/// <summary>
/// Get the <see cref="Glx.XVisualInfo"/> set on the specified X window.
/// </summary>
/// <param name="xWindow">
/// The <see cref="IntPtr"/> that specifies the handle of the X window.
/// </param>
/// <returns>
/// It returns the <see cref="Glx.XVisualInfo"/> set on <paramref name="xWindow"/>.
/// </returns>
private Glx.XVisualInfo GetVisualInfoFromXWindow(IntPtr xWindow)
{
Glx.XVisualInfo xVisualInfo;
uint[] windowFBConfigId = new uint[1];
int screen = Glx.XDefaultScreen(_Display);
// Get the FB configuration associated to the native window
Glx.QueryDrawable(_Display, _WindowHandle, Glx.FBCONFIG_ID, windowFBConfigId);
if (windowFBConfigId[0] == 0)
{
KhronosApi.LogComment("Glx.QueryDrawable cannot query Glx.FBCONFIG_ID. Query manually.");
return(NativeWindow._InternalVisual);
}
unsafe {
int[] attributes = new int[] {
Glx.FBCONFIG_ID, (int)windowFBConfigId[0],
0,
};
int[] choosenConfigCount = new int[1];
IntPtr *choosenConfigs = Glx.ChooseFBConfig(_Display, screen, attributes, choosenConfigCount);
if (choosenConfigCount[0] == 0)
{
throw new InvalidOperationException("unable to find X Window visual configuration");
}
IntPtr configId = *choosenConfigs;
xVisualInfo = Glx.GetVisualFromFBConfig(_Display, configId);
Glx.XFree((IntPtr)choosenConfigs);
}
return(xVisualInfo);
}