Mercurial > hg > openttd
changeset 7905:63c86d0b97e7 draft
(svn r11456) -Fix [FS#1412] (r10070): Viewport is bound to its top-left corner
author | smatz <smatz@openttd.org> |
---|---|
date | Sun, 18 Nov 2007 13:13:59 +0000 |
parents | ed094cb05df3 |
children | 170816015868 |
files | src/viewport.cpp src/zoom.hpp |
diffstat | 2 files changed, 47 insertions(+), 4 deletions(-) [+] |
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line diff
--- a/src/viewport.cpp +++ b/src/viewport.cpp @@ -296,10 +296,13 @@ vp->virtual_left = x; vp->virtual_top = y; - old_left = UnScaleByZoom(old_left, vp->zoom); - old_top = UnScaleByZoom(old_top, vp->zoom); - x = UnScaleByZoom(x, vp->zoom); - y = UnScaleByZoom(y, vp->zoom); + /* viewport is bound to its left top corner, so it must be rounded down (UnScaleByZoomLower) + * else glitch described in FS#1412 will happen (offset by 1 pixel with zoom level > NORMAL) + */ + old_left = UnScaleByZoomLower(old_left, vp->zoom); + old_top = UnScaleByZoomLower(old_top, vp->zoom); + x = UnScaleByZoomLower(x, vp->zoom); + y = UnScaleByZoomLower(y, vp->zoom); old_left -= x; old_top -= y;
--- a/src/zoom.hpp +++ b/src/zoom.hpp @@ -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 */