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我一直在阅读/寻找一个答案来检测两个数组中精灵的冲突。我不明白如何将两个数组传递给检测函数并让它检查每个数组的所有内容。任何投入将不胜感激。

<script type="text/javascript">

        var FIRE = 0;
        var NORTH = 38;
        var SOUTH = 40;
        var EAST  = 39;
        var WEST  = 37;
        var destX = 350;
        var destY = 500;
        var canvas = null;
        var context = null;
        var sprites = null;
        var player = null;
        var island = null;
        var enemies = [];
        var fires = [];
        var gameLoopInterval = null;
        var offScreenFire = null;
        var isShooting = false;
        var intersect = null;

    var Fire = function() {
            this.spriteX = 278;
            this.spriteY = 110;
            this.spriteWidth = 13;
            this.spriteHeight = 16;
            this.destX = player.destX + 25;
            this.destY = player.destY;
            this.speed = 5;
        }

    var Player = function(name) {
            this.name = name;
            this.spriteX = 5;
            this.spriteY = 400;
            this.spriteWidth = 64;
            this.spriteHeight = 64;
            this.destX = 350;
            this.destY = 500;
            this.speed = 5;
            this.level = 1;
        }

    var Enemy = function() {

            this.spriteX = 4;
            this.spriteY = 4;
            this.spriteWidth = 32;
            this.spriteHeight = 32;
            this.destX = Math.ceil(Math.random() * (800 - this.spriteWidth));
            this.destY = this.spriteWidth;
            this.speed = Math.ceil(Math.random() * 5);
        }

    var Island = function() {

            this.spriteX = 168;
            this.spriteY = 500;
            this.spriteWidth = 64;
            this.spriteHeight = 64;
            this.destX = Math.ceil(Math.random() * (800 - this.spriteWidth));
            this.destY = this.spriteWidth - 64;
            this.speed = 2;
        }

    Fire.prototype.takeTurn = function() {

        var intersect;
        var projdestX  = this.destX;
        var projdestY  = this.destY;
        var projspriteWidth  = this.spriteWidth;
        var projspriteHeight  = this.spriteHeight;


        for (enemy in enemies)  {
             intersect = intersect || intersects(enemy.destX, enemy.destY, enemy.spriteWidth, enemy.spriteHeight, projdestX, projdestY, projspriteWidth, projspriteHeight);
        }
            if(intersect == true) { alert("colliding"); }
        else{drawImage(this);}
            // if (intersect != true){
                // drawImage(this);
            // }
            // else {
                // alert("boom");
            // }

            if(this.destY <= 0){
            offScreenFire = fires.indexOf(this);
            fires.splice(offScreenFire, 1);
            }
            else
            this.destY -= this.speed;

        }

    Player.prototype.takeTurn = function() {
            drawImage(this);
        }

    Enemy.prototype.takeTurn = function() {

            drawImage(this);


         if (this.destY < canvas.height)
                this.destY += this.speed;
         else 
             this.destY = -32;
        }

    Island.prototype.takeTurn = function() {
            drawImage(this);
            this.destY += this.speed;
        }

function fireAction() {

            var fire = new Fire();

                drawImage(fire);
                fires.push(fire);

    } 

function drawImage(sprite) {
            context.drawImage(sprites, sprite.spriteX, sprite.spriteY, sprite.spriteWidth, sprite.spriteHeight, sprite.destX, sprite.destY, sprite.spriteWidth, sprite.spriteHeight );
    }

function gameLoop () {

            context.clearRect(0, 0, canvas.width, canvas.height);

            island.takeTurn();
            player.takeTurn();

            //console.log(fires); //debug

            for (fire in fires) {
                fires[fire].takeTurn();

               }
            for (enemy in enemies) {
                enemies[enemy].takeTurn();

                    }   

        }


function intersects(x1, y1, w1, h1, x2, y2, w2, h2) {
        if (w2 !== Infinity && w1 !== Infinity) {
                 w2 += x2;
                 w1 += x1;
            if (isNaN(w1) || isNaN(w2) || x2 > w1 || x1 > w2)
                return false;
            }

        if (y2 !== Infinity && h1 !== Infinity) {
                h2 += y2;
                h1 += y1;
              if (isNaN(h1) || isNaN(y2) || y2 > h1 || y1 > h2)
                return false;
            }

         return true;
}

window.onload = function() {
        //alert('here');
            canvas =  document.getElementById('gameWorld');
            context = canvas.getContext("2d");
            sprites = new Image();

            player = new Player('Brad');
            island = new Island();


            sprites.onload = function() {
                drawImage(player);  
                for (i = 0; i < 3; i++) {
                    var enemy = new Enemy();
                    drawImage(enemy);
                    enemies.push(enemy);
                }
            }

            sprites.src = "Sprites/1945.png";

            gameLoopInterval = setInterval('gameLoop()', 100)
    }




    window.onkeypress = function(e){
            var evt = window.event ? event : e;
            //alert(evt.keyCode);
            switch(evt.keyCode) {
                case NORTH:

                 if (player.destY > 0)
                    player.destY -= player.speed;
                else
                    player.destY == player.destY;   

                    break;

                case SOUTH:

                 if (player.destY < canvas.height - player.spriteWidth)
                    player.destY += player.speed;
                else
                    player.destY == player.destY;   

                    break;

                case EAST:

                    if (player.destX < canvas.width - player.spriteWidth)
                       player.destX += player.speed;
                else
                    player.destX == player.destY;

                    break;

                case WEST:

                if (player.destX > 0)
                    player.destX -= player.speed;
                else
                    player.destX == player.destX;

                    break;

                case FIRE:

                        fireAction();

                    break;
            }
    }
</script>
4

1 回答 1

0

你的问题似乎在：

for (enemy in enemies) {
    intersect = intersects(enemy.destX, enemy.destY, enemy.spriteWidth, enemy.spriteHeight, projdestX, projdestY, projspriteWidth, projspriteHeight);
}

intersect将始终保存最后一个值。（这意味着您实际上只检查它是否与最后一个敌人相交。）

一个快速的解决方案是将内线更改为：

intersect = intersect || intersects(enemy.destX, enemy.destY, enemy.spriteWidth, enemy.spriteHeight, projdestX, projdestY, projspriteWidth, projspriteHeight);

这将使相交停留，就true好像火不与下一个敌人相交一样。

编辑：

您的第二个问题与 for() 相同。在 javascript 中，当您执行 a 时for in，第一个变量没有对实例的引用，而只是键。

您的最终结果应该如下所示：

for (enemy in enemies) {
    intersect = intersect || intersects(enemies[enemy].destX, enemies[enemy].destY, enemies[enemy].spriteWidth, enemies[enemy].spriteHeight, projdestX, projdestY, projspriteWidth, projspriteHeight);
}

你似乎也没有产生任何敌人。在您的代码（http://jsfiddle.net/path411/umjnQ/）中，我将以下代码段添加到您的代码中gameLoop()：

if(enemies.length < 1) {
    enemies.push(new Enemy());
}

如果您还没有敌人，这只会创建一个新敌人。（您可能稍后会想要更改）。

于 2013-05-08T19:30:47.120 回答