javascript - HTML5 Javascript 对象已被点击

Question

我正在制作一款游戏，你的鼠标是十字线，你点击在屏幕上移动的僵尸。我无法弄清楚如何确定鼠标是否点击了僵尸。僵尸是用 JavaScript 制作的，所以我无法在 HTML 中使用 onclick 属性。这是我的代码。

var mouseX;
var mouseY;

$(document).ready(function(){
var canvasWidth = 640;
var canvasHeight = 480;

var canvas = $("#gameCanvas")[0];
var context = canvas.getContext("2d");

var score = 0;
var timer = 0;
var spawnZombie = false;

//crosshair
var crossHair = new Image();
var crosshairX = 50;
var crosshairY = 50;
crossHair.src = "media/crosshair.png";

//zombies
var zombies = [];
var zombieLeft = new Image();
zombieLeft.src = "media/zombieLEFT.gif";
var zombieRight = new Image();
zombieRight.src = "media/zombieRIGHT.gif";

var fps = 30;
setInterval(function(){
    update();
    draw();
}, 1000/fps);

function update(){
    timer += 1;

    crosshairX = mouseX - 445;
    crosshairY = mouseY - 125;

    if(timer >= 70){
        timer = 0;
        spawnZombie = true;
    }

    zombies.forEach(function(zombie) {
        zombie.update();
        document.body.onmousedown = function() { 
            console.log(zombie.x.toString() + ", " + zombie.y.toString());
            //if(mouseX)
        };
    });

    zombies = zombies.filter(function(zombie){
        return zombie.active;
    });

    if(spawnZombie){
        zombies.push(Zombie(null, "left"));
        zombies.push(Zombie(null, "right"));
        spawnZombie = false;
    }
}
function draw(){
    context.clearRect(0,0, canvasWidth, canvasHeight);

    context.fillStyle = "#000";
    context.font = "20px Comic Sans MS";
    context.fillText("Score: " + score, 50, 50);

    zombies.forEach(function(zombie) {
        zombie.draw();
    });

    context.drawImage(crossHair, crosshairX, crosshairY, 100, 100);
}

function Zombie(I, dir){
    I = I || {};
    I.active = true;

    I.speed = 5;

    I.y = getRandomInt(50, 350);
    if(dir == "left"){
        I.x = 800;
    }
    else if(dir == "right"){
        I.x = -100;
    }
    I.width = 100;
    I.height = 100;

    I.inBounds = function() {
        return I.x >= 0 && I.x <= canvasWidth &&
        I.y >= 0 && I.y <= canvasHeight;
    };

    I.draw = function(){
        if(dir == "left"){
            context.drawImage(zombieLeft, this.x, this.y, this.width, this.height);
        }
        else if(dir == "right"){
            context.drawImage(zombieRight, this.x, this.y, this.width, this.height);
        }
    };

    I.update = function(){
        if(dir == "left"){
            this.x -= this.speed;
        }
        else if(dir == "right"){
            this.x += this.speed;
        }
    };

    I.onclick = function(){
        I.remove();
    };
    return I;
}

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}
});
$( document ).on( "mousemove", function( event ) {
    mouseX = event.pageX;
    mouseY = event.pageY;
});

这是我试图检测更新函数中是否单击了僵尸的特定位置

zombies.forEach(function(zombie) {
            zombie.update();
            document.body.onmousedown = function() { 
                console.log(zombie.x.toString() + ", " + zombie.y.toString());
                //if(mouseX)
            };
        });

Answer 1

I can't use the onclick attribute in HTML.

但是您可以在 JavaScript 中使用 addEventListener 方法:

例如。

zombieLeft.addEventListener('click', myFunction, false);