Provided by: opengl-4-man-doc_1.0~svn33624-1_all 
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 │ 1.10 │ 1.20 │ 1.30 │ 1.40 │ 1.50 │ 3.30 │ 4.00 │ 4.10 │ 4.20 │ 4.30 │ 4.40 │ 4.50 │
│Name │ │ │ │ │ │ │ │ │ │ │ │ │
├─────────────────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
│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
[FIXME: source] 01/03/2018 TEXTUREGRAD(3G)