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//------------------------------------------------------------------------------
// Microsoft Avalon
// Copyright (c) Microsoft Corporation, 2001, 2002
//
// File: Rect.cs
//------------------------------------------------------------------------------
using System;
using System.Diagnostics;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Reflection;
using System.Text;
using System.Collections;
using System.Globalization;
using MS.Internal;
using System.Windows;
using System.Windows.Media;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Permissions;
using MS.Internal.WindowsBase;
namespace System.Windows
{
/// <summary>
/// Rect - The primitive which represents a rectangle. Rects are stored as
/// X, Y (Location) and Width and Height (Size). As a result, Rects cannot have negative
/// Width or Height.
/// </summary>
public partial struct Rect
{
#region Constructors
/// <summary>
/// Constructor which sets the initial values to the values of the parameters
/// </summary>
public Rect(Point location,
Size size)
{
if (size.IsEmpty)
{
this = s_empty;
}
else
{
_x = location._x;
_y = location._y;
_width = size._width;
_height = size._height;
}
}
/// <summary>
/// Constructor which sets the initial values to the values of the parameters.
/// Width and Height must be non-negative
/// </summary>
public Rect(double x,
double y,
double width,
double height)
{
if (width < 0 || height < 0)
{
throw new System.ArgumentException(SR.Get(SRID.Size_WidthAndHeightCannotBeNegative));
}
_x = x;
_y = y;
_width = width;
_height = height;
}
/// <summary>
/// Constructor which sets the initial values to bound the two points provided.
/// </summary>
public Rect(Point point1,
Point point2)
{
_x = Math.Min(point1._x, point2._x);
_y = Math.Min(point1._y, point2._y);
// Max with 0 to prevent double weirdness from causing us to be (-epsilon..0)
_width = Math.Max(Math.Max(point1._x, point2._x) - _x, 0);
_height = Math.Max(Math.Max(point1._y, point2._y) - _y, 0);
}
/// <summary>
/// Constructor which sets the initial values to bound the point provided and the point
/// which results from point + vector.
/// </summary>
public Rect(Point point,
Vector vector): this(point, point+vector)
{
}
/// <summary>
/// Constructor which sets the initial values to bound the (0,0) point and the point
/// that results from (0,0) + size.
/// </summary>
public Rect(Size size)
{
if(size.IsEmpty)
{
this = s_empty;
}
else
{
_x = _y = 0;
_width = size.Width;
_height = size.Height;
}
}
#endregion Constructors
#region Statics
/// <summary>
/// Empty - a static property which provides an Empty rectangle. X and Y are positive-infinity
/// and Width and Height are negative infinity. This is the only situation where Width or
/// Height can be negative.
/// </summary>
public static Rect Empty
{
get
{
return s_empty;
}
}
#endregion Statics
#region Public Properties
/// <summary>
/// IsEmpty - this returns true if this rect is the Empty rectangle.
/// Note: If width or height are 0 this Rectangle still contains a 0 or 1 dimensional set
/// of points, so this method should not be used to check for 0 area.
/// </summary>
public bool IsEmpty
{
get
{
// The funny width and height tests are to handle NaNs
Debug.Assert((!(_width < 0) && !(_height < 0)) || (this == Empty));
return _width < 0;
}
}
/// <summary>
/// Location - The Point representing the origin of the Rectangle
/// </summary>
public Point Location
{
get
{
return new Point(_x, _y);
}
set
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotModifyEmptyRect));
}
_x = value._x;
_y = value._y;
}
}
/// <summary>
/// Size - The Size representing the area of the Rectangle
/// </summary>
public Size Size
{
get
{
if (IsEmpty)
return Size.Empty;
return new Size(_width, _height);
}
set
{
if (value.IsEmpty)
{
this = s_empty;
}
else
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotModifyEmptyRect));
}
_width = value._width;
_height = value._height;
}
}
}
/// <summary>
/// X - The X coordinate of the Location.
/// If this is the empty rectangle, the value will be positive infinity.
/// If this rect is Empty, setting this property is illegal.
/// </summary>
public double X
{
get
{
return _x;
}
set
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotModifyEmptyRect));
}
_x = value;
}
}
/// <summary>
/// Y - The Y coordinate of the Location
/// If this is the empty rectangle, the value will be positive infinity.
/// If this rect is Empty, setting this property is illegal.
