winfnws@dutrun.UUCP (Aadjan van der Helm) (11/17/89)
I want to use X-Windows as a graphical interface for a modelling-program.
The program can produce output on screen when used interactive and when used
off-line, output is generated in memory and saved on disk when finished.
I guess you should know the program and the X-server run on the same cpu.
The program demands the following of X-Windows:
1) a frame-buffer (max depth: 24-bit, max size: 1024x1024 pixels),
2) drawing lines and filled rectangles to the frame-buffer should be
possible
3) a copy of the contents of a window must be kept in memory (since the
generation of a picture is computational expensive),
4) writing and reading pixel-values from the frame-buffer should be
possible.
Demands 1, 2 and 3 are not hard to implement: create a window and a pixmap,
draw in the pixmap and use XCopyArea to keep the window up-to-date.
To satisfy both demand 2 and 4, the modelling-program has to maintain a
pixmap and an image. I would like to avoid this!
My questions to you NetHeads are:
a) How can I combine demand 2 and 4 in X-Windows?
b) And what does that mean for the memory-requirements of the program?
I would appreciate any comments on this!
--Aadjan
Real name: Aadjan van der Helm
TU Delft, The Netherlands
Mail to: aadjan@duticg.tudelft.nl