GLSTENCILMASKSEPARAT(3G)

✨ GLSTENCILMASKSEPARAT(3G) — stencil mask, but make it separate ✨

okay bestie, welcome to the 3G manual page for glStencilMaskSeparate, and honestly? she's a little niche but she is SO worth knowing 🎀

---

🌸 NAME 🌸

glStencilMaskSeparate — control the front and/or back writing of individual bits in the stencil planes 💅

like, which bits in the stencil planes are even allowed to be written, and for which faces. that's her whole job. periodt.

---

🦋 C SPECIFICATION 🦋

void glStencilMaskSeparate(GLenum face, GLuint mask);

two args, no drama ✨

---

💖 PARAMETERS 💖

• face — tells us whether the front stencil writemask, the back stencil writemask, or both get updated. only three symbolic constants are valid here, and they are literally GL_FRONT, GL_BACK, and GL_FRONT_AND_BACK. no cap.
• mask — a bit mask that enables and disables writing of individual bits in the stencil planes 🔥 initially, the mask is all 1's. iconic default behavior.

---

🧚 DESCRIPTION 🧚

so glStencilMaskSeparate controls the writing of individual bits in the stencil planes. the least significant n bits of mask — where n is the number of bits in the stencil buffer — specify a mask. where a 1 shows up in the mask, it's possible to write to the corresponding bit in the stencil buffer ✨ where a 0 shows up, that corresponding bit is write-protected 🚫 initially, all bits are enabled for writing.

and here's the fun part: there can be two separate mask writemasks — one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives 🫶

glStencilMask() sets both front and back stencil writemasks to the same values, as if glStencilMaskSeparate() were called with face set to GL_FRONT_AND_BACK. so like… the non-separate version is just this one doing both at once, iykyk 💀

---

😭 ERRORS 😭

• GL_INVALID_ENUM is generated if face is not one of the accepted tokens. so like, don't be cute and invent a new one 🙈

---

⭐ ASSOCIATED GETS ⭐

glGet() with argument GL_STENCIL_WRITEMASK, GL_STENCIL_BACK_WRITEMASK, or GL_STENCIL_BITS 👑

---

👑 VERSION SUPPORT 👑

the original page ships this as a big table with the columns Function / Feature Name down the side and OpenGL Version across the top, and the row for glStencilMaskSeparate has a ✔ in, like, every single one. so bestie: it's supported in 2.0, 2.1, 3.0, 3.1, 3.2, 3.3, 4.0, 4.1, 4.2, 4.3, 4.4, and 4.5 🔥 all of them. every last one. ate and left no crumbs 💅

---

🌈 SEE ALSO 🌈

• glColorMask()
• glDepthMask()
• glStencilFunc()
• glStencilFuncSeparate()
• glStencilMask()
• glStencilOp()
• glStencilOpSeparate()

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

---

💜 COPYRIGHT 💜

Copyright © 2006 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 © 1991-2006 Silicon Graphics, Inc.

---

and that's the whole page, bestie 🌸 this came from [FIXME: source], dated 08/09/2021, and yes the header up top said GLSTENCILMASKSEPARAT(3G) — go forth and mask your stencil bits separately, you absolute main character 💖✨🎀