我最近问了一个问题，但还是不明白，我的意思是答案很好，但我就是不明白。我试图让玩家跳得越高，空格键保持的时间越长。高度也需要有一个最大值。
我有一个播放器类示例，我正在尝试向其中添加这样的功能。如果有人可以看看这个类，添加功能，然后添加一些评论来帮助我，我将非常感激。- 谢谢。
播放器.cs
namespace Jumping
{
class Player
{
public Texture2D Texture;
public Vector2 Velocity;
public Vector2 Position;
public float ground;
private float Speed;
private Rectangle screenBound;
public bool isJumping; //are we jumping or not
public bool goingUp; //if going up or not
public float u; //initial velocity
private float jumpU;
private float g; //gravity
public float t; //time
private KeyboardState prevKB;
public Player(Texture2D Texture, Vector2 Position, float Speed, Rectangle screenBound)
{
this.Texture = Texture;
this.Position = Position;
ground = Position.Y;
this.Speed = Speed;
this.screenBound = screenBound;
Velocity = Vector2.Zero;
isJumping = goingUp = false;
jumpU = 2.5f;
g = -9.8f;
t = 0;
}
public void Update(GameTime gameTime)
{
Position.X += (Velocity.X * Speed);
//Set the Y position to be subtracted so that the upward movement would be done by decreasing the Y value
Position.Y -= (Velocity.Y * Speed);
goingUp = (Velocity.Y > 0);
// TODO: Add your update logic here
if (isJumping == true)
{
//motion equation using velocity: v = u + at
Velocity.Y = (float)(u + (g * t));
//Increase the timer
t += (float)gameTime.ElapsedGameTime.TotalSeconds;
}
if (isJumping == true && Position.Y > screenBound.Height - Texture.Height)
{
Position.Y = ground = screenBound.Height - Texture.Height;
Velocity.Y = 0;
isJumping = false;
t = 0;
}
if (Position.X < 0)
{
//if Texture touches left side of the screen, set the position to zero and the velocity to zero.
Position.X = 0;
Velocity.X = 0;
}
else if (Position.X + Texture.Width > screenBound.Width)
{
//if Texture touches left side of the screen, set the position to zero and the velocity to zero.
Position.X = screenBound.Width - Texture.Width;
Velocity.X = 0;
}
if (Position.Y < 0)
{
//if the Texture touches the top of the screen, reset the timer and set the initial velocity to zero.
Position.Y = 0;
t = 0;
u = 0;
}
}
public void Input(KeyboardState keyState)
{
if (keyState.IsKeyDown(Keys.Space) && (isJumping == false || Position.Y == ground))
{
isJumping = true;
u = jumpU;
}
if (keyState.IsKeyDown(Keys.Left) && !keyState.IsKeyDown(Keys.Right))
{
if (keyState.IsKeyDown(Keys.A))
{
if (Velocity.X > -2.0f)
Velocity.X -= (1.0f / 10);
}
else if (Velocity.X > -1.0f)
{
Velocity.X -= (1.0f / 10);
}
else
{
Velocity.X = -1.0f;
}
}
else if (!keyState.IsKeyDown(Keys.Left) && keyState.IsKeyDown(Keys.Right))
{
if (keyState.IsKeyDown(Keys.A))
{
if (Velocity.X < 2.0f)
Velocity.X += (1.0f / 10);
}
else if (Velocity.X < 1.0f)
{
Velocity.X += (1.0f / 10);
}
else
{
Velocity.X = 1.0f;
}
}
else
{
if (Velocity.X > 0.05 || Velocity.X < -0.05)
Velocity.X *= 0.90f;
else
Velocity.X = 0;
}
prevKB = keyState;
}
public void Fall()
{
t = 0;
u = 0;
}
public void Draw(SpriteBatch spriteBatch)
{
spriteBatch.Draw(Texture, new Rectangle((int)Position.X, (int)Position.Y, Texture.Width, Texture.Height), Color.White);
}
}
}