Thank you very much!<br><br><div class="gmail_quote">On Thu, Jun 4, 2009 at 2:25 PM, <span dir="ltr"><<a href="mailto:kate.alhola@nokia.com">kate.alhola@nokia.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
________________________________________<br>
<div class="im">>From: <a href="mailto:maemo-developers-bounces@maemo.org">maemo-developers-bounces@maemo.org</a> [<a href="mailto:maemo-developers-bounces@maemo.org">maemo-developers-bounces@maemo.org</a>] On Behalf Of ext Qole [<a href="mailto:qole.tablet@gmail.com">qole.tablet@gmail.com</a>]<br>
</div>>Sent: Thursday, June 04, 2009 9:47 PM<br>
>To: maemo-dev<br>
>Subject: Re: Fremantle OpenGL wrapper?<br>
<div class="im">><br>
>I hoped to start a discussion about making an OpenGL -> GL ES 2 translation library for porting games to Maemo 5, in the manner that is being done in the Pandora community.<br>
<br>
</div>I have been having several presentations to maemo community how to use OpenGL-ES in maemo<br>
You can find them from my blog <a href="http://blogs.forum.nokia.com/blog/kate-alholas-forum-nokia-blog" target="_blank">http://blogs.forum.nokia.com/blog/kate-alholas-forum-nokia-blog</a><br>
It is ot so much question of transition libraries but understanding what is OpenGL-ES and<br>
how it relates to desktop OpenGL<br>
<br>
I checked openpandora wiki <a href="http://pandorawiki.org/Development_tutorials" target="_blank">http://pandorawiki.org/Development_tutorials</a> . It looks a like<br>
they are having very similar approach, no silver bullet OpenGL to OpenGL-ES translation library<br>
but just OpenGL-ES1.1 tutorial and example how to use OpenGL-ES with SDL.<br>
I have had my tutorials about how to use OpenGL-ES2.0 and how to use it with Qt .<br>
<br>
If you read <a href="http://pandorawiki.org/OpenGL_ES_1.1_Tutorial" target="_blank">http://pandorawiki.org/OpenGL_ES_1.1_Tutorial</a> . It tells a lot what is<br>
the qestion. There is just no single "OpenGL" but desktop OpenGL has many, many<br>
legacy layers of API's . Mobile OpenGL implements only the most efficient subset of them.<br>
Because there is hundreds of ways to use OpenGL, there is no simple way to convert.<br>
<br>
The Openpandora OpenGL-ES1.1 wiki tries to explain ( as i had in my presentations/blog and maemo wiki page )<br>
that as example OpenGL has legacy API glBegin/glVertex/gEnd that are obsoleted in OpenGL-ES<br>
and OpenGL-ES only supports way to pass vertexes as array. Of course passing them as array is much<br>
more efficient, just one API call with big number of vertexes as opposed one call for one coordinate point.<br>
That just an example what is the difference.<br>
<br>
For game developer it is much more sense port the application to use vertex arrays because it is<br>
more efficient also in desktop.<br>
<br>
When we go to OpenGL-ES2.0 or Desktop OpenGL-2.0, we have thing called programmable shaders.<br>
OpenGL1.x or OpenGL-ES1.x has fixed function non programmable pipeline doing transformations and lighting.<br>
In OpenGL-(ES)2.0 it is all programmable and it offers much more features to make much better<br>
looking games. I strongly recommend to take it in use.<br>
<br>
If you still would like use fixed function pipeline to port old not so advanced games, you can<br>
still use OpenGL-ES1.x emulation libraries in maemo. I hope that we can get them in to next<br>
SDK release.<br>
<br>
<br>
Kate<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>enthusiast, n. "One whose mind is wholly possessed and heated by what engages it; one who is influenced by a peculiar fervor of mind; an ardent and imaginative person."<br>