Handling Score When Collision of XNA

Question

I just want to handle score when the Land collide on a ship i created in 2D game in XNA game studio.. Life(Score) is settled to 100 variable called Life in GameLife class...

i want to reduce life by 2 points when two objects collided...

But the problem is when the ship collided on a Land the the the life is instantly going to minus values till ship object keep away from land object... please give me a help...

the Code is provided here

`private void HandleLandCollition(List<LandTile> landtiles)
{
    foreach (LandTile landtile in landtiles)
    {
        rectangle1 = new Rectangle((int)landtile.position.X - landtile.texture.Width / 2,
                    (int)landtile.position.Y - landtile.texture.Height / 2,
                    landtile.texture.Width, landtile.texture.Height);//land object

        rectangle2 = new Rectangle((int)position.X - texture.Width / 2,
                    (int)position.Y - texture.Height / 2,
                    texture.Width, texture.Height);//rectangle2 is defined to ship object
        if (rectangle1.Intersects(rectangle2))
        {
            shiplife.Life = shiplife.Life - 2;
        }
    }
}

Answer 1

Your problem is probably that you call this method every frame. Usually XNA calls Update() 60 times per second, so if your ship touches the landtile for a second, it loses 2*60 = 120 healthpoints, which results in the minus values you're seeing.

My solution would be this:

protected override void Update(GameTime gameTime)
{
    float elapsedTime = (float) gameTime.ElapsedTime.TotalSeconds;
    HandleCollision(landtiles, elapsedTime);
}
float landDamagePerSecond = 2;
private void HandleLandCollision(List<LandTile> landtiles, float elapsedTime)
{
    shipRectangle= new Rectangle((int)position.X - texture.Width / 2,
                (int)position.Y - texture.Height / 2,
                texture.Width, texture.Height);//rectangle2 is defined to ship object

    foreach (LandTile landtile in landtiles)
    {
                landRectangle= new Rectangle(
                (int)landtile.position.X - landtile.texture.Width / 2,
                (int)landtile.position.Y - landtile.texture.Height / 2,
                landtile.texture.Width, landtile.texture.Height);//land object

        if (landRectangle.Intersects(shipRectangle))
        {
            shiplife.Life -= landDamagePerSecond * elapsedTime;
        }
    }
}

elapsedTime is the time since the last frame was called, by multiplicating this with the damage the landtile deals to the ship per second will result that the ship loses 2 healthpoints per second when it touches a landtile ;)