Realized we can include the UV offsets into the UVs stored in the exported map file, so we don't need to add those at runtime. Easy performance win.

main.cpp

@@ -187,8 +187,8 @@ int process_faces(const world_t* world, const std::vector<ps1bsp_texture_t>& tex
 			if (minT < 0 || maxT > 1) t = (t - minT) / tRange;
 
 			// Rescale the UVs to the dimensions of the mipmap we've selected for our texture atlas
-			faceVertex.u = (unsigned char)(s * (ps1tex.w - 1));
-			faceVertex.v = (unsigned char)(t * (ps1tex.h - 1));
+			faceVertex.u = (unsigned char)(s * (ps1tex.w - 1)) + ps1tex.uoffs;
+			faceVertex.v = (unsigned char)(t * (ps1tex.h - 1)) + ps1tex.voffs;
 
 			outFaceVertices.push_back(faceVertex);
 		}