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Re: Different behaviours of the QPainter object on Mac OS X and Linux

Subject: Re: Different behaviours of the QPainter object on Mac OS X and Linux
From: Dimitri
Date: Thu, 23 Mar 2006 23:15:34 +0100
Hi,

I use a QPen of width 'w'. I want to draw a line between (x1,y) and (x2,y). The method QPainter::drawPolyline() draws a line if I give an array of 2 points. We can see this line (horizontal in this example) as a rectangle of lenght (x1-x2) or (x2-x1) and of width 'w'. If you look at the different coordonates of this rectangle, you will find :
 -Under Linux  (x1, y-(w/2)), (x2,y-(w/2)), (x2, y+(w/2)),  (x1, y+(w/2)).
 -Under Mac (x1,y) , (x2,y), (x2,y+w), (x1, y+w).

It shouldn't be like that. I looked for this bug on the internet but I didn't find anything related to it. Is there a way to change the behaviour of the QPainter? Is it an unknow bug? Will it be corrected (or do I need to introduce some code for specific plateforms in my sources files)?

I seem to recall this is a known issue that has been fixed in Qt 4. Unfortunately I don't have Mac OS here to test.

Also I doubt this can be fixed in the Qt 3.3 series as it could break existing programs.

--
Dimitri

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