<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
* {
margin: 0;
padding: 0;
}
#canvas {
display: block;
margin: 0 auto;
}
</style>
</head>
<body>
<canvas id="canvas">
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</canvas>
</body>
<script>
var canvas = document.getElementById("canvas"),
c = canvas.getContext("2d"),
W = canvas.width = 1200,
H = canvas.height = 800;
var ballX = W / 2, ballY = H / 2, ballR = 10, ballVx = 5, ballVy = 1,
panelW = 10, panelH = 100, panel1Y = (H - panelH) / 2, panel2Y = (H - panelH) / 2,
player1Score = 0, player2Score = 0, winnerScore = 3,
isEnd = 0;
animate();
canvas.addEventListener("click", function () {
if (isEnd) {
player1Score = 0;
player2Score = 0;
isEnd = 0;
animate();
}
});
canvas.addEventListener("mousemove", function (e) {
panel1Y = e.clientY - canvas.getBoundingClientRect().top - panelH / 2;
});
function animate() {
fillRect(0, 0, W, H, "black");
if (isEnd) {
if (player1Score >= winnerScore) {
fillText("恭喜，你赢了!", W / 2, H / 2);
} else {
fillText("抱歉，你输了!", W / 2, H / 2);
}
fillText("再来一次?", W / 2, H / 3 * 2, "32px DejaVu Sans Mono");
return;
}
drawNet();
if (panel2Y + panelH / 2 < ballY - 40) {
panel2Y = panel2Y + 5;
} else if (panel2Y + panelH / 2 > ballY + 40) {
panel2Y = panel2Y - 5;
}
ballX += ballVx;
ballY += ballVy;
if (ballX - ballR - panelW < 0) {
if (ballY > panel1Y && ballY < panel1Y + panelH) {
ballVx = -ballVx;
ballVy = (ballY - (panel1Y + panelH / 2)) * .3;
} else {
player2Score++;
ballReset();
}
}
if (ballX + ballR + panelW > W) {
if (ballY > panel2Y && ballY < panel2Y + panelH) {
ballVx = -ballVx;
ballVy = (ballY - (panel2Y + panelH / 2)) * .3;
} else {
player1Score++;
ballReset();
}
}
if (ballY + ballR < 0 || ballY - ballR > H) {
ballVy = -ballVy;
}
fillRect(1, panel1Y, panelW, panelH, "white");
fillRect(W - panelW - 1, panel2Y, panelW, panelH, "white");
fillCircle(ballX, ballY, ballR, "white");
fillText(player1Score, 100, 100);
fillText(player2Score, W - 100, 100);
requestAnimationFrame(animate);
}
function drawNet() {
for (var i = 0; i < H; i += 40) {
fillRect(W / 2 - 1, i + 10, 2, 20, "white");
}
}
function ballReset() {
if (player1Score >= winnerScore || player2Score >= winnerScore) {
isEnd = 1;
}
ballVx = -ballVx;
ballX = W / 2;
ballY = H / 2;
}
function fillRect(x, y, w, h, style) {
c.fillStyle = style;
c.fillRect(x, y, w, h);
}
function fillCircle(x, y, r, style) {
c.fillStyle = style;
c.beginPath();
c.arc(x, y, r, 0, Math.PI * 2);
c.fill();
}
function fillText(txt, x, y, font, style) {
c.fillStyle = style || "white";
c.font = font || "40px DejaVu Sans Mono";
c.textAlign = "center";
c.textBaseline = "middle";
c.fillText(txt, x, y);
}
</script>
</html>
