org.eclipse.gef.geometry.internal.utils

Class PrecisionUtils

java.lang.Object

org.eclipse.gef.geometry.internal.utils.PrecisionUtils

public class PrecisionUtils
extends java.lang.Object

A utility class for floating point calculations and comparisons that should guarantee a precision of a given scale, and ignore differences beyond this scale.

Method Summary

Modifier and Type	Method and Description
static double	calculateFraction(int shift) Computes the smallest double that is yet recognizable (by comparison) when shifting the default scale up by the given amount.
static boolean	equal(double d1, double d2)
static boolean	equal(double d1, double d2, int shift) Tests whether the two values are regarded to be equal w.r.t. the given shift.
static boolean	greater(double d1, double d2)
static boolean	greater(double d1, double d2, int shift) Tests whether the first given value is regarded to be greater than the second value w.r.t. the given shift.
static boolean	greaterEqual(double d1, double d2)
static boolean	greaterEqual(double d1, double d2, int shift) Tests whether the first given value is regarded to be greater or equal than the second value w.r.t. the given shift.
static boolean	smaller(double d1, double d2)
static boolean	smaller(double d1, double d2, int shift) Tests whether the first given value is regarded to be smaller than the second value w.r.t. the given shift.
static boolean	smallerEqual(double d1, double d2)
static boolean	smallerEqual(double d1, double d2, int shift) Tests whether the first given value is regarded to be smaller or equal than the second value w.r.t. the given shift.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

calculateFraction

public static final double calculateFraction(int shift)

Computes the smallest double that is yet recognizable (by comparison) when shifting the default scale up by the given amount.

Parameters:

shift - the number of digits to shift precision up (may be negative number)

Returns:

the smallest double that will yet be recognizable by the methods of this class during comparison, when using the default scale shifted by the given amount.

equal

public static final boolean equal(double d1,
                                  double d2)

Parameters:

d1 - The first operand.

d2 - The second operand.

Returns:

result of the comparison

See Also:

equal(double, double, int)

equal

public static final boolean equal(double d1,
                                  double d2,
                                  int shift)

Tests whether the two values are regarded to be equal w.r.t. the given shift.

Parameters:

d1 - the first value to test

d2 - the second value to test

shift - the delta shift used for this test

Returns:

true in case the given two values are identical or differ from each other by an amount that is smaller than what is recognizable by the shifted delta, false otherwise

greater

public static final boolean greater(double d1,
                                    double d2)

Parameters:

d1 - The first operand.

d2 - The second operand.

Returns:

result of the comparison

See Also:

greater(double, double, int)

greater

public static final boolean greater(double d1,
                                    double d2,
                                    int shift)

Tests whether the first given value is regarded to be greater than the second value w.r.t. the given shift.

Parameters:

d1 - the first value to test

d2 - the second value to test

shift - the delta shift used for this test

Returns:

true in case the first value is greater than the second value by an amount recognizable by the shifted delta, false otherwise

greaterEqual

public static final boolean greaterEqual(double d1,
                                         double d2)

Parameters:

d1 - The first operand.

d2 - The second operand.

Returns:

result of the comparison

See Also:

greaterEqual(double, double, int)

greaterEqual

public static final boolean greaterEqual(double d1,
                                         double d2,
                                         int shift)

Tests whether the first given value is regarded to be greater or equal than the second value w.r.t. the given shift.

Parameters:

d1 - the first value to test

d2 - the second value to test

shift - the delta shift used for this test

Returns:

true in case the first value is greater than the second value by an amount recognizable by the given scale or differs from it by an amount not recognizable by the shifted delta, false otherwise

smaller

public static final boolean smaller(double d1,
                                    double d2)

Parameters:

d1 - The first operand.

d2 - The second operand.

Returns:

result of the comparison

See Also:

smaller(double, double, int)

smaller

public static final boolean smaller(double d1,
                                    double d2,
                                    int shift)

Tests whether the first given value is regarded to be smaller than the second value w.r.t. the given shift.

Parameters:

d1 - the first value to test

d2 - the second value to test

shift - the delta shift used for this test

Returns:

true in case the first value is smaller than the second value by an amount recognizable by the shifted delta, false otherwise

smallerEqual

public static final boolean smallerEqual(double d1,
                                         double d2)

Parameters:

d1 - The first operand.

d2 - The second operand.

Returns:

result of the comparison

See Also:

smallerEqual(double, double, int)

smallerEqual

public static final boolean smallerEqual(double d1,
                                         double d2,
                                         int shift)

Tests whether the first given value is regarded to be smaller or equal than the second value w.r.t. the given shift.

Parameters:

d1 - the first value to test

d2 - the second value to test

shift - the delta shift used for this test

Returns:

true in case the first value is smaller than the second value by an amount recognizable by the given scale or differs from it by an amount not recognizable by the shifted delta, false otherwise