Deep wrote:

"The others such as CoreGraphics, Quartz, OpenGL, etc, all use the bottom
left as the origin point. This takes it's cue from PostScript. Apple used to
refer to CoreGraphics and Quartz as "Display PostScript" until they were
given the official Apple names."

Actually it wasn't Apple but NexT (and perhaps other companies) who 
started with "Display PostScript".

Origin at Bottom-Left is just what Monsieur Rene Descartes proposed 
about 350 years ago and what is used since in mathematics. It was 
only with computer science (informatics) that the origin was 
transfered to Top-Left and producing a lot of silly confusion...

Best
-- 

                   Herbie

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