74

XSCROLL & YSCROLL (see Chapter 14(
Use
XSCROLL and YSCROLL are functions which return the position of the window on
the virtual screen, in user coordinates.
Syntax
XSCROLL(([#)streatn-number)J
YSCROLL(([#jstrearn-number)]
XUSABLE & YUSABLE (see Chapter 9)
Use XUSABLE and YUSABLE are functions which return the usabte size of a graphics
device, in device pivels.
Syntax
XUSABLE[([#]stream-number)j
YUSA8LEI(f#Jstream-number)]
XVIRTUAL & YVIRTUAL (see Chapter 9)
Use XVIRTUAL and YVIRTUAL are functions which return the size of a graphics virtual
screen, or other graphics device, in user coordinates..
Syntax
XVI RIUAL[l[#]stream-numberlJ
XVI RTUAL[l[#Jsfream-numberl)
XWINDOW & YWINDOW (see Chapter 14)
Use XWINDOW and YWINDUW arefunctions which return the size of a window, in screen
device pioels.
Syntax
XWI NDOW(l(#)stream-numberlJ
YWINDOWIIfl}Jstream-numberl]
YASPECT (see Chapters 9 & 12)
Use YASPECT is a function which gives the aspect ratio of a user coordinate pixel.
Syntax
YASPECT[l[#Jstream-numberl]
ZONE (see Chapter 11)
Use
ZONE sets the print zone size forthe Dialogue Screen.
Syntax
ZVNE zone-size
74

74