/// </summary>
public double Y
{
get
{
return _y;
}
set
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotModifyEmptyRect));
}
_y = value;
}
}
/// <summary>
/// Width - The Width component of the Size. This cannot be set to negative, and will only
/// be negative if this is the empty rectangle, in which case it will be negative infinity.
/// If this rect is Empty, setting this property is illegal.
/// </summary>
public double Width
{
get
{
return _width;
}
set
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotModifyEmptyRect));
}
if (value < 0)
{
throw new System.ArgumentException(SR.Get(SRID.Size_WidthCannotBeNegative));
}
_width = value;
}
}
/// <summary>
/// Height - The Height component of the Size. This cannot be set to negative, and will only
/// be negative if this is the empty rectangle, in which case it will be negative infinity.
/// If this rect is Empty, setting this property is illegal.
/// </summary>
public double Height
{
get
{
return _height;
}
set
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotModifyEmptyRect));
}
if (value < 0)
{
throw new System.ArgumentException(SR.Get(SRID.Size_HeightCannotBeNegative));
}
_height = value;
}
}
/// <summary>
/// Left Property - This is a read-only alias for X
/// If this is the empty rectangle, the value will be positive infinity.
/// </summary>
public double Left
{
get
{
return _x;
}
}
/// <summary>
/// Top Property - This is a read-only alias for Y
/// If this is the empty rectangle, the value will be positive infinity.
/// </summary>
public double Top
{
get
{
return _y;
}
}
/// <summary>
/// Right Property - This is a read-only alias for X + Width
/// If this is the empty rectangle, the value will be negative infinity.
/// </summary>
public double Right
{
get
{
if (IsEmpty)
{
return Double.NegativeInfinity;
}
return _x + _width;
}
}
/// <summary>
/// Bottom Property - This is a read-only alias for Y + Height
/// If this is the empty rectangle, the value will be negative infinity.
/// </summary>
public double Bottom
{
get
{
if (IsEmpty)
{
return Double.NegativeInfinity;
}
return _y + _height;
}
}
/// <summary>
/// TopLeft Property - This is a read-only alias for the Point which is at X, Y
/// If this is the empty rectangle, the value will be positive infinity, positive infinity.
/// </summary>
public Point TopLeft
{
get
{
return new Point(Left, Top);
}
}
/// <summary>
/// TopRight Property - This is a read-only alias for the Point which is at X + Width, Y
/// If this is the empty rectangle, the value will be negative infinity, positive infinity.
/// </summary>
public Point TopRight
{
get
{
return new Point(Right, Top);
}
}
/// <summary>
/// BottomLeft Property - This is a read-only alias for the Point which is at X, Y + Height
/// If this is the empty rectangle, the value will be positive infinity, negative infinity.
/// </summary>
public Point BottomLeft
{
get
{
return new Point(Left, Bottom);
}
}
/// <summary>
/// BottomRight Property - This is a read-only alias for the Point which is at X + Width, Y + Height
/// If this is the empty rectangle, the value will be negative infinity, negative infinity.
/// </summary>
public Point BottomRight
{
get
{
return new Point(Right, Bottom);
}
}
#endregion Public Properties
#region Public Methods
/// <summary>
/// Contains - Returns true if the Point is within the rectangle, inclusive of the edges.
/// Returns false otherwise.
/// </summary>
/// <param name="point"> The point which is being tested </param>
/// <returns>
/// Returns true if the Point is within the rectangle.
/// Returns false otherwise
/// </returns>
public bool Contains(Point point)
{
return Contains(point._x, point._y);
}
/// <summary>
/// Contains - Returns true if the Point represented by x,y is within the rectangle inclusive of the edges.
/// Returns false otherwise.
/// </summary>
/// <param name="x"> X coordinate of the point which is being tested </param>
/// <param name="y"> Y coordinate of the point which is being tested </param>
/// <returns>
/// Returns true if the Point represented by x,y is within the rectangle.
/// Returns false otherwise.
/// </returns>
public bool Contains(double x, double y)
{
if (IsEmpty)
{
return false;
}
return ContainsInternal(x,y);
}
/// <summary>
/// Contains - Returns true if the Rect non-Empty and is entirely contained within the
/// rectangle, inclusive of the edges.
/// Returns false otherwise
/// </summary>
public bool Contains(Rect rect)
{
if (IsEmpty || rect.IsEmpty)
{
return false;
}
return (_x <= rect._x &&
_y <= rect._y &&
_x+_width >= rect._x+rect._width &&
_y+_height >= rect._y+rect._height );
}
/// <summary>
/// IntersectsWith - Returns true if the Rect intersects with this rectangle
/// Returns false otherwise.
