View.Set ("graphics:500,500,nobuttonbar,title:Grey Scale Patterns,nocursor")
View.Set ("xor")
var corner : int := maxy + maxx
var dl : int := 1
var procs : array 1 .. 8 of procedure x ()
var pattern : array 1 .. 11 of procedure x ()
var randAmount : int
var answer : string (1)
var font : int := Font.New ("Arial:12")
Text.ColourBack (7)
Text.Colour (42)

%%% D=Direction then 8 point direction using numpad dark-light
proc D28
    for y : 0 .. maxy
        Draw.Line (0, y, maxx, y, RGB.AddColour (y / (maxy + 1), y / (maxy + 1), y / (maxy + 1)))
        Time.Delay (dl)
    end for
end D28
procs (1) := D28
proc D82
    for decreasing y : maxy .. 0
        Draw.Line (0, y, maxx, y, RGB.AddColour ((maxy - y) / (maxy + 1), (maxy - y) / (maxy + 1), (maxy - y) / (maxy + 1)))
        Time.Delay (dl)
    end for
end D82
procs (2) := D82
proc D46
    for x : 0 .. maxx
        Draw.Line (x, 0, x, maxy, RGB.AddColour (x / (maxx + 1), x / (maxx + 1), x / (maxx + 1)))
        Time.Delay (dl)
    end for
end D46
procs (3) := D46
proc D64
    for decreasing x : maxx .. 0
        Draw.Line (x, 0, x, maxy, RGB.AddColour ((maxx - x) / (maxx + 1), (maxx - x) / (maxx + 1), (maxx - x) / (maxx + 1)))
        Time.Delay (dl)
    end for
end D64
procs (4) := D64
proc D19
    for c : 0 .. corner
        Draw.Line (0, c, c, 0, RGB.AddColour (c / (corner + 1), c / (corner + 1), c / (corner + 1)))
        Time.Delay (dl)
    end for
end D19
procs (5) := D19
proc D91
    for decreasing c : corner .. 0
        Draw.Line (0, c, c, 0, RGB.AddColour ((corner - c) / (corner + 1), (corner - c) / (corner + 1), (corner - c) / (corner + 1)))
        Time.Delay (dl)
    end for
end D91
procs (6) := D91
proc D37
    for c : 0 .. corner
        Draw.Line (maxy, c, corner - c - maxx, 0, RGB.AddColour (c / (corner + 1), c / (corner + 1), c / (corner + 1)))
        Time.Delay (dl)
    end for
end D37
procs (7) := D37
proc D73
    for decreasing c : corner .. 0
        Draw.Line (maxy, c, corner - c - maxx, 0, RGB.AddColour ((corner - c) / (corner + 1), (corner - c) / (corner + 1), (corner - c) / (corner + 1)))
        Time.Delay (dl)
    end for
end D73
procs (8) := D73
proc TriLeft
    cls
    procs (3)
    procs (6)
    procs (8)
end TriLeft
pattern (1) := TriLeft
proc TriUp
    cls
    procs (1)
    procs (6)
    procs (8)
end TriUp
pattern (2) := TriUp
proc FanLeft
    cls
    procs (1)
    procs (3)
    procs (5)
    procs (7)
end FanLeft
pattern (3) := FanLeft
proc FanRight
    cls
    procs (1)
    procs (4)
    procs (5)
    procs (7)
end FanRight
pattern (4) := FanRight
proc CrossBlack
    cls
    procs (2)
    procs (5)
    procs (8)
    procs (7)
    procs (2)
    procs (6)
end CrossBlack
pattern (5) := CrossBlack
proc CrossWhite
    cls
    procs (1)
    procs (5)
    procs (8)
    procs (7)
    procs (2)
    procs (6)
end CrossWhite
pattern (6) := CrossWhite
proc TileBottom
    cls
    procs (2)
    procs (3)
    procs (4)
    procs (5)
    procs (6)
    procs (7)
    procs (8)
end TileBottom
pattern (7) := TileBottom
proc TileTop
    cls
    procs (1)
    procs (3)
    procs (4)
    procs (5)
    procs (6)
    procs (7)
    procs (8)
end TileTop
pattern (8) := TileTop
proc Random
    cls
    randAmount := Rand.Int (2, 8)
    for i : 1 .. randAmount
        procs (Rand.Int (1, 8))
    end for
end Random
pattern (9) := Random
cls
loop
    Font.Draw ("1-Triangle Left", 10, 180, font, 9)
    Font.Draw ("2-Triangle Up", 10, 160, font, 9)
    Font.Draw ("3-Fan Left", 10, 140, font, 9)
    Font.Draw ("4-Fan Right", 10, 120, font, 9)
    Font.Draw ("5-Cross Black", 10, 100, font, 9)
    Font.Draw ("6-Cross White", 10, 80, font, 9)
    Font.Draw ("7-Tile Bottom", 10, 60, font, 9)
    Font.Draw ("8-Tile Top", 10, 40, font, 9)
    Font.Draw ("9-Random", 10, 20, font, 9)
    Font.Draw ("Delay= " + intstr (dl), maxx - 70, 20, font, 9)
    getch (answer)
    if strintok (answer) then
        pattern (strint (answer))
    elsif answer = "+" then
        if dl < 9 then
            dl += 1
            cls
        end if
    elsif answer = "-" then
        if dl > 0 then
            dl -= 1
            cls
        end if
    else
        exit
    end if
end loop