CODEWITHSUNDEEP
javascripthtmlcanvas
Rizzzler
Rizzzler

Reputation: 193

canvas - How to center ontop

I have a problem i have been battling for the last hour. Basically this code shows a clock, and an image of a deer. I want the clock and the deer centered and the clock on top of the deer as in this image:

But whatever I do I cant get it to work. Anyone got a solution for this ?

<!DOCTYPE html>
<html>
<body>

<body bgcolor="#000000">

<style type="text/css">
.bgimg {
    background-image: url(klockren.png);
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-position: center; 
    height:800px;
}
#canvas {
       margin-left:85px;
    margin-top:420px;
}
</style>

<div align="center" class="bgimg">

   <div class="canvas">
      <canvas id="canvas" width="100" height="100"></canvas>
   </div>
</div>

<script>
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var radius = canvas.height / 2;
ctx.translate(radius, radius);
radius = radius * 0.90
setInterval(drawClock, 1000);

function drawClock() {
  drawFace(ctx, radius);
  drawNumbers(ctx, radius);
  drawTime(ctx, radius);
}

function drawFace(ctx, radius) {
  var grad;
  ctx.beginPath();
  ctx.arc(0, 0, radius, 0, 2*Math.PI);
  ctx.fillStyle = 'white';
  ctx.fill();
  grad = ctx.createRadialGradient(0,0,radius*0.95, 0,0,radius*1.05);
  grad.addColorStop(0, '#333');
  grad.addColorStop(0.5, 'black');
  grad.addColorStop(1, '#333');
  ctx.strokeStyle = grad;
  ctx.lineWidth = radius*0.1;
  ctx.stroke();
  ctx.beginPath();
  ctx.arc(0, 0, radius*0.1, 0, 2*Math.PI);
  ctx.fillStyle = '#000';
  ctx.fill();
}

function drawNumbers(ctx, radius) {
  var ang;
  var num;
  ctx.font = radius*0.15 + "px arial";
  ctx.textBaseline="middle";
  ctx.textAlign="center";
  for(num = 1; num < 13; num++){
    ang = num * Math.PI / 6;
    ctx.rotate(ang);
    ctx.translate(0, -radius*0.85);
    ctx.rotate(-ang);
    ctx.fillText(num.toString(), 0, 0);
    ctx.rotate(ang);
    ctx.translate(0, radius*0.85);
    ctx.rotate(-ang);
  }
}

function drawTime(ctx, radius){
    var now = new Date();
    var hour = now.getHours();
    var minute = now.getMinutes();
    var second = now.getSeconds();
    //hour
    hour=hour%12;
    hour=(hour*Math.PI/6)+
    (minute*Math.PI/(6*60))+
    (second*Math.PI/(360*60));
    drawHand(ctx, hour, radius*0.5, radius*0.07);
    //minute
    minute=(minute*Math.PI/30)+(second*Math.PI/(30*60));
    drawHand(ctx, minute, radius*0.8, radius*0.07);
    // second
    second=(second*Math.PI/30);
    drawHand(ctx, second, radius*0.9, radius*0.02);
}

function drawHand(ctx, pos, length, width) {
    ctx.beginPath();
    ctx.lineWidth = width;
    ctx.lineCap = "round";
    ctx.moveTo(0,0);
    ctx.rotate(pos);
    ctx.lineTo(0, -length);
    ctx.stroke();
    ctx.rotate(-pos);
}
</script>

</body>
</html>

Upvotes: 0

Views: 231

Answers (4)

Nana Owusu-Marfo
Nana Owusu-Marfo

Reputation: 147

The height of your deer image is 800 * 591 Pixels.

Set .bgimg to a relative position. Add class (.canvas) to the div around the canvas itself and set its position to absolute. Now set the top and left position until it fits into the middle where you want it.

Find an example below. You may want to edit it to suit your style.

<!DOCTYPE html>
<html>
<body>

<style type="text/css">
.bgimg {
    background-image: url(http://klockren.se/klockren.png);
    background-repeat: no-repeat;
    position:relative;
}
.canvas {position:absolute; top:250px; left:380px;}
</style>

<div align="center" class="bgimg">

   <div class="canvas">
      <canvas id="canvas" width="100" height="100"></canvas>
   </div>
</div>

<script>
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var radius = canvas.height / 2;
ctx.translate(radius, radius);
radius = radius * 0.90
setInterval(drawClock, 1000);

function drawClock() {
  drawFace(ctx, radius);
  drawNumbers(ctx, radius);
  drawTime(ctx, radius);
}

function drawFace(ctx, radius) {
  var grad;
  ctx.beginPath();
  ctx.arc(0, 0, radius, 0, 2*Math.PI);
  ctx.fillStyle = 'white';
  ctx.fill();
  grad = ctx.createRadialGradient(0,0,radius*0.95, 0,0,radius*1.05);
  grad.addColorStop(0, '#333');
  grad.addColorStop(0.5, 'white');
  grad.addColorStop(1, '#333');
  ctx.strokeStyle = grad;
  ctx.lineWidth = radius*0.1;
  ctx.stroke();
  ctx.beginPath();
  ctx.arc(0, 0, radius*0.1, 0, 2*Math.PI);
  ctx.fillStyle = '#000';
  ctx.fill();
}

