Re: simple point function seems strange
Posted by
Henrik Sperre Johansen on
Jul 07, 2010; 10:26pm
URL: https://forum.world.st/simple-point-function-seems-strange-tp2281587p2281607.html
On 08.07.2010 00:11, Stéphane Ducasse wrote:
> Hi
>
> (10@20) rotateBy: #left centerAt: 0 @0
> returns
> 20@ -10
>
> and my math tells me that this is a rotation to the right.
>
> Am I correct?
> Then why I'm wrong? screen coordinates vs. math coordinate?
>
> Stef
You rotate around the center, left is compared to the center -> point vector, not the other way around.
Cheers,
Henry
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