The shadowOffsetY property
This sets the y-axis
offset of the shadow. Values can be positive (the shadows
are cast
down) or negative (the shadows are cast up).
Inner shadows are not supported but are achievable if you:
- Draw a shape
- Clip the
canvas
to that shape - Draw an outline of that shape just outside the clipped area with shadow enabled
- Set the shadow X/Y offsets to 0
- Half the shadow will fall inside the clipped area and will thus be drawn on your
canvas
You can find details of inner shadows at the link below.
An example
<script>
window.onload = function ()
{
var canvas = document.getElementById("cvs");
var context = canvas.getContext('2d');
var x = 50;
var y = 50;
var width = 100;
var height = 100;
context.shadowColor = '#ccc';
context.shadowOffsetX = 0;
context.shadowOffsetY = 30;
context.shadowBlur = 15;
context.fillStyle = 'red';
context.fillRect(x, y, width, height);
}
</script>