VIEWPORT

Finds coordinates of the viewport associated with a transformation number

Operating state:

GKOP, SGOP, WSAC, WSOP

Syntax

Details

Syntax

CALL GASK('VIEWPORT', n, llx, lly, urx, ury, return-code-variable);

Required Arguments

n: numeric constant or numeric variable name; indicates the transformation number assigned to the viewport to check. Valid values are 0 to 20, inclusive. If n is expressed as a variable, the variable must be initialized to a value between 0 and 20.

llx: numeric variable name; returns the x coordinate of the lower left corner.

lly: numeric variable name; returns the y coordinate of the lower left corner.

urx: numeric variable name; returns the x coordinate of the upper right corner.

ury: numeric variable name; returns the y coordinate of the upper right corner.

return-code-variable: numeric variable name; returns the return code of the routine call. The return code can be 0, 8, or 50. See Return Codes for DSGI Routines and Functions.

Details

The GASK('VIEWPORT', . . . ) routine returns the coordinates of the viewport associated with the specified transformation. If a viewport has not been defined with the GSET('VIEWPORT', . . . ) function for the specified transformation, n, GASK('VIEWPORT', . . . ) returns the default coordinates for the viewport, (0,0) and (1,1).