.exe uses an internal coordinate system, the logical device coordinate system (LDCS), fixed on the entire drawing rectangle, the paper, defined on opening a window. In the LDCS, a point on the paper is specified by [u,v] with u to the right and v to the bottom from the origin at the top-left. On printing, the unit lengths in the LDCS are mapped to the unit pixel lengths of the printer.
The normalized logical coordinate system (NLCS) is used to define a view port, a temporal drawing rectangle set inside the paper, by calling GWVPORT. The unit in the NLCS is determined by normalizing the width and the height of the paper in the LDCS with the same fraction to give the unit length of the shorter of the width and the height. The origin of the NLCS is at the bottom-left of the paper.
The world coordinate system (WCS) is the user's coordinate system defined by calling GWINDOW to give the coordinates of the bottom-left and the top-right corners of the view port in this coordinate system. Almost all routines of the GrWin Library assume this world coordinate system.
In each of the following items of this manual, [F] stands for a declaration in Fortarn, and [C] in C.
In Fortran, there is no need to use capital letters as in the body of this manual below, since a capital letter and the corresponding small letter are not distinguished at all in Fortran except in character constants, and in contrast, of course, they are distinguished in C. As seen in the above table each of all subroutines and functions in Fortran except the last 8 routines (# .. #) has the counterpart in C. Unless stated explicitly the first argument IRTN of each subroutine for Fortran has a nonzero value if succeeded, and 0 otherwise, and is the same as the return value of the corresponding function in C. Output variables in the argument list of the Fortran counterpart are listed at "Output".
In C any pointer argument for output, except those for GWsize, can be NULL if the output parameter is not used.
The routines GWTxxxxx's are for the tortoise graphics (a.k.a. the turtle graphics). Also available, though not described here, are the GWDTxxxxx's, which are the double precision counterparts of the GWTxxxxx's. To use GWDTxxxxx's you must read REAL as REAL*8 or DOUBLE PRECISION for [F], and float as double for [C] in this manual. Those tortoise graphics routines maintain the world coordinate internally in real ( for GWTxxxxx's ) or in double precision ( for GWDTxxxxx's ) , accumulated errors in coordinates expected, in drawings using relative coordinates for example, to be very small, compared with other GWxxxxx routines, which internally maintain the logical device coordinate.
The last 8 subroutines in the above table, which are written using GrWin intrinsic routines, GWxxxxx's, are for least compatibility to programs using Calcomp routines. There is no [C] counterparts for them as noted above.
There is no problem if some of the routines for the tortoise graphics and/or the Calcomp compatible routines with some of the GrWin intrinsics are used in a program.
The column 'n' stands for the number the object(s) created by the routine. The stored objects are used to redraw the window, etc. By using gwsaveas/GWsaveas or gwload/GWload the objects can be saved to a file or can be loaded from a file.Index sorted by Function is available at the end of this manual.