/// Note that if one edge is coincident, this is considered an intersection.
/// </summary>
/// <returns>
/// Returns true if the Rect intersects with this rectangle
/// Returns false otherwise.
/// or Height
/// </returns>
/// <param name="rect"> Rect </param>
public bool IntersectsWith(Rect rect)
{
if (IsEmpty || rect.IsEmpty)
{
return false;
}
return (rect.Left <= Right) &&
(rect.Right >= Left) &&
(rect.Top <= Bottom) &&
(rect.Bottom >= Top);
}
/// <summary>
/// Intersect - Update this rectangle to be the intersection of this and rect
/// If either this or rect are Empty, the result is Empty as well.
/// </summary>
/// <param name="rect"> The rect to intersect with this </param>
public void Intersect(Rect rect)
{
if (!this.IntersectsWith(rect))
{
this = Empty;
}
else
{
double left = Math.Max(Left, rect.Left);
double top = Math.Max(Top, rect.Top);
// Max with 0 to prevent double weirdness from causing us to be (-epsilon..0)
_width = Math.Max(Math.Min(Right, rect.Right) - left, 0);
_height = Math.Max(Math.Min(Bottom, rect.Bottom) - top, 0);
_x = left;
_y = top;
}
}
/// <summary>
/// Intersect - Return the result of the intersection of rect1 and rect2.
/// If either this or rect are Empty, the result is Empty as well.
/// </summary>
public static Rect Intersect(Rect rect1, Rect rect2)
{
rect1.Intersect(rect2);
return rect1;
}
/// <summary>
/// Union - Update this rectangle to be the union of this and rect.
/// </summary>
public void Union(Rect rect)
{
if (IsEmpty)
{
this = rect;
}
else if (!rect.IsEmpty)
{
double left = Math.Min(Left, rect.Left);
double top = Math.Min(Top, rect.Top);
// We need this check so that the math does not result in NaN
if ((rect.Width == Double.PositiveInfinity) || (Width == Double.PositiveInfinity))
{
_width = Double.PositiveInfinity;
}
else
{
// Max with 0 to prevent double weirdness from causing us to be (-epsilon..0)
double maxRight = Math.Max(Right, rect.Right);
_width = Math.Max(maxRight - left, 0);
}
// We need this check so that the math does not result in NaN
if ((rect.Height == Double.PositiveInfinity) || (Height == Double.PositiveInfinity))
{
_height = Double.PositiveInfinity;
}
else
{
// Max with 0 to prevent double weirdness from causing us to be (-epsilon..0)
double maxBottom = Math.Max(Bottom, rect.Bottom);
_height = Math.Max(maxBottom - top, 0);
}
_x = left;
_y = top;
}
}
/// <summary>
/// Union - Return the result of the union of rect1 and rect2.
/// </summary>
public static Rect Union(Rect rect1, Rect rect2)
{
rect1.Union(rect2);
return rect1;
}
/// <summary>
/// Union - Update this rectangle to be the union of this and point.
/// </summary>
public void Union(Point point)
{
Union(new Rect(point, point));
}
/// <summary>
/// Union - Return the result of the union of rect and point.
/// </summary>
public static Rect Union(Rect rect, Point point)
{
rect.Union(new Rect(point, point));
return rect;
}
/// <summary>
/// Offset - translate the Location by the offset provided.
/// If this is Empty, this method is illegal.
/// </summary>
public void Offset(Vector offsetVector)
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotCallMethod));
}
_x += offsetVector._x;
_y += offsetVector._y;
}
/// <summary>
/// Offset - translate the Location by the offset provided
/// If this is Empty, this method is illegal.
/// </summary>
public void Offset(double offsetX, double offsetY)
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotCallMethod));
}
_x += offsetX;
_y += offsetY;
}
/// <summary>
/// Offset - return the result of offsetting rect by the offset provided
/// If this is Empty, this method is illegal.
/// </summary>
public static Rect Offset(Rect rect, Vector offsetVector)
{
rect.Offset(offsetVector.X, offsetVector.Y);
return rect;
}
/// <summary>
/// Offset - return the result of offsetting rect by the offset provided
/// If this is Empty, this method is illegal.
/// </summary>
public static Rect Offset(Rect rect, double offsetX, double offsetY)
{
rect.Offset(offsetX, offsetY);
return rect;
}
/// <summary>
/// Inflate - inflate the bounds by the size provided, in all directions
/// If this is Empty, this method is illegal.
