glUnmapBuffer

glUnmapBuffer: man4/glUnmapBuffer.xml

glUnmapBuffer and glUnmapNamedBuffer unmap (release) any mapping of a specified buffer object into the client's address space (see glMapBufferRange and glMapBuffer ). If a mapping is not unmapped before the corresponding buffer object's data store is used by the GL, an error will be generated by any GL command that attempts to dereference the buffer object's data store, unless the buffer was successfully mapped with GL_MAP_PERSISTENT_BIT (see glMapBufferRange ). When a data store is unmapped, the mapped pointer becomes invalid. glUnmapBuffer returns GL_TRUE unless the data store contents have become corrupt during the time the data store was mapped. This can occur for system-specific reasons that affect the availability of graphics memory, such as screen mode changes. In such situations, GL_FALSE is returned and the data store contents are undefined. An application must detect this rare condition and reinitialize the data store. A buffer object's mapped data store is automatically unmapped when the buffer object is deleted or its data store is recreated with glBufferData ).

If an error is generated, glUnmapBuffer returns GL_FALSE. The GL_ATOMIC_COUNTER_BUFFER target is accepted 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.