Hello I want to know how can I make the canvas shape circle in the below code. The code is about moving a object with keyboard keys. I tried to make the circle out of this box but it just disappeared and i am not really sharp. Can some help me make this canvas circle without affecting code.
sorry but i have to write something more because SO says body has all code… i don’t know what to say now (make the canvas circle)(make the canvas circle)(make the canvas circle)
<!DOCTYPE html>
<html>
<head></head>
<body>
<canvas id="myCanvas" width='800' height='800' border-radius= ></canvas>
</body>
</html>
<script>
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
var centerX = canvas.width / 2;
var centerY = canvas.height / 2;
var radius = 70;
let circle = new Path2D(); // <<< Declaration
circle.arc(centerX, centerY, radius, 0, 2 * Math.PI, false);
context.fillStyle = 'lightblue';
context.fill(circle); // <<< pass circle to context
context.lineWidth = 10;
context.strokeStyle = '#000066';
context.stroke(circle);
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
window.requestAnimationFrame = requestAnimationFrame;
})();
//event listener
window.addEventListener("keydown", onKeyDown, false);
window.addEventListener("keyup", onKeyUp, false);
function onKeyDown(event) {
var keyCode = event.keyCode;
switch (keyCode) {
case 68: //d
keyD = true;
break;
case 83: //s
keyS = true;
break;
case 65: //a
keyA = true;
break;
case 87: //w
keyW = true;
break;
}
}
function onKeyUp(event) {
var keyCode = event.keyCode;
switch (keyCode) {
case 68: //d
keyD = false;
break;
case 83: //s
keyS = false;
break;
case 65: //a
keyA = false;
break;
case 87: //w
keyW = false;
break;
}
}
//neccessary variables
var tickX = 10;
var tickY = 10;
var keyW = false;
var keyA = false;
var keyS = false;
var keyD = false;
//main animation function
function drawStuff() {
window.requestAnimationFrame(drawStuff);
var canvas = document.getElementById("myCanvas");
var c = canvas.getContext("2d");
c.clearRect(0, 0, 800, 800);
c.fillStyle = "lightblue";
c.fillRect(tickX, tickY, 100, 100);
if (keyD == true) {
tickX += 1;
}
if (keyS == true) {
tickY += 1;
}
if (keyA == true) {
tickX--;
}
if (keyW == true) {
tickY--;
}
}
window.requestAnimationFrame(drawStuff);
</script>
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Answer
I moved the circle code into the drawstuff function as that is where it has to run, and removed the use of fillRect.
You can see the result here:
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
window.requestAnimationFrame = requestAnimationFrame;
})();
//event listener
window.addEventListener("keydown", onKeyDown, false);
window.addEventListener("keyup", onKeyUp, false);
function onKeyDown(event) {
var keyCode = event.keyCode;
switch (keyCode) {
case 68: //d
keyD = true;
break;
case 83: //s
keyS = true;
break;
case 65: //a
keyA = true;
break;
case 87: //w
keyW = true;
break;
}
}
function onKeyUp(event) {
var keyCode = event.keyCode;
switch (keyCode) {
case 68: //d
keyD = false;
break;
case 83: //s
keyS = false;
break;
case 65: //a
keyA = false;
break;
case 87: //w
keyW = false;
break;
}
}
//neccessary variables
var tickX = 10;
var tickY = 10;
var keyW = false;
var keyA = false;
var keyS = false;
var keyD = false;
//main animation function
function drawStuff() {
window.requestAnimationFrame(drawStuff);
var canvas = document.getElementById("myCanvas");
var c = canvas.getContext("2d");
c.clearRect(0, 0, 200, 200);
let circle = new Path2D(); // <<< Declaration
circle.arc(100 + tickX, 100 + tickY, 70, 0, 2 * Math.PI, false);
c.fillStyle = 'purple';
c.fill(circle); // <<< pass circle to context
c.lineWidth = 10;
c.strokeStyle = '#000066';
c.stroke(circle);
if (keyD == true) {
tickX += 1;
}
if (keyS == true) {
tickY += 1;
}
if (keyA == true) {
tickX--;
}
if (keyW == true) {
tickY--;
}
}
window.requestAnimationFrame(drawStuff);Focus this area, then use keys <b>d, s, a, w</b><br /> <canvas id="myCanvas" width='200' height='200' style="border: 1px solid #f4f4f4" ></canvas>