/* $Id$ */ /* * This file is part of OpenTTD. * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2. * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>. */ /** @file cmd_helper.h Helper functions to extract data from command parameters. */ #ifndef CMD_HELPER_H #define CMD_HELPER_H #include "direction_type.h" #include "road_type.h" template<uint N> static inline void ExtractValid(); template<> inline void ExtractValid<1>() {} template<typename T> struct ExtractBits; template<> struct ExtractBits<Axis> { static const uint Count = 1; }; template<> struct ExtractBits<DiagDirection> { static const uint Count = 2; }; template<> struct ExtractBits<RoadBits> { static const uint Count = 4; }; template<typename T, uint N, typename U> static inline T Extract(U v) { /* Check if there are enough bits in v */ ExtractValid<N + ExtractBits<T>::Count <= sizeof(U) * 8>(); return (T)GB(v, N, ExtractBits<T>::Count); } #endif