[osg-users] Please test OpenSceneGraph-3.6 branch in prep for 3.6.1

[Daniel Emminizer, Code 5773]

Hi Terry,

Hey I might know this one.  Thanks for that additional info about your driver.  Do you mind retesting with a change?

See references:

- https://devtalk.nvidia.com/default/topic/971330/opengl/bug-report-crash-in-glcompileshader-if-using-pragma/
- https://software.intel.com/en-us/forums/graphics-driver-bug-reporting/topic/623485
- https://github.com/gwaldron/osgearth/issues/1017
- https://github.com/gwaldron/osgearth/pull/1106
- https://github.com/gwaldron/osgearth/pull/1100

There are some older intel drivers that crash on shaders that include pragmas with too many "arguments".  The spec says that pragmas should be ignored.  But testing demonstrates severe problems with several intel drivers over a few years' period where lines like:

#pragma import_defines( BACKDROP_COLOR, SHADOW, OUTLINE, SIGNED_DISTANCE_FIELD, TEXTURE_DIMENSION, GLYPH_DIMENSION)

... could cause a failure.  Breaking it up into separate lines of no more than 2 arguments each works.

We found that the magic number for drivers is 3 -- once you get over 3 parameters, it starts to break (depending on driver version).  Could you try to edit your text.frag file to change:

#pragma import_defines( BACKDROP_COLOR, SHADOW, OUTLINE, SIGNED_DISTANCE_FIELD, TEXTURE_DIMENSION, GLYPH_DIMENSION)

To:

#pragma import_defines( BACKDROP_COLOR, SHADOW, OUTLINE)
#pragma import_defines( SIGNED_DISTANCE_FIELD, TEXTURE_DIMENSION, GLYPH_DIMENSION)

This breaks it into 2 lines of 3 params each.  If it's the same bug that we encountered, this might fixyour problem.

Robert, I haven't reported this because we haven't explicitly ran into this same problem with 3.6 and text shaders yet, because we haven't run on those drivers.  Newer drivers do fix the issue.

 - Dan


-----Original Message-----
From: osg-users [mailto:osg-users-bounces at lists.openscenegraph.org] On Behalf Of Terry Welsh
Sent: Wednesday, April 25, 2018 11:10 AM
To: osg-users at lists.openscenegraph.org
Subject: Re: [osg-users] Please test OpenSceneGraph-3.6 branch in prep for 3.6.1

Looks like I had a graphics driver problem. Originally, I didn't think
that was the problem because the computer I'm working on has dual
graphics and it was crashing in Intel graphics mode and AMD graphics
mode. As it turns out, my dual graphics was broken and running Intel
graphics the whole time.

Now that's fixed and both drivers are broken, but at least they're
broken in different ways :P Sorry for the false alarm.
- Terry

P.S. Buy NVidia graphics.