truelight@7120: /* $Id$ */
truelight@7120: 
glx@8844: /** @file zoom_func.hpp */
truelight@7120: 
rubidium@8619: #ifndef ZOOM_FUNC_H
rubidium@8619: #define ZOOM_FUNC_H
truelight@7120: 
rubidium@8619: #include "zoom_type.h"
truelight@7120: 
truelight@7120: extern ZoomLevel _saved_scrollpos_zoom;
truelight@7120: 
smatz@8401: /**
smatz@8401:  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
smatz@8401:  * When shifting right, value is rounded up
smatz@8401:  * @param value value to shift
smatz@8401:  * @param zoom  zoom level to shift to
smatz@8401:  * @return shifted value
smatz@8401:  */
truelight@7122: static inline int ScaleByZoom(int value, ZoomLevel zoom)
truelight@7122: {
truelight@7149: 	if (zoom == ZOOM_LVL_NORMAL) return value;
smatz@8591: 	int izoom = zoom - ZOOM_LVL_NORMAL;
truelight@7329: 	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : (value + (1 << -izoom) - 1) >> -izoom;
truelight@7122: }
truelight@7122: 
smatz@8401: /**
smatz@8401:  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
smatz@8401:  * When shifting right, value is rounded up
smatz@8401:  * @param value value to shift
smatz@8401:  * @param zoom  zoom level to shift to
smatz@8401:  * @return shifted value
smatz@8401:  */
truelight@7122: static inline int UnScaleByZoom(int value, ZoomLevel zoom)
truelight@7122: {
truelight@7149: 	if (zoom == ZOOM_LVL_NORMAL) return value;
smatz@8591: 	int izoom = zoom - ZOOM_LVL_NORMAL;
truelight@7327: 	return (zoom > ZOOM_LVL_NORMAL) ? (value + (1 << izoom) - 1) >> izoom : value << -izoom;
truelight@7122: }
truelight@7122: 
smatz@8401: /**
smatz@8401:  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
smatz@8401:  * @param value value to shift
smatz@8401:  * @param zoom  zoom level to shift to
smatz@8401:  * @return shifted value
smatz@8401:  */
smatz@8401: static inline int ScaleByZoomLower(int value, ZoomLevel zoom)
smatz@8401: {
smatz@8401: 	if (zoom == ZOOM_LVL_NORMAL) return value;
smatz@8591: 	int izoom = zoom - ZOOM_LVL_NORMAL;
smatz@8401: 	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : value >> -izoom;
smatz@8401: }
smatz@8401: 
smatz@8401: /**
smatz@8401:  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
smatz@8401:  * @param value value to shift
smatz@8401:  * @param zoom  zoom level to shift to
smatz@8401:  * @return shifted value
smatz@8401:  */
smatz@8401: static inline int UnScaleByZoomLower(int value, ZoomLevel zoom)
smatz@8401: {
smatz@8401: 	if (zoom == ZOOM_LVL_NORMAL) return value;
smatz@8591: 	int izoom = zoom - ZOOM_LVL_NORMAL;
smatz@8401: 	return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << -izoom;
smatz@8401: }
smatz@8401: 
rubidium@8619: #endif /* ZOOM_FUNC_H */