GTKD Cairo get pixel color

[Ola Fosheim Grøstad via Digitalmars-d-learn]

On Wednesday, 6 January 2016 at 01:41:03 UTC, Basile B. wrote:
> Until a certain "time" my answers were useful. But I recognize 
> that after this "time" I've managed to turn the topic into 
> something totally delirious because, to be honest I was 
> completly sratched by alcohool. I'm sorry but life is so...

No worries! The OP got his question answered, an other people got 
entertained, so it worked out ok :-)