Re: possible bug in GraphicsContext.DrawText

I seem to have narrowed it down to something to do with the 
GraphicsContext. If I don't create a GraphicsContext and just use the DC 
functions then I don't experience the problem.

On Saturday, June 18, 2016 at 4:24:17 PM UTC-5, Royce Mitchell III wrote:
>
> First of all, I can't seem to find where I can file a 
> bug/ticket/tracker/jira/etc for this project. If someone can point me in 
> that direction, I'll be happy to do that. In the meantime, please accept my 
> apologies if this isn't the appropriate place to send this information.
>
> I'm experiencing a rendering problem with GraphicsContext.DrawText. I've 
> created a relatively simple test case illustrating the problem which I've 
> attached here. I've also included a dropbox link below in case the 
> attachment get stripped.
>
> https://www.dropbox.com/s/zzlrwvbqpb76i4u/phoenix_drawtext_bug.zip?dl=0
>
> The problem I'm experiencing is this:
>
> As the line of text being rendered gets longer, the background that's 
> painted and the dimensions being returned by 
> GraphicsContext.GetTextExtent() are wider than the actual text rendered.
>
> Another thing I noticed, which I didn't included in the code demo above, 
> is as the length of text being drawn increases, you can observe letters 
> that start off with a bit more spacing between them will get packed 
> together.
>
> It looks like it might be a floating point / rounding issue.
>
> I can work around the problem by rendering characters independently, but 
> that's a performance hit I don't want to take if I don't have to.
>
> Just in case this is a video driver or screen DPI kind of issue and you 
> have difficult reproducing it, I have also attached a screenshot.
>
> https://www.dropbox.com/s/z6h5l4daem6x0hd/screenshot.png?dl=0
>
> I'm running on Windows 10, screen resolution is 1820x1026, Desktop DPI 
> scaling is set to 125%, video card is a NVIDIA GeForce GTX 970 with the 
> latest drivers.
>
> I just updated Phoenix to make sure it hasn't already been fixed:
>
> D:\cvs\teledigm\teledigm>pip install --upgrade --trusted-host wxpython.org 
> --pre -f http://wxpython.org/Phoenix/snapshot-builds/ wxPython_Phoenix
> Collecting wxPython_Phoenix
>   Downloading 
> http://wxpython.org/Phoenix/snapshot-builds/wxPython_Phoenix-3.0.3.dev2163+2b688df-cp35-cp35m-win32.whl 
> (11.8MB)
>     100% |################################| 11.8MB 3.3MB/s
> Installing collected packages: wxPython-Phoenix
>   Found existing installation: wxPython-Phoenix 3.0.3.dev2158+4d05434
>     Uninstalling wxPython-Phoenix-3.0.3.dev2158+4d05434:
>       Successfully uninstalled wxPython-Phoenix-3.0.3.dev2158+4d05434
> Successfully installed wxPython-Phoenix-3.0.3.dev2163+2b688df
>
> I also ran this on my desktop at the office and it is experiencing the 
> same thing.
>
> It is also Windows 10, 1920x1080, DPI scaling is 100%. Video card is an 
> AMD Radeon HD 6900 Series that hasn't had it's drivers updated in a while.
>
> I just updated that computer from wxPython-Phoenix-3.0.3.dev1964+f780b21 
> to wxPython-Phoenix-3.0.3.dev2163+2b688df, exists in both places.
>
> wxPython 3.0 (non-phoenix) also seems to have this same problem.
>
> Please forgive me, I don't have the time to setup a C++ environment to 
> confirm that this may be a bug in native wxWidgets and not the Python 
> wrapper.
>
>
>

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