Mercurial > hg > svgui
changeset 1020:69c4f8403ebf colourschemes
Fix integer overflow in getFrameForX
| author | Chris Cannam |
|---|---|
| date | Fri, 22 Jan 2016 15:16:36 +0000 |
| parents | 25ec2390fad3 |
| children | 33d7e1a6747b |
| files | view/View.cpp |
| diffstat | 1 files changed, 6 insertions(+), 5 deletions(-) [+] |
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--- a/view/View.cpp Fri Jan 22 13:39:45 2016 +0000 +++ b/view/View.cpp Fri Jan 22 15:16:36 2016 +0000 @@ -49,7 +49,6 @@ //#define DEBUG_VIEW 1 //#define DEBUG_VIEW_WIDGET_PAINT 1 - View::View(QWidget *w, bool showProgress) : QFrame(w), m_centreFrame(0), @@ -365,15 +364,17 @@ sv_frame_t View::getFrameForX(int x) const { - int z = m_zoomLevel; + sv_frame_t z = m_zoomLevel; // nb not just int, or multiplication may overflow sv_frame_t frame = m_centreFrame - (width()/2) * z; + frame = (frame / z) * z; // this is start frame + frame = frame + x * z; + #ifdef DEBUG_VIEW_WIDGET_PAINT - SVDEBUG << "View::getFrameForX(" << x << "): z = " << z << ", m_centreFrame = " << m_centreFrame << ", width() = " << width() << ", frame = " << frame << endl; + cerr << "View::getFrameForX(" << x << "): z = " << z << ", m_centreFrame = " << m_centreFrame << ", width() = " << width() << ", frame = " << frame << endl; #endif - frame = (frame / z) * z; // this is start frame - return frame + x * z; + return frame; } double