gl4java-usergroup

[gl4java-usergroup] Glitches with GLCanvas

[Thorsten R. <tho...@iv...>]

Hi *,

when using a GLCanvas combined with JPanels in a JFrame I'm getting a
problem:

All JPanels and the GLCanvas are located on the same position. With
<component>.setVisible() I can get the wanted component in front of the
others. When the GLCanvas is visible it's on top till its hidden,
independent of other setVisible() calls. That's OK and works fine!

But when the GLCanvas is shown, before it renders the first frame, the
canvas ist cleared white for a short moment. And when the GLCanvas ist
hidden, the freed space is first cleared with the "Windows-Background-Color"
before the JPanel is repainted.

Solutions like overwriting update() and paint() of JFrame didn't work.

Any other solutions ? Who the hell is clearing the canvas with the
background color ???

regards, Thorsten

[gl4java-usergroup] accumulation buffer

[Thorsten R. <tho...@iv...>]

Hi *,

is it right using the accumulation buffer is really _slow_ ?

Regardless of the value of accum bits set, I've 0,5fps in the accanti demo...
(1GHz, 512Ram, RedHat7.1, GeForce2MX, nvidia-1.0-1251)

I'm trying to use the accum buffer because I need to set an alpha value to a 
fixed display list with glColor's in it. With the accum buffer I should be 
able to add an already rendered display list with any alpha by glAccum 
(GL_ADD, alpha), right ?

Is there a way to set the color (r,g,b) without setting the alpha too ?

regards,

Thorsten Roemer

Re: [gl4java-usergroup] accumulation buffer

[Jiba <a1...@So...>]

Thorsten Roemer wrote:
> 
> Hi *,
> 
> is it right using the accumulation buffer is really _slow_ ?

My own experiments (on a TNT2) show the same thing...

> Regardless of the value of accum bits set, I've 0,5fps in the accanti demo...
> (1GHz, 512Ram, RedHat7.1, GeForce2MX, nvidia-1.0-1251)
> 
> I'm trying to use the accum buffer because I need to set an alpha value to a
> fixed display list with glColor's in it. With the accum buffer I should be
> able to add an already rendered display list with any alpha by glAccum
> (GL_ADD, alpha), right ?
> 
> Is there a way to set the color (r,g,b) without setting the alpha too ?

If I remember, there is an OpenGL extension (maybe not supported by all
card), that allow to add a second alpha value.
I don't remember the name of this extension :-( but OpenGL.org has a doc
that lists all of them; you should look at it.

> regards,
> 
> Thorsten Roemer

Jiba