Re: Failing VCL complextext rendering unit test on Windows

On Fri, Mar 24, 2017 at 11:29:52AM +0100, Jan-Marek Glogowski wrote:
> Hi everyone,
>
> when running
>
> $ /opt/lo/bin/make-4.2.1-msvc -C vcl CppunitTest_vcl_complextext
>
> on Windows 7, KVM QXL GUI via Spice I get the following failures:
[…] 
> All height values are the same, just the width and x-offsets change.

Hmm, might be related to Windows font rendering settings, AFAIK Windows
disables anti-aliasing for rdesktop (and I guess this what Spice uses)
and different font rendering strategy can result in different glyph
widths. Only bounding box is affected since we still use Windows API
for it (unlike glyph widths for layout).

> From the documentation, the provided matrix to the function is the
> identity matrix, which just leaves some room for different HDC.
>
> AFAIK HDC is driver dependent (whatever driver is used for SSH) and so
> I'm not sure this is fixable at all.
>
> So I propose disabling it also on Windows.

I suppose we have no way to change the font settings during the testing,
so disabling this part of the test would be the simplest. Alternatively
we can add some tolerance to the test (a pixel or two?) but no idea how.

Regards,
Khaled