Built-In Functions - Praise for OpenGL ES 30 Programming Guide - page 482

Table B-9 Texture Lookup Functions (continued)

Syntax Description

gvec4 textureProjGrad (gsampler2D sampler , vec3 P , vec2
dPdx , vec2 dPdy )
gvec4 textureProjGrad (gsampler2D sampler , vec4 P , vec2 dPdx ,
vec2 dPdy )
gvec4 textureProjGrad (gsampler3D sampler , vec4 P , vec3 dPdx ,
vec3 dPdy )
float textureProjGrad (sampler2DShadow sampler , vec4 P , vec2
dPdx , vec2 dPdy )

Do a texture lookup both projectively, as
described in textureProj , and with explicit
gradient, as described in textureGrad . The
partial derivatives dPdx and dPdy are assumed
to be already projected.

gvec4 textureProjGradOffset (gsampler2D sampler , vec3 P , vec2
dPdx , vec2 dPdy , ivec2 offset)
gvec4 textureProjGradOffset (gsampler2D sampler , vec4 P , vec2
dPdx , vec2 dPdy , ivec2 offset)
gvec4 textureProjGradOffset (gsampler3D sampler , vec4 P , vec3
dPdx , vec3 dPdy , ivec3 offset)
float textureProjGradOffset (sampler2DShadow sampler , vec4 P ,
vec2 dPdx , vec2 dPdy , ivec2 offset)

Do a texture lookup projectively and
with explicit gradient as described in
textureProjGrad , as well as with offset, as
described in textureOffset .