// This file contains various helper declarations for declaring and sampling members of the ShadowContext struct.

// shadow lookup routines when dynamic array access is possible
#if SHADOW_SUPPORTS_DYNAMIC_INDEXING != 0

// Shader model >= 5.1
#	define SHADOW_DEFINE_SAMPLING_FUNC_T2DA_COMP( _Tex2DArraySlots  , _SamplerCompSlots )	float4 SampleCompShadow_T2DA( ShadowContext ctxt, uint texIdx, uint sampIdx, float3 tcs, float slice					)	{ return SAMPLE_TEXTURE2D_ARRAY_SHADOW( ctxt.tex2DArray[texIdx], ctxt.compSamplers[sampIdx], tcs, slice );		}
#	define SHADOW_DEFINE_SAMPLING_FUNC_T2DA_SAMP( _Tex2DArraySlots  , _SamplerSlots )		float4 SampleShadow_T2DA(	  ShadowContext ctxt, uint texIdx, uint sampIdx, float2 tcs, float slice, float lod = 0.0	)	{ return SAMPLE_TEXTURE2D_ARRAY_LOD( ctxt.tex2DArray[texIdx], ctxt.samplers[sampIdx], tcs, slice, lod );		}
#   define SHADOW_DEFINE_SAMPLING_FUNC_T2DA_LOAD( _Tex2DArraySlots  )	                    float4 LoadShadow_T2DA(	      ShadowContext ctxt, uint texIdx,               uint2  tcs, uint  slice, uint lod = 0	    )   { return LOAD_TEXTURE2D_ARRAY_LOD( ctxt.tex2DArray[texIdx], tcs, slice, lod ).x;                                }
#	define SHADOW_DEFINE_SAMPLING_FUNC_TCA_COMP(  _TexCubeArraySlots, _SamplerCompSlots )	float4 SampleCompShadow_TCA(  ShadowContext ctxt, uint texIdx, uint sampIdx, float4 tcs, float cubeIdx					)	{ return SAMPLE_TEXTURECUBE_ARRAY_SHADOW( ctxt.texCubeArray[texIdx], ctxt.compSamplers[sampIdx], tcs, cubeIdx );}
#	define SHADOW_DEFINE_SAMPLING_FUNC_TCA_SAMP(  _TexCubeArraySlots, _SamplerSlots )		float4 SampleShadow_TCA(	  ShadowContext ctxt, uint texIdx, uint sampIdx, float3 tcs, float cubeIdx, float lod = 0.0 )	{ return SAMPLE_TEXTURECUBE_ARRAY_LOD( ctxt.texCubeArray[texIdx], ctxt.samplers[sampIdx], tcs, cubeIdx, lod );	}

#else // helper macros if dynamic indexing does not work

// Sampler and texture combinations are static. No shadowmap will ever be sampled with two different samplers.
// Once shadowmaps and samplers are fixed consider writing custom dispatchers directly accessing textures and samplers.
#	define SHADOW_DEFINE_SAMPLING_FUNC_T2DA_COMP( _Tex2DArraySlots, _SamplerCompSlots )											\
		float4 SampleCompShadow_T2DA( ShadowContext ctxt, uint texIdx, uint sampIdx, float3 tcs, float slice )					\
		{																														\
			float4 res = 1.0.xxxx;																								\
			[unroll] for( uint i = 0; i < _Tex2DArraySlots; i++ )																\
			{																													\
				[unroll] for( uint j = 0; j < _SamplerCompSlots; j++ )															\
				{																												\
					[branch] if( i == texIdx && j == sampIdx )																	\
					{																											\
						res = SAMPLE_TEXTURE2D_ARRAY_SHADOW( ctxt.tex2DArray[i], ctxt.compSamplers[j], tcs, slice );			\
						break;																									\
					}																											\
				}																												\
			}																													\
			return res;																											\
		}

#	define SHADOW_DEFINE_SAMPLING_FUNC_T2DA_SAMP( _Tex2DArraySlots, _SamplerSlots )												\
		float4 SampleShadow_T2DA( ShadowContext ctxt, uint texIdx, uint sampIdx, float2 tcs, float slice, float lod = 0.0 )		\
		{																														\
			float4 res = 1.0.xxxx;																								\
			[unroll] for( uint i = 0; i < _Tex2DArraySlots; i++ )																\
			{																													\
				[unroll] for( uint j = 0; j < _SamplerSlots; j++ )																\
				{																												\
					[branch] if( i == texIdx && j == sampIdx )																	\
					{																											\
						res = SAMPLE_TEXTURE2D_ARRAY_LOD( ctxt.tex2DArray[i], ctxt.samplers[j], tcs, slice, lod );				\
						break;																									\
					}																											\
				}																												\
			}																													\
			return res;																											\
		}

