32 lines
694 B
JavaScript
32 lines
694 B
JavaScript
var canvas = document.getElementById("myCanvas");
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var ctx = canvas.getContext("2d");
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var ballRadius = 12;
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var x = ballRadius;
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var y = ballRadius;
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var dx = 2;
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var dy = -2;
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function drawBall() {
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ctx.beginPath();
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ctx.arc(x, y, ballRadius, 0, 2 * Math.PI);
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ctx.fillStyle = "#FF0000";
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ctx.fill();
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ctx.closePath();
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}
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function draw() {
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ctx.clearRect(0, 0, canvas.width, canvas.height);
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drawBall();
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if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
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dx = -dx;
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}
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if(y + dy > canvas.height-ballRadius || y + dy < ballRadius) {
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dy = -dy;
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}
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x += dx;
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y += dy;
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}
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setInterval(draw, 10); |