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Index › Programming Questions & Help › Syntax Questions › Coordinate problems after using rotate().
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Coordinate problems after using rotate(). (Read 1196 times)
Nnd.
Coordinate problems after using rotate().
Nov 27th, 2009, 12:43pm  
Hey guys. I am new to Processing so would appreciate any help.

I have three ellipses, constructed by:

translating to the center (width/2, height/2).
draw one ellipse.
rotate by some amount of degrees.
draw second ellipse.
rotate again.
draw final ellipse.

I am trying to connect the ellipses with lines to the center, but obviously the coordinates are completely different for the rotated ellipses.

This poses a problem when entering the x and y position of the lines, as i imagine the second and third ellipses are effectively on a new rotated grid. Or i may be completely wrong?

Is there a way around this?

Thanks a lot.
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antiplastik
Re: Coordinate problems after using rotate().
Reply #1 - Nov 27th, 2009, 1:00pm  
Since you change the model space after each call to rotate(), you may need these modelX() and modelY() methods to retrieve the position of your ellipses :
http://processing.org/reference/modelX_.html
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Cedric
Re: Coordinate problems after using rotate().
Reply #2 - Nov 27th, 2009, 1:22pm  
wtf?! when did they introduce that command? thats new to me and i was really waiting for something like that. There should be a page where updates like this are listed so people can easily see what new features are added.
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antiplastik
Re: Coordinate problems after using rotate().
Reply #3 - Nov 27th, 2009, 2:13pm  
mmm... I guess it's been here since the beginning :-p

See
http://processing.org/reference/changes.html
and
revisions.txt which comes with every new version.
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Cedric
Re: Coordinate problems after using rotate().
Reply #4 - Nov 27th, 2009, 2:44pm  
i always read the revisions.txt but i missed that. but you are right, it was there from the beginning but was called objectX instead of modelX.... good to know
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Nnd.
Re: Coordinate problems after using rotate().
Reply #5 - Nov 27th, 2009, 6:06pm  
Thanks a lot for your help. It's much appreciated!
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