private void UpdateCollisions()
{
sentries = (List <Sentry>)Game.Services.GetService(typeof(List <Sentry>));
player = (TilePlayer)Game.Services.GetService(typeof(TilePlayer));
playerProjectile = (Projectile)Game.Services.GetService(typeof(Projectile));
projectile = (Ricochet)Game.Services.GetService(typeof(Ricochet));
sentryProjectiles = (List <Projectile>)Game.Services.GetService(typeof(List <Projectile>));
CollideWithProjectile(playerProjectile);
CollideWithProjectile(projectile);
CollideWithTank(player);
for (int i = 0; i < sentries.Count; i++)
{
if (!sentries[i].IsDead)
{
CollideWithTank(sentries[i]);
}
}
for (int i = 0; i < sentryProjectiles.Count; i++)
{
CollideWithProjectile(sentryProjectiles[i]);
}
}
private void MinkowskiSum(Ricochet obj)
{
w = 0.5f * (obj.BoundingRectangle.Width + CollisionField.Width);
h = 0.5f * (obj.BoundingRectangle.Height + CollisionField.Height);
dx = obj.BoundingRectangle.Center.X - CollisionField.Center.X;
dy = obj.BoundingRectangle.Center.Y - CollisionField.Center.Y;
if (Math.Abs(dx) <= w && Math.Abs(dy) <= h)
{
/* collision! */
wy = w * dy;
hx = h * dx;
if (wy > hx)
{
if (wy > -hx)
{
/* collision at the top */
obj.Direction.Y = -obj.Direction.Y;
return;
}
else
{
/* on the left */
obj.Direction.X = -obj.Direction.X;
obj.Scale = -obj.Scale;
return;
}
}
else
{
if (wy > -hx)
{
/* on the right */
obj.Direction.X = -obj.Direction.X;
obj.Scale = -obj.Scale;
return;
}
else
{
/* at the bottom */
obj.Direction.Y = -obj.Direction.Y;
return;
}
}
}
}
private void CollideWithProjectile(Ricochet obj)
{
if (obj != null && obj.ProjectileState != Projectile.PROJECTILE_STATUS.Idle)
{
projectileBounds = new Rectangle(
new Point(
(int)obj.CentrePos.X - (obj.ProjectileWidth),
(int)obj.CentrePos.Y),
new Point(obj.ProjectileWidth, obj.ProjectileHeight));
if (projectileBounds.Intersects(CollisionField))
{
obj.PixelPosition = obj.PreviousPosition;
obj.angleOfRotation = -obj.angleOfRotation;
MinkowskiSum(obj);
}
}
}