Built-In Functions - Praise for OpenGL ES 30 Programming Guide - page 479

Table B-9 Texture Lookup Functions (continued)

Syntax Description

gvec4 textureProj (gsampler2D sampler , vec3 P [, float bias ] )
gvec4 textureProj (gsampler2D sampler , vec4 P [, float bias ] )
gvec4 textureProj (gsampler3D sampler , vec4 P [, float bias ] )

Do a texture lookup with projection. The texture
coordinates consumed from P , not including
the last component of P , are divided by the last
component of P to form projected coordinates P' .
The resulting third component of P' in the shadow
forms is used as Dref. The third component of P is
ignored when sampler has type gsampler2D and
P has type vec4. After these values are computed,

loat textureProj (sampler2DShadow sampler , vec4 P [, float bias ] )

texture lookup proceeds as in texture .

gvec4 textureLod (gsampler2D sampler , vec2 P , float lod )
gvec4 textureLod (gsampler3D sampler , vec3 P , float lod )
gvec4 textureLod (gsamplerCube sampler , vec3 P , float lod )

Do a texture lookup as in texture but with
explicit LOD; lod specifies λ base and sets
the partial derivatives used for the texture
minification equations to 0.

loat textureLod (sampler2DShadow sampler , vec3 P, loat lod )

gvec4 textureLod (gsampler2DArray sampler , vec3 P , float lod )

(continues)