//NOTE - Not every kernel has been tested

uint _Width;
uint _Height;
uint _Depth;

uint _IdxX;
uint _IdxY;
uint _IdxZ;

float4 _UV;

Texture2D _Tex2D;
Texture3D _Tex3D;

SamplerState _LinearClamp;

//-----------------------------------------------------------------------//

//-- read from 1 channel 2D render texture --//

#pragma kernel read2DC1

RWStructuredBuffer<float> _Buffer2DC1;

[numthreads(8,8,1)]
void read2DC1(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width;

	if(id.x < _Width && id.y < _Height)
   		_Buffer2DC1[idx] = _Tex2D[id.xy].x;

}

//-- read from 2 channel 2D render texture --//

#pragma kernel read2DC2

RWStructuredBuffer<float2> _Buffer2DC2;

[numthreads(8,8,1)]
void read2DC2(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width;
	
	if(id.x < _Width && id.y < _Height)
    	_Buffer2DC2[idx] = _Tex2D[id.xy].xy;

}

//-- read from 3 channel 2D render texture --//

#pragma kernel read2DC3

RWStructuredBuffer<float3> _Buffer2DC3;

[numthreads(8,8,1)]
void read2DC3(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width;

	if(id.x < _Width && id.y < _Height)
    	_Buffer2DC3[idx] = _Tex2D[id.xy].xyz;

}

//-- read from 4 channel 2D render texture --//

#pragma kernel read2DC4

RWStructuredBuffer<float4> _Buffer2DC4;

[numthreads(8,8,1)]
void read2DC4(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width;

	if(id.x < _Width && id.y < _Height)
    	_Buffer2DC4[idx] = _Tex2D[id.xy];

}

//-- read single pixel from 2D render texure. Always reads all 4 channes --//

#pragma kernel readSingle2D

RWStructuredBuffer<float4> _BufferSingle2D;

[numthreads(1,1,1)]
void readSingle2D(uint3 id : SV_DispatchThreadID)
{

    _BufferSingle2D[0] = _Tex2D[uint2(_IdxX,_IdxY)];

}

//-- read single pixel from 2D render texure using bilinear filtering. Always reads all 4 channes --//

#pragma kernel readSingleBilinear2D

[numthreads(1,1,1)]
void readSingleBilinear2D(uint3 id : SV_DispatchThreadID)
{

    _BufferSingle2D[0] = _Tex2D.SampleLevel(_LinearClamp, _UV.xy, 0);

}

//-----------------------------------------------------------------------//

//-- read from 1 channel 3D render texture --//

#pragma kernel read3DC1

RWStructuredBuffer<float> _Buffer3DC1;

[numthreads(8,8,8)]
void read3DC1(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width + id.z * _Width * _Height;

	if(id.x < _Width && id.y < _Height && id.z < _Depth)
    	_Buffer3DC1[idx] = _Tex3D[id].x;

}

//-- read from 2 channel 3D render texture --//

#pragma kernel read3DC2

RWStructuredBuffer<float2> _Buffer3DC2;

[numthreads(8,8,8)]
void read3DC2(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width + id.z * _Width * _Height;

	if(id.x < _Width && id.y < _Height && id.z < _Depth)
    	_Buffer3DC2[idx] = _Tex3D[id].xy;

}

//-- read from 3 channel 3D render texture --//

#pragma kernel read3DC3

RWStructuredBuffer<float3> _Buffer3DC3;

[numthreads(8,8,8)]
void read3DC3(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width + id.z * _Width * _Height;

	if(id.x < _Width && id.y < _Height && id.z < _Depth)
    	_Buffer3DC3[idx] = _Tex3D[id].xyz;

}

//-- read from 4 channel 3D render texture --//

#pragma kernel read3DC4

RWStructuredBuffer<float4> _Buffer3DC4;

[numthreads(8,8,8)]
void read3DC4(uint3 id : SV_DispatchThreadID)
{

    int idx = id.x + id.y * _Width + id.z * _Width * _Height;

	if(id.x < _Width && id.y < _Height && id.z < _Depth)
    	_Buffer3DC4[idx] = _Tex3D[id];

}

//-- read single pixel from 3D render texure. Always reads all 4 channes --//

#pragma kernel readSingle3D

RWStructuredBuffer<float4> _BufferSingle3D;

[numthreads(1,1,1)]
void readSingle3D(uint3 id : SV_DispatchThreadID)
{
    _BufferSingle3D[0] = _Tex3D[uint3(_IdxX,_IdxY,_IdxZ)];

}

//-- read single pixel from 3D render texure using bilinear filtering. Always reads all 4 channes --//

#pragma kernel readSingleBilinear3D

[numthreads(1,1,1)]
void readSingleBilinear3D(uint3 id : SV_DispatchThreadID)
{
    _BufferSingle3D[0] = _Tex3D.SampleLevel(_LinearClamp, _UV.xyz, 0);

}