CS 1.6 OPENGL FIX UPDATED 2019 100% WORKING - YouTube
Quartz GL FX [Counter-Strike 1.6] [Mods]
Steam Community :: Screenshot :: "Counter-Strike: Condition Zero" and "Day of Defeat" - Differences of Direct3D renderer, and OpenGL renderer with detail textures enabled.
MangoHud, the excellent Linux overlay layer adds OpenGL support in addition to Vulkan | GamingOnLinux