src/zoom_func.h
author belugas
Tue, 01 Jan 2008 14:20:48 +0000
changeset 8667 c916a5375166
parent 8619 c2434269c3eb
child 8844 b4f9ff470b85
permissions -rw-r--r--
(svn r11734) -Change: Allow ToggleFullScreen to return the result of the operation' attempt. Previously, only visual clues were available.
-Fix[FS#1519]: When you can not use this resolution at full screen, now you'll know that it failed.
As for the reason it did not work, each computer/OS has its reason.
/* $Id$ */

/** @file zoom.hpp */

#ifndef ZOOM_FUNC_H
#define ZOOM_FUNC_H

#include "zoom_type.h"

extern ZoomLevel _saved_scrollpos_zoom;

/**
 * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
 * When shifting right, value is rounded up
 * @param value value to shift
 * @param zoom  zoom level to shift to
 * @return shifted value
 */
static inline int ScaleByZoom(int value, ZoomLevel zoom)
{
	if (zoom == ZOOM_LVL_NORMAL) return value;
	int izoom = zoom - ZOOM_LVL_NORMAL;
	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : (value + (1 << -izoom) - 1) >> -izoom;
}

/**
 * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
 * When shifting right, value is rounded up
 * @param value value to shift
 * @param zoom  zoom level to shift to
 * @return shifted value
 */
static inline int UnScaleByZoom(int value, ZoomLevel zoom)
{
	if (zoom == ZOOM_LVL_NORMAL) return value;
	int izoom = zoom - ZOOM_LVL_NORMAL;
	return (zoom > ZOOM_LVL_NORMAL) ? (value + (1 << izoom) - 1) >> izoom : value << -izoom;
}

/**
 * Scale by zoom level, usually shift left (when zoom > ZOOM_LVL_NORMAL)
 * @param value value to shift
 * @param zoom  zoom level to shift to
 * @return shifted value
 */
static inline int ScaleByZoomLower(int value, ZoomLevel zoom)
{
	if (zoom == ZOOM_LVL_NORMAL) return value;
	int izoom = zoom - ZOOM_LVL_NORMAL;
	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : value >> -izoom;
}

/**
 * Scale by zoom level, usually shift right (when zoom > ZOOM_LVL_NORMAL)
 * @param value value to shift
 * @param zoom  zoom level to shift to
 * @return shifted value
 */
static inline int UnScaleByZoomLower(int value, ZoomLevel zoom)
{
	if (zoom == ZOOM_LVL_NORMAL) return value;
	int izoom = zoom - ZOOM_LVL_NORMAL;
	return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << -izoom;
}

#endif /* ZOOM_FUNC_H */