NAME

       textureGatherOffset - gathers four texels from a texture with offset

DECLARATION

       gvec4 textureGatherOffset(gsampler2D sampler, vec2 P, ivec2 offset, [int comp]);

       gvec4 textureGatherOffset(gsampler2DArray sampler, vec3 P, ivec2 offset, [int comp]);

       gvec4 textureGatherOffset(gsampler2DRect sampler, vec3 P, ivec2 offset, [int comp]);

       vec4 textureGatherOffset(gsampler2DShadow sampler, vec2 P, float refZ, ivec2 offset);

       vec4 textureGatherOffset(gsampler2DArrayShadow sampler, vec3 P, float refZ, ivec2 offset);

       vec4 textureGatherOffset(gsampler2DRectShadow sampler, vec3 P, float refZ, ivec2 offset);

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.

       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.

DESCRIPTION

       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.

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                │      │      │      │      │      │      │      │      │      │      │      │      │
       ├────────────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │textureGatherOffset │  -   │  -   │  -   │  -   │  -   │  -   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │
       └────────────────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘

SEE ALSO

       texelFetch(), texelFetchOffset(), texture(), textureGather(), textureGatherOffsets(),
       textureGrad(), 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                    TEXTUREGATHEROFFSET(3G)