Class DoubleUtil

Provides utility methods for floating-point number comparisons and operations with epsilon tolerance.

Inheritance

System.Object

DoubleUtil

Inherited Members

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: Telerik.WinControls

Assembly: Telerik.WinControls.dll

Syntax

public static class DoubleUtil

Remarks

DoubleUtil addresses the common problem of floating-point precision errors by providing comparison methods that use an epsilon tolerance value. This is essential for reliable comparisons in graphics and layout calculations where small rounding errors can occur.

The class provides methods for comparing float values, points, rectangles, and sizes with appropriate tolerance for equality, greater-than, and less-than operations. It also includes utility methods for safe float-to-integer conversion.

This utility is used throughout the Telerik WinControls framework for layout calculations, hit testing, and other operations that require robust floating-point comparisons.

Methods

AreClose(PointF, PointF)

Determines whether two PointF structures are close enough to be considered equal within epsilon tolerance.

Declaration

public static bool AreClose(PointF point1, PointF point2)

Parameters

System.Drawing.PointF point1 The first PointF to compare.

System.Drawing.PointF point2 The second PointF to compare.

Returns

System.Boolean true if both X and Y coordinates are close enough to be considered equal; otherwise, false.

AreClose(RectangleF, RectangleF)

Determines whether two RectangleF structures are close enough to be considered equal within epsilon tolerance.

Declaration

public static bool AreClose(RectangleF rect1, RectangleF rect2)

Parameters

System.Drawing.RectangleF rect1 The first RectangleF to compare.

System.Drawing.RectangleF rect2 The second RectangleF to compare.

Returns

System.Boolean true if all rectangle properties (X, Y, Width, Height) are close enough to be considered equal; otherwise, false.

Remarks

Empty rectangles are compared for exact emptiness rather than using epsilon tolerance.

AreClose(SizeF, SizeF)

Determines whether two SizeF structures are close enough to be considered equal within epsilon tolerance.

Declaration

public static bool AreClose(SizeF size1, SizeF size2)

Parameters

System.Drawing.SizeF size1 The first SizeF to compare.

System.Drawing.SizeF size2 The second SizeF to compare.

Returns

System.Boolean true if both Width and Height values are close enough to be considered equal; otherwise, false.

Remarks

This method compares both the Width and Height properties of the size structures using epsilon tolerance to account for floating-point precision errors.

AreClose(Single, Single)

Determines whether two float values are close enough to be considered equal within epsilon tolerance.

Declaration

public static bool AreClose(float value1, float value2)

Parameters

System.Single value1 The first float value to compare.

System.Single value2 The second float value to compare.

Returns

System.Boolean true if the values are close enough to be considered equal; otherwise, false.

Remarks

This method accounts for floating-point precision errors by using an epsilon tolerance value that adjusts based on the magnitude of the numbers being compared.

DoubleToInt(Single)

Converts a float value to an integer using proper rounding.

Declaration

public static int DoubleToInt(float val)

Parameters

System.Single val The float value to convert.

Returns

System.Int32 The rounded integer value.

Remarks

This method performs proper rounding by adding or subtracting 0.5 based on the sign of the value before truncating to integer. This ensures consistent rounding behavior compared to simple casting.

For positive values, 0.5 is added before truncation. For negative values, 0.5 is subtracted. This provides symmetrical rounding around zero.

GreaterThan(Single, Single)

Determines whether the first value is greater than the second value with epsilon tolerance.

Declaration

public static bool GreaterThan(float value1, float value2)

Parameters

System.Single value1 The first value to compare.

System.Single value2 The second value to compare.

Returns

System.Boolean true if value1 is greater than value2 and they are not close enough to be equal; otherwise, false.

Remarks

This method returns true only if value1 is definitively greater than value2, taking into account floating-point precision. Values that are close enough to be considered equal will return false.

GreaterThanOrClose(Single, Single)

Determines whether the first value is greater than or approximately equal to the second value.

Declaration

public static bool GreaterThanOrClose(float value1, float value2)

Parameters

System.Single value1 The first value to compare.

System.Single value2 The second value to compare.

Returns

System.Boolean true if value1 is greater than value2 or they are close enough to be considered equal; otherwise, false.

Remarks

This method returns true if value1 is either definitively greater than value2 or if they are close enough to be considered equal within epsilon tolerance.

IsBetweenZeroAndOne(Single)

Determines whether a value is between 0 and 1 (inclusive) using epsilon tolerance.

Declaration

public static bool IsBetweenZeroAndOne(float val)

Parameters

System.Single val The value to check.

Returns

System.Boolean true if the value is greater than or equal to 0 and less than or equal to 1 (within epsilon tolerance); otherwise, false.

Remarks

This method is commonly used for validating normalized values, percentages, and alpha values that should be constrained to the 0-1 range.

IsLessThan(Double, Double)

Declaration

public static bool IsLessThan(double value1, double value2)

Parameters

System.Double value1

System.Double value2

Returns

System.Boolean

IsNaN(Single)

Declaration

public static bool IsNaN(float value)

Parameters

System.Single value

Returns

System.Boolean

IsOne(Single)

Determines whether a float value is approximately equal to 1.0 within epsilon tolerance.

Declaration

public static bool IsOne(float value)

Parameters

System.Single value The value to check.

Returns

System.Boolean true if the value is close enough to 1.0 to be considered equal; otherwise, false.

Remarks

This method uses a tighter epsilon tolerance (10 times the base epsilon) to determine if a value represents unity, accounting for floating-point precision errors.

IsZero(Single)

Determines whether a float value is approximately equal to 0.0 within epsilon tolerance.

Declaration

public static bool IsZero(float value)

Parameters

System.Single value The value to check.

Returns

System.Boolean true if the value is close enough to 0.0 to be considered equal; otherwise, false.

Remarks

This method uses a tighter epsilon tolerance (10 times the base epsilon) to determine if a value represents zero, accounting for floating-point precision errors.

LessThan(Double, Double)

Declaration

public static bool LessThan(double value1, double value2)

Parameters

System.Double value1

System.Double value2

Returns

System.Boolean

LessThan(Single, Single)

Declaration

public static bool LessThan(float value1, float value2)

Parameters

System.Single value1

System.Single value2

Returns

System.Boolean

LessThanOrClose(Single, Single)

Declaration

public static bool LessThanOrClose(float value1, float value2)

Parameters

System.Single value1

System.Single value2

Returns

System.Boolean