FACEFORWARD(3G)

📦
version 1.0~svn33624 · 4 versions
, in ubuntu jammy, ubuntu noble

okay bestie, pull up a chair 🫶 this is faceforward, and it lives in section 3G of the manual. it's a lil GLSL icon and honestly it's giving "tiny function, big feelings." let's get into it 💅

✨ NAME ✨

faceforward — returns a vector pointing in the same direction as another. that's it. that's the whole personality. no cap.

🌸 DECLARATION 🌸

here's the exact shape of it, don't freestyle these:

genType faceforward(genType N, genType I, genType Nref);

genDType faceforward(genDType N, genDType I, genDType Nref);

🎀 PARAMETERS 🎀

  • N — bestie this is the vector you wanna orient. the one getting flipped around.
  • I — the incident vector. it's the vibe-check-er, lowkey.
  • Nref — the reference vector. the blueprint. the moment.

🦋 DESCRIPTION 🦋

so what does it actually do? faceforward orients a vector to point away from a surface, as defined by its normal. literally its whole job is making sure the vector faces outward and not into the void 💀

the logic? if dot()(Nref, I) < 0, faceforward returns N. otherwise it returns -N.

that's the entire decision tree. she's simple, she's effective, she ate 🍓

👑 VERSION SUPPORT 👑

ngl this is the part where the original flexes a whole grid at you. here it is, un-gridded but with zero facts dropped, periodt:

faceforward (genType) — iconic in EVERY version, no skips

  • OpenGL Shading Language Version 1.10 — ✔
  • OpenGL Shading Language Version 1.20 — ✔
  • OpenGL Shading Language Version 1.30 — ✔
  • OpenGL Shading Language Version 1.40 — ✔
  • OpenGL Shading Language Version 1.50 — ✔
  • OpenGL Shading Language Version 3.30 — ✔
  • OpenGL Shading Language Version 4.00 — ✔
  • OpenGL Shading Language Version 4.10 — ✔
  • OpenGL Shading Language Version 4.20 — ✔
  • OpenGL Shading Language Version 4.30 — ✔
  • OpenGL Shading Language Version 4.40 — ✔
  • OpenGL Shading Language Version 4.50 — ✔

faceforward (genDType) — late bloomer energy 🌱

  • OpenGL Shading Language Version 1.10 — -
  • OpenGL Shading Language Version 1.20 — -
  • OpenGL Shading Language Version 1.30 — -
  • OpenGL Shading Language Version 1.40 — -
  • OpenGL Shading Language Version 1.50 — -
  • OpenGL Shading Language Version 3.30 — -
  • OpenGL Shading Language Version 4.00 — ✔
  • OpenGL Shading Language Version 4.10 — ✔
  • OpenGL Shading Language Version 4.20 — ✔
  • OpenGL Shading Language Version 4.30 — ✔
  • OpenGL Shading Language Version 4.40 — ✔
  • OpenGL Shading Language Version 4.50 — ✔

so like, genDType didn't show up until 4.00 and then she arrived and immediately understood the assignment. queen behavior 👑

🌈 SEE ALSO 🌈

  • reflect()
  • refract()

go read those too, they're the friend group 🫶

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

aaaand that's the page 💖 this was [FIXME: source], dated 01/03/2018, and it's filed under FACEFORWARD(3G). mwah, go flip some vectors the right way around ✨💅

📦 where this page comes from