DynamicShadowMapChannelBindingHelper.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
/*=============================================================================
    DynamicShadowMapChannelBindingHelper.h: 
=============================================================================*/
 
#pragma once
 
#include "CoreMinimal.h"
#include "LightSceneInfo.h"
 
class FLightSceneInfo;
class FLightSceneInfoCompact;
 
// This is used in forward only
class FDynamicShadowMapChannelBindingHelper
{
public:
 
    // The number of valid dynamic shadowmap channels
    static const int32 CHANNEL_COUNT = 4;
    // This is used in GetPriority().
    static const int32 STATIC_SHADOWING_PRIORITY = 2;
 
    FDynamicShadowMapChannelBindingHelper() : AvailableChannelCount(CHANNEL_COUNT) {}
 
    FORCEINLINE bool IsChannelEnabled(int32 ChannelIndex)
    {
        check(ChannelIndex >= 0 && ChannelIndex < CHANNEL_COUNT);
        return Channels[ChannelIndex].bIsAvailable;
    }
 
    FORCEINLINE bool HasAnyChannelEnabled() const
    {
        return AvailableChannelCount > 0;
    }
 
    FORCEINLINE const TArray<FLightSceneInfo*, TInlineAllocator<8>>& GetLights(int32 ChannelIndex) const
    {
        check(ChannelIndex >= 0 && ChannelIndex < CHANNEL_COUNT);
        return Channels[ChannelIndex].Lights;
    }
 
    void DisableChannel(int32 ChannelIndex);
    void DisableAllOtherChannels(int32 EnabledChannelIndex);
 
    // Update channel usage based on the current enabled channels. Channels with light of MaxPriority or more will be disabled.
    void UpdateAvailableChannels(const TSparseArray<FLightSceneInfoCompact, TAlignedSparseArrayAllocator<alignof(FLightSceneInfoCompact)>>& Lights, FLightSceneInfo* LightInfo);
 
    int32 GetBestAvailableChannel() const;
 
    void SortLightByPriority(int32 ChannelIndex);
 
private:
 
    struct FChannelInfo
    {
        FChannelInfo() : bIsAvailable(true) {}
        // Lights currently bound at that channel.
        TArray<FLightSceneInfo*, TInlineAllocator<8>> Lights;
        // Whether this channel is available for analysis.
        bool bIsAvailable;
    };
 
    FChannelInfo Channels[CHANNEL_COUNT];
    int32 AvailableChannelCount;
 
    FORCEINLINE void AddLight(int32 ChannelIndex, FLightSceneInfo* Light)
    {
        check(IsChannelEnabled(ChannelIndex) && Light);
        Channels[ChannelIndex].Lights.Add(Light);
    }
 
    static int32 GetPriority(const FLightSceneInfo* Light);
};