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From Tim Moore, "Here is initial support for uniform buffer objects. The binding between a buffer object and an indexed target is implemented as a new StateAttribute, UniformBufferBinding. I've included an example program based on the code in the ARB_uniform_buffer_object specification.

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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."
This commit is contained in:
Robert Osfield
2010-11-29 17:43:27 +00:00
parent 0739c15e0a
commit e5a9eaa711
13 changed files with 789 additions and 3 deletions
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28
include/osg/Program
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@@ -113,11 +113,22 @@ class OSG_EXPORT Program : public osg::StateAttribute
/** Remove an frag data location binding. */
void removeBindFragDataLocation( const std::string& name );
/** Add a uniform block binding to an index target. XXX This
* should not be an attribute of the program. It should be a
* pseudo-uniform that can live in StateSet objects because
* it is cheap to set. */
void addBindUniformBlock(const std::string& name, GLuint index);
/** Remove a uniform block binding. */
void removeBindUniformBlock(const std::string& name);
typedef std::map<std::string,GLuint> AttribBindingList;
typedef std::map<std::string,GLuint> FragDataBindingList;
typedef std::map<std::string,GLuint> UniformBlockBindingList;
const AttribBindingList& getAttribBindingList() const { return _attribBindingList; }
const FragDataBindingList& getFragDataBindingList() const { return _fragDataBindingList; }
const UniformBlockBindingList& getUniformBlockBindingList() const { return _uniformBlockBindingList; }
/** Return true if this Program represents "fixed-functionality" rendering */
bool isFixedFunction() const;
@@ -151,7 +162,18 @@ class OSG_EXPORT Program : public osg::StateAttribute
typedef std::map< std::string, ActiveVarInfo > ActiveVarInfoMap;
const ActiveUniformMap& getActiveUniforms(unsigned int contextID) const;
const ActiveVarInfoMap& getActiveAttribs(unsigned int contextID) const;
struct UniformBlockInfo
{
UniformBlockInfo() : _index(GL_INVALID_INDEX), _size(0) {}
UniformBlockInfo(GLuint index, GLsizei size)
: _index(index), _size(size)
{
}
GLuint _index;
GLsizei _size;
};
typedef std::map<std::string, UniformBlockInfo> UniformBlockMap;
const UniformBlockMap& getUniformBlocks(unsigned contextID) const;
public:
// make PerContextProgram a friend to allow it access Program's protected
@@ -214,7 +236,7 @@ class OSG_EXPORT Program : public osg::StateAttribute
const ActiveUniformMap& getActiveUniforms() const {return _uniformInfoMap;}
const ActiveVarInfoMap& getActiveAttribs() const {return _attribInfoMap;}
const UniformBlockMap& getUniformBlocks() const {return _uniformBlockMap; }
inline GLint getUniformLocation( unsigned int uniformNameID ) const { ActiveUniformMap::const_iterator itr = _uniformInfoMap.find(uniformNameID); return (itr!=_uniformInfoMap.end()) ? itr->second._location : -1; }
inline GLint getAttribLocation( const std::string& name ) const { ActiveVarInfoMap::const_iterator itr = _attribInfoMap.find(name); return (itr!=_attribInfoMap.end()) ? itr->second._location : -1; }
@@ -246,6 +268,7 @@ class OSG_EXPORT Program : public osg::StateAttribute
ActiveUniformMap _uniformInfoMap;
ActiveVarInfoMap _attribInfoMap;
UniformBlockMap _uniformBlockMap;
typedef std::pair<osg::ref_ptr<const osg::Uniform>, unsigned int> UniformModifiedCountPair;
typedef std::vector<UniformModifiedCountPair> LastAppliedUniformList;
@@ -272,6 +295,7 @@ class OSG_EXPORT Program : public osg::StateAttribute
mutable osg::buffered_value< osg::ref_ptr<PerContextProgram> > _pcpList;
AttribBindingList _attribBindingList;
FragDataBindingList _fragDataBindingList;
UniformBlockBindingList _uniformBlockBindingList;
typedef std::vector< ref_ptr<Shader> > ShaderList;
ShaderList _shaderList;