Re: Do we really need to replace gnuplot?

[Berk Geveci]

There are many implementations of offscreen rendering with OpenGL:
* All platforms: Mesa (software), framebuffer (hardware, based on driver support)
* Windows: Win32 implementation of OpenGL
* Unix/Linux: glxpixmaps (most probably software), pbuffers (sometimes hardware, depends on driver support)

We use all of these in VTK and they work reasonably well. We run into driver issues now and then but I wouldn't hold off using OpenGL because of those.

In addition, if you stick to a subset of OpenGL, you can use gl2ps to produce (offscreen) vector graphics output to ps, eps, pdf or svg.

-berk

On 10/15/07, Shai Ayal <address@hidden> wrote:

On 10/15/07, John W. Eaton <address@hidden> wrote:
> On 15-Oct-2007, Shai Ayal wrote:
>
> | But are you willing to sacrifce offscreen rendering for them?
>
> Precisely what do you mean by offscreen rendering?

I mean the ability to produce a plot in a file (e.g ps or png) w/o the
need for opening a window or indeed using any graphical capabilities
in the computer. gnuplot does this easily, However OpenGL is meant for
screen rendering, so even if you wish to produce a png file, you must
first render the scene to the screen and then convert it to a png
file.

There might be a solution for this using OpenGL pbuffers. I'm looking into it ..

Shai