View.Set ("graphics:max;max;offscreenonly;nocursor")
const base := 60
const movement := 10
const jump_dis := 25
const gravity := 2
var keyslah : array char of boolean
var tcoins : nat := 0
var jumponly := true
% player position and velocity
var posx := 20
var velx := 0.0
var posy := base
var vely := 0.0


loop
    cls
    Input.KeyDown (keyslah)
    % left and right keyt
    if keyslah (KEY_LEFT_ARROW) and posx - 10 > 0 then
        velx := -movement
    elsif keyslah (KEY_RIGHT_ARROW) and posx + 10 < maxx - 10 then
        velx := movement
    else
        velx := 0
    end if
    %% up key
    if keyslah (KEY_UP_ARROW) and jumponly = true then
        vely := jump_dis
        jumponly := false
    end if
    % subtract your gravity constant from the velocity
    if View.WhatDotColor (posx, posy - 1) not= black then
        vely -= gravity
        posx += round (velx)
        posy += round (vely)
    end if
    % on the ground ?
    if posy < base then
        posy := base
        vely := 0
        jumponly := true
    end if
    if View.WhatDotColor (posx, posy-1) = black then
        vely := 0
        vely += gravity
        jumponly := true
        delay (40)
    end if
    % change if colors if you can't jump
    if jumponly = true then
        drawfillbox (posx , posy, posx + 20, posy + 20, green)
    else
        drawfillbox (posx , posy, posx + 20, posy + 20, 79)
    end if
    % drawing stuff in the background
    Draw.ThickLine (25, 180, 100, 180, 2, black)
    Draw.ThickLine(200, 220, 315, 220, 2, black)
    Draw.ThickLine(450, 240, 575, 240, 2, black)
    Draw.ThickLine(660, 260, 785, 260, 2, black)
    drawline (0, base, maxx, base, 64)
    %% just so I know where posx and posy are
    drawfilloval (posx, posy, 1, 1, 12)
    drawbg
    level_tut_1
    delay (25)
    View.Update
end loop