Graphics Objects -> Line Lists?

[Martin Werner]

Hello all,

I am working with octave on a simulation system which relies on external 
CAD-Data.

For the time being, the CAD-Data is externally rendered down to a list 
of lines and imported in octave as a matrix, each row representing a 
lines starting and endpoint.

LINES=[x1,y1,x2,y2;...]

Now, if I want to transport this data into a plot, I have severe 
performance problems:

For a small CAD file (~200m^2) containing ~4500 lines, rendering them 
all with a for loop using either plot or line command takes ~50 seconds.

for i = 1:size(LINES)(1);
   plot(LINES(...))
endfor

If I use a better type of plotting creating exactly one line object with 
4500 lines, it is fast enough:

line([A(:,1),A(:,3)],[A(:,2),A(:,4)])

runs below 15ms. But of course, this does not what I want. It 
essentially renders a line strip. Is there a possibility to render a 
line list in a fast manner? Quickly diving into the code of plot,line 
and __do_line__  functions, it seems to me, that there is no possibility 
to do that, am I right?

Wouldn't it be good to have a plotting primitive set similar to OpenGL 
rendering primitives:

GL_LINES, GL_LINESTRIP,GL_TRIANGLES,...


Am I missing something? The question in short:

Given a list of (many) independent lines, how can I (quickly) draw them 
to a plot window?

Best regards,
  Martin Werner




--
Martin Werner
Mobile and Distributed Systems Group
Institute for Computer Science, Ludwig-Maximilians-Universität München
Room E 011, Oettingenstraße 67, 80538 Munich, Germany
Phone: +49 89 2180 9127
http://www.mobile.ifi.lmu.de/