XNA Windows Phone 7 Sprite 运动

Question

我正在开发一款 Windows 手机游戏，但我在精灵移动方面遇到了困难。 我想要做的是让精灵逐渐移动到屏幕上触摸的位置，当只有一个快速触摸和释放时。 在这一刻，我所能做的就是让精灵立即跳转到触摸位置，或者在按住触摸时移动到触摸位置。

跳转到触摸位置的代码：

TouchCollection touchCollection = TouchPanel.GetState();
        foreach (TouchLocation tl in touchCollection)
        {
            if ((tl.State == TouchLocationState.Pressed)
                 || (tl.State == TouchLocationState.Moved))
            {
                Vector2 newPos = new Vector2(tl.Position.X,tl.Position.Y);

                    if (position != newPos)
                    {
                        while (position.X < newPos.X)
                        {
                            position.X += (float)theGameTime.ElapsedGameTime.Milliseconds / 10.0f * spriteDirectionRight;
                        }
                    }
            }
        }

按住触摸时逐渐移动的代码：

TouchCollection touchCollection = TouchPanel.GetState();
        foreach (TouchLocation tl in touchCollection)
        {
            if ((tl.State == TouchLocationState.Pressed)
                 || (tl.State == TouchLocationState.Moved))
            {
                Vector2 newPos = new Vector2(tl.Position.X,tl.Position.Y);

                    if (position != newPos)
                    {

                            position.X += (float)theGameTime.ElapsedGameTime.Milliseconds / 10.0f * spriteDirectionRight;

                    }
            }
         }

这些在 Sprite 类的 Update() 方法中。

Answer 1

类似这样的东西...对不起，我没有通过编译器运行它，所以可能存在一些语法错误。将这些声明为类中的字段：

Vector2 newPos;
bool moving = false;

然后在Update方法中：

        TouchCollection touchCollection = TouchPanel.GetState();
        foreach (TouchLocation tl in touchCollection)
        {
            if ((tl.State == TouchLocationState.Pressed)
                 || (tl.State == TouchLocationState.Moved)
                 || (tl.State == TouchLocationState.Released))
            {
                newPos = new Vector2(tl.Position.X, tl.Position.Y);
                moving = true;
            }
        }
        if (moving && newPos != position)
        {
            Vector2 delta = newPos - position;
            Vector2 norm = delta;
            norm.Normalize();
            Vector2 distanceToMove = norm * ((float)gameTime.ElapsedGameTime.TotalMilliseconds * .5f);
            if (distanceToMove.LengthSquared() > delta.LengthSquared())
            {
                position = newPos;
                moving = false;
            }
            else
            {
                position += distanceToMove;
            }
        }