NAME

VI_MDefnCur, VI_FDefnCur, VI_EnCur, VI_DisCur, VI_PosnCur − control the display cursor

SYNOPSIS

VI_MDefnCur(xoff,yoff,black,white)
int xoff;/∗ x offset of cursor center ∗/
int yoff;/∗ y offset of cursor center ∗/
unsigned short ∗black;/∗ first byte of black mask ∗/
unsigned short ∗white;/∗ first byte of white mask ∗/

VI_FDefnCur(filename)
char ∗filename;/∗ name of cursor definition file ∗/

VI_EnCur()

VI_DisCur()

VI_PosnCur(x,y)
int x,y;/∗ new cursor position ∗/

DESCRIPTION

These subroutines allow programs to control the display cursor by defining it, enabling and disabling it, and changing its position.  Disabling and reenabling the cursor do not affect its pattern or position.  Because the display maintains the cursor separately from the display buffer, the cursor does not have to be removed when a graphics primitive intersects its position.  Initially the cursor is transparent and disabled, and is positioned at the center of the screen. 

VI_MDefnCurSets the cursor as specified.  xoff,yoff is the displacement of the cursor pattern from the current position of the cursor.  For example, a value of (32,32) would center the cursor pattern around the current point.  The cursor pattern itself is a 64-by-64 bit image, with two planes.  A 1 in the black plane indicates that that bit of the cursor should be black.  A 1 in the white plane indicates that the cursor should be white in that position.  If a bit has a 0 in both planes, the cursor is transparent in that position.  If a bit is 1 in both planes, the cursor is white.  The two planes are images in the same format as accepted by MImage, and must be 64-by-64, or 512 bytes each. 

VI_FDefnCurSets the cursor to the definition in the specified file.  The file has the format shown below; the fields are explained under MDefnCur. 

Offset (bytes)Description
 
  0XOFF
  2YOFF
  4BLACK bit pattern
516WHITE bit pattern

See the description of MDefnCur for a description of the fields. 

VI_EnCurEnables the cursor and displays it if it is not already present. 

VI_DisCurDisables the cursor and removes it from the screen if it is present. 

VI_PosnCurMoves the cursor to the specified position.  It cannot be moved off the screen. 

NOTE

VI_Cursor applies only to the IBM Academic Information Systems experimental display. 

SEE ALSO

image(3G)

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  30 Sep 1985