glGetBufferPointerv — return the pointer to a mapped buffer object's data store
void glGetBufferPointerv( | GLenum target, | 
| GLenum pname, | |
GLvoid ** params); | 
target
                    Specifies the target buffer object.
                    The symbolic constant must be
                    GL_ARRAY_BUFFER,
                    GL_ATOMIC_COUNTER_BUFFER,
                    GL_COPY_READ_BUFFER,
                    GL_COPY_WRITE_BUFFER,
                    GL_DRAW_INDIRECT_BUFFER,
                    GL_DISPATCH_INDIRECT_BUFFER,
                    GL_ELEMENT_ARRAY_BUFFER,
                    GL_PIXEL_PACK_BUFFER,
                    GL_PIXEL_UNPACK_BUFFER,
                    GL_QUERY_BUFFER,
                    GL_SHADER_STORAGE_BUFFER,
                    GL_TEXTURE_BUFFER,
                    GL_TRANSFORM_FEEDBACK_BUFFER, or
                    GL_UNIFORM_BUFFER.
                
pname
                    Specifies the pointer to be returned.  The symbolic constant must be GL_BUFFER_MAP_POINTER.
                
params
                    Returns the pointer value specified by pname.
                
            glGetBufferPointerv returns pointer information. pname is a symbolic constant
            indicating the pointer to be returned, which must be GL_BUFFER_MAP_POINTER, the pointer
            to which the buffer object's data store is mapped.  If the data store is not currently mapped, NULL is returned.
            params is a pointer to a location in which to place the returned pointer value.
        
            If an error is generated,
            no change is made to the contents of params.
        
            The initial value for the pointer is NULL.
        
            The GL_ATOMIC_COUNTER_BUFER target is available only if the GL version is 4.2 or greater.
        
            The GL_DISPATCH_INDIRECT_BUFFER and GL_SHADER_STORAGE_BUFFER targets are available only if the GL version is 4.3 or greater.
        
            The GL_QUERY_BUFFER target is available only if the GL version is 4.4 or greater.
        
            GL_INVALID_ENUM is generated if target or pname is not an
            accepted value.
        
            GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.
        
Copyright © 2005 Addison-Wesley. Copyright © 2011-2013 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.