function drawNumbers(ctx, radius) {
  var ang;
  var num;
  ctx.font = radius*0.15 + "px arial";
  ctx.textBaseline="middle";
  ctx.textAlign="center";
  for(num = 1; num < 13; num++){
    ang = num * Math.PI / 6;
    ctx.rotate(ang);
    ctx.translate(0, -radius*0.85);
    ctx.rotate(-ang);
    ctx.fillText(num.toString(), 0, 0);
    ctx.rotate(ang);
    ctx.translate(0, radius*0.85);
    ctx.rotate(-ang);
  }
}

function drawTime(ctx, radius){
    var now = new Date();
    var hour = now.getHours();
    var minute = now.getMinutes();
    var second = now.getSeconds();
    //hour
    hour=hour%12;
    hour=(hour*Math.PI/6)+
    (minute*Math.PI/(6*60))+
    (second*Math.PI/(360*60));
    drawHand(ctx, hour, radius*0.5, radius*0.07);
    //minute
    minute=(minute*Math.PI/30)+(second*Math.PI/(30*60));
    drawHand(ctx, minute, radius*0.8, radius*0.07);
    // second
    second=(second*Math.PI/30);
    drawHand(ctx, second, radius*0.9, radius*0.02);
}

function drawHand(ctx, pos, length, width) {
    ctx.beginPath();
    ctx.lineWidth = width;
    ctx.lineCap = "round";
    ctx.moveTo(0,0);
    ctx.rotate(pos);
    ctx.lineTo(0, -length);
    ctx.stroke();
    ctx.rotate(-pos);
}
</script>

</body>
</html>

Upvotes: 0

MrVentzi
MrVentzi

Reputation: 669

#clock {
    position: absolute;
    top: 270px;
    right: 340px;
}

Instead of background image, use image tag and then absolute position the clock.

See jsfiddle below.

https://jsfiddle.net/m3s7tvtc/

Upvotes: 0

Vishal
Vishal

Reputation: 394

You can use below code to align canvas properly:

 #canvas{
    position: relative;
    top: 40%;
}

Upvotes: 0

Nitin
Nitin

Reputation: 149

I have added a css for this hope this helps

    <div align="center" class="bgimg">

<div align="center">

<canvas id="canvas" width="100" height="100"

style="background-color:#fff">

</canvas>
</div>
</div>



    var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var radius = canvas.height / 2;
ctx.translate(radius, radius);
radius = radius * 0.90
setInterval(drawClock, 1000);

function drawClock() {
  drawFace(ctx, radius);
  drawNumbers(ctx, radius);
  drawTime(ctx, radius);
}

function drawFace(ctx, radius) {
  var grad;
  ctx.beginPath();
  ctx.arc(0, 0, radius, 0, 2*Math.PI);
  ctx.fillStyle = 'white';
  ctx.fill();
  grad = ctx.createRadialGradient(0,0,radius*0.95, 0,0,radius*1.05);
  grad.addColorStop(0, '#333');
  grad.addColorStop(0.5, 'white');
  grad.addColorStop(1, '#333');
  ctx.strokeStyle = grad;
  ctx.lineWidth = radius*0.1;
  ctx.stroke();
  ctx.beginPath();
  ctx.arc(0, 0, radius*0.1, 0, 2*Math.PI);
  ctx.fillStyle = '#000';
  ctx.fill();
}

function drawNumbers(ctx, radius) {
  var ang;
  var num;
  ctx.font = radius*0.15 + "px arial";
  ctx.textBaseline="middle";
  ctx.textAlign="center";
  for(num = 1; num < 13; num++){
    ang = num * Math.PI / 6;
    ctx.rotate(ang);
    ctx.translate(0, -radius*0.85);
    ctx.rotate(-ang);
    ctx.fillText(num.toString(), 0, 0);
    ctx.rotate(ang);
    ctx.translate(0, radius*0.85);
    ctx.rotate(-ang);
  }
}

function drawTime(ctx, radius){
    var now = new Date();
    var hour = now.getHours();
    var minute = now.getMinutes();
    var second = now.getSeconds();
    //hour
    hour=hour%12;
    hour=(hour*Math.PI/6)+
    (minute*Math.PI/(6*60))+
    (second*Math.PI/(360*60));
    drawHand(ctx, hour, radius*0.5, radius*0.07);
    //minute
    minute=(minute*Math.PI/30)+(second*Math.PI/(30*60));
    drawHand(ctx, minute, radius*0.8, radius*0.07);
    // second
    second=(second*Math.PI/30);
    drawHand(ctx, second, radius*0.9, radius*0.02);
}

function drawHand(ctx, pos, length, width) {
    ctx.beginPath();
    ctx.lineWidth = width;
    ctx.lineCap = "round";
    ctx.moveTo(0,0);
    ctx.rotate(pos);
    ctx.lineTo(0, -length);
    ctx.stroke();
    ctx.rotate(-pos);
}

.bgimg {
    background-image: url(http://klockren.se/klockren.png);
    background-repeat: no-repeat;
    height:570px;
}
#canvas {
       margin-left:370px;
    margin-top:240px;
}

https://jsfiddle.net/4heaex79/

Upvotes: 1

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