> ## Name

> tex1D - performs a texture lookup in a given 1D sampler and, in some cases, a shadow comparison. May also use pre computed derivatives if those are provided.

> ## Synopsis

>     float4 tex1D(sampler1D samp, float  s)
>     float4 tex1D(sampler1D samp, float  s, int texelOff)
>     float4 tex1D(sampler1D samp, float2 s)
>     float4 tex1D(sampler1D samp, float2 s, int texelOff)

>     float4 tex1D(sampler1D samp, float  s, float dx, float dy)
>     float4 tex1D(sampler1D samp, float  s, float dx, float dy, int texelOff)
>     float4 tex1D(sampler1D samp, float2 s, float dx, float dy)
>     float4 tex1D(sampler1D samp, float2 s, float dx, float dy, int texelOff)

>     int4 tex1D(isampler1D samp, float  s);
>     int4 tex1D(isampler1D samp, float  s, int texelOff);

>     int4 tex1D(isampler1D samp, float  s, float dx, float dy)
>     int4 tex1D(isampler1D samp, float  s, float dx, float dy, int texelOff)

>     unsigned int4 tex1D(usampler1D samp, float  s);
>     unsigned int4 tex1D(usampler1D samp, float  s, int texelOff);

>     unsigned int4 tex1D(usampler1D samp, float  s, float dx, float dy)
>     unsigned int4 tex1D(usampler1D samp, float  s, float dx, float dy,
>                         int texelOff)

> ## Parameters

> samp
>   Sampler to lookup.
> s
>   Coordinates to perform the lookup. If an extra coordinate compared to the texture dimensionality is present it is used to perform a shadow comparison. The value used in the shadow comparison is always the last component of the coordinate vector.
> dx
>   Pre computed derivative along the x axis.
> dy
>   Pre computed derivative along the y axis.
> texelOff
>   Offset to be added to obtain the final texel.

> ## Description

> Performs a texture lookup in sampler samp using coordinates s, may use and derivatives dx and dy, also may perform shadow comparison and use texel offset texelOff to compute final texel.

> ## Profile Support

> tex1D is supported in all fragment profiles and all vertex profiles starting with vp40, variants with shadow comparison are only supported in fp40 and newer profiles, variants with texel offsets are only supported in gp4 and newer profiles, variants with integer textures are also only supported in gp4 and newer profiles.

> ## See Also

> tex1Dbias, tex1Dlod, tex1Dproj