Touch input demo - Coders

-- Touch demo
-- by @beezing

sin = math.sin
cos = math.cos
random = math.random
drawText = writeTextAtPosition

x0 = -1
y0 = -1

function setRandomColors(val)
  setColor(random(val), random(val), random(val))
end

function rectangle(x, y, width, height)
  move(x, y)
  draw(x+width, y)
  draw(x+width, y+height)
  draw(x, y+height)
  draw(x, y)
end

function circle(x, y, r)
  move(x+r, y)
  for i = 0, 3.14*2+0.1, 0.1 do
    draw(x+r*cos(i), y+r*sin(i))
  end
end

function follow(x,y)
  setLineWidth(2)
  setColor(255,255,255)
  circle(x0,y0,29)
  circle(x0,y0,30)
  circle(x0,y0,31)
  setLineWidth(1)
  setColor(0,0,0)
  circle(x,y,30)
end

function doodle(x,y)
  --drawPoint(x,y)
  draw(x,y)
end

function dot(x,y)
  setRandomColors(192)
  setLineWidth(25)
  circle(x,y,1)
  setLineWidth(random(3))
end

function drawButton(x,y,w,h,t)
  setLineWidth(2)
  rectangle(x,y,w,h)
  drawText(t,x+28,y+24)
  drawText(t,x+29,y+24)
end

function setupCanvas()
  clearCanvas()
  setColor(0,0,0)
  drawButton(100,110,124,30,'C L E A R')
  drawText('Touch and doodle...', 100,100)
  move(384,384)
  setRandomColors(192)
end

function touched(x, y)
  return (x > 0) and (y > 0)
end

function touch()
  x,y = currentTouch()
  if touched(x,y) then
    --draw(x,y)
    --move(x,y)

    if (x > 100) and (x < 224) and
       (y > 110) and (y < 140) then
      setColor(192,0,0)
      drawButton(100,110,124,30,'C L E A R')
    else
      doodle(x,y)
      --follow(x,y)
    end

    x0 = x
    y0 = y
  end
end

function tap()
  x,y = lastTouch()
  if touched(x,y) then
    --draw(x,y)
    move(x,y)

    if (x > 100) and (x < 224) and
       (y > 110) and (y < 140) then
      setupCanvas()
    else
      dot(x,y)
    end

    x0 = x
    y0 = y
  end
end

setupCanvas()
while true do
  disableScreenRefresh()
  touch()
  tap()
  enableScreenRefresh()
end