false negatives (errors) about missing buffers, etc..
From the internet https://stackoverflow.com/questions/15335510/opengl-glvalidateprogram-error-on-mac-os-x :
« […] The purpose of glValidateProgram is not to use it as an added "check" step after linking the program, because the GL and application state is hardly ready for actually using that program at this point, probably it's even before we get around to initializing the default framebuffer (its bitdepth, its multisample buffers, etc), and that's what the error hints at.
An appropriate place to call glValidateProgram would be right before you make a real render call. »
This approach unifies much of the code handling the clean up of OpenGL graphics data, avoids lots of local mutexes and static variables that were previously required,
and enables the clean up scheme to be easily extended by users providing their own GraphicsObjectManager subclasses.
git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15130 16af8721-9629-0410-8352-f15c8da7e697
But for glPrograms, in order to get all osg's uniform management system to work, I had to subclass osg::program::PerContextProgram.
Here is a modified version of this class, which add some "virtual" method to allow easy subclassing."
- add non square matrix
- add double
- add all uniform type available in OpenGL 4.2
- backward compatibility for Matrixd to set/get an float uniform matrix
- update of IVE / Wrapper ReadWriter
implementation of AtomicCounterBuffer based on BufferIndexBinding
add example that use AtomicCounterBuffer and show rendering order of fragments,
original idea from geeks3d.com."
A few things remain to do:
* The binding between a uniform block in a shader program and a buffer indexed target number is fixed, like a vertex attribute binding. This is too restrictive because that binding can be changed without relinking the program. This mapping should be done by name in the same way that uniform values are handled i.e., like a pseudo state attribute;
* There's no direct way yet to query for the offset of uniforms in uniform block, so only the std140 layout is really usable. A helper class that implemented the std140 rules would be quite helpful for setting up uniform blocks without having to link a program first;
* There's no direct support for querying parameters such as the maximum block length, minimum offset alignment, etc. Having that information available outside of the draw thread would make certain instancing techniques easier to implement."
Added support for automatic aliasing of vertex, normal, color etc. arrays to Vertex Attribute equivelants.
Added new osg::GLBeginEndAdapter class for runtime conversion from glBegin/glEnd codes to vertex arrray equivelants.
Added automatic shader source conversion from gl_ to osg_ builtins.
-Added copying of shaders and attributes in osg::Program copy constructor.
-Changed StateSet::compare function to compare Uniforms and their
override values. Previously it compared a RefUniformPair."
- GL2Extensions, Program and Program.cpp
Features:
- Support for fragment output binding. (e.g. You can now specify in the fragment shader varying out vec3 fragOut; fragOut = vec3(1,0,1); to write to the fragOut variable. In your program you call glBindFragDataLocation(program, 1, "fragOut") to bind the fragOut variable with the MRT 1 - GL_COLOR_ATTACHMENT1_EXT)
- new methods Program::add/removeBindFragDataLocation Program::getFragDataBindingList
"
