rota and alphaglue shaders

Jan 9, 2007 at 9:23am

rota and alphaglue shaders

I’m having trouble with both the alphaglue and rota shaders. Just installed the 1.63beta on XP and still have the same issues. I’m using a mobility 9800 on a Dell Inspiron 9100. There are some alternate versions of the shaders in question that have been posted. So, before I try and troubleshoot further, could someone please mail me any alternate/fix versions of the shaders at the following mail (minus the ?)
shader@?killingfrenzy.?com

Once I get the two shaders working, I’ll be trying to roll my own version combining the two, so any insight into the peculiarities that would make the rota shader or the alphaglue shader finicky on this system or others would be good to know.

#29570
Jan 9, 2007 at 4:46pm

What version of Jitter do you use? There have been a couple versions of
the rota shader since we first started including it. The big hangup
with this shader is the “boundmode” logic. If you don’t need all the
different boundmodes, the shader is actually pretty lightweight. You
might search the forum archives, as there are a couple of alternate
versions posted.

On the alphaglue shader, I think there may be a problem with the array
notation that I use to select the alpha channel on some cards. If you
don’t need to switch which plane is used as alpha, the shader would look
something like this:

vec4 in1 = texture2DRect(tex0, texcoord0);
vec4 in2 = texture2DRect(tex1, texcoord1);

gl_FragColor = vec4 (in1.rgb,in2.a);

Totally simple.

Note that all the luminance calculation and the smoothstep() function is
unnecessary unless you need to apply a threshold to the alpha channel
and/or use the lum2alpha capability.

#92790
Jan 10, 2007 at 8:39am

Thanks for the advice on the alphaglue, I think I can run with that.

I’m now using Jitter 1.63b and the included rota.jxs
I’ve also tried the attachement on the forums that is listed as rota4.jxs

I think most of the forum postings don’t retain proper formatting, so that’s why I was hoping for an email of some of the previous rota variations, since I don’t trust forum cut and paste at this point.

I’ll try and search through and see if there is a posted rota2 or rota3 that maintain formatting.

#92791
Jan 11, 2007 at 10:51am

Well, in a fit of frustration I decided to ditch the “safe” recommended drivers supplied by Dell, which are about 2 years old, and apply the Omega drivers, which are a modified version of the ATI supplied Catalyst drivers which actually work on my Mobility Radeon 9800.
Now all the various shaders work.
So, I wouldn’t normally recommend non-standard drivers… but, if the standard drivers are going to be so pathetically out of date, I suppose this is a case where it becomes necessary.

Summation
Applying latest “Omega” drivers will enable proper shader behavior on a Mobility Radeon 9800 under Win/XP on a Dell Inspiron 9100 Laptop.

#92792
Jan 11, 2007 at 5:28pm

On Jan 11, 2007, at 2:51 AM, Leo Mayberry wrote:

>
> Well, in a fit of frustration I decided to ditch the “safe”
> recommended drivers supplied by Dell, which are about 2 years old,
> and apply the Omega drivers, which are a modified version of the
> ATI supplied Catalyst drivers which actually work on my Mobility
> Radeon 9800.
> Now all the various shaders work.
> So, I wouldn’t normally recommend non-standard drivers… but, if
> the standard drivers are going to be so pathetically out of date, I
> suppose this is a case where it becomes necessary.

Yes, laptop manufacturer supplied drivers are unfortunately often
outdated or problematic with no hope of the vendor updating them.
It’s actually pretty embarrassing for the HW vendors that things like
Omega drivers are often required for people to effectively use the
hardware they paid for, with the current software drivers they are
not allowed access to. Now, some of the Graphics card manufacturers
are becoming more liberal about providing driver updates for laptop
graphics cards, but it’s mostly for the newer machines, and even then
not for all vendors.

I hate recommending these unoffical drivers too, but I suppose I hate
the restrictive driver policies of these vendors even more.

Glad to hear you got things working!

-Joshua

#92793

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