(svn r11456) -Fix [FS#1412] (r10070): Viewport is bound to its top-left corner

This commit is contained in:
smatz
2007-11-18 13:13:59 +00:00
parent 5b21a839a9
commit b48c5a3c92
2 changed files with 47 additions and 4 deletions

View File

@@ -32,6 +32,13 @@ enum ZoomLevel {
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;
@@ -39,6 +46,13 @@ static inline int ScaleByZoom(int value, ZoomLevel zoom)
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;
@@ -46,4 +60,30 @@ static inline int UnScaleByZoom(int value, ZoomLevel zoom)
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 = (int)zoom - (int)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 = (int)zoom - (int)ZOOM_LVL_NORMAL;
return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << -izoom;
}
#endif /* ZOOM_HPP */