[cairo] Running cairo-test-suite with -as / cairo_surface_set_device_scale() and the test suite / image scaling madness

[Bill Spitzak]

Use the mouse to scale the picture. Any click in the lower-right 
quadrant will cause scale + rotate. Clicks in the other 3 quadrants 
cause translation.

You can also hit a lot of letter keys to change the filtering algorithm. 
But basically we are testing 'd' (default) and 'b' (best).

On 07/08/2014 06:25 PM, Bryce W. Harrington wrote:
> On Tue, Jun 10, 2014 at 01:46:08PM -0700, Bill Spitzak wrote:
>> Attached is my test program for the filtering. This uses the xlib
>> cairo backend (and thus requires patching cairo so that the fallback
>> image is used for xlib).
>>
>> To build, extract the tar file, cd to the cairot directory, and type
>> make. The test program is ./image.
>>
>> Edit the source code to change the size of the checkerboard pattern.
>> Most tests were done with 1-pixel stripes, by setting CHECKER to 1
>> and YCHECKER to 1000.
>
> Hi Bill,
>
> Thanks for providing this test case.  I've built and run it, but am not
> sure what I'm looking for...  I see a properly drawn checkerboard with
> the defaults, and a set of thin lines with the modified settings.  I'm
> assuming I should be seeing some artifacts or corruption?
>
> Bryce
>