ScriptableRenderPipeline/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Decal/Decal.hlsl

#include "CoreRP/ShaderLibrary/Debug.hlsl"
#include "Decal.cs.hlsl"

#define DBufferType0 float4
#define DBufferType1 float4
#define DBufferType2 float4
#define DBufferType3 float4

#ifdef DBUFFERMATERIAL_COUNT

#if DBUFFERMATERIAL_COUNT == 1

#define OUTPUT_DBUFFER(NAME)                            \
        out DBufferType0 MERGE_NAME(NAME, 0) : SV_Target0

#define DECLARE_DBUFFER_TEXTURE(NAME)   \
        TEXTURE2D(MERGE_NAME(NAME, 0));  

#define FETCH_DBUFFER(NAME, TEX, unCoord2)                                        \
        DBufferType0 MERGE_NAME(NAME, 0) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 0), unCoord2);

#define ENCODE_INTO_DBUFFER(DECAL_SURFACE_DATA, NAME) EncodeIntoDBuffer(DECAL_SURFACE_DATA, MERGE_NAME(NAME,0))
#define DECODE_FROM_DBUFFER(NAME, DECAL_SURFACE_DATA) DecodeFromDBuffer(MERGE_NAME(NAME,0), DECAL_SURFACE_DATA)


#elif DBUFFERMATERIAL_COUNT == 2

#define OUTPUT_DBUFFER(NAME)                            \
        out DBufferType0 MERGE_NAME(NAME, 0) : SV_Target0,	\
		out DBufferType1 MERGE_NAME(NAME, 1) : SV_Target1	

#define DECLARE_DBUFFER_TEXTURE(NAME)   \
        TEXTURE2D(MERGE_NAME(NAME, 0));  \
        TEXTURE2D(MERGE_NAME(NAME, 1));

#define FETCH_DBUFFER(NAME, TEX, unCoord2)                                        \
        DBufferType0 MERGE_NAME(NAME, 0) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 0), unCoord2); \
        DBufferType1 MERGE_NAME(NAME, 1) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 1), unCoord2);

#define ENCODE_INTO_DBUFFER(DECAL_SURFACE_DATA, NAME) EncodeIntoDBuffer(DECAL_SURFACE_DATA, MERGE_NAME(NAME,0), MERGE_NAME(NAME,1))
#define DECODE_FROM_DBUFFER(NAME, DECAL_SURFACE_DATA) DecodeFromDBuffer(MERGE_NAME(NAME,0), MERGE_NAME(NAME,1), DECAL_SURFACE_DATA)

#elif DBUFFERMATERIAL_COUNT == 3

#define OUTPUT_DBUFFER(NAME)                            \
        out DBufferType0 MERGE_NAME(NAME, 0) : SV_Target0,	\
		out DBufferType1 MERGE_NAME(NAME, 1) : SV_Target1,	\
		out DBufferType2 MERGE_NAME(NAME, 2) : SV_Target2	

#define DECLARE_DBUFFER_TEXTURE(NAME)   \
        TEXTURE2D(MERGE_NAME(NAME, 0));  \
        TEXTURE2D(MERGE_NAME(NAME, 1));  \
        TEXTURE2D(MERGE_NAME(NAME, 2));

#define FETCH_DBUFFER(NAME, TEX, unCoord2)                                        \
        DBufferType0 MERGE_NAME(NAME, 0) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 0), unCoord2); \
        DBufferType1 MERGE_NAME(NAME, 1) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 1), unCoord2); \
        DBufferType2 MERGE_NAME(NAME, 2) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 2), unCoord2);

#define ENCODE_INTO_DBUFFER(DECAL_SURFACE_DATA, NAME) EncodeIntoDBuffer(DECAL_SURFACE_DATA, MERGE_NAME(NAME,0), MERGE_NAME(NAME,1), MERGE_NAME(NAME,2))
#define DECODE_FROM_DBUFFER(NAME, DECAL_SURFACE_DATA) DecodeFromDBuffer(MERGE_NAME(NAME,0), MERGE_NAME(NAME,1), MERGE_NAME(NAME,2), DECAL_SURFACE_DATA)

