clip_indicator(3G)

NAME

clip_indicator − enable/disable clipping to clip rectangle and virtual device coordinate extent

SYNOPSIS

C Syntax:

void clip_indicator ( fildes, clip_level )
int fildes, clip_level;

FORTRAN77 Syntax:

subroutine clip_indicator ( fildes, clip_level )
integer*4 fildes, clip_level

Pascal Syntax:

procedure clip_indicator ( fildes, clip_level:integer );

DESCRIPTION

Input Parameters

fildes Integer file descriptor returned by gopen when the I/O path to the output graphic device is opened.

clip_level Determines whether clipping to clip_rectangle (CLIP_TO_RECT), virtual device coordinate extent (CLIP_TO_VDC), viewport (CLIP_TO_VIEWPORT), or not at all (CLIP_OFF).

Discussion

The clip_level parameter can be one of the following:

CLIP_OFF Disable clipping of output primitives. Warning: with clipping disabled, attempts to draw outside the bounds of the current display surface (window) may produce unpredictable behavior. Such drawing may produce device-dependent wraparound, errors, reduce the X server’s response time for input events, or even cause the X server to become inoperable.

CLIP_TO_RECT Clipping is performed to the intersection of clip rectangle and virtual device coordinate extent.

CLIP_TO_VDC Clipping is performed to the virtual device coordinate extent boundary.

CLIP_TO_VIEWPORT Clipping is performed to the current viewport area.

CLIP_OFF should only be used when the output primitives are known to be within the currently specified clip area. By disabling clip operations − i.e., setting clip_indicator to CLIP_OFF − you may see an improvement in performance on some output devices. (This is not guaranteed, since some drivers and/or devices support highly efficient clipping operations.)

DEFAULTS

clip_level = CLIP_TO_RECT

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