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Index › Programming Questions & Help › Syntax Questions › stopping a rotation
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stopping a rotation (Read 478 times)
ma201rb
stopping a rotation
Apr 7th, 2006, 11:03pm  
Say I have a sphere that you can rotate freely with the mouse, and on top of that sphere I wanted a small ellipse with a crosshair on it as a static anchor to slelect areas of the sphere, how can I write the draw() part so the rotate() part doesn't affect the crosshair?

At the moment, the ellipse I draw moves with the sphere in the rotation!

thanks for anyone who can help

R
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JohnG
Re: stopping a rotation
Reply #1 - Apr 7th, 2006, 11:32pm  
pushMatrix() and popMatrix willhelp you do what you want.

They basicly save and load rotation/translation states.

So if you do a pushMatrix() before you draw the sphere, then a popMatrix() once you've drawn it, you should be able to draw the ellipse as if the sphere had never been rotated.
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ma201rb
Re: stopping a rotation
Reply #2 - Apr 8th, 2006, 10:34am  
Thanks for the speedy reply!

The ellipse I've drawn is now static but it's behind the rotating sphere. Is there anyway to bring it to the front, so it's almost like a static cursor over the top of this sphere?

-R
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JohnG
Re: stopping a rotation
Reply #3 - Apr 8th, 2006, 12:15pm  
Add a translate(0,0,50); or possibly a larger value before the ellipse call, that'll move it closer to the camera.
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ma201rb
Re: stopping a rotation
Reply #4 - Apr 8th, 2006, 6:50pm  
Many thanks.

Issue solved!
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