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

#pragma once

// Must match C++ constants in PCGComputeCommon.h
#ifndef PCG_NUM_RESERVED_ATTRS
#define PCG_NUM_RESERVED_ATTRS 32
#endif
#ifndef PCG_MAX_NUM_ATTRS
#define PCG_MAX_NUM_ATTRS 128
#endif

// TODO pass in attribute IDs to copy?
#define PCG_COPY_ATTRIBUTES_TO_OUTPUT(TargetPin, SourcePin, Target_DataIndex, Target_ElementIndex, Source_DataIndex, Source_ElementIndex, bMetadataOnly, bInitNonCopiedAttributes) \
	{ \
		const uint NumAttributes = TargetPin##_GetDataNumAttributesInternal(Target_DataIndex); \
		uint NumAttributesProcessed = 0; \
		\
		const int FirstAttributeId = (bMetadataOnly) ? PCG_NUM_RESERVED_ATTRS : 0; \
		\
		for (int AttributeId = FirstAttributeId; AttributeId < PCG_MAX_NUM_ATTRS; ++AttributeId) \
		{ \
			const uint Target_Stride = TargetPin##_GetAttributeStrideInternal(Target_DataIndex, AttributeId); \
			\
			if (Target_Stride == 0) \
			{ \
				/* No output attribute to write to. */ \
				continue; \
			} \
			\
			const uint Source_Stride = SourcePin##_GetAttributeStrideInternal(Source_DataIndex, AttributeId); \
			const uint Target_ElementAddress = TargetPin##_GetElementAddressInternal(Target_DataIndex, Target_ElementIndex, AttributeId); \
			\
			if (Source_Stride == Target_Stride) \
			{ \
				const uint Source_ElementAddress = SourcePin##_GetElementAddressInternal(Source_DataIndex, Source_ElementIndex, AttributeId); \
				\
				for (uint Offset = 0; Offset < Target_Stride; Offset += 4) \
				{ \
					TargetPin##_StoreBufferInternal(Target_ElementAddress + Offset, SourcePin##_LoadBufferInternal(Source_ElementAddress + Offset)); \
				} \
			} \
			else if (bInitNonCopiedAttributes) \
			{ \
				for (uint Offset = 0; Offset < Target_Stride; Offset += 4) \
				{ \
					/* Initialize output data (only header part of buffer will be initialized). */ \
					TargetPin##_StoreBufferInternal(Target_ElementAddress + Offset, 0u); \
				} \
			} \
			\
			if (++NumAttributesProcessed >= NumAttributes) \
			{ \
				/* We can early-out when we've looked at all the possible attributes. */ \
				break; \
			} \
		} \
	}

#define PCG_COPY_METADATA_ATTRIBUTES_TO_OUTPUT(TargetPin, SourcePin, Target_DataIndex, Target_ElementIndex, Source_DataIndex, Source_ElementIndex) \
	PCG_COPY_ATTRIBUTES_TO_OUTPUT(TargetPin, SourcePin, Target_DataIndex, Target_ElementIndex, Source_DataIndex, Source_ElementIndex, /*bMetadataOnly=*/true, /*bInitNonCopiedAttributes=*/true)

#define PCG_COPY_ALL_ATTRIBUTES_TO_OUTPUT(TargetPin, SourcePin, Target_DataIndex, Target_ElementIndex, Source_DataIndex, Source_ElementIndex) \
	PCG_COPY_ATTRIBUTES_TO_OUTPUT(TargetPin, SourcePin, Target_DataIndex, Target_ElementIndex, Source_DataIndex, Source_ElementIndex, /*bMetadataOnly=*/false, /*bInitNonCopiedAttributes=*/true)