如何检测此 JavaScript 游戏的对象碰撞

Question

在尝试制作一个小游戏进行练习时，我遇到了一个问题。关键是要抓住妖精，但我不知道如何让游戏检测到玩家已经击中了妖精。

到目前为止，只有当你的 Y 和 X 位置与敌人的轴匹配时，你才能检测到触摸。我怎样才能增加两者的宽度或更好的检测触摸的方法。

风格：

#map{
        margin: 0 auto;
        height: 510px;
        width: 510px;
        background-image:url(background.png);

    } 

    .character{
        background-image:url(character.png);
        z-index:1;
        position: relative;
        top: 150px;
        left: 150px;
        height: 32px;
        width: 33px;
    }

    .monster{
        background-image:url(monster.png);

        position: relative;
        height: 32px;
        width: 30px;
    }

Javascript:

 $(document).ready(function(){

            var char = { 

                player : $(".character"),
                x: 150,
                y: 150

            };

            var monster = {

                npc : $(".monster"),
                x: 100,
                y: 100
            };

            var keypush = {};


        $(document).on("keydown keyup", function(e){

            var keyN = e.which;
            keypush[keyN] = e.type === "keydown";


        });





    function moveCharacter(){

        if (keypush[37]) char.x -=2;
        if (keypush[38]) char.y -=2;
        if (keypush[39]) char.x +=2;
        if (keypush[40]) char.y +=2;

        char.player.css({transform:"translate3D("+ char.x +"px, "+ char.y +"px, 0)"});
        monster.npc.css({transform:"translate3D("+ monster.x +"px, "+ monster.y +"px, 0)"});


        var playerPosX = char.player.position().top;
        var monsterPosX = monster.npc.position().top;

        var playerPosY = char.player.position().left;
        var monsterPosY = monster.npc.position().left;


        if ( playerPosX === monsterPosX
            && playerPosY === monsterPosY 
           ){

            document.getElementById("pos").innerHTML="Touched"; 

        } else {

            document.getElementById("pos").innerHTML="Off";
        }




//backend logs

 console.log(char.x);            
    }






        (function engine(){
        moveCharacter();
        window.requestAnimationFrame(engine);
    }());    

  });

HTML:

<div id = "map">
        <div class = "character">

        </div>
        <div class = "monster">
            <p id = "pos" style = "color:yellow;font-  weight:bold;position:relative;left:5px;font-size:20px;">Position: </p>
        </div>
    </div>

Answer 1

最简单快捷的方法是计算角色与怪物的距离：fiddle using circle collision.

    var dx = playerPosX - monsterPosX,
        dy = playerPosY - monsterPosY,
        touchDistance = 30; 

    if ( Math.sqrt( dx * dx + dy * dy ) < touchDistance )           
       document.getElementById("pos").innerHTML="Touched";                
    else
       document.getElementById("pos").innerHTML="Off";

这里我看了touchDistance，实际值应该是玩家精灵半径和怪物精灵半径之和。如果它们是圆圈，效果最好：

/**
 * (ax,ay) and (bx,by) are the center positions, and ar, br their radii.
 */
function circleCollision( ax, ay, ar, bx, by, br ) {
    return Math.sqrt( (ax-bx)*(ax-bx) + (ay-by)*(ay-by) ) <= ar + br;
}

确定冲突的第二种常用方法是使用 'bounding boxes'，或者在这种情况下，rectangles/squares：Fiddle using rectangle collision。

function rectangleCollision( pLeft, pTop, pRight, pBottom, mLeft, mTop, mRight, mBottom ) {
  return
     ( (pLeft   >= mLeft && pLeft   < mRight ) || (pRight >= mLeft && pRight < mRight ) )
  && ( (pBottom >= mTop  && pBottom < mBottom) || (pTop   >= mTop  && pTop   < mBottom) )
}

如何检测此 JavaScript 游戏的对象碰撞

How to detect object collision for this JavaScript game

javascript

object

collision