Hello!

I'm looking for techniques to speed up the painting of a lot of pixels, each of which requires up to a 1 millisecond to calculate. What I have so far is that I precalculate the colors of a 640x480 patch and then draw it pixel by pixel in paintEvent() using drawPoint(). The pure drawing takes several seconds, which is way too long. Is there something I can do to speed this up? Something like painting into an off screen pixmap and then showing that somehow?

Soon I will have to be able to draw lines and curves on top of this 640x480 patch, which frequently change. How can I achieve that only the foreground is repainted and the patch stays in the background and doesn't need to be repainted at all?

Thanks
Cruz