HTML5 canvas: Draw a circle move any direction


Read first: HTML5 canvas draw animated circle

HTML:

<canvas id="myCanvas" width="600" height="600"></canvas>

CSS:

body {
    margin: 0px;
    padding: 0px;
}

Javascript:

var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
var myCircle = {
    x: 20,
    y: 20,
    radius: 20,
    color: "red",
    borderwidth: 1,
    bordercolor: '#003300',
    txt: "TutorialSpots",
    txtcolor: 'blue',
    txtfont: 'Calibri'
};

function draw(){
    //speed: pixels per second
    Speed = 60; 
    directionAngle = Math.PI / 6;//30d 
    myCircle.x += Speed /60 * Math.cos(directionAngle) ;
    myCircle.y += Speed /60 * Math.sin(directionAngle) ;
    context.clearRect(0,0,canvas.width,canvas.height);
    context.beginPath();
    context.arc(myCircle.x, myCircle.y, myCircle.radius, 0, 2 * Math.PI, false);
    context.fillStyle = myCircle.color;
    context.fill();  
    context.lineWidth = myCircle.borderwidth;
    context.strokeStyle = myCircle.bordercolor;
    context.stroke();
    context.font = myCircle.radius+'px '+myCircle.txtfont;
    context.fillStyle = myCircle.txtcolor;
 
    context.fillText(myCircle.txt, myCircle.x-context.measureText(myCircle.txt).width/2, myCircle.y+myCircle.radius/4);
}
 
setInterval(draw ,1000/60)

Result:

Try it Yourself:
https://jsfiddle.net/qfs8entc/1/

In this tutorial, we can learn how to determine the text width in canvas by use measureText method.

Read more: HTML5 canvas: a circle follows the mouse

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  1. HTML5 canvas: a circle follows the mouse | Free Online Tutorials - August 28, 2015

    […] Read first: HTML5 canvas: Draw a circle move any direction […]

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