Graphics Reference
In-Depth Information
(continued)
GL_MAP_INVALIDATE_BUFFER_BIT
Indicates that the contents
of the entire buffer can be
discarded by the driver before
returning the pointer. This flag
can only be used in combination
with
GL_MAP_READ_BIT
.
GL_MAP_FLUSH_EXPLICIT_BIT
Indicates that the application
will explicitly flush
operations to subranges of
the mapped range using
glFlushMappedBufferRange
.
This flag cannot be used
in combination with
GL_MAP_WRITE_BIT
.
GL_MAP_UNSYNCHRONIZED_BIT
Indicates that the driver does
not need to wait for pending
operations on the buffer object
before returning a pointer to
the buffer range. If there are
pending operations, the results
of outstanding operations and
any future operations on the
buffer object become undefined.
glMapBufferRange
returns a pointer to the buffer data storage range
requested. If an error occurs or an invalid request is made, the function
will return
NULL
. The
glUnmapBuffer
command unmaps a previously
mapped buffer.
GLboolean
glUnmapBuffer
(GLenum
target
)
target
must be set to
GL_ARRAY_BUFFER
glUnmapBuffer
returns
GL_TRUE
if the unmap operation is successful.
The pointer returned by
glMapBufferRange
can no longer be used after
a successful unmap has been performed.
glUnmapBuffer
returns
GL_FALSE
if the data in the vertex buffer object's data storage have become
corrupted after the buffer has been mapped. This can occur due to a change
