rubidium@8123: /* $Id$ */
rubidium@8123: 
rubidium@9111: /** @file zoom_func.h Functions related to zooming. */
rubidium@8123: 
rubidium@8123: #ifndef ZOOM_FUNC_H
rubidium@8123: #define ZOOM_FUNC_H
rubidium@8123: 
rubidium@8123: #include "zoom_type.h"
rubidium@8123: 
rubidium@8123: extern ZoomLevel _saved_scrollpos_zoom;
rubidium@8123: 
rubidium@8123: /**
rubidium@8123:  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
rubidium@8123:  * When shifting right, value is rounded up
rubidium@8123:  * @param value value to shift
rubidium@8123:  * @param zoom  zoom level to shift to
rubidium@8123:  * @return shifted value
rubidium@8123:  */
rubidium@8123: static inline int ScaleByZoom(int value, ZoomLevel zoom)
rubidium@8123: {
rubidium@8123: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@8123: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@8123: 	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : (value + (1 << -izoom) - 1) >> -izoom;
rubidium@8123: }
rubidium@8123: 
rubidium@8123: /**
rubidium@8123:  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
rubidium@8123:  * When shifting right, value is rounded up
rubidium@8123:  * @param value value to shift
rubidium@8123:  * @param zoom  zoom level to shift to
rubidium@8123:  * @return shifted value
rubidium@8123:  */
rubidium@8123: static inline int UnScaleByZoom(int value, ZoomLevel zoom)
rubidium@8123: {
rubidium@8123: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@8123: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@8123: 	return (zoom > ZOOM_LVL_NORMAL) ? (value + (1 << izoom) - 1) >> izoom : value << -izoom;
rubidium@8123: }
rubidium@8123: 
rubidium@8123: /**
rubidium@8123:  * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
rubidium@8123:  * @param value value to shift
rubidium@8123:  * @param zoom  zoom level to shift to
rubidium@8123:  * @return shifted value
rubidium@8123:  */
rubidium@8123: static inline int ScaleByZoomLower(int value, ZoomLevel zoom)
rubidium@8123: {
rubidium@8123: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@8123: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@8123: 	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : value >> -izoom;
rubidium@8123: }
rubidium@8123: 
rubidium@8123: /**
rubidium@8123:  * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
rubidium@8123:  * @param value value to shift
rubidium@8123:  * @param zoom  zoom level to shift to
rubidium@8123:  * @return shifted value
rubidium@8123:  */
rubidium@8123: static inline int UnScaleByZoomLower(int value, ZoomLevel zoom)
rubidium@8123: {
rubidium@8123: 	if (zoom == ZOOM_LVL_NORMAL) return value;
rubidium@8123: 	int izoom = zoom - ZOOM_LVL_NORMAL;
rubidium@8123: 	return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << -izoom;
rubidium@8123: }
rubidium@8123: 
rubidium@8123: #endif /* ZOOM_FUNC_H */