Comments on: 17.07.2007 OpenGL for Gdk/Gtk+

By: API » Blog Archive » Reviving GLSL

API » Blog Archive » Reviving GLSL — Fri, 10 Aug 2007 21:02:32 +0000

[...] post continues, in some way, a post written by Tim Janick on his blog, about OpenGL for Gdk/Gtk+, that summarizes some of problems about using OpenGL with [...]

By: Widget skeletons, GPU theming « Owen’s Blog

Widget skeletons, GPU theming « Owen’s Blog — Sat, 28 Jul 2007 18:42:41 +0000

[...] skeletons, GPU theming I agree 100% with Tim that using OpenGL directly as a rendering API for GTK+ makes no sense. The OpenGL 2D API is [...]

By: API » Blog Archive » There’s no place like home

API » Blog Archive » There’s no place like home — Mon, 23 Jul 2007 20:55:28 +0000

[...] really interesting posts on planet gnome (off the record): OpenGL for Gdk/Gtk+ and (in some way his response) Widget skeletons, GPU [...]

By: Cameron

Cameron — Thu, 19 Jul 2007 17:29:44 +0000

The page you linked to seemed to promote OpenGL rendering using Texture AA: http://homepage.mac.com/arekkusu/bugs/invariance/TexAA.html. And I haven’t noticed any quality difference using Quartz 2D Extreme with OS X.

By: tko

tko — Wed, 18 Jul 2007 22:46:15 +0000

While I can appreciate the idea of pixel perfect output I can’t help but feel that if your UI (with pixel densities of displays these days) requires pixel perfect input/output you have much bigger problems than just that. Similarly if the UI design is sane enough, not being pixel perfect wouldn’t really make much of a difference.

By: Peteris Krisjanis

Peteris Krisjanis — Wed, 18 Jul 2007 08:26:02 +0000

Question: wasn’t that Cairo uses hardware renderers only when explictly set, not automatically?

By: Jon Smirl

Jon Smirl — Tue, 17 Jul 2007 20:36:13 +0000

This is not an OpenGL only issue, similar antialiasing artifacts are present in different X server implementations that use hardware antialiasing. You’re just noticing that the various graphics chip makers don’t all implement the identical antialiasing algorithm (patent issues at work). If you want pixel reproducible antialiasing it all has to be done in software for any graphics system.

The bigger question is, do you really need pixel level, reproducible antialiasing. This is a real question since LCDs and CRTs don’t want the same type of antialiasing.

Go read Carl Worth’s blog posts about how the best Xrender (EXA) implementation is still half the speed not using any acceleration. Hundreds of man years have gone into optimizing OpenGL. It will take a lot of effort before EXA implementations are as fast as OpenGL, plus OpenGL is a moving target.

More important to me is does the interface scale from VGA to 3K x 2K screens without the drawing messing up. Read this about scalability.
http://www.antigrain.com/research/font_rasterization/index.html