int tabb = 0;
ImGui::Begin("##1", 0)
if(ImGui::Button(u8"player", ImVec2(SizeX, SizeY)))
{
tabb = 0;
}
ImGui::PushFont(fontname);
if(ImGui::Button(u8"veh", ImVec2(SizeX, SizeY)))
{
tabb = 1;
}
ImGui::PopFont();
if(tabb == 0) { ImGui::Text("open tab: player"); }
else if(tabb == 1)...