#	define SHADOW_DEFINE_SAMPLING_FUNC_T2DA_LOAD( _Tex2DArraySlots )												            \
		float LoadShadow_T2DA( ShadowContext ctxt, uint texIdx, uint2 tcs, uint slice, uint lod = 0 )		                    \
		{																														\
			float res = 1.0;																								    \
			[unroll] for( uint i = 0; i < _Tex2DArraySlots; i++ )																\
			{																													\
				[branch] if( i == texIdx )																	                    \
				{																											    \
					res = LOAD_TEXTURE2D_ARRAY_LOD( ctxt.tex2DArray[i], tcs, slice, lod ).x;				                    \
					break;																									    \
				}																											    \
			}																													\
			return res;																											\
		}


#	define SHADOW_DEFINE_SAMPLING_FUNC_TCA_COMP( _TexCubeArraySlots, _SamplerCompSlots )										\
		float4 SampleCompShadow_TCA( ShadowContext ctxt, uint texIdx, uint sampIdx, float4 tcs, float cubeIdx )					\
		{																														\
			float4 res = 1.0.xxxx;																								\
			[unroll] for( uint i = 0; i < _TexCubeArraySlots; i++ )																\
			{																													\
				[unroll] for( uint j = 0; j < _SamplerCompSlots; j++ )															\
				{																												\
					[branch] if( i == texIdx && j == sampIdx )																	\
					{																											\
						res = SAMPLE_TEXTURECUBE_ARRAY_SHADOW( ctxt.texCubeArray[i], ctxt.compSamplers[j], tcs, cubeIdx );		\
						break;																									\
					}																											\
				}																												\
			}																													\
			return res;																											\
		}

#	define SHADOW_DEFINE_SAMPLING_FUNC_TCA_SAMP( _TexCubeArraySlots, _SamplerSlots )											\
		float4 SampleShadow_TCA( ShadowContext ctxt, uint texIdx, uint sampIdx, float3 tcs, float cubeIdx, float lod = 0.0 )	\
		{																														\
			float4 res = 1.0.xxxx;																								\
			[unroll] for( uint i = 0; i < _TexCubeArraySlots; i++ )																\
			{																													\
				[unroll] for( uint j = 0; j < _SamplerSlots; j++ )																\
				{																												\
					[branch] if( i == texIdx && j == sampIdx )																	\
					{																											\
						res = SAMPLE_TEXTURECUBE_ARRAY_LOD( ctxt.texCubeArray[i], ctxt.samplers[j], tcs, cubeIdx, lod );		\
						break;																									\
					}																											\
				}																												\
			}																													\
			return res;																											\
		}
#endif // SHADOW_SUPPORTS_DYNAMIC_INDEXING != 0

// helper macro to suppress code generation if _cnt is 0
#define SHADOW_DECLARE_SAMPLING_FUNC_T2DA_COMP( _Tex2DArraySlots  , _SamplerCompSlots )	float4 SampleCompShadow_T2DA( ShadowContext ctxt, uint texIdx, uint sampIdx, float3 tcs, float slice					);
#define SHADOW_DECLARE_SAMPLING_FUNC_T2DA_SAMP( _Tex2DArraySlots  , _SamplerSlots )		float4 SampleShadow_T2DA(	  ShadowContext ctxt, uint texIdx, uint sampIdx, float2 tcs, float slice, float lod = 0.0	);
#define SHADOW_DECLARE_SAMPLING_FUNC_T2DA_LOAD( _Tex2DArraySlots  )	                    float4 LoadShadow_T2DA(	      ShadowContext ctxt, uint texIdx,               uint2  tcs, uint  slice, uint lod = 0	    );
#define SHADOW_DECLARE_SAMPLING_FUNC_TCA_COMP(  _TexCubeArraySlots, _SamplerCompSlots )	float4 SampleCompShadow_TCA(  ShadowContext ctxt, uint texIdx, uint sampIdx, float4 tcs, float cubeIdx					);
#define SHADOW_DECLARE_SAMPLING_FUNC_TCA_SAMP(  _TexCubeArraySlots, _SamplerSlots )		float4 SampleShadow_TCA(	  ShadowContext ctxt, uint texIdx, uint sampIdx, float3 tcs, float cubeIdx, float lod = 0.0 );

