Slow image rotation



I have a component that does a pretty simple drawImageTransformed in its paint method. The transformation is a rotation (arbitrary angle) + scaling (to fit the bounding box).

However, it’s slow (on a Core2, it takes 300ms for a 640x480 picture).
I’ve tried in Release mode it’s twice faster, but still not fast enough.

I wonder if there is a simple way to speed this up (I want this to be very smooth, and I need at least 20fps => less than 50ms).

I don’t want to rewrite the whole component in OpenGL (as it would mean changing the design).

Just a though, you might be interested in:


Ok, I can answer to myself:
Gives me a drawing time of 15ms!

So, finally, it’s ok.