testz6scroll.inf

! A z6 test for window-local scrolling.
!
! Window 0 is filled with a pattern of '#'. A small window 1 is then opened in
! the middle of it and given more lines than it can hold, so it has to scroll.
! A correct interpreter scrolls window 1's rectangle and nothing else: the
! window shows the LAST lines printed, and the '#' pattern around it -- above,
! below, and on both sides of every one of its rows -- is untouched.
!
! Both windows are made unbuffered so that no [MORE] prompt interrupts the
! test; printing then goes straight to the screen, which is the path the
! window's own scrolling hangs off.

! A v6 unit is whatever the interpreter says a character cell is worth
! (property 13): a cell under the old model, an art pixel under the pixel one.
! So the layout below is written in CELLS and converted, exactly as testz6.inf
! does - passing cell counts raw made window 1 six PIXELS tall on a pixel-unit
! interpreter, which is no rows at all, and a window with no rows is not a
! scrolling test.
Global fw = 1;
Global fh = 1;
[ ux c; return (c - 1) * fw + 1; ];   ! 1-based cell column -> 1-based units
[ uy r; return (r - 1) * fh + 1; ];   ! 1-based cell row    -> 1-based units
[ cw n; return n * fw; ];             ! a width or count in cells -> units
[ ch n; return n * fh; ];

[main i j w h;
#iftrue (#version_number == 6);
	@get_wind_prop 0 13 -> i;   ! height in the high byte, width in the low
	fh = i / 256;
	fw = i % 256;
	if (fw == 0) fw = 1;
	if (fh == 0) fh = 1;
	@erase_window (-1);
	w = $21->0; ! screen width in characters
	h = $20->0; ! screen height in characters

	@window_style 0 8 2; ! clear bit 3 (buffered): no [MORE] prompts
	@window_style 1 8 2;
	@window_style 0 3 1; ! set bits 0 and 1: wrapping and scrolling
	@window_style 1 3 1;

	! Fill window 0 (the whole screen) with the pattern, leaving the last row
	! empty so that the fill itself never reaches the bottom and scrolls.
	@set_window 0;
	@set_cursor 1 1;
	for (i = 1: i <= h - 1: i++) {
		for (j = 1: j <= w: j++) { print "#"; }
	}

	! A small window in the middle of the pattern: six rows by twenty columns,
	! at row 9, column 11.
	i = ch(6); j = cw(20);
	@window_size 1 i j;
	i = uy(9); j = ux(11);
	@move_window 1 i j;
	@set_window 1;
	@erase_window 1;

	! Ten lines into six rows: the last four must scroll it.
	for (i = 1: i <= 10: i++) {
		print "line ", i, "^";
	}

	@set_window 0;
	@read_char 1 -> i;
#endif;
	print "done!^";
];