Re: screen capture?

[Keith W. <kw...@cs...>]

On Nov 6, 2005, at 12:15 PM, James W. Walker wrote:

> On Nov 6, 2005, at 9:48 AM, Keith Wiley wrote:
>
>> How do I grab a screen capture of a rendered window?  If I do the  
>> fairly straight forward process of copybiting the window's  
>> contents into a gworld, the gworld comes up blank (white) even  
>> though the window is showing a rendered image.
>
> An OpenGL drawing surface isn't exactly part of a window.  I don't  
> know how Grab does it.  If you'd be satisfied to grab just the  
> OpenGL part rather than the whole window, you could either render  
> to a bitmap, or use glReadPixels.  It is possible, though tricky,  
> to use glReadPixels with Quesa.  If you'd like to try that, let me  
> know, and I can give some more details.

Yeah, I don't need the title bar or anything like that.  I want to  
grab a continuous series of frames and then later build a quicktime  
movie from the frames to show a video clip from my program.  I'm  
disappointed I can't find the old program ConvertToMovie anymore, but  
that's a separate issue.  Why will glReadPixels be difficult to use  
if Quesa is just QD3D which is just OpenGL anyway?  Are you saying  
the Quesa reimplementation of the equivalent of glReadPixels hasn't  
been done yet?

I suppose one way to do it is to render into a gworld, as you said.   
I would have to rewrite the draw context setup code to use a gworld  
of my creation instead of a window.  I could probably figure that out  
I at least as fast as glReadPixels.

If you have any further thoughts, I would appreciate it.

Thanks.

________________________________________________________________________
Keith Wiley         kw...@cs...         http://www.unm.edu/~keithw

"I do not feel obliged to believe that the same God who has endowed us
with sense, reason, and intellect has intended us to forgo their use."
                                            --  Galileo Galilei
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