传递变量以便以角度移动子弹

so basically I am currently implementing shooting at cursor mechanic into my game. I have a mousemove eventListener to check for mouse coordinates and to calculate the angle at what my character should shoot. I just need to pass the final vx and vy variables from my handleMouse function to my update function, but I can't figure out how. It's probably going to be very simple solution, but I can't get my head around it since I am pretty new to programming. Thank you very much.

所以基本上我目前正在将光标机制射击到我的游戏中。我有一个mousemove eventListener来检查鼠标坐标并计算我的角色应该拍摄的角度。我只需要将最终的vx和vy变量从我的handleMouse函数传递给我的更新函数，但我无法弄清楚如何。它可能是一个非常简单的解决方案，但我不能理解它，因为我对编程很新。非常感谢你。

window.addEventListener("mousemove", handleMouse, false);

function getMousePosition(e){
    var x, y;
    x = e.clientX - backgroundCanvas.getBoundingClientRect().left;
    y = e.clientY - backgroundCanvas.getBoundingClientRect().top;
    return {x:x, y:y};
}

function handleMouse(e){    
    var pos = getMousePosition(e);
    posx = pos.x; //mouse x position
    posy = pos.y; //mouse y position

    var delta = {x: posx - player.x, y: posy - player.y}; //y2 - y1, x2 - x1
    var angle = Math.atan2(delta.y, delta.x) ; 

    var vx = Math.cos(angle - (Math.PI/2)) * game.bulletSpeed;
    var vy = Math.sin(angle - (Math.PI/2)) * game.bulletSpeed;
    return {vx:vx, vy:vy};
}

function update(){
    //move bullets - this is where I need to pass the vx and vy variables
    var vector = handleMouse(e); // this is probably wrong
    vx = vector.vx;
    vy = vector.vy;

    for (i in game.bullets){
        game.bullets[i].x -= vx;
        game.bullets[i].y -= vy;    
    }
}

2 个解决方案

#1

Maybe this would help, assuming that you directly want to pass vx and vy variables from handleMouse method to update method.

也许这会有所帮助，假设您直接想要将handleMouse方法中的vx和vy变量传递给update方法。

function handleMouse(e){    
    var pos = getMousePosition(e);
    posx = pos.x; //mouse x position
    posy = pos.y; //mouse y position

    var delta = {x: posx - player.x, y: posy - player.y}; //y2 - y1, x2 - x1
    var angle = Math.atan2(delta.y, delta.x) ; 

    var vx = Math.cos(angle - (Math.PI/2)) * game.bulletSpeed;
    var vy = Math.sin(angle - (Math.PI/2)) * game.bulletSpeed;

    //call update method
    update(vx, vy);

    return {vx:vx, vy:vy};
}

and the update method

和更新方法

function update(vx, vy){   
    for (i in game.bullets){
        game.bullets[i].x -= vx;
        game.bullets[i].y -= vy;    
    }
}

2 个解决方案

#1

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