rubidium@9723: /* $Id$ */
rubidium@9723: 
glx@10294: /** @file zoom_func.h */
rubidium@9723: 
rubidium@9723: #ifndef ZOOM_FUNC_H
rubidium@9723: #define ZOOM_FUNC_H
rubidium@9723: 
rubidium@9723: #include "zoom_type.h"
rubidium@9723: 
rubidium@9723: extern ZoomLevel _saved_scrollpos_zoom;
rubidium@9723: 
rubidium@9723: /**
rubidium@9723:  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
rubidium@9723:  * When shifting right, value is rounded up
rubidium@9723:  * @param value value to shift
rubidium@9723:  * @param zoom  zoom level to shift to
rubidium@9723:  * @return shifted value
rubidium@9723:  */
rubidium@9723: static inline int ScaleByZoom(int value, ZoomLevel zoom)
rubidium@9723: {
rubidium@9723: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@9723: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@9723: 	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : (value + (1 << -izoom) - 1) >> -izoom;
rubidium@9723: }
rubidium@9723: 
rubidium@9723: /**
rubidium@9723:  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
rubidium@9723:  * When shifting right, value is rounded up
rubidium@9723:  * @param value value to shift
rubidium@9723:  * @param zoom  zoom level to shift to
rubidium@9723:  * @return shifted value
rubidium@9723:  */
rubidium@9723: static inline int UnScaleByZoom(int value, ZoomLevel zoom)
rubidium@9723: {
rubidium@9723: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@9723: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@9723: 	return (zoom > ZOOM_LVL_NORMAL) ? (value + (1 << izoom) - 1) >> izoom : value << -izoom;
rubidium@9723: }
rubidium@9723: 
rubidium@9723: /**
rubidium@9723:  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
rubidium@9723:  * @param value value to shift
rubidium@9723:  * @param zoom  zoom level to shift to
rubidium@9723:  * @return shifted value
rubidium@9723:  */
rubidium@9723: static inline int ScaleByZoomLower(int value, ZoomLevel zoom)
rubidium@9723: {
rubidium@9723: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@9723: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@9723: 	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : value >> -izoom;
rubidium@9723: }
rubidium@9723: 
rubidium@9723: /**
rubidium@9723:  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
rubidium@9723:  * @param value value to shift
rubidium@9723:  * @param zoom  zoom level to shift to
rubidium@9723:  * @return shifted value
rubidium@9723:  */
rubidium@9723: static inline int UnScaleByZoomLower(int value, ZoomLevel zoom)
rubidium@9723: {
rubidium@9723: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@9723: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@9723: 	return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << -izoom;
rubidium@9723: }
rubidium@9723: 
rubidium@9723: #endif /* ZOOM_FUNC_H */