C# XNA 确定 Vector2 是否面对另一个 Vector2

Question

我正在开发一款 2D 游戏。我正在尝试弄清楚如何确定一个 Vector2 是否面对另一个。

这是我目前的情况：

public void update(GameTime gameTime, Vector2 playerPosition)
{
    // position is "enemy" Vector2
    // rotationAngle is the angle which the "enemy" is facing
    // I need to determine if the "enemy" should rotate left, right, or move forward
    // The goal is to have the "enemy" move towards the player
    float angle = MathHelper.ToDegrees((float)Math.Atan2(playerPosition.Y - position.Y, playerPosition.X - position.X));
    float rotationDegrees = MathHelper.ToDegrees(rotationAngle);
    // Now what????





    update(gameTime);
}

Answer 1

啊，在尝试了一些东西后我想通了。

public void update(GameTime gameTime, Vector2 playerPosition)
{
    float angle = MathHelper.ToDegrees((float)Math.Atan2(playerPosition.Y - position.Y, playerPosition.X - position.X));
    float rotationDegrees = MathHelper.ToDegrees(rotationAngle);
    var diff = ((rotationDegrees - angle) + 360) % 360;
    if (diff > 90)
    {
        // bool for rotate method determines if rotating left or right
        rotate(false);
    }
    else
    {
        rotate(true);
    }

    if (diff < 180 && diff > 0)
    {
        moveForward();
    }

    update(gameTime);
}

编辑：我的计算有一些问题。在某些情况下，敌人会被卡住。问题是有时每次游戏更新时该值都会从负值变为正值。解决方案是确保 diff 始终为正值。

C# XNA 确定 Vector2 是否面对另一个 Vector2

C# XNA determine if Vector2 is facing another Vector2

c#

xna

vector