44 lines
1.1 KiB
Groff
44 lines
1.1 KiB
Groff
<!doctype html>
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<html>
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<head>
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<title>Canvas HTML5</title>
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<style>
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#canvas {
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border: 1px solid black;
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}
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</style>
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</head>
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<body>
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<div><canvas id="canvas"></canvas></div>
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<script>
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const canvas = document.getElementById("canvas");
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const ctx = canvas.getContext("2d");
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const ballSize = 10;
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let x = canvas.width / 2;
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let y = canvas.height / 2;
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let dirX = 1;
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let dirY = 1;
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function drawBall() {
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ctx.beginPath();
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ctx.arc(x, y, ballSize, 0, Math.PI * 2);
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ctx.fillStyle = "red";
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ctx.fill();
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ctx.closePath();
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}
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function move() {
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ctx.clearRect(0, 0, canvas.width, canvas.height);
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drawBall();
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if (x > canvas.width - ballSize || x < ballSize) {
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dirX *= -1;
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}
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if (y > canvas.height - ballSize || y < ballSize) {
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dirY *= -1;
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}
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x += dirX;
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y += dirY;
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}
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setInterval(move, 10);
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</script>
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</body>
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</html>
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