[gl2ps] Showing hidden lines

[Sergi Díaz]

Hello,

In my application (a renderer) I have an option to show hidden lines. It
renders the lines, or part of lines, that should be covered by triangles
using a stipple pattern.
To achieve this I first make a first pass rendering as usual, and then
render the lines again using the stipple pattern, with the depth buffer
deactivated. This way the hidden lines show up stippled and the rest of the
lines show as normal. This works, in a bitmap, but when I try to render as
vector a problem arises, there is no way to tell gl2ps that the depth buffer
has been deactivated. Or I don't see it.

Is there a way to achieve this? Or, if I must do it myself, where should I
look at inside gl2ps code to add a "depth activation/deactivation token"?

Oh, BTW, I can't just render lines from back faces stippled, that only works
when objects cover their own lines, but not when covering other objects'
lines.

Thanks in advance,

--
Sergi Díaz
Penguin Development Team
McNeel Europe
www.penguin3d.com
www.rhino3d.com