Question

I’m learning how to use the XNA framework in C#, and I’m struggling with a basic error when calculating a basic form of friction.

The code for calculating the friction is:

//Check X deadzone movement
if (Velocity.X < 0.1f && Velocity.X > -0.1f)
{
    Velocity.X = 0f;
}
else
{
    //Friction Calculation
    if (Velocity.X > 0) Velocity.X -= Friction;
    if (Velocity.X < 0) Velocity.X += Friction;
}

//Check Y deadzone movement
if (Velocity.Y < 0.1f && Velocity.Y > -0.1f)
{
    Velocity.Y = 0f;
}
else 
{
    //Friction Calculation
    if (Velocity.Y > 0) Velocity.Y -= Friction;
    if (Velocity.Y < 0) Velocity.Y += Friction;
}

Where

Friction = 0.2f;`

My issue, is whenever I move the player to the right or down (positive directions), the velocity “sticks” and it is not being affected by friction. It stays at a constant value of around 0.4, too high to be affected by my deadzone. This doesn’t happen on negative velocites.

This seems like a simple error in my logic, but I can’t seem to figure it out, any help?

Answer 1

Your logic will immediately reverse the change in friction for values between .1 and .2. Try adding ‘else’ so you don’t immediately reverse the change.

if (Velocity.X > 0) Velocity.X -= Friction;
else if (Velocity.X < 0) Velocity.X += Friction;