[PD] processing images with GEM?

IOhannes m zmoelnig zmoelnig at iem.at
Mon Jan 21 18:51:31 CET 2008

Derek Holzer wrote:
> Hi IOhannes,
> IOhannes m zmoelnig wrote:
>> the problem is, that some pix-sources (platform dependent!) supply the 
>> images with (0/0) in the upper-left corner, whereas others (0/0) is 
>> the lower-left corner (like openGL expects it).
> Would be good to know which platforms do it right, and which ones wrong. 

it's not a matter of "right" and "wrong".

mathematicians tend to put the origin in the lower-left corner (like a 
coordinate system)
computer-graphics prefer the upper-left corner (back in the old days, 
the cursor would appear in the 1st line on the screen)

openGL has been designed by mathematicians.
tcl/tk comes from the computer geeks...

btw, this fuzz is the reason why the tables in Pd are never oriented the 
right way...


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