TEXTUREGRAD(3G)

NAME
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
 | OpenGL Shading Language Version
Function Name | 1.10 | 1.20 | 1.30 | 1.40 | 1.50 | 3.30 | 4.00 | 4.10 | 4.20 | 4.30 | 4.40 | 4.50
textureGrad | - | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔
textureGrad (gsampler2DRect{Shadow}) | - | - | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔
textureGrad (gsamplerCubeArray) | - | - | - | - | - | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔

SEE ALSO

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

COPYRIGHT

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/.

COPYRIGHT
Copyright © 2011-2014 Khronos Group