// Translate path to origin (0, 0)
public static void CenterToOrigin(this List<Vector2> positions)
{
Vector2 center = positions.Center();
for (int i = 0; i < positions.Count; i++)
{
positions[i] -= center;
}
}
// Rotate path by given angle
public static List<Vector2> Rotate(this List<Vector2> positions, float angle)
{
List<Vector2> result = new List<Vector2>(positions.Count);
Vector2 c = positions.Center();
float cos = (float)Math.Cos(angle);
float sin = (float)Math.Sin(angle);
foreach (Vector2 p in positions)
{
float dx = p.X - c.X;
float dy = p.Y - c.Y;
Vector2 rotatePoint = Vector2.Zero;
rotatePoint.X = dx * cos - dy * sin + c.X;
rotatePoint.Y = dx * sin + dy * cos + c.Y;
result.Add(rotatePoint);
}
return result;
}
public static Point ImmediateInteriorSouth(this Rect rectangle)
{
return new Point(rectangle.Center().X, rectangle.Bottom - 1);
}
public static Point ImmediateInteriorNorth(this Rect rectangle)
{
return new Point(rectangle.Center().X, rectangle.Top + 1);
}
public static Point ImmediateInteriorEast(this Rect rectangle)
{
return new Point((int) (rectangle.Right - 1), rectangle.Center().Y);
}
public static Point ImmediateExteriorWest(this Rect rectangle)
{
return new Point((int) (rectangle.Left - 1), rectangle.Center().Y);
}
public static Point East(this Rect rectangle, int by)
{
return new Point((int)(rectangle.Right + by), rectangle.Center().Y);
}
public static Vector2 Center(this Texture2D texture, Vector2 scale)
{
return texture.Center() * scale;
}
/// <summary>
/// Changes the envelope extent by the specified amount relative
/// to it's current extent in that dimension (preserving the aspect ratio).
/// So Zoom(10) on a 100 unit wide envelope creates a 110 unit wide envlope,
/// while Zoom(-10) on a 100 unit wide envelope creates a 90 unit wide envelope.
/// Zoom(-100) on an envelope makes it 100% smaller, or effectively a point.
/// Tragically, a point cannot be "zoomed" back in, so a check should be used
/// to ensure that the envelope is not currently a point before attempting
/// to zoom in.
/// </summary>
/// <param name="self">The IEnvelope that this zoom method modifies</param>
/// <param name="percent">
/// Positive 50 makes the envelope 50% larger
/// Negative 50 makes the envelope 50% smaller
/// </param>
/// <example>
/// perCent = -50 compact the envelope a 50% (make it smaller).
/// perCent = 200 enlarge envelope by 2.
/// </example>
public static void Zoom(this IEnvelope self, double percent)
{
if (self == null) return;
if (self.IsNull) return;
double ratio = percent / 100;
Coordinate size = new Coordinate();
for (int i = 0; i < self.NumOrdinates; i++)
{
double oldSize = self.Maximum[i] - self.Minimum[i];
size[i] = oldSize + ratio * oldSize;
}
SetCenter(self, self.Center(), size);
}
/// <summary>
/// Returns Box.Max in Box coordinates
/// </summary>
public static Vector3 Extents(this BoundingBox box)
{
return (box.Max - box.Center());
}
public static Point West(this Rect rectangle, int by = 0)
{
return new Point((int)(rectangle.Left + by), rectangle.Center().Y);
}
public static Point South(this Rect rectangle, int by = 0)
{
return new Point(rectangle.Center().X, rectangle.Bottom + by);
}
public static Point North(this Rect rectangle, int by = 0)
{
return new Point(rectangle.Center().X, rectangle.Top + by);
}
/// <summary>
/// Zooms out for factor > 1, zooms in for factor < 1
/// </summary>
public static IRealInterval ZoomBy(this IRealInterval interval, double factor)
{
factor = Math.Abs(factor);
return RealInterval.Make
(
interval.Center() - interval.Span() * factor / 2,
interval.Center() + interval.Span() * factor / 2
);
}