/// </summary>
public void Inflate(Size size)
{
Inflate(size._width, size._height);
}
/// <summary>
/// Inflate - inflate the bounds by the size provided, in all directions.
/// If -width is > Width / 2 or -height is > Height / 2, this Rect becomes Empty
/// If this is Empty, this method is illegal.
/// </summary>
public void Inflate(double width, double height)
{
if (IsEmpty)
{
throw new System.InvalidOperationException(SR.Get(SRID.Rect_CannotCallMethod));
}
_x -= width;
_y -= height;
// Do two additions rather than multiplication by 2 to avoid spurious overflow
// That is: (A + 2 * B) != ((A + B) + B) if 2*B overflows.
// Note that multiplication by 2 might work in this case because A should start
// positive & be "clamped" to positive after, but consider A = Inf & B = -MAX.
_width += width;
_width += width;
_height += height;
_height += height;
// We catch the case of inflation by less than -width/2 or -height/2 here. This also
// maintains the invariant that either the Rect is Empty or _width and _height are
// non-negative, even if the user parameters were NaN, though this isn't strictly maintained
// by other methods.
if ( !(_width >= 0 && _height >= 0) )
{
this = s_empty;
}
}
/// <summary>
/// Inflate - return the result of inflating rect by the size provided, in all directions
/// If this is Empty, this method is illegal.
/// </summary>
public static Rect Inflate(Rect rect, Size size)
{
rect.Inflate(size._width, size._height);
return rect;
}
/// <summary>
/// Inflate - return the result of inflating rect by the size provided, in all directions
/// If this is Empty, this method is illegal.
/// </summary>
public static Rect Inflate(Rect rect, double width, double height)
{
rect.Inflate(width, height);
return rect;
}
/// <summary>
/// Returns the bounds of the transformed rectangle.
/// The Empty Rect is not affected by this call.
/// </summary>
/// <returns>
/// The rect which results from the transformation.
/// </returns>
/// <param name="rect"> The Rect to transform. </param>
/// <param name="matrix"> The Matrix by which to transform. </param>
public static Rect Transform(Rect rect, Matrix matrix)
{
MatrixUtil.TransformRect(ref rect, ref matrix);
return rect;
}
/// <summary>
/// Updates rectangle to be the bounds of the original value transformed
/// by the matrix.
/// The Empty Rect is not affected by this call.
/// </summary>
/// <param name="matrix"> Matrix </param>
public void Transform(Matrix matrix)
{
MatrixUtil.TransformRect(ref this, ref matrix);
}
/// <summary>
/// Scale the rectangle in the X and Y directions
/// </summary>
/// <param name="scaleX"> The scale in X </param>
/// <param name="scaleY"> The scale in Y </param>
public void Scale(double scaleX, double scaleY)
{
if (IsEmpty)
{
return;
}
_x *= scaleX;
_y *= scaleY;
_width *= scaleX;
_height *= scaleY;
// If the scale in the X dimension is negative, we need to normalize X and Width
if (scaleX < 0)
{
// Make X the left-most edge again
_x += _width;
// and make Width positive
_width *= -1;
}
// Do the same for the Y dimension
if (scaleY < 0)
{
// Make Y the top-most edge again
_y += _height;
// and make Height positive
_height *= -1;
}
}
#endregion Public Methods
#region Private Methods
/// <summary>
/// ContainsInternal - Performs just the "point inside" logic
/// </summary>
/// <returns>
/// bool - true if the point is inside the rect
/// </returns>
/// <param name="x"> The x-coord of the point to test </param>
/// <param name="y"> The y-coord of the point to test </param>
private bool ContainsInternal(double x, double y)
{
// We include points on the edge as "contained".
// We do "x - _width <= _x" instead of "x <= _x + _width"
// so that this check works when _width is PositiveInfinity
// and _x is NegativeInfinity.
return ((x >= _x) && (x - _width <= _x) &&
(y >= _y) && (y - _height <= _y));
}
static private Rect CreateEmptyRect()
{
Rect rect = new Rect();
// We can't set these via the property setters because negatives widths
// are rejected in those APIs.
rect._x = Double.PositiveInfinity;
rect._y = Double.PositiveInfinity;
rect._width = Double.NegativeInfinity;
rect._height = Double.NegativeInfinity;
return rect;
}
#endregion Private Methods
#region Private Fields
private readonly static Rect s_empty = CreateEmptyRect();
#endregion Private Fields
}
}
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