nav2

gistfile1.txt

-- Navigator


function setup()
    x,y=200,200  --starting position
    d,a=0,0 --starting velocity / angle
    sd,sa=10,5 --speed/angle change per tap
    rad=math.pi/180 --constant to convert degrees to radians
end


function draw()
    background(220)
    pushStyle()
    fill(255,255,0,100)
    local dx=d*DeltaTime*math.sin(a*rad)
    local dy=d*DeltaTime*math.cos(a*rad)
    x,y=x+dx,y+dy
    pushStyle()
    translate(x,y)
    rotate(-a)
    ellipse(0,0,50,100)
    popStyle()
    popStyle()
end

function touched(touch)
    local t=false --to tell us if touch has been located yet
    --change y speed if in outer 1/4 of screen
    if touch.y<HEIGHT/4 then d=d-sd        t=true
    elseif touch.y>HEIGHT*.75 then d=d+sd  t=true
    end
    --change x speed if in top/bottom 1/4 of screen
    if touch.x<WIDTH/4 then a=a-sa         t=true
    elseif touch.x>WIDTH*.75 then a=a+sa   t=true
    end
    --stop moving otherwise
    if t==false then d=0 end
end