display-sub(7)

NAME
display-sub : Make a child visual that is a window to the parent

SYNOPSIS
display-sub: <target-spec>

DESCRIPTION
Creates a "child" visual within a "parent". This can be thought of as a window and the display-sub target is intended for simple windowing systems. No textual arguments, since this target can only be used by applications. argptr must contain the parent visual. The sub target behaves a bit special with respect to (i.e. abuses the semantics of :) the ggiSetMode(3) call. It uses the "visible" size for the top left corner position of the window within the visual, and the "virtual" size for window width and height. Note, that moving/resizing the window does not cause any drawing action. You have to perform those yourself. All it does for you is providing a virtual visual within an existing one, which is convenient to allow for window system canvases to be about any GGI program.
    Important: It is possible to have (0, 0) as upper, left corner. But beware, 0 means GGI_AUTO and therefore it may get overridden by GGI_DEFMODE environment variable. In this case, you may get unintended results.

OPTIONS

target-spec
    Specifies the target which to draw on (the parent target). This defaults to automatic selection (just like using ggiOpen(NULL) when GGI_DISPLAY is not set).

FEATURES

•   DirectBuffer not supported.

•   Accelerated to the point of the parent. Calls are mapped through with modified clipping and coordinates.