From: Paul Harness <gapa83 AT udcf DOT gla DOT ac DOT uk>
Subject: Re: Blit region with GRX ?
To: flaregun AT strauss DOT udel DOT edu (Edwin L Phillips Jr)
Date: Wed, 2 Mar 1994 10:18:59 +0000 (GMT)
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu (djgpp)

> 
> What I do is:
> 
>  GrContext *gc;
>  gc = GrCreateContext(...);  /* This can be any size... 1000x1000 etc. */
> 
>  GrSetContext(gc);  /* This is the trick */
> 
> ... draw to gc ...
> 
>  GrSetContext(NULL);  /* Go back to the screen context */
> 
>  GrBitBlt(gc, 100, 100, 300, 300, NULL, 0, 0);  /* parms may be out of order */
>           ^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^
>               src context region   dest region (screen)
>               (100,100)<=>(300,300)    (0,0)
> 
>   This is convenient for when you want to make a huge picture, and display 
> part of it on the screen (or in a window).  Just bitblt the region you 
> want to see into the window.
> 
>   Ed
>
Thanks :-)) My mistake was to use GrCreateSubContext() rather than
GrCreateContext(). 

-- 
Paul Harness,                        |  Internet: gapa83 AT udcf DOT gla DOT ac DOT uk
Department of Physics and Astronomy, |
University of Glasgow,               |  Tel +44-41-339-8855 ext 8359
Glasgow, G12 8QQ, SCOTLAND.          |  Fax +44-41-334-9029