--- a/src/zoom.hpp Thu Nov 22 23:01:41 2007 +0000
+++ b/src/zoom.hpp Fri Nov 23 16:59:30 2007 +0000
@@ -32,6 +32,13 @@
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 @@
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 @@
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 */