/// <summary>
/// Get bounding rectangle of the specified list of points.
/// </summary>
///
/// <param name="cloud">Collection of points to get bounding rectangle for.</param>
/// <param name="minXY">Point comprised of smallest X and Y coordinates.</param>
/// <param name="maxXY">Point comprised of biggest X and Y coordinates.</param>
///
public static void GetBoundingRectangle( IEnumerable<IntPoint> cloud, out IntPoint minXY, out IntPoint maxXY )
{
int minX = int.MaxValue;
int maxX = int.MinValue;
int minY = int.MaxValue;
int maxY = int.MinValue;
foreach ( IntPoint pt in cloud )
{
int x = pt.X;
int y = pt.Y;
// check X coordinate
if ( x < minX )
minX = x;
if ( x > maxX )
maxX = x;
// check Y coordinate
if ( y < minY )
minY = y;
if ( y > maxY )
maxY = y;
}
if ( minX > maxX ) // if no point appeared to set either minX or maxX
throw new ArgumentException( "List of points can not be empty." );
minXY = new IntPoint( minX, minY );
maxXY = new IntPoint( maxX, maxY );
}
/// <summary>
/// Calculate Euclidean distance between two points.
/// </summary>
///
/// <param name="anotherPoint">Point to calculate distance to.</param>
///
/// <returns>Returns Euclidean distance between this point and
/// <paramref name="anotherPoint"/> points.</returns>
///
public float DistanceTo( IntPoint anotherPoint )
{
int dx = X - anotherPoint.X;
int dy = Y - anotherPoint.Y;
return (float) System.Math.Sqrt( dx * dx + dy * dy );
}
/// <summary>
/// Shift cloud by adding specified value to all points in the collection.
/// </summary>
///
/// <param name="cloud">Collection of points to shift their coordinates.</param>
/// <param name="shift">Point to shift by.</param>
///
public static void Shift( IList<IntPoint> cloud, IntPoint shift )
{
for ( int i = 0, n = cloud.Count; i < n; i++ )
{
cloud[i] = cloud[i] + shift;
}
}
/// <summary>
/// Find the furthest point from the specified line.
/// </summary>
///
/// <param name="cloud">Collection of points to search furthest points in.</param>
/// <param name="linePoint1">First point forming the line.</param>
/// <param name="linePoint2">Second point forming the line.</param>
/// <param name="distance">Distance between the furthest found point and the given line.</param>
///
/// <returns>Returns a point, which is the furthest away from the
/// specified line.</returns>
///
/// <remarks><para>The method finds the furthest point from the specified line.
/// Unlike the <see cref="GetFurthestPointsFromLine( IEnumerable{IntPoint}, IntPoint, IntPoint, out IntPoint, out float, out IntPoint, out float )"/>
/// method, this method find only one point, which is the furthest away from the line
/// regardless of side from the line.</para></remarks>
///
public static IntPoint GetFurthestPointFromLine( IEnumerable<IntPoint> cloud, IntPoint linePoint1, IntPoint linePoint2, out float distance )
{
IntPoint furthestPoint = linePoint1;
distance = 0;
if ( linePoint2.X != linePoint1.X )
{
// line's equation y(x) = k * x + b
float k = (float) ( linePoint2.Y - linePoint1.Y ) / ( linePoint2.X - linePoint1.X );
float b = linePoint1.Y - k * linePoint1.X;
float div = (float) Math.Sqrt( k * k + 1 );
float pointDistance = 0;
foreach ( IntPoint point in cloud )
{
pointDistance = Math.Abs( ( k * point.X + b - point.Y ) / div );
if ( pointDistance > distance )
{
distance = pointDistance;
furthestPoint = point;
}
}
}
else
{
int lineX = linePoint1.X;
float pointDistance = 0;
foreach ( IntPoint point in cloud )
{
distance = Math.Abs( lineX - point.X );
if ( pointDistance > distance )
{
distance = pointDistance;
furthestPoint = point;
}
}
}
return furthestPoint;
}
/// <summary>
/// Find the furthest point from the specified line.
