.BG
.VE $Header: /usr3/s/current/s/.help/RCS/blit,v 1.3 84/05/14 09:06:58 rab Exp $
.FN blit
.TL
blit: Bell Labs Bitmap Terminal
.CS
blit(ask, load)
.PP
.AG ask
logical, should device driver ask before clearing 
graphic display for a new figure?
Default TRUE.
.AG load
logical, should the appropriate terminal program be loaded
into the Blit?
Default TRUE.
.SH COMMENTS
The function `blit' is the device driver for Bell Laboratories
bitmap terminal, functioning in the multiplex (layers) mode.
The terminal contains an MC68000 microprocessor that must
be down-loaded with the S terminal driver.
.PP
When the terminal program is first activated, it requests that the user
point to any layer and hit button 3.  This layer is where all graphical
output will be directed.  Neither the graphics layer nor the S layer
may be reshaped.
If you wish to draw in another layer, you can use `blit(load=F)' to
return layer-selection.
.PP
If `ask' is TRUE,
whenever a new plot is about to be produced the message "GO?" appears.
This allows further viewing,
before the graphics screen is erased.  When ready
to proceed, simply hit carriage return.
.PP
For graphic input, position the mouse and push any button.
Hitting two buttons together terminates graphic input.
At present, graphic input only works in standalone mode.
.PP
At present, the terminal cannot change character size or line type.
Characters can be horizontal or rotated 90 degrees.
The terminal can fill polygons,
for example in histograms, bargraphs, and pie charts
with various patterns.  This is activated
by the color parameter (`col=').
Colors are 1=solid black, 2=grey, ....
Color 0 fills with white (useful for blanking out areas).
.PP
A device must be specified before any graphics functions can be used.
.PP
Related functions include: `blitid', `spin', `scatmat'.
.KW device*
.WR
