Re: Problem with Grouping the rotated object.
Re: Problem with Grouping the rotated object.
- Subject: Re: Problem with Grouping the rotated object.
- From: Gregory Weston <email@hidden>
- Date: Wed, 2 Apr 2008 14:47:06 -0400
Quincey Morris wrote:
On Apr 2, 2008, at 04:00, Ghufran Ahamad wrote:
[xform translateXBy:center.x yBy:center.y];
[xform rotateByDegrees:[curGraphic GetAngle]];
[xform translateXBy:-center.x yBy:-center.y];
This looks kind of wrong. Mathematically, wouldn't you want:
[xform translateXBy:-center.x yBy:-center.y];
[xform rotateByDegrees:[curGraphic GetAngle]];
[xform translateXBy:center.x yBy:center.y];
?
Nope. The way the matrix multiplication works, the effect is that the
transformations take place in the opposite order of the way they
appeared in code.
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