d3d_lockable

If this variable is set at 1, the frame buffer will be swapped using the D3DSWAPEFFECT_COPY mode. This can reduce the frame rate, but allows rendering into a different target window under C++ by using the hWndTarget and hRectTarget variables.

Range:

0 - don't allow target window (default).
1 - allow target window.

Type:

var, redefine

Example: 

var d3d_lockable = 1; // allow external target window

See also:

hWndTarget