NAME

       glBufferStorage - creates and initializes a buffer object's immutable data store

C SPECIFICATION

       void glBufferStorage(GLenum target, GLsizeiptr size, const GLvoid * data,
                            GLbitfield flags);

PARAMETERS

       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.

       size
           Specifies the size in bytes of the buffer object's new data store.

       data
           Specifies a pointer to data that will be copied into the data store for
           initialization, or NULL if no data is to be copied.

       flags
           Specifies the intended usage of the buffer's data store. Must be a bitwise combination
           of the following flags.  GL_DYNAMIC_STORAGE_BIT, GL_MAP_READ_BITGL_MAP_WRITE_BIT,
           GL_MAP_PERSISTENT_BIT, GL_MAP_COHERENT_BIT, and GL_CLIENT_STORAGE_BIT.

DESCRIPTION

       glBufferStorage creates a new immutable data store for the buffer object currently bound
       to target. The size of the data store is specified by size. If an initial data is
       available, its address may be supplied in data. Otherwise, to create an uninitialized data
       store, data should be NULL.

       The flags parameters specifies the intended usage of the buffer's data store. It must be a
       bitwise combination of a subset of the following flags:

       GL_DYNAMIC_STORAGE_BIT
           The contents of the data store may be updated after creation through calls to
           glBufferSubData(). If this bit is not set, the buffer content may not be directly
           updated by the client. The data argument may be used to specify the initial content of
           the buffer's data store regardless of the presence of the GL_DYNAMIC_STORAGE_BIT.
           Regardless of the presence of this bit, buffers may always be updated with server-side
           calls such as glCopyBufferSubData() and glClearBufferSubData().

       GL_MAP_READ_BIT
           The data store may be mapped by the client for read access and a pointer in the
           client's address space obtained that may be read from.

       GL_MAP_WRITE_BIT
           The data store may be mapped by the client for write access and a pointer in the
           client's address space obtained that may be written through.

       GL_MAP_PERSISTENT_BIT
           The client may request that the server read from or write to the buffer while it is
           mapped. The client's pointer to the data store remains valid so long as the data store
           is mapped, even during execution of drawing or dispatch commands.

       GL_MAP_COHERENT_BIT
           Shared access to buffers that are simultaneously mapped for client access and are used
           by the server will be coherent, so long as that mapping is performed using
           glMapBufferRange(). That is, data written to the store by either the client or server
           will be immediately visible to the other with no further action taken by the
           application. In particular,

           •   If GL_MAP_COHERENT_BIT is not set and the client performs a write followed by a
               call to the glMemoryBarrier() command with the GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT
               set, then in subsequent commands the server will see the writes.

           •   If GL_MAP_COHERENT_BIT is set and the client performs a write, then in subsequent
               commands the server will see the writes.

           •   If GL_MAP_COHERENT_BIT is not set and the server performs a write, the application
               must call glMemoryBarrier() with the GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT set and
               then call glFenceSync() with GL_SYNC_GPU_COMMANDS_COMPLETE (or glFinish). Then the
               CPU will see the writes after the sync is complete.

           •   If GL_MAP_COHERENT_BIT is set and the server does a write, the app must call
               FenceSync with GL_SYNC_GPU_COMMANDS_COMPLETE (or glFinish()). Then the CPU will
               see the writes after the sync is complete.

       GL_CLIENT_STORAGE_BIT
            When all other criteria for the buffer storage allocation
                               are met, this bit may be used by an implementation to determine
           whether to use storage that is local to the
                               server or to the client to serve as the backing store for the
           buffer.
                           .RE

           The allowed combinations of flags are subject to certain restrictions. They are as
           follows:

           •   If flags contains GL_MAP_PERSISTENT_BIT, it must also contain at least one of
               GL_MAP_READ_BIT or GL_MAP_WRITE_BIT.

           •   If flags contains GL_MAP_COHERENT_BIT, it must also contain GL_MAP_PERSISTENT_BIT.

NOTES

       glBufferStorage is available only if the GL version is 4.4 or greater.

       If data is NULL, a data store of the specified size is still created, but its contents
       remain uninitialized and thus undefined.

ERRORS

       GL_INVALID_ENUM is generated if target is not one of the accepted buffer targets.

       GL_INVALID_VALUE is generated if size is less than or equal to zero.

       GL_INVALID_OPERATION is generated if the reserved buffer object name 0 is bound to target.

       GL_OUT_OF_MEMORY is generated if the GL is unable to create a data store with the
       properties requested in flags.

       GL_INVALID_VALUE is generated if flags has any bits set other than those defined above.

       GL_INVALID_VALUE error is generated if flags contains GL_MAP_PERSISTENT_BIT but does not
       contain at least one of GL_MAP_READ_BIT or GL_MAP_WRITE_BIT.

       GL_INVALID_VALUE is generated if flags contains GL_MAP_COHERENT_BIT, but does not also
       contain GL_MAP_PERSISTENT_BIT.

       GL_INVALID_OPERATION is generated if the GL_BUFFER_IMMUTABLE_STORAGE flag of the buffer
       bound to target is GL_TRUE.

ASSOCIATED GETS

       glGetBufferSubData()

       glGetBufferParameter() with argument GL_BUFFER_SIZE or GL_BUFFER_USAGE

SEE ALSO

       glBindBuffer(), glBufferSubData(), glMapBuffer(), glUnmapBuffer()

COPYRIGHT

       Copyright © 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/.

AUTHORS

       opengl.org