/// </summary>
///
/// <param name="cloud">Collection of points to search furthest point in.</param>
/// <param name="linePoint1">First point forming the line.</param>
/// <param name="linePoint2">Second point forming the line.</param>
///
/// <returns>Returns a point, which is the furthest away from the
/// specified line.</returns>
///
/// <remarks><para>The method finds the furthest point from the specified line.
/// Unlike the <see cref="GetFurthestPointsFromLine( IEnumerable{IntPoint}, IntPoint, IntPoint, out IntPoint, out IntPoint )"/>
/// method, this method find only one point, which is the furthest away from the line
/// regardless of side from the line.</para></remarks>
///
public static IntPoint GetFurthestPointFromLine( IEnumerable<IntPoint> cloud, IntPoint linePoint1, IntPoint linePoint2 )
{
float d;
return GetFurthestPointFromLine( cloud, linePoint1, linePoint2, out d );
}
/// <summary>
/// Find two furthest points from the specified line.
/// </summary>
///
/// <param name="cloud">Collection of points to search furthest points in.</param>
/// <param name="linePoint1">First point forming the line.</param>
/// <param name="linePoint2">Second point forming the line.</param>
/// <param name="furthestPoint1">First found furthest point.</param>
/// <param name="distance1">Distance between the first found point and the given line.</param>
/// <param name="furthestPoint2">Second found furthest point (which is on the
/// opposite side from the line compared to the <paramref name="furthestPoint1"/>);</param>
/// <param name="distance2">Distance between the second found point and the given line.</param>
///
/// <remarks><para>The method finds two furthest points from the specified line,
/// where one point is on one side from the line and the second point is on
/// another side from the line.</para></remarks>
///
public static void GetFurthestPointsFromLine( IEnumerable<IntPoint> cloud, IntPoint linePoint1, IntPoint linePoint2,
out IntPoint furthestPoint1, out float distance1, out IntPoint furthestPoint2, out float distance2 )
{
furthestPoint1 = linePoint1;
distance1 = 0;
furthestPoint2 = linePoint2;
distance2 = 0;
if ( linePoint2.X != linePoint1.X )
{
// line's equation y(x) = k * x + b
float k = (float) ( linePoint2.Y - linePoint1.Y ) / ( linePoint2.X - linePoint1.X );
float b = linePoint1.Y - k * linePoint1.X;
float div = (float) Math.Sqrt( k * k + 1 );
float distance = 0;
foreach ( IntPoint point in cloud )
{
distance = ( k * point.X + b - point.Y ) / div;
if ( distance > distance1 )
{
distance1 = distance;
furthestPoint1 = point;
}
if ( distance < distance2 )
{
distance2 = distance;
furthestPoint2 = point;
}
}
}
else
{
int lineX = linePoint1.X;
float distance = 0;
foreach ( IntPoint point in cloud )
{
distance = lineX - point.X;
if ( distance > distance1 )
{
distance1 = distance;
furthestPoint1 = point;
}
if ( distance < distance2 )
{
distance2 = distance;
furthestPoint2 = point;
}
}
}
distance2 = -distance2;
}
/// <summary>
/// Find two furthest points from the specified line.
/// </summary>
///
/// <param name="cloud">Collection of points to search furthest points in.</param>
/// <param name="linePoint1">First point forming the line.</param>
/// <param name="linePoint2">Second point forming the line.</param>
/// <param name="furthestPoint1">First found furthest point.</param>
/// <param name="furthestPoint2">Second found furthest point (which is on the
/// opposite side from the line compared to the <paramref name="furthestPoint1"/>);</param>
///
/// <remarks><para>The method finds two furthest points from the specified line,
/// where one point is on one side from the line and the second point is on
/// another side from the line.</para></remarks>
///
public static void GetFurthestPointsFromLine( IEnumerable<IntPoint> cloud, IntPoint linePoint1, IntPoint linePoint2,
out IntPoint furthestPoint1, out IntPoint furthestPoint2 )
{
float d1, d2;
GetFurthestPointsFromLine( cloud, linePoint1, linePoint2,
out furthestPoint1, out d1, out furthestPoint2, out d2 );
}
/// <summary>
/// Find furthest point from the specified point.
