setscreen ("graphics:600;610, position:center;center, offscreenonly, nobuttonbar, title:Connect 4")
var board, piece1, piece2, mousex, mousey, button, turn, column, board_clr, background_clr, player_1_clr,
    player_2_clr : int
var column_height : array 1 .. 7 of int := init (0, 0, 0, 0, 0, 0, 0)
var clicked : boolean := false
var keys : array char of boolean
var win_font := Font.New ("Comic Sans MS:30")

%%% CUSTOMIZABLE PREDEFS %%%
board_clr := 43
background_clr := white
player_1_clr := brightred
player_2_clr := brightblue

forward proc Main

Main

proc DrawPictures
    colourback (background_clr)
    cls
    % BOARD %
    drawfillbox (0, 0, 600, 515, board_clr)
    drawbox (0, 0, 600, 515, black)
    for x : 1 .. 7
        for y : 1 .. 6
            drawfilloval (x * 85 - 40, y * 85 - 40, 40, 40, background_clr)
            drawoval (x * 85 - 40, y * 85 - 40, 40, 40, black)
        end for
    end for
    board := Pic.New (0, 0, 700, 585)
    cls
    % PIECES %
    drawfilloval (100, 100, 40, 40, player_1_clr)
    drawoval (100, 100, 40, 40, black)
    piece1 := Pic.New (60, 60, 140, 140)
    drawfilloval (200, 200, 40, 40, player_2_clr)
    drawoval (200, 200, 40, 40, black)
    piece2 := Pic.New (160, 160, 240, 240)
end DrawPictures

proc Win (clr : int)
    if clr = player_1_clr then
        Font.Draw ("RED WINS", 193, 550, win_font, player_1_clr)
    elsif clr = player_2_clr then
        Font.Draw ("BLUE WINS", 182, 550, win_font, player_2_clr)
    end if
    View.Update
    % frees image IDs so pictures can be redrawn
    Pic.Free (board)
    Pic.Free (piece1)
    Pic.Free (piece2)
    loop
        Mouse.Where (mousex, mousey, button)
        exit when button = 1 or hasch
    end loop
    Main
end Win

proc CheckForLines (x, y, clr : int)
    var scan_dist := 85
    var line := 1
    %% CHECK FOR VERTICAL LINES %%
    if y div 85 <= 3 then
        loop
            if whatdotcolour (x, y + scan_dist) = clr then
                line += 1
                scan_dist += 85
            else
                exit
            end if
            if line = 4 then
                Win (clr)
            end if
        end loop
    end if
    scan_dist := 85
    line := 1
    %% CHECK FOR HORIZONTAL LINES %%
    if x div 85 <= 4 then
        loop
            if whatdotcolour (x + scan_dist, y) = clr then
                line += 1
                scan_dist += 85
            else
                exit
            end if
            if line = 4 then
                Win (clr)
            end if
        end loop
    end if
    scan_dist := 85
    line := 1
    %% CHECK FOR UP/RIGHT DIAGONAL LINES %%
    if x div 85 <= 4 and y div 85 <= 3 then
        loop
            if whatdotcolour (x + scan_dist, y + scan_dist) = clr then
                line += 1
                scan_dist += 85
            else
                exit
            end if
            if line = 4 then
                Win (clr)
            end if
        end loop
    end if
    scan_dist := 85
    line := 1
    %% CHECK FOR DOWN/RIGHT DIAGONAL LINES %%
    if x div 85 <= 4 and y div 85 >= 4 then
        loop
            if whatdotcolour (x + scan_dist, y - scan_dist) = clr then
                line += 1
                scan_dist += 85
            else
                exit
            end if
            if line = 4 then
                Win (clr)
            end if
        end loop
    end if
    scan_dist := 85
    line := 1
    %% CHECK FOR DOWN/LEFT DIAGONAL LINES %%
    if x div 85 >= 4 and y div 85 >= 4 then
        loop
            if whatdotcolour (x - scan_dist, y - scan_dist) = clr then
                line += 1
                scan_dist += 85
            else
                exit
            end if
            if line = 4 then
                Win (clr)
            end if
        end loop
    end if
    scan_dist := 85
    line := 1
    %% CHECK FOR UP/LEFT DIAGONAL LINES %%
    if x div 85 >= 4 and y div 85 <= 3 then
        loop
            if whatdotcolour (x - scan_dist, y + scan_dist) = clr then
                line += 1
                scan_dist += 85
            else
                exit
            end if
            if line = 4 then
                Win (clr)
            end if
        end loop
    end if
end CheckForLines

proc Scan
    var clr : int
    for x : 1 .. 7
        for y : 1 .. 6
            clr := whatdotcolour (x * 85 - 40, y * 85 - 40)
            if clr not= white then
                CheckForLines (x * 85 - 40, y * 85 - 40, clr)
            end if
        end for
    end for
end Scan

proc PieceDraw (piece, x, y : int)
    if piece = 1 then
        Pic.Draw (piece1, x, y, picMerge)
    elsif piece = 2 then
        Pic.Draw (piece2, x, y, picMerge)
    end if
end PieceDraw

proc Drop (x, column : int)
    var y : real := 525
    loop
        PieceDraw (turn, x, round (y))
        Pic.Draw (board, 0, 0, picMerge)
        y -= 15
        Time.DelaySinceLast (1)
        View.Update
        cls
        exit when y <= 5 + (85 * column_height (column))
    end loop
    y := 5 + (85 * column_height (column))
    cls
    PieceDraw (turn, x, round (y))
    Pic.Draw (board, 0, 0, picMerge)
    View.Update
    Pic.Free (board)
    board := Pic.New (0, 0, 700, 585)
    Scan
    % next turn
    if turn = 1 then
        turn := 2
    elsif turn = 2 then
        turn := 1
    end if
end Drop

proc PickSpot
    var x, y : int
    y := 525
    Mouse.Where (mousex, mousey, button)
    if mousex >= 0 and mousex <= 580 then
        for count : 1 .. 7
            if mousex < count * 85 then
                x := count * 85 - 80
                column := count
                exit
            end if
        end for
    elsif mousex < 0 then
        x := 5
    elsif mousex > 580 then
        x := 515
    end if
    if button = 1 then
        if not clicked then
            if column_height (column) < 6 then
                Drop (x, column)
                column_height (column) += 1
            end if
        end if
        clicked := true
    else
        clicked := false
    end if
    /* % Keyboard Controls (mouse controls must be disabled to use)
     Input.KeyDown (keys)
     if keys (KEY_LEFT_ARROW) and x > 5 then
     x -= 85
     end if
     if keys (KEY_RIGHT_ARROW) and x < 515 then
     x += 85
     end if
     if keys (KEY_DOWN_ARROW) then
     Drop (x, column)
     end if
     */
    PieceDraw (turn, x, y)
end PickSpot

body proc Main
    loop % full loop (for restarting the game)
        DrawPictures
        randint (turn, 1, 2)
        loop % main loop (for playing)
            cls
            Pic.Draw (board, 0, 0, picMerge)
            PickSpot
            View.Update
        end loop
    end loop
end Main