Jens Gruschel wrote:


Thank you Jens for input.

> > Really, I'd like to see an official POV.
> 
> Officially you have to lock bitmaps, but not if the main thread is
> blocked :-)

....

> So you can: start a number of treads processing the pixel data (avoid
> using other methods or properties of TBitmap) if you make sure the
> main thread is blocked (use WaitForMultipleObjects with the handles
> of all threads or some events used by your threads signaling they
> have finished their work).

Very special case. Freezing GUI is not acceptable.


---


OK, consider scenario:
- main thread works as usual (GUI, reactions on Sinchronize where some
drawing can occur);
- thread acquires images frame by frame;
- another threads process frames, export pictures into bitmaps with
preset size using Scanline, and display them via Sinchronize.


So Canvas methods or resizing are not used in threads.


I would like to know for sure: do I have to do Canvas.Lock or such the
lock is unnecessary?
-- 
Alex