public Movement()
{
Hits = new Hit[0];
}
private static Hit ResolveNarrow(Vector2 origin, Vector2 destination, RectangleF other)
{
// if starts inside, push it outside at the neareast place
if (other.Contains(origin))
{
var outside = PushOutside(origin, other);
return(new Hit()
{
Amount = 0,
Position = outside.Item1,
Normal = outside.Item2,
});
}
var velocity = (destination - origin);
Vector2 invEntry, invExit, entry, exit;
if (velocity.X > 0)
{
invEntry.X = other.Left - origin.X;
invExit.X = other.Right - origin.X;
}
else
{
invEntry.X = other.Right - origin.X;
invExit.X = other.Left - origin.X;
}
if (velocity.Y > 0)
{
invEntry.Y = other.Top - origin.Y;
invExit.Y = other.Bottom - origin.Y;
}
else
{
invEntry.Y = other.Bottom - origin.Y;
invExit.Y = other.Top - origin.Y;
}
if (Math.Abs(velocity.X) < Constants.Threshold)
{
entry.X = float.MinValue;
exit.X = float.MaxValue;
}
else
{
entry.X = invEntry.X / velocity.X;
exit.X = invExit.X / velocity.X;
}
if (Math.Abs(velocity.Y) < Constants.Threshold)
{
entry.Y = float.MinValue;
exit.Y = float.MaxValue;
}
else
{
entry.Y = invEntry.Y / velocity.Y;
exit.Y = invExit.Y / velocity.Y;
}
if (entry.Y > 1.0f)
{
entry.Y = float.MinValue;
}
if (entry.X > 1.0f)
{
entry.X = float.MinValue;
}
var entryTime = Math.Max(entry.X, entry.Y);
var exitTime = Math.Min(exit.X, exit.Y);
if (
(entryTime > exitTime || entry.X < 0.0f && entry.Y < 0.0f) ||
(entry.X < 0.0f && (origin.X < other.Left || origin.X > other.Right)) ||
entry.Y < 0.0f && (origin.Y < other.Top || origin.Y > other.Bottom))
{
return(null);
}
var result = new Hit()
{
Amount = entryTime,
Position = origin + velocity * entryTime,
Normal = GetNormal(invEntry, invExit, entry),
};
return(result);
}
private static Hit ResolveNarrow(RectangleF origin, RectangleF destination, RectangleF other)
{
// if starts inside, push it outside at the neareast place
if (other.Contains(origin) || other.Intersects(origin))
{
var outside = PushOutside(origin, other);
return(new Hit()
{
Amount = 0,
Position = outside.Item1.Location,
Normal = outside.Item2,
});
}
var velocity = (destination.Location - origin.Location);
//the smallest vector from the origin rect to the hit rect
Vector2 invEntry;
// the longest vector from the origin rect to the hit rect
Vector2 invExit;
//the time until collision
Vector2 entry;
//the time until completly passing the hit rect
Vector2 exit;
/*
* invEntry.X = Math.Min(other.Left - origin.Right, other.Right - origin.Left);
* invEntry.Y = Math.Min(other.Top - origin.Bottom, other.Bottom - origin.Top);
* invExit.X = Math.Max(other.Left - origin.Right, other.Right - origin.Left);
* invExit.Y = Math.Max(other.Top - origin.Bottom, other.Bottom - origin.Top);
*/
if (velocity.X > 0)
{
invEntry.X = other.Left - origin.Right;
invExit.X = other.Right - origin.Left;
}
else
{
invEntry.X = other.Right - origin.Left;
invExit.X = other.Left - origin.Right;
}
if (velocity.Y > 0)
{
invEntry.Y = other.Top - origin.Bottom;
invExit.Y = other.Bottom - origin.Top;
}
else
{
invEntry.Y = other.Bottom - origin.Top;
invExit.Y = other.Top - origin.Bottom;
}
// calc the time in the current velocity until theres a collision in the
// x axis and untill the rect passes the collided object in the x axis
if (Math.Abs(velocity.X) < Constants.Threshold)
{
entry.X = float.MinValue;
exit.X = float.MaxValue;
}
else
{
entry.X = invEntry.X / velocity.X;
exit.X = invExit.X / velocity.X;
}
// calc the time in the current velocity until theres a collision in the
// y axis and untill the rect passes the collided object in the y axis
if (Math.Abs(velocity.Y) < Constants.Threshold)
{
entry.Y = float.MinValue;
exit.Y = float.MaxValue;
}
else
{
entry.Y = invEntry.Y / velocity.Y;
exit.Y = invExit.Y / velocity.Y;
}
//if the entry is smalle than one in x then the x axis will not collide after applying the velocity so there is no chace
// the object wont colide or is already intersecting in the x axis, same for the y.
if (entry.Y > 1.0f)
{
entry.Y = float.MinValue;
}
if (entry.X > 1.0f)
{
entry.X = float.MinValue;
}
// get rid for the min value by taking the max value of the x or the y,
// min value indicates that theres no collision or already coliding,
// if the exit x and y is maxvalue then theres no collision for sure
//
// the time untill the collision starts
var entryTime = Math.Max(entry.X, entry.Y);
// time until the collision ends
var exitTime = Math.Min(exit.X, exit.Y);
// if the time untill impact in y is less than 0 and the
if (
(entryTime > exitTime || entry.X < 0.0f && entry.Y < 0.0f) ||
(entry.X < 0.0f && (origin.Right < other.Left || origin.Left > other.Right)) ||
entry.Y < 0.0f && (origin.Bottom < other.Top || origin.Top > other.Bottom))
{
return(null);
}
Vector2 normal = GetNormal(invEntry, invExit, entry);
if (normal.Y == 1)
{
Console.WriteLine("collide top");
}
Vector2 distance = velocity * entryTime;
Vector2 position = origin.Location + distance;
if (velocity.X > Constants.Threshold)
{
distance.X += origin.Width;
}
if (velocity.Y > Constants.Threshold)
{
distance.Y += origin.Height;
}
var result = new Hit()
{
Amount = entryTime,
Position = position,
Normal = normal,
};
result.distance = invEntry;
return(result);
}
