[wx-dev] #9554: wxDC.SetUserScale + wxDC.DrawBitmap = incorrect scaling when scaling by a factor of 7+

[wxTrac]

Ticket URL: <http://trac.wxwidgets.org/ticket/9554>

#9554: wxDC.SetUserScale + wxDC.DrawBitmap = incorrect scaling when scaling by a
factor of 7+
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 Reporter:  Vladiuz                       |       Owner:         
     Type:  defect                        |      Status:  new    
 Priority:  normal                        |   Milestone:         
Component:  wxMSW                         |     Version:  2.8.7.1
 Keywords:  SetUserScale, DrawBitmap, DC  |   Blockedby:         
    Patch:  0                             |    Blocking:         
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 I am using SetUserScale to zoom on images (more efficient way than
 resizing the image). In wxPython (Windows Vista) this does not work
 correctly when scaling to large magnitudes (7+). In particular the
 resulting image size is always off by a few pixels, and sometimes the
 positioning is off too by a pixel.

 (I suspect the same problem may occur on other systems and in APIs for
 other languages.)

 I will attach an image with example of the problem.

 Please point me to a way to fix this, or someone write and apply a patch
 please. I am ready to compensate for your time! :)


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Ticket URL: <http://trac.wxwidgets.org/ticket/9554>