From: Isabelle Lafon (isabelle++at++discreet.com)
Date: 10/23/2001 11:34:21
Hi,
Do I miss something about the pfGeoState::apply and pfTexture::apply
behaviour or is this a Performer Bug ?
Perhaps someone can explain me what exactly pfTexture::apply does or
does not in that case ?
I'm using the multiProcess mode PFMP_APPCULLDRAW | PFMP_CULL_DL_DRAW.
and I am drawing bins.
I have an object with a pfGeoState on it. The pfGeoState has a
pfTexture set on it and texture mode on. The pfTexture image pointer
is null at the beginning (we use image subloading). There is a preFunc
method on the pfGeoState in which the pfTexture::setLoadImage followed
by the pfTexture::load is done, if required (if we have a new image
buffer ready to use).
It happens that the GL_TEXTURE_2D state is still enable at the end of
the first frame draw even the pfState says that texture is disable.
I was expected that the GL_TEXTURE_2D state would be DISABLE and so
coherent with pfState current value.
Note that I do a pfFlushState at the end of the frame draw.
First frame:
===========
- pfGeoState::apply. Perhaps pfTexture::apply doesn't do much here
because the image pointer is null. But GL_TEXTURE_2D is enable. That
seems OK since the texture mode is on in my pfGeoState.
- pfGeoState::preFunc: the image buffer is set on the pfTexture and
the pfTexture::load call is issued.
- Then the object is drawn.
- End of the frame draw: pfFlushState is called. GL_TEXTURE_2D on!
- SwapBuffer: Object is visible with the texture image.
When performer draw an object with a pfGeoState attach to it, he is
doing some pfPushState before applying the pfGeoState and some
pfPopState after drawing the object. I can see that in the pfState
stack. But at the end of this first frame draw, pfState says texture is
disable but GL_TEXTURE_2D is still enable. WHY ?
Second frame:
============
Now that there is an image pointer and that the texture has been
loaded, I suppose that pfGeoState::apply do a bit more when it applies
the texture. In the pfGeoState preFunc nothing is done on the
texture. And at the end of the frame draw pfState and OpenGL agree
that texture is disable.
First frame - explicit pfTexture::apply call:
=============================================
NOW, If I add a pfTexture::apply call in the pfGeoState preFunc, the
GL_TEXTURE_2D state is disable at the end of the first frame draw,
which is what I was expected in the first place.
Why do I need this second call to pfTexture::apply?
-- Isabelle Lafon Discreet Logic Tel: (514) 954-7157 10 Duke Fax: (514) 393-0110 Montreal (Quebec) isabelle++at++discreet.com Canada, H3C 2L7
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