/// </summary>
///
/// <param name="cloud">Collection of points to search furthest point in.</param>
/// <param name="referencePoint">The point to search furthest point from.</param>
///
/// <returns>Returns a point, which is the furthest away from the <paramref name="referencePoint"/>.</returns>
///
public static IntPoint GetFurthestPoint( IEnumerable<IntPoint> cloud, IntPoint referencePoint )
{
IntPoint furthestPoint = referencePoint;
float maxDistance = -1;
int rx = referencePoint.X;
int ry = referencePoint.Y;
foreach ( IntPoint point in cloud )
{
int dx = rx - point.X;
int dy = ry - point.Y;
// we are not calculating square root for finding "real" distance,
// since it is really not important for finding furthest point
float distance = dx * dx + dy * dy;
if ( distance > maxDistance )
{
maxDistance = distance;
furthestPoint = point;
}
}
return furthestPoint;
}
/// <summary>
/// Division operator - divides coordinates of the specified point by scalar value.
/// </summary>
///
/// <param name="point">Point to divide coordinates of.</param>
/// <param name="factor">Division factor.</param>
///
/// <returns>Returns new point which coordinates equal to coordinates of
/// the specified point divided by specified value.</returns>
///
public static IntPoint Divide( IntPoint point, int factor )
{
return new IntPoint( point.X / factor, point.Y / factor );
}
/// <summary>
/// Multiplication operator - multiplies coordinates of the specified point by scalar value.
/// </summary>
///
/// <param name="point">Point to multiply coordinates of.</param>
/// <param name="factor">Multiplication factor.</param>
///
/// <returns>Returns new point which coordinates equal to coordinates of
/// the specified point multiplied by specified value.</returns>
///
public static IntPoint Multiply( IntPoint point, int factor )
{
return new IntPoint( point.X * factor, point.Y * factor );
}
/// <summary>
/// Subtraction operator - subtracts scalar from the specified point.
/// </summary>
///
/// <param name="point">Point to decrease coordinates of.</param>
/// <param name="valueToSubtract">Value to subtract from coordinates of the specified point.</param>
///
/// <returns>Returns new point which coordinates equal to coordinates of
/// the specified point decreased by specified value.</returns>
///
public static IntPoint Subtract( IntPoint point, int valueToSubtract )
{
return new IntPoint( point.X - valueToSubtract, point.Y - valueToSubtract );
}
/// <summary>
/// Addition operator - adds scalar to the specified point.
/// </summary>
///
/// <param name="point">Point to increase coordinates of.</param>
/// <param name="valueToAdd">Value to add to coordinates of the specified point.</param>
///
/// <returns>Returns new point which coordinates equal to coordinates of
/// the specified point increased by specified value.</returns>
///
public static IntPoint Add( IntPoint point, int valueToAdd )
{
return new IntPoint( point.X + valueToAdd, point.Y + valueToAdd );
}
/// <summary>
/// Subtraction operator - subtracts values of two points.
/// </summary>
///
/// <param name="point1">Point to subtract from.</param>
/// <param name="point2">Point to subtract.</param>
///
/// <returns>Returns new point which coordinates equal to difference of corresponding
/// coordinates of specified points.</returns>
///
public static IntPoint Subtract( IntPoint point1, IntPoint point2 )
{
return new IntPoint( point1.X - point2.X, point1.Y - point2.Y );
}
/// <summary>
/// Addition operator - adds values of two points.
/// </summary>
///
/// <param name="point1">First point for addition.</param>
/// <param name="point2">Second point for addition.</param>
///
/// <returns>Returns new point which coordinates equal to sum of corresponding
/// coordinates of specified points.</returns>
///
public static IntPoint Add( IntPoint point1, IntPoint point2 )
{
return new IntPoint( point1.X + point2.X, point1.Y + point2.Y );
}
