static void DrawCallback(IntPtr voidptr, IntPtr cgcontextptr)
{
GCHandle gch = GCHandle.FromIntPtr(voidptr);
CGPattern container = (CGPattern)gch.Target;
CGContext ctx = null;
if (cgcontextptr == container.last_cgcontext_ptr)
{
ctx = container.last_cgcontext.Target as CGContext;
}
if (ctx == null)
{
ctx = new CGContext(cgcontextptr);
container.last_cgcontext = new WeakReference(ctx);
container.last_cgcontext_ptr = cgcontextptr;
}
container.draw_pattern(ctx);
}
