From b66be87ab92e7416961a1e5dd07db85e08c97a2c Mon Sep 17 00:00:00 2001
From: Krishna Ayyalasomayajula <krishna@ayyalasomayajula.net>
Date: Sat, 30 May 2026 18:00:58 -0500
Subject: [PATCH] fix: add missing glossary entry for present-mode

---
 docs/concepts/GLOSSARY.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/docs/concepts/GLOSSARY.md b/docs/concepts/GLOSSARY.md
index 6a102c4..efddd5c 100644
--- a/docs/concepts/GLOSSARY.md
+++ b/docs/concepts/GLOSSARY.md
@@ -70,6 +70,10 @@ A compiled GPU configuration bundling: [[vertex shader]](#vertex-shader) + [[fra
 
 The strategy passed to `device.poll()`. `PollType::Wait` blocks the calling thread until all pending GPU work finishes — equivalent to a fence wait. `PollType::Poll` checks for completed work once and returns immediately, regardless of whether work is done. For the rainbow triangle, `Wait` is correct: we need the GPU to finish the frame before requesting the next surface texture.
 
+## Present Mode
+
+How the display compositor handles frame buffer presentation: `PresentMode::Mailbox` uses triple buffering for tear-free rendering, `PresentMode::Fifo` provides VSYNC-locked double buffering, `PresentMode::Immediate` renders without synchronization (may show tearing).
+
 ## Ndc
 
 Normalized Device Coordinates. The GPU's native intermediate coordinate space. X and Y range from -1.0 (left/bottom) to +1.0 (right/top). Z ranges from 0.0 (near clipping plane) to 1.0 (far clipping plane). Geometry is mapped into NDC by the GPU after perspective division. Anything outside this cube is clipped. See [[coordinate-systems.md]](coordinate-systems.md).