#elif DBUFFERMATERIAL_COUNT == 4

#define OUTPUT_DBUFFER(NAME)                            \
        out DBufferType0 MERGE_NAME(NAME, 0) : SV_Target0,	\
		out DBufferType1 MERGE_NAME(NAME, 1) : SV_Target1,	\
		out DBufferType2 MERGE_NAME(NAME, 2) : SV_Target2,	\
		out DBufferType3 MERGE_NAME(NAME, 3) : SV_Target3	

#define DECLARE_DBUFFER_TEXTURE(NAME)   \
        TEXTURE2D(MERGE_NAME(NAME, 0));  \
        TEXTURE2D(MERGE_NAME(NAME, 1));  \
        TEXTURE2D(MERGE_NAME(NAME, 2));  \
        TEXTURE2D(MERGE_NAME(NAME, 3));

#define FETCH_DBUFFER(NAME, TEX, unCoord2)                                        \
        DBufferType0 MERGE_NAME(NAME, 0) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 0), unCoord2); \
        DBufferType1 MERGE_NAME(NAME, 1) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 1), unCoord2); \
        DBufferType2 MERGE_NAME(NAME, 2) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 2), unCoord2); \
        DBufferType3 MERGE_NAME(NAME, 3) = LOAD_TEXTURE2D(MERGE_NAME(TEX, 3), unCoord2);

#define ENCODE_INTO_DBUFFER(DECAL_SURFACE_DATA, NAME) EncodeIntoDBuffer(DECAL_SURFACE_DATA, MERGE_NAME(NAME,0), MERGE_NAME(NAME,1), MERGE_NAME(NAME,2), MERGE_NAME(NAME,3))
#define DECODE_FROM_DBUFFER(NAME, DECAL_SURFACE_DATA) DecodeFromDBuffer(MERGE_NAME(NAME,0), MERGE_NAME(NAME,1), MERGE_NAME(NAME,2), MERGE_NAME(NAME,3), DECAL_SURFACE_DATA)

#endif
#endif // #ifdef DBUFFERMATERIAL_COUNT

CBUFFER_START(UnityDecalParameters)
	uint _EnableDBuffer;
	float2 _DecalAtlasResolution;
CBUFFER_END

UNITY_INSTANCING_BUFFER_START(Decal)      
	UNITY_DEFINE_INSTANCED_PROP(float4x4, _NormalToWorld)
UNITY_INSTANCING_BUFFER_END(matrix)       

RW_TEXTURE2D(float, _DecalHTile); // DXGI_FORMAT_R8_UINT is not supported by Unity
TEXTURE2D(_DecalHTileTexture);

uint _DecalCount;
StructuredBuffer<DecalData> _DecalDatas;

TEXTURE2D_ARRAY(_DecalAtlas);          
SAMPLER(sampler_DecalAtlas);

// Must be in sync with RT declared in HDRenderPipeline.cs ::Rebuild
void EncodeIntoDBuffer( DecalSurfaceData surfaceData,
                        out DBufferType0 outDBuffer0,
                        out DBufferType1 outDBuffer1,
						out DBufferType2 outDBuffer2
                        )
{
	outDBuffer0 = surfaceData.baseColor;
	outDBuffer1 = surfaceData.normalWS;	
	outDBuffer2 = surfaceData.mask;	
}

void DecodeFromDBuffer(
    DBufferType0 inDBuffer0,
    DBufferType1 inDBuffer1,
    DBufferType2 inDBuffer2,
    out DecalSurfaceData surfaceData
)
{
    ZERO_INITIALIZE(DecalSurfaceData, surfaceData);
	surfaceData.baseColor = inDBuffer0;
	surfaceData.normalWS.xyz = inDBuffer1.xyz * 2.0f - 1.0f;
	surfaceData.normalWS.w = inDBuffer1.w;
	surfaceData.mask = inDBuffer2;
}