Date: Mon, 6 Jan 2003 08:42:23 -0600 (CST)
From: "Stephen J Baker" <sjbaker@link.com>
Reply-To: <sjbaker@link.com>
To: Narendhar Rao <naren@aquila.co.in>
cc: <ogl-sample@oss.sgi.com>
Subject: Re: 2D application development - performance related query
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On Thu, 26 Dec 2002, Narendhar Rao wrote:

>                 I am an application developer intending to use OpenGL.
> I understand OpenGL works with 3D geometry Only and all 2D geometry are
> treated as 3D with z=0; Is this understanding correct?

Yes. That's correct.

> Is there any other API for 2D application development which is
> performance wise better over OpenGL?

No.  OpenGL is hardware accellerated on all modern graphics cards
and that hardware runs the same speed for 3D and 2D graphics.  If
there were a 2D-only API, it wouldn't be hardware accellerated and
even if it were, it would just leave some of the 3D hardware unused.

It wouldn't run any faster than OpenGL.

> This is in the context of development of a viewer application for
> display of semi conductor layout geometry containing millions of
> polygons and all present on a 2D plane.

Perfectly applicable to OpenGL rendering.

You'll likely have lots of layers of geometry - and rendering
that using the Z coordinate as the layer number would make a
lot of sense.  This is a case where using the 3D capability
of OpenGL to do 2D rendering makes a lot of sense.

----
Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
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