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."
in osg::Program::PerContextProgram :
typedef std::vector<UniformModifiedCountPair> LastAppliedUniformList;
should be
typedef std::map<unsigned int, UniformModifiedCountPair> LastAppliedUniformList;
Intel driver can use index uniform value > 200000.
With a std::vector, this index uniform value generate an out of memory error
Nothing in OpenGL or GLSL specification define index uniform value rules.
And all other implementation that deal with uniform index in osg::Program
use a std::map.
This fix could have a little performance impact but this is the cost
to pay to work with
all driver."
I see that we should expect some performance penalty for using this method. It won’t be painful in my current case because I have only a few animated characters. But I suspect some day I will have to fix osgCal to use int UniformIds natively for larger crowds."
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.
- 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
"
Note, this required adding a unsigned int context ID to the osg::isGLUExtensionSupported(,)
and osg::isGLExtensionSupported(,) functions. This may require reimplementation
of end user code to accomodate the new calling convention.
"updates for GLSL core integration:
Code compiles and runs on win32.
Basic functionality of Program and Shader in place.
Program derived from StateAttribute.
Uniform value propagation is not yet functional (in development)
Includes some patches by Nathan Cournia.
includes example testcase to demo use of new classes."
