NAME
QueryOverscan -- Inquire about a standard overscan region. (V36)
SYNOPSIS
success = QueryOverscan( DisplayID, Rect, OScanType )
D0 A0 A1 D0
LONG QueryOverscan( ULONG, struct Rectangle *, WORD );
FUNCTION
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.
INPUTS
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).
RESULT
0 (FALSE) if the MonitorSpec your NewScreen requests
does not exist. Non-zero (TRUE) if it does.
BUGS
Change in parameter V36.A17 might cause problems for some.
SEE ALSO
OpenScreen(), Intuition V36 update documentation