Drawing inside images

[Jim Lyons]

JB recently wrote:

> Yesterday evening I made some experiments about displaying
> waveforms in realtime inside an image...
>
> The idea was to use transcript to update the imagedata.
> So far the conclusion is that it works on small images (100 x
> 100 pixels, or 150 x 150 pixels) ... But when the image size
> reaches 200 x 200, it becomes way too slow...

If you're just plotting x-y data, it is very fast to set the points of 
a polygon to the scaled data. I just plotted a sine wave 300 pixels 
wide and the response to adjusting the amplitude with a slider is 
virtually instantaneous.

Jim Lyons