[Lazarus] Rotating a bitmap

[Graeme Geldenhuys]

2008/10/27 Michael Van Canneyt <michael at freepascal.org>:
> Hi,
>
> How can I rotate a bitmap 90° counterclockwise ?

Wouldn't a rotation matrix do the trick?  I remember the old fpGUI
code (gfxbase.pas) unit used a 3x3 matrix to do translations and
scalations calculations. I would imagine the same could be applied for
rotation.

Wikipedia has some articles on rotation matrix, but the formulas look
scary.  ;-)  Google revealed a lot of links on rotation matrix.


> Alternatively, how can I read/write the pixels in the bitmap ?

The TFPCustomCanvas.Colors[] array?



Regards,
  - Graeme -


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