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

/*=============================================================================
        WorldCompositionUtility.h: Support structures for world composition
=============================================================================*/

#pragma once

#include "CoreMinimal.h"

#define WORLDTILE_LOD_PACKAGE_SUFFIX	TEXT("_LOD")
#define WORLDTILE_LOD_MAX_INDEX			4

/** World layer information for tile tagging */
class FWorldTileLayer
{
public:
    FWorldTileLayer()
        : Name(TEXT("Uncategorized")), Reserved0(8000), Reserved1(ForceInit), StreamingDistance(15000), DistanceStreamingEnabled(true), IOSStreamingDistance(0)
    {
    }

    bool operator==(const FWorldTileLayer& OtherLayer) const
    {
        return (Name == OtherLayer.Name) &&
               (StreamingDistance == OtherLayer.StreamingDistance) &&
               (DistanceStreamingEnabled == OtherLayer.DistanceStreamingEnabled);
    }

    friend FArchive& operator<<(FArchive& Ar, FWorldTileLayer& D);
    friend void operator<<(FStructuredArchive::FSlot Slot, FWorldTileLayer& D);

public:
    /** Human readable name for this layer */
    FString Name;
    int32 Reserved0;
    FIntPoint Reserved1;
    /** Distance starting from where tiles belonging to this layer will be streamed in */
    int32 StreamingDistance;
    bool DistanceStreamingEnabled;
    int32 IOSStreamingDistance;
};

/**
 *  Describes LOD entry in a world tile
 */
class FWorldTileLODInfo
{
public:
    FWorldTileLODInfo()
        : RelativeStreamingDistance(10000), Reserved0(0), Reserved1(0), Reserved2(0), Reserved3(0)
    {
    }

    friend FArchive& operator<<(FArchive& Ar, FWorldTileLayer& D);
    friend void operator<<(FStructuredArchive::FSlot Slot, FWorldTileLayer& D);

    bool operator==(const FWorldTileLODInfo& OtherInfo) const
    {
        return RelativeStreamingDistance == OtherInfo.RelativeStreamingDistance;
    }

public:
    /**  Relative to LOD0 streaming distance, absolute distance = LOD0 + StreamingDistanceDelta */
    int32 RelativeStreamingDistance;

    /**  Reserved for additional options */
    float Reserved0;
    float Reserved1;
    int32 Reserved2;
    int32 Reserved3;
};

/**
 *  Tile information used by WorldComposition.
 *  Defines properties necessary for tile positioning in the world. Stored with package summary
 */
class FWorldTileInfo
{
public:
    FWorldTileInfo()
        : Position(0, 0, 0), AbsolutePosition(0, 0, 0), Bounds(ForceInit), bHideInTileView(false), ZOrder(0), RealStreamingDistance(0)
    {
    }

    COREUOBJECT_API friend FArchive& operator<<(FArchive& Ar, FWorldTileInfo& D);
    COREUOBJECT_API friend void operator<<(FStructuredArchive::FSlot Slot, FWorldTileInfo& D);

    bool operator==(const FWorldTileInfo& OtherInfo) const
    {
        return (Position == OtherInfo.Position) &&
               (Bounds.Min.Equals(OtherInfo.Bounds.Min, 0.5f)) &&
               (Bounds.Max.Equals(OtherInfo.Bounds.Max, 0.5f)) &&
               (ParentTilePackageName == OtherInfo.ParentTilePackageName) &&
               (Layer == OtherInfo.Layer) &&
               (bHideInTileView == OtherInfo.bHideInTileView) &&
               (ZOrder == OtherInfo.ZOrder) &&
               (LODList == OtherInfo.LODList);
    }

    /** @return Streaming distance for a particular tile LOD */
    int32 GetStreamingDistance(int32 LODIndex) const
    {
        int32 Distance = RealStreamingDistance;
        if (LODList.IsValidIndex(LODIndex))
        {
            Distance += LODList[LODIndex].RelativeStreamingDistance;
        }
        return Distance;
    }

    /** Reads FWorldTileInfo from a specified package */
    COREUOBJECT_API static bool Read(const FString& InPackageFileName, FWorldTileInfo& OutInfo);

public:
    /** Tile position in the world relative to parent */
    FIntVector Position;
    /** Absolute tile position in the world. Calculated in runtime */
    FIntVector AbsolutePosition;
    /** Tile bounding box  */
    FBox Bounds;
    /** Tile assigned layer  */
    FWorldTileLayer Layer;
    /** Whether to hide sub-level tile in tile view*/
    bool bHideInTileView;
    /** Parent tile package name */
    FString ParentTilePackageName;
    /** LOD information */
    TArray<FWorldTileLODInfo> LODList;
    /** Sorting order */
    int32 ZOrder;

    int32 RealStreamingDistance;
};