textureGatherOffset - gathers four texels from a texture with offset

       Copyright © 2011-2014 Khronos Group

[FIXME: source]                                    11/18/2024                            TEXTUREGATHEROFFSET(3G)

gvec4textureGatherOffset(gsampler2Dsampler,vec2P,ivec2offset,[intcomp]);gvec4textureGatherOffset(gsampler2DArraysampler,vec3P,ivec2offset,[intcomp]);gvec4textureGatherOffset(gsampler2DRectsampler,vec3P,ivec2offset,[intcomp]);vec4textureGatherOffset(gsampler2DShadowsampler,vec2P,floatrefZ,ivec2offset);vec4textureGatherOffset(gsampler2DArrayShadowsampler,vec3P,floatrefZ,ivec2offset);vec4textureGatherOffset(gsampler2DRectShadowsampler,vec3P,floatrefZ,ivec2offset);

textureGatherOffset returns the value:

               vec4(Sample_i0_j1(P + offset, base).comp,
                    Sample_i1_j1(P + offset, base).comp,
                    Sample_i1_j0(P + offset, base).comp,
                    Sample_i0_j1(P + offset, base).comp);

       It perfoms as textureGather() but with offset applied as described in textureOffset(), except that the
       implementation-dependent minimum and maximum offset values are given by
       GL_MIN_PROGRRAM_TEXTURE_GATHER_OFFSET and GL_MAX_PROGRAM_TEXTURE_GATHER_OFFSET, respectively.

       If specified, the value of comp must ba constant integer expression with a value of 0, 1, 2, or 3,
       identifying the x, y, z or w component of the four-component vector lookup result for each texel,
       respectively. If comp is not specified, it is treated as 0, selecting the x component of each texel to
       generate the result.

       textureGatherOffset - gathers four texels from a texture with offset

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.

       comp
           Specifies the component of the source texture that will be used to generate the resulting vector.

       refZ
           Specifies the reference Z value used in the comparison for shadow forms.

       offset
           Specifies the offset from the specified texture coordinate P from which the texels will be gathered.

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

       ┌─────────────────────┬───────────────────────────────────────────────────────────────────────────────────┐
       │                     │        OpenGLShadingLanguageVersion                                            │
       ├─────────────────────┼──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┤
       │ 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                │      │      │      │      │      │      │      │      │      │      │      │      │
       ├─────────────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │ textureGatherOffset │  -   │  -   │  -   │  -   │  -   │  -   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │
       └─────────────────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