QueryOverscan

Inquire about a standard overscan region. (V36)

This function fills in a rectangle with one of the system overscan dimensions, scaled appropriately for the mode of the DisplayID it is passed.

There are three types of system overscan values:

OSCAN_TEXT

completely visible, by user preference. Used for Workbench screen and screen dimensions STDSCREENWIDTH and STDSCREENHEIGHT. Left/Top is always 0,0.

OSCAN_STANDARD

just beyond visible bounds of monitor, by user preference. Left/Top may be negative.

OSCAN_MAX

The largest region we can display, AND display any smaller region (see note below).

OSCAN_VIDEO

The absolute largest region that the graphics.library can display. This region must be used as-is.

DisplayID

A 32-bit identifier for a display mode, as defined in the graphics/modeid.h include file (V39 and up) or in graphics/displayinfo.h (V37/V38).

NOTE:

If you only intend to use one of the four standard

overscan dimensions as is, and open your screen to exactly the DisplayClip dimensions, you can specify one of the OSCAN_ values using the SA_Overscan tag to the OpenScreenTagList() function and omit all of SA_Left, SA_Top, SA_Width, and SA_Height. This also requires that you do not supply a NewScreen structure, since it always contains left/top/width/height information.

If you wish to supply a NewScreen structure, then you are supplying left/top/width/height information. This information can be taken from the rectangle resulting from this function:

NewScreen.LeftEdge = Rect.MinX; NewScreen.TopEdge = Rect.MinY; NewScreen.Width = STDSCREENWIDTH;

/* or ( Rect.MaxX - Rect.MinX + 1 ) */

NewScreen.Height = STDSCREENHEIGHT;

/* or ( Rect.MaxY - Rect.Miny + 1 ) */

Rect

pointer to a Rectangle structure which this function will fill out with its return values. Note that to convert a rectangle to a screen "Height" you do (MaxY - MinY + 1), and similarly for "Width." The rectangle may be passed directly to OpenScreen() as a DisplayClip region (SA_DClip).

0 (FALSE) if the MonitorSpec your NewScreen requests does not exist. Non-zero (TRUE) if it does.

Change in parameter V36.A17 might cause problems for some.

OpenScreen(), Intuition V36 update documentation