumeTexture->Source2DTileSizeX = Source.GetSizeX() / NumTilesBySide;
                NewVolumeTexture->Source2DTileSizeY = Source.GetSizeY() / NumTilesBySide;

                NewVolumeTexture->UpdateSourceFromSourceTexture();
                NewVolumeTexture->UpdateResource();
            }
        }
    }
    else
    {
        // Initialize the texture with a single texel of data
        const uint8 Texel[] = {0, 0, 0, 255};
        NewVolumeTexture->Source.Init(1, 1, 1, 1, TSF_BGRA8, Texel);
        NewVolumeTexture->UpdateResource();
    }

    return NewVolumeTexture;
}

#undef LOCTEXT_NAMESPACE