JavaScript Canvas实现井字棋游戏

本文实例为大家分享了JavaScript Canvas实现井字棋游戏的具体代码，供大家参考，具体内容如下

index.html

<!DOCTYPE html>
<html>
    <head>
        <title>Tic Tac Toe</title>
        <style>
            * {
                padding: 0;
                margin: 0;
            }

            body, html, #game {
                height: 100%;
                background: #FCFCFC;
            }

            #game {
                display: flex;
                align-items: center;
                justify-content: center;
            }
        </style>
    </head>
    <body>
        <div id="game">
            <canvas id="canvas" width="300" height="300"></canvas>
        </div>
        <script src="game.js"></script>
    </body>
</html>

game.js

players = 2;
cell_count = 3;
winCount = 3;
cell_size = 100;
size = cell_size * cell_count;

var canvas = document.getElementById('canvas');
canvas.width = size;
canvas.height = size;

canvas.addEventListener('click', click, false);

var ctx = canvas.getContext('2d');

ctx.imageSmoothingEnabled = false;
ctx.lineWidth = 3;

function clear() {
    ctx.clearRect(0, 0, canvas.width, canvas.height);
}

function line(x, y, w, h, color = '#ccc') {
    ctx.beginPath();
    ctx.moveTo(x, y);
    ctx.lineTo(x + w, y + h);
    ctx.strokeStyle = color;
    ctx.stroke();
    ctx.closePath();
}

function fillRect(i, j, color = '#F5F5F5') {
    ctx.fillStyle = color;
    ctx.fillRect(i * cell_size, j * cell_size, cell_size, cell_size);
}

var draw = {
    grid: (color = '#ccc') => {
        for (let i = 1; i < cell_count; i++) {
            line(cell_size * i, 0, 0, size, color);
            line(0, cell_size * i, size, 0, color);
    }
    },

    // draw nothing, stub
    0: (i, j, _) => {
    },

    // draw X figure
    1: (i, j, color = '#3F51B5') => {
        let left = (i + 0.1) * cell_size,
                top = (j + 0.1) * cell_size,
                size = 0.8 * cell_size;

        line(left, top, size, size, color);
        line(left + size, top, -size, size, color);
    },

    // draw O figure
    2: (i, j, color = '#FF5722') => {
        ctx.beginPath();
        ctx.arc((i + 0.5) * cell_size, (j + 0.5) * cell_size, 0.4 * cell_size, 0, Math.PI * 2, false);
        ctx.strokeStyle = color;
        ctx.stroke();
        ctx.closePath();
    },

    // draw Δ figure
    3: (i, j, color = '#FDE619'/*'#FFEB3B'*/) => {
        let center = (i + 0.5) * cell_size,
                size = Math.sqrt(3) * 0.525 * cell_size,
                top = (j + 0.125) * cell_size,
                height = 0.75 * cell_size,
                step = size / 2;

        line(center, top, -step, height, color);
        line(center, top, step, height, color);
        line(center - step, top + height, size, 0, color);
    }
};

let grid = new Array(cell_count * cell_count).fill(0),
        get = (i, j) => grid[j * cell_count + i],
        set = (i, j, val = 0) => grid[j * cell_count + i] = val,
        isFree = (i, j) => get(i, j) == 0,
        checkVictory = (who) => {
    let iterate = getter => {
        for (let i = 0; i < winCount; i++)
            if (getter(i) != who)
                return false;
        return true;
    };

    let row, col, path = {
        vertical: _ => iterate(i => get(row + i, col)),
        horizntl: _ => iterate(j => get(col, row + j)),
        diagonal: _ => iterate(i => get(row + i, col + i)),
        opposite: _ => iterate(i => get(row + i, col + winCount - 1 - i)),
    };

    for (row = 0; row <= cell_count - winCount; row++) {
        for (col = 0; col < cell_count; col++) {
            if (path.vertical())
                return ['vertical', row, col];
            if (path.horizntl())
                return ['horizntl', col, row];
        }

        for (col = 0; col <= cell_count - winCount; col++) {
            if (path.diagonal())
                return ['diagonal', row, col];
            if (path.opposite())
                return ['opposite', row, col];
        }
    }

    return [];
},
        onWin = ([type, row, col]) => {
    if (!type)
        return;

    let iterate = action => {
        for (let i = 0; i < winCount; i++)
            action(i);
    };

    let drawSequence = {
        vertical: _ => iterate(i => fillRect(row + i, col)),
        horizntl: _ => iterate(j => fillRect(row, col + j)),
        diagonal: _ => iterate(i => fillRect(row + i, col + i)),
        opposite: _ => iterate(i => fillRect(row + i, col + winCount - 1 - i)),
    };

    clear();
    drawSequence[type]();
    draw.grid();

    for (let i = 0; i < cell_count; i++) {
        for (let j = 0; j < cell_count; j++)
            draw[get(i, j)](i, j);
    }

    return true;
};

let playerTurn = 0;

function click(e) {
    let i = e.offsetX / cell_size | 0,
            j = e.offsetY / cell_size | 0;

    if (isFree(i, j)) {
        let figure = playerTurn++ % players + 1;

        set(i, j, figure);
        draw[figure](i, j);
        onWin(checkVictory(figure)) && canvas.removeEventListener('click', click, false);
        ;
    }
}

draw.grid();

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。