Vector based printing

• To: <visad-list@xxxxxxxxxxxxxxxx>
• Subject: Vector based printing
• From: "Rob Hackett" <r.hackett@xxxxxxxxxx>
• Date: Thu, 8 Jul 2004 15:15:30 +1000

Hi

        I have a requirement to produce hardcopy charts from a visad 
application.
Due to the complexity of the data, the charts will likely be on A1 paper at
a resolution way beyond what is possible using a simple raster based screen
dump of a visad display. The only solution is to plot the components of the
display via a vector based printing system such as postscript or CGM.

        First of all, has anybody else done this already? I'd hate to reinvent 
the
weel.

        If not, I have worked out a simple prototype of a system of doing this
which appears to work. It goes as follows:

        Prepare your data as normal and visualise using a DisplayImplJ3D.
        When the chart is ready to plot, create a DisplayImplJ2D off-screen.
        Use getMapVector() method of DisplayImplJ3D to get all the ScalarMaps 
used
in the on-screen display
        Clone each of these ScalarMaps and add them to the off-screen display
        Use getRenderers() method of DisplayImplJ3D to get the DataRenderers 
from
the on-screen display
        From each of the DataRenderers, use getLink().getData() to get the data
rendered on-screen
        Create a DataReferenceImpl for each of these data items, and add to the
off-screen display
        Tweak the off-screen ScalarMaps and Controls so that they have suitable
scales for an A1 image (or A4, etc)
        Get the DisplayRendererJ2D from the off-screen display using
getDisplayRenderer()
        Get the root VisADGroup from the display renderer using getRoot()
        Recursively parse this group to access its VisADAppearance children
        From these, extract the VisADGeometryArray objects and plot them to a
postscript file, PDF file, etc
        Send the postscript file, PDF file, etc to the A1 printer

        Does anybody have any comments on this way of printing? I have tested it
with some success, but before I invest more time in implementing it I would
be interested to know if anybody has any better ideas.

Thanks,

Rob

• Follow-Ups:
  • Re: Vector based printing
    • From: Bill Hibbard