00001 /* $Id$ */ 00002 00003 /* 00004 * This file is part of OpenTTD. 00005 * 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. 00006 * 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. 00007 * 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/>. 00008 */ 00009 00012 #ifndef ZOOM_FUNC_H 00013 #define ZOOM_FUNC_H 00014 00015 #include "zoom_type.h" 00016 00024 static inline int ScaleByZoom(int value, ZoomLevel zoom) 00025 { 00026 if (zoom == ZOOM_LVL_NORMAL) return value; 00027 int izoom = zoom - ZOOM_LVL_NORMAL; 00028 return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : (value + (1 << -izoom) - 1) >> -izoom; 00029 } 00030 00038 static inline int UnScaleByZoom(int value, ZoomLevel zoom) 00039 { 00040 if (zoom == ZOOM_LVL_NORMAL) return value; 00041 int izoom = zoom - ZOOM_LVL_NORMAL; 00042 return (zoom > ZOOM_LVL_NORMAL) ? (value + (1 << izoom) - 1) >> izoom : value << -izoom; 00043 } 00044 00051 static inline int ScaleByZoomLower(int value, ZoomLevel zoom) 00052 { 00053 if (zoom == ZOOM_LVL_NORMAL) return value; 00054 int izoom = zoom - ZOOM_LVL_NORMAL; 00055 return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : value >> -izoom; 00056 } 00057 00064 static inline int UnScaleByZoomLower(int value, ZoomLevel zoom) 00065 { 00066 if (zoom == ZOOM_LVL_NORMAL) return value; 00067 int izoom = zoom - ZOOM_LVL_NORMAL; 00068 return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << -izoom; 00069 } 00070 00071 #endif /* ZOOM_FUNC_H */