GLFRONTFACE(3G)

📦
version 1.1 · 7 versions
, in centos-stream 9

🦋 NAME 🦋

glFrontFace — define front- and back-facing polygons

okay so this is glFrontFace, from the GLFRONTFACE(3G) manual (with its lil [FIXME: manual] header placeholder, ngl). It's the function that decides which winding direction counts as front-facing, and honestly it's kinda iconic for culling vibes. ✨

💅 C SPECIFICATION 💅

void glFrontFace(GLenum mode);

🎀 PARAMETERS 🎀

  • mode — specifies the orientation of front-facing polygons. Accepted values are GL_CW and GL_CCW. The initial value is GL_CCW. 💖

✨ DESCRIPTION ✨

okay so picture a scene composed entirely of opaque closed surfaces. In that setup, back-facing polygons are literally never visible. Eliminating those invisible polygons has the obvious benefit of speeding up the rendering of the image. To enable and disable elimination of back-facing polygons, call glEnable() and glDisable with argument GL_CULL_FACE. slay. 🫶

The projection of a polygon to window coordinates is said to have clockwise winding if an imaginary object following the path from its first vertex, its second vertex, and so on, to its last vertex, and finally back to its first vertex, moves in a clockwise direction about the interior of the polygon. The polygon's winding is said to be counterclockwise if the imaginary object following the same path moves in a counterclockwise direction about the interior of the polygon. iykyk. 🌀

glFrontFace specifies whether polygons with clockwise winding in window coordinates, or counterclockwise winding in window coordinates, are taken to be front-facing. Passing GL_CCW to mode selects counterclockwise polygons as front-facing; GL_CW selects clockwise polygons as front-facing. By default, counterclockwise polygons are taken to be front-facing. periodt. 👑

💀 ERRORS 💀

GL_INVALID_ENUM is generated if mode is not an accepted value. that's the whole error section, bestie — no cap. 💀

🔥 ASSOCIATED GETS 🔥

glGet() with argument GL_FRONT_FACE. yes ma'am. 🔥

🌈 VERSION SUPPORT 🌈

Version support check: the Function / Feature Name is glFrontFace, and it gets a ✔ in literally every OpenGL Version listed:

  • 2.0 — ✔
  • 2.1 — ✔
  • 3.0 — ✔
  • 3.1 — ✔
  • 3.2 — ✔
  • 3.3 — ✔
  • 4.0 — ✔
  • 4.1 — ✔
  • 4.2 — ✔
  • 4.3 — ✔
  • 4.4 — ✔
  • 4.5 — ✔

👑 SEE ALSO 👑

glCullFace(), — the one and only SEE ALSO reference, periodt. 👑

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group

okay that's the whole page, bestie — signed off with [FIXME: source] source/version placeholder energy and date 08/09/2021 💅✨

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