2005
Sams Publishing
glGetBufferParameteriv
3G

# glGetBufferParameteriv

return parameters of a buffer object

## C Specification

                    void glGetBufferParameteriv
                    GLenum target
                    GLenum value
                    GLint * data

## Parameters

`target`

  Specifies the target buffer object. The symbolic constant must be `GL_ARRAY_BUFFER`, `GL_ELEMENT_ARRAY_BUFFER`, `GL_PIXEL_PACK_BUFFER`, or `GL_PIXEL_UNPACK_BUFFER`.

`value`

  Specifies the symbolic name of a buffer object parameter. Accepted values are `GL_BUFFER_ACCESS`, `GL_BUFFER_MAPPED`, `GL_BUFFER_SIZE`, or `GL_BUFFER_USAGE`.

`data`

  Returns the requested parameter.

## Description

`glGetBufferParameteriv` returns in `data` a selected parameter of the buffer object specified by `target`.

`value` names a specific buffer object parameter, as follows:

`GL_BUFFER_ACCESS`

  `params` returns the access policy set while mapping the buffer object. The initial value is `GL_READ_WRITE`.

`GL_BUFFER_MAPPED`

  `params` returns a flag indicating whether the buffer object is currently mapped. The initial value is `GL_FALSE`.

`GL_BUFFER_SIZE`

  `params` returns the size of the buffer object, measured in bytes. The initial value is 0.

`GL_BUFFER_USAGE`

  `params` returns the buffer object's usage pattern. The initial value is `GL_STATIC_DRAW`.

## Notes

If an error is generated, no change is made to the contents of `data`.

`glGetBufferParameteriv` is available only if the GL version is 1.5 or greater.

Targets `GL_PIXEL_PACK_BUFFER` and `GL_PIXEL_UNPACK_BUFFER` are available only if the GL version is 2.1 or greater.

## Errors

`GL_INVALID_ENUM` is generated if `target` or `value` is not an accepted value.

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

`GL_INVALID_OPERATION` is generated if `glGetBufferParameteriv` is executed between the execution of glBegin and the corresponding execution of glEnd.

## See Also

glBindBuffer, glBufferData, glMapBuffer, glUnmapBuffer

## Copyright

Copyright 2005 Addison-Wesley. 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/.