On a Intel HD graphics Linux system with Mesa 10.1.3, I found that osg's Extensions::isTextureCompressionS3TCSupported() returned false, even though S3TC compressed textures *are* in fact working. I tested this by loading and rendering various DXT1, DXT3 and DXT5 compressed textures in the OSG.
"glxinfo | grep s3tc" gives:
GL_S3_s3tc
Note, if I install the package "libtxc-dxtn-s2tc0", I get in addition:
glxinfo | grep s3tc
GL_EXT_texture_compression_s3tc
GL_S3_s3tc
However, S3TC compressed textures worked correctly within the OSG even without libtxc-dxtn-s2tc0 installed.
I'm not sure what the differences between these extensions are, but based on the description at https://www.opengl.org/registry/specs/S3/s3tc.txt I would assume that both will work for OSG's purposes. The attached patch changes isTextureCompressionS3TCSupported() to accept either extension."
git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15035 16af8721-9629-0410-8352-f15c8da7e697
2nd - Script to use a 3rd party directory with basic libraries: libjpeg,libpng,libtiff,giflib,freetype,curl,gdal.
3rd - Change in the GLES library loading for Android. That should make GLES2 work properly.
4rth- Included two defines RGB8_OES and RGBA8_OES as a substitute in GLES for RGB8 and RGBA8
5th - OpenGL and GLSL version identification changed to recognize GLES versions properly
"
In osg::isGLExtensionOrVersionSupported in src/osg/GLExtensions.cpp when
using indirect X11 rendering,
glGetIntegerv( GL_NUM_EXTENSIONS, &numExt );
is leaving numExt uninitilized causing the following glGetStringi to
return NULL when the extension number isn't present. Passing NULL to
std::string() then crashes. This is with the following nVidia driver.
OpenGL version string: 3.3.0 NVIDIA 256.35
I went ahead and initialized some of the other variables before
glGetInitegerv in other files as well. I don't know for sure
which ones can fail, so I don't know which are strictly required.
"
changed extensions from .c to .cpp and got compiling as C files as part of the osg core library.
Updated and cleaned up the rest of the OSG to use the new internal GLU.
- compile errors on windows when compiled with UNICODE flag
- warnings for duplicate WIN32_LEAN_AND_MEAN. I think this should
better fixed by adding WIN32_LEAN_AND_MEAN to vcproj preprocessor
list."
The fix is basically as follows:
if( GL3 )
Query indexed extension strings.
else
Query the old way.
The "else" branch is re-indented but otherwise shouldn't contain any changes."
From Robert Osfield, added #if !defined(OSG_GLES1_AVAILABLE) && !defined(OSG_GLES2_AVAILABLE) to new block to prevent it
being compiled under GLES where no glGetStringi exists.
The fix is basically as follows:
if( GL3 )
Query indexed extension strings.
else
Query the old way.
The "else" branch is re-indented but otherwise shouldn't contain any changes."
Removed EXT postfix of FrameBufferObject functions, and added support for checking non EXT versions frame buffer object GL functions.
Introduced usage of OSG_GL*_FEATURES to avoid some #if #else #endif code blocks.
Using a submissions from Paul Martz as a guide added perliminary GL3 support to a range of OSG classes
returns true if (the extension string is supported or GL version is greater than or equal to a specified version) and
non extension disable is used. This makes it possible to disable extensions that are now
available as parts of the core OpenGL spec.
Updated Texture.cpp is use this method.
The fix was to check whether glGetString( GL_VERSION ) returned a null pointer (Ref. svn diff below). The altered src/osg/GLExtensions.cpp is zipped and attached to this email."
pbuffer functions or exactly ask for the extensions we need to call the
apropriate glx extension functions for and around pbuffers extensions.
The glx 1.3 version of this functios are prefered. If this is not pressent we
are looking for the glx extensions and check for them.
Prevously we just used some mix of the glx 1.3 functions or the extension
functions without making sure that this extension is present.
"
dlopen/dlsym instead of NS*Symbol* functions for 10.3 or later. The
latter is now deprecated.
I'm not completely sure how to test the changes. But I compiled these
new changes in and ran the osgvertexprogram and osgshaders examples
and they seemed to display the same results as before.
With respect to the use of dlopen and dlsym, I was uncertain if the
usage should look like Sun or FreeBSD (or something else). Apple's man
pages discourage the use of RTLD_DEFAULT so I avoided the FreeBSD
implementation and copied the Sun implementation. I'm not sure if this
is correct/ideal or not."
