Compared to GS, Xash3D applies different brightness-gamma curve to lightmaps and doesn't apply it to textures at all. It result in dark lightmaps and even darker textures. This patch fixes it. Does not affect 2D skybox art (although it should).
Download and extract xash.dll into Xash3D root directory.
Launch Xash3D with "-console" parameter, and then in console set gamma 2.5, brightness 1.2
Picture should look just like it was in Goldsource.
- In common.h set texgamma to 0.655 (found experimentally, although Goldsource seem to use 0.666 but it doesn't exactly look the same)
-in Image_SetPalette wrap 3 texture channels of LUMP_NORMAL into TextureToGamma(). Just wrap, it's expecting 1 parameter.
-In BuildGammaTable() set g3 = 0.125 unconditionally.
Tested on Xash3D build 4529