To use multisampling in your application, select a multisampling-capable visual by calling glXChooseVisual() with the following items in attr_list:
GLX_SAMPLES_SGIS
Must be followed by the minimum number of samples required in multisample buffers.glXChooseVisual() gives preference to visuals with the smallest number of samples that meet or exceed the specified number. Color samples in the multisample buffer may have fewer bits than colors in the main color buffers. However, multisampled colors maintain at least as much color resolution in aggregate as the main color buffers.
GLX_SAMPLE_BUFFERS_SGIS
This attribute is optional. Currently there are no visuals with more than one multisample buffer, so the returned value is either zero or one. When GLX_SAMPLES_SGIS is non-zero, this attribute defaults to 1. When specified, the attribute must be followed by the minimum acceptable number of multisample buffers. Visuals with the smallest number of multisample buffers that meet or exceed this minimum number are preferred.