HTML5 Canvas Minimal Excample

html5_canvas_minimal_example.html

<script>

    var canvas = document.getElementById('mycanvas');
    var ctx = canvas.getContext('2d');
    ctx.beginPath();
    ctx.moveTo(startX, startY);
    ctx.lineCap = 'round';
    ctx.lineWidth = 3;

    var red = (((Math.random() * 64) + 128) >> 0);
    var green = (((Math.random() * 64) + 128) >> 0);
    var blue = (((Math.random() * 64) + 128) >> 0);

    ctx.strokeStyle = 'rgb(' + red + ',' + green + ',' + blue + ')'; 
    var newX = startX;
    var newY = startY - STEP_SIZE;
    ctx.lineTo(newX, newY);
    ctx.stroke(); // nur am Ende 

</script>
<canvas id="mycanvas" width=2800, height=2260>Your browser doesn't support the HTML5 canvas element. Please install a decent browser (e.g. Firefox)</canvas>