How to use Win32's BitBlt using Ruby?

Question

Does anyone know how to use Win32's BitBlt() using Ruby? It seems like you need to use a destination DC (device context) and how can Ruby handle that? I use GetPixel() and it is really slow even to get 100 pixels (takes about 10 seconds). thanks.

Answer 1

Second Carl's other post: use win32 screenshot http://github.com/jarmo/win32screenshot

Answer 2

How about writing all of your image processing code in C++ as a Win32 executable and launching it as a separate process or calling into it from Ruby using the Win32API class? It makes sense to do it this way instead of writing a cludge in Ruby which will never perform as well.

Answer 3

I'd just like to note that I'm seeing a similar thing. GetPixel is exceedingly slow on Vista. I've determined that this is the case when you're using that Aero thing. If you set desktop theme to one of the "Classic" settings, it's fast again. And the OP's estimate of ~10 seconds is not wrong, believe it or not. It's really exceedingly slow.

I, too, am looking for a BitBlt in Ruby. I expect I'll need to figure it out/write it, but was hoping someone else has already posted an example.

Answer 4

I wouldn't go quite as far as Ed; chances are you only want to do some relatively simple and commonplace things that a normal GUI would do. For this, such libraries already exist and don't need to be written.

One example would be wxRuby.

I'm afraid I'm not familiar with it, but maybe it already offers some screen-grabbing utility methods.