TEXTUREGATHER(3G)

✨ NAME ✨

textureGather — gathers four texels from a texture 🧚 (this is the 3G manual page, so like, GLSL shader function territory, iykyk)

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🎀 DECLARATION 🎀

okay bestie, here's the whole roster, every single overload, no skips:

gvec4 textureGather(gsampler2D sampler, vec2 P, [int comp]);

gvec4 textureGather(gsampler2DArray sampler, vec3 P, [int comp]);

gvec4 textureGather(gsamplerCube sampler, vec3 P, [int comp]);

gvec4 textureGather(gsamplerCubeArray sampler, vec4 P, [int comp]);

gvec4 textureGather(gsampler2DRect sampler, vec3 P, [int comp]);

vec4 textureGather(gsampler2DShadow sampler, vec2 P, float refZ);

vec4 textureGather(gsampler2DArrayShadow sampler, vec3 P, float refZ);

vec4 textureGather(gsamplerCubeShadow sampler, vec3 P, float refZ);

vec4 textureGather(gsamplerCubeArrayShadow sampler, vec4 P, float refZ);

vec4 textureGather(gsampler2DRectShadow sampler, vec3 P, float refZ);

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🌸 PARAMETERS 🌸

• sampler — the sampler that the texture you're stealing texels from is bound to. it's giving "who am I even sampling" energy 💀
• P — the texture coordinates, like the spot where the sampling happens. the coordinates, periodt.
• comp — which component of the source texture gets used to build the resulting vector. pick your fighter 🎀
• refZ — the reference Z value, used for the comparison in the shadow forms. only shows up for the shadow girlies.

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💅 DESCRIPTION 💅

so textureGather returns this value, verbatim, no cap:

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

If comp is specified, its value must be a 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. (Yes, that's x, y, z, w in order, bestie, matching 0, 1, 2, 3 🫶)

If comp is not specified, it gets treated as 0, which selects the x component of each texel to generate the result. default behaviour, love that for you ✨

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👑 VERSION SUPPORT 👑

which OpenGL Shading Language versions let textureGather in the club? here's the vibe check on the function named textureGather:

• 1.10 — ❌ not invited
• 1.20 — ❌ not invited
• 1.30 — ❌ not invited
• 1.40 — ❌ not invited
• 1.50 — ❌ not invited
• 3.30 — ❌ not invited
• 4.00 — ✔️ she's here 💖
• 4.10 — ✔️
• 4.20 — ✔️
• 4.30 — ✔️
• 4.40 — ✔️
• 4.50 — ✔️

so from 4.00 onward it's main character energy 🌈

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🦋 SEE ALSO 🦋

the whole friend group, go read these too:

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

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💜 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 © 2011-2014 Khronos Group

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and that's the whole page, bestie 🥹 this came from the [FIXME: source] and it's dated 01/03/2018 — so if you ever need to cite it, that's the receipt. mwah 💅✨