set_cull_size(3G)

NAME

set_cull_size − define a threshold cull size for setting the value of the cull condition

SYNOPSIS

C Syntax:

void set_cull_size(fildes, cull_size)
int fildes;
float cull_size;

FORTRAN77 Syntax:

subroutine set_cull_size(fildes, cull_size)
integer*4 fildes
real cull_size

Pascal Syntax:

procedure set_cull_size(fildes:integer;cull_size:real)

DESCRIPTION

Input Parameters

fildes Integer file descriptor returned by gopen when an I/O path to a graphics device is opened.

cull_size New value of the cull size in Device Coordinates.

Discussion

Set_cull_size sets the current cull size to the value of cull_size. Set_extent compares this cull size against a diagonal length to set the cull condition value. Set_extent calculates this length by projecting the bounding box of an extent onto the XY Device Coordinate plane and measuring the diagonal of the resulting rectangle. It sets the cull condition value TRUE if the diagonal length is less than the current cull size and sets it FALSE otherwise. As the diagonal length is an approximate measure of the area the objects described by the extent occupy on the screen, increasing the current cull size will generally cause the cull condition value to be set TRUE more often during display list traversal. This in turn will cause cond_call_segment, cond_execute_segment and cond_return to traverse paths containing less detailed representations. On the other hand, decreasing the current cull size will generally result in traversal following paths showing more detail.

ERRORS

1 Graphics device is not initialized for this operation.

DEFAULTS

The cull size is set to 0.0 when a device is opened.

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