closePath (a path command)

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context.closePath()

Draws a line from the current pen location back to the beginning path coordinate.

For example, if you draw 2 lines forming 2 legs of a triangle, closePath will “close” the triangle by drawing the third leg of the triangle from the 2nd leg’s endpoint back to the first leg’s starting point.

A Misconception explained!

This command’s name often causes it to be misunderstood.

context.closePath is NOT an ending delimiter to context.beginPath.

Again, the closePath command draws a line – it does not “close” a beginPath.

This example draws 2 legs of a triangle and uses closePath to complete (close?!) the triangle by drawing the third leg. What closePath is actually doing is drawing a line from the second leg’s endpoint back to the first leg’s starting point.

<!doctype html>
<html>
<head>
<style>
    body{ background-color:white; }
    #canvas{border:1px solid red; }
</style>
<script>
window.onload=(function(){

    // get a reference to the canvas element and it's context
    var canvas=document.getElementById("canvas");
    var ctx=canvas.getContext("2d");

    // arguments
    var topVertexX=50;
    var topVertexY=50;
    var rightVertexX=75;
    var rightVertexY=75;
    var leftVertexX=25;
    var leftVertexY=75;

    // A set of line segments drawn to form a triangle using
    //     "moveTo" and multiple "lineTo" commands
    ctx.beginPath();
    ctx.moveTo(topVertexX,topVertexY);
    ctx.lineTo(rightVertexX,rightVertexY);
    ctx.lineTo(leftVertexX,leftVertexY);

    // closePath draws the 3rd leg of the triangle
    ctx.closePath()

    ctx.stroke();

}); // end window.onload
</script>
</head>
<body>
    <canvas id="canvas" width=200 height=150></canvas>
</body>
</html>

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