#define SHADOW_CAT( _left, _right ) _left ## _right

#define SHADOW_CHECK_0( _macro ) 
#define SHADOW_CHECK_1( _macro ) _macro
#define SHADOW_CHECK_2( _macro ) _macro
#define SHADOW_CHECK_3( _macro ) _macro
#define SHADOW_CHECK_4( _macro ) _macro
#define SHADOW_CHECK_5( _macro ) _macro
#define SHADOW_CHECK_6( _macro ) _macro
#define SHADOW_CHECK_7( _macro ) _macro
#define SHADOW_CHECK_8( _macro ) _macro
#define SHADOW_CHECK_9( _macro ) _macro
#define SHADOW_CHECK( _cnt, _macro ) SHADOW_CAT( SHADOW_CHECK_ , _cnt ) ( _macro )


#define SHADOW_CHECK_ALT_0( _macro, _alt ) _alt
#define SHADOW_CHECK_ALT_1( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_2( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_3( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_4( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_5( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_6( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_7( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_8( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT_9( _macro, _alt ) _macro
#define SHADOW_CHECK_ALT( _cnt, _macro, _alt ) SHADOW_CAT( SHADOW_CHECK_ALT_ , _cnt ) ( _macro, _alt )

// helper macro to declare texture members for the shadow context.
#define SHADOWCONTEXT_DECLARE_TEXTURES( _Tex2DArraySlots, _TexCubeArraySlots, _SamplerCompSlots, _SamplerSlots )	\
	SHADOW_CHECK( _Tex2DArraySlots	, Texture2DArray			tex2DArray[_Tex2DArraySlots];		)				\
	SHADOW_CHECK( _TexCubeArraySlots, TextureCubeArray			texCubeArray[_TexCubeArraySlots];	)				\
	SHADOW_CHECK( _SamplerCompSlots	, SamplerComparisonState	compSamplers[_Tex2DArraySlots];		)				\
	SHADOW_CHECK( _SamplerSlots		, SamplerState				samplers[_Tex2DArraySlots];			)
// helper macro to declare texture sampling functions for the shadow context.
#define SHADOW_DEFINE_SAMPLING_FUNCS( _Tex2DArraySlots, _TexCubeArraySlots, _SamplerCompSlots, _SamplerSlots )	\
	SHADOW_CHECK( _Tex2DArraySlots  , SHADOW_CHECK_ALT( _SamplerCompSlots, SHADOW_DEFINE_SAMPLING_FUNC_T2DA_COMP( _Tex2DArraySlots, _SamplerCompSlots ), SHADOW_DECLARE_SAMPLING_FUNC_T2DA_COMP( _Tex2DArraySlots, _SamplerCompSlots ) ) )	\
	SHADOW_CHECK( _Tex2DArraySlots  , SHADOW_CHECK_ALT( _SamplerSlots    , SHADOW_DEFINE_SAMPLING_FUNC_T2DA_SAMP( _Tex2DArraySlots, _SamplerSlots     ), SHADOW_DECLARE_SAMPLING_FUNC_T2DA_SAMP( _Tex2DArraySlots, _SamplerSlots     ) ) )	\
									  SHADOW_CHECK_ALT( _Tex2DArraySlots , SHADOW_DEFINE_SAMPLING_FUNC_T2DA_LOAD( _Tex2DArraySlots                    ), SHADOW_DECLARE_SAMPLING_FUNC_T2DA_LOAD( _Tex2DArraySlots                    ) )	\
	SHADOW_CHECK( _TexCubeArraySlots, SHADOW_CHECK_ALT( _SamplerCompSlots, SHADOW_DEFINE_SAMPLING_FUNC_TCA_COMP(_TexCubeArraySlots, _SamplerCompSlots ), SHADOW_DECLARE_SAMPLING_FUNC_TCA_COMP(_TexCubeArraySlots, _SamplerCompSlots ) ) )	\
	SHADOW_CHECK( _TexCubeArraySlots, SHADOW_CHECK_ALT( _SamplerSlots    , SHADOW_DEFINE_SAMPLING_FUNC_TCA_SAMP(_TexCubeArraySlots, _SamplerSlots     ), SHADOW_DECLARE_SAMPLING_FUNC_TCA_SAMP(_TexCubeArraySlots, _SamplerSlots     ) ) )