[Openev-discuss] Re: display list changes (Paul Spencer)

[Norman V. <nh...@ca...>]

> Date: Sun, 06 Oct 2002 15:19:17 -0400
> From: Paul Spencer <sp...@dm...>
> Reply-To: sp...@dm...
> To: ope...@li...
> Subject: [Openev-discuss] Re: display list changes
> 
> > 6)  Instead of rebuilding the entire display list you could add new
> > display lists consisting only of a glTranslate() around the effected
> > displaylist and just change these.  This could also be done with only
> > one extra display list per by adding a glPushMatrix() in the new list
> > and a glPopMatrix() at the end of the succeeding list.
> > 
> 
> I wonder if this will work.  The affected part of the display list is 
> actually rasters which are drawn with glDrawPixels (at least for the 
> symbols) and are positioned with glRasterPos*() ... does glTranslate 
> affect glRasterPos*() calls?  I'm willing to give this a shot :)

I think so,  but I have not tried this trick with glRasterPos() 

FYI  - following snipped from 
% man glrasterpos

"""
 The  object  coordinates  presented  by  glRasterPos   are
 treated  just  like  those of a glVertex command: They are
 transformed by the current modelview and projection matri-
 ces  and  passed  to the clipping stage.  If the vertex is
 not culled, then it is  projected  and  scaled  to  window
 coordinates, which become the new current raster position,
 and the GL_CURRENT_RASTER_POSITION_VALID flag is set.   If
 the  vertex  is  culled, then the valid bit is cleared and
 the current raster position and associated color and  tex-
 ture coordinates are undefined.
"""

Cheers

Norman