2011 Khronos Group
textureGrad 3G
textureGrad perform a texture lookup with explicit gradients

## Declaration

gvec4 `textureGrad` gsampler1D sampler float P float dPdx float dPdy gvec4 `textureGrad` gsampler2D sampler vec2 P vec2 dPdx vec2 dPdy gvec4 `textureGrad` gsampler3D sampler vec3 P vec3 dPdx vec3 dPdy gvec4 `textureGrad` gsamplerCube sampler vec3 P vec3 dPdx vec3 dPdy gvec4 `textureGrad` gsampler2DRect sampler vec2 P vec2 dPdx vec2 dPdy float `textureGrad` gsampler2DRectShadow sampler vec2 P vec2 dPdx vec2 dPdy float `textureGrad` sampler1DShadow sampler vec3 P float dPdx float dPdy float `textureGrad` sampler2DShadow sampler vec3 P vec2 dPdx vec2 dPdy gvec4 `textureGrad` gsampler1DArray sampler vec2 P float dPdx float dPdy gvec4 `textureGrad` gsampler2DArray sampler vec3 P vec2 dPdx vec2 dPdy float `textureGrad` sampler1DArrayShadow sampler vec3 P float dPdx float dPdy gvec4 `textureGrad` gsamplerCubeArray sampler vec4 P vec3 dPdx vec3 dPdy

## Parameters

sampler

  Specifies the sampler to which the texture from which texels will be retrieved is bound.

P

  Specifies the texture coordinates at which texture will be sampled.

dPdx

  Specifies the partial derivative of P with respect to window x.

dPdy

  Specifies the partial derivative of P with respect to window y.

## Description

`textureGrad` performs a texture lookup at coordinate P from the texture bound to sampler with explicit texture coordinate gradiends as specified in dPdx and dPdy. Set:

δs δx = δP δx for a 1D texture, δP.s δx otherwise

δs δy = δP δy for a 1D texture, δP.s δy otherwise

δt δx = 0.0 for a 1D texture, δP.t δx otherwise

δt δy = 0.0 for a 1D texture, δP.t δy otherwise

δr δx = 0.0 for a 1D or 2D texture, δP.p δx otherwise

δr δy = 0.0 for a 1D or 2D texture, δP.p δy otherwise

For the cube version, the partial derivatives of P are assumed to be in the coordinate system used before texture coordinates are projected onto the appropriate cube face.

## Version Support

#VARTABLECOLS#
#FUNCTABLEHEADER#
textureGrad#newin13#
textureGrad (gsampler2DRect{Shadow})#newin14#
textureGrad (gsamplerCubeArray)#newin40#

## See Also

texelFetch, texelFetchOffset, texture, textureGather, textureGatherOffset, textureGatherOffsets, textureGradOffset, textureLod, textureLodOffset, textureOffset, textureProj, textureProjGrad, textureProjGradOffset, textureProjLod, textureProjLodOffset, textureProjOffset, textureQueryLod, textureSize

## Copyright

Copyright 2011 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.