Re: [Plib-devel] disappearing texture problem

[Steve B. <sjb...@ai...>]

ke...@fl... wrote:
> 
> I've seen the disappearing texture before using a Rage Pro -
> then took the same app to another Mac with a Rage 128, and the
> textures appear.  Just got to have the texture memory on the
> card...

So why do only the alpha textures appear - and how come forcing
them all to be alpha fixes it?

I suppose you could hypothesise that since I render translucent
surfaces after opaque ones (for Z-buffer reasons), the system 
renders the opaque surfaces on the first frame - then the translucent
ones - but since it doesn't have enough texture memory, that
would push the opaque ones out to make room.

THEN, on subsequent frames, the system is too stupid to realise
that the opaque maps are no longer in texture memory and doesn't
reload them - so only the last handful of maps to be rendered
on the first frame are visible subsequently.

So, if that's true - then making all maps have alpha components
(and hence appear to be translucent) would randomize the draw
order - so *perhaps* some OTHER textures are now not being rendered...
but whatever those things are doesn't happen to be so noticable as
the entire terrain AND the hero of the game being missing.

Well, it's an interesting theory.

The way to test it is to get some kind of image processing
program and chop all the texture maps down to (say) 8x8 texels.

Then they should all fit in memory - and even without forcing them
all to have alpha components, you should be able to see every
object in the scene.

Anyway - if that's it then it's CERTAINLY an OpenGL bug that should
be reported.


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