textureGrad

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Perform a texture lookup with explicit gradients.

Declaration[edit]

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[edit]

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[edit]

 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:

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 [math][/math] 

 [math][/math] 

 [math][/math] 

 [math][/math] 

 [math][/math] 

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[edit]

textureGrad 1.3+
textureGrad (gsampler2DRect{Shadow}) 1.4+
textureGrad (gsamplerCubeArray) 4.0+

See Also[edit]

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


Copyright[edit]

Copyright© 2011-2014 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/.