TextChar
TextChar (Function)
Format
Description
Returns the single character standing at a square of the character screen, as a string. Columns and rows are counted from zero, the same way round as Locate.
This is how a program reads back what is already drawn -- useful for a game that needs to know what is in the square it is about to move into, and the same idea as SCREEN$ on the ZX Spectrum or reading the screen memory on a Commodore 64. A square nothing has been printed to holds a space.
An empty string is returned when there is nothing to read:
- when the column or row is off the edge of the screen;
- when the window is not a fixed screen, that is when TextScreen has not been used, because the ordinary scrolling window has no squares to read;
- when the program is being run with
--silent, which has no window at all.
textchar reads the screen as it is now. After the screen has scrolled it reports what has moved into the square, not what was printed there to begin with.
Example
textscreen 20, 8
textcolor rgb(255,220,0)
locate 4, 2
print "HELLO";
print
textcolor rgb(0,255,128)
locate 0, 4
print "the square at 4,2 holds [" + textchar(4,2) + "]"
print "the square at 8,2 holds [" + textchar(8,2) + "]"
print "a square that was never printed to holds [" + textchar(0,7) + "]"
print "off the screen gives [" + textchar(99,99) + "]"
will print
the square at 4,2 holds [H]
the square at 8,2 holds [O]
a square that was never printed to holds [ ]
off the screen gives []
Reading a whole row back is a loop over the columns:
row$ = ""
for c = 0 to 19
row$ = row$ + textchar(c, 2)
next c
print "row 2 reads: " + row$
See Also
Chr, Locate, Print, TextBackground, TextCol, TextColor, TextFont, TextRow, TextScreen
History
| 2.3 | New To Version |