Optional open state in Uint8Array[0]. Write only 0 (closed)
or 1 (open); the close button writes 0. Null omits the close button.
The native call accesses this writable backing memory directly.
Returns
void
Remarks
create Demo window.
demonstrate most ImGui features.
call this to learn about the library!
try to make it always available in your application!
Show the Dear ImGui demo window.