PEXDBTestVisual - Test a Visual for Double Buffering Capability

Synopsis

 
   int PEXDBTestVisual (
       Display *display,
       Drawable drawable,
       VisualID visualid
   )
 

Arguments

display

A pointer to a display structure returned by a successful XOpenDisplay call.

drawable

The ID of a drawable used to identify the screen for which the visual is tested.

visualid

The ID of the visual to test.

Returns

True if the specified visual supports double buffering. False if the specified visual does not support double buffering.

Description

Invoke PEXDBTestVisual to determine if a window created with the given visual supports double buffering through the use of the PEXlib double buffering functions described in PEXlib Access and Information Functions.

You use this function to "pre-screen" a visual prior to specifying it in a PEXMatchRenderingTargets invocation, or you use this function to test visuals returned by PEXMatchRenderingTargets to determine if they can be used for creating windows that are double buffered.

Errors

BadDrawable

The specified drawable is invalid.

See Also

• PEXDBAllocateBackBufferName
• PEXMatchRenderingTargets
• PEXSelectVisual

For an overview, see PEXlib Access and Information Functions.