private static CollisionDetails doOnlyYMovement(ref Vector2 velocity, CollisionDetails ret, ref Vector2 slidingYPosition)
{
velocity.X *= -0.5f; //bounce from wall
ret.m_speedAfterCollision = velocity;
ret.m_positionAfterCollision = slidingYPosition;
return(ret);
}
private static CollisionDetails doStandStill(CollisionDetails ret, Vector2 velocity)
{
if (velocity.Y > 0)
{
ret.m_hasCollidedWithGround = true;
}
ret.m_speedAfterCollision = new Vector2(0, 0);
return(ret);
}
private static CollisionDetails doOnlyXMovement(ref Vector2 velocity, CollisionDetails ret, ref Vector2 slidingXPosition)
{
ret.m_positionAfterCollision = slidingXPosition;
//did we slide on ground?
if (velocity.Y > 0)
{
ret.m_hasCollidedWithGround = true;
}
ret.m_speedAfterCollision = doSetSpeedOnVerticalCollision(velocity);
return(ret);
}
private void UpdatePlayer(float totalElapsedSeconds)
{
Vector2 oldPosition = m_player.Position;
m_player.Update(totalElapsedSeconds);
Vector2 newPosition = m_player.Position;
m_hasCollidedWithGround = false;
Vector2 velocity = m_player.Velocity;
if (CollisionHandler.didCollide(newPosition, m_player.Size, m_level))
{
CollisionDetails details = CollisionHandler.getCollisionDetails(oldPosition, newPosition, m_player.Size, velocity, m_level);
m_hasCollidedWithGround = details.m_hasCollidedWithGround;
m_player.Position = details.m_positionAfterCollision;
m_player.Velocity = details.m_speedAfterCollision;
}
}
public static CollisionDetails getCollisionDetails(Vector2 oldPos, Vector2 newPosition, Vector2 size, Vector2 velocity, Level level)
{
CollisionDetails ret = new CollisionDetails(oldPos, velocity);
Vector2 slidingXPosition = new Vector2(newPosition.X, oldPos.Y); //Y movement ignored
Vector2 slidingYPosition = new Vector2(oldPos.X, newPosition.Y); //X movement ignored
if (didCollide(slidingXPosition, size, level) == false)
{
return(doOnlyXMovement(ref velocity, ret, ref slidingXPosition));
}
else if (didCollide(slidingYPosition, size, level) == false)
{
return(doOnlyYMovement(ref velocity, ret, ref slidingYPosition));
}
else
{
return(doStandStill(ret, velocity));
}
}
