diff options
| -rw-r--r-- | core/java/android/hardware/camera2/Rational.java | 83 | ||||
| -rw-r--r-- | media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/RationalTest.java | 51 |
2 files changed, 105 insertions, 29 deletions
diff --git a/core/java/android/hardware/camera2/Rational.java b/core/java/android/hardware/camera2/Rational.java index 0260e02..77b8c26 100644 --- a/core/java/android/hardware/camera2/Rational.java +++ b/core/java/android/hardware/camera2/Rational.java @@ -26,22 +26,17 @@ public final class Rational { /** * <p>Create a Rational with a given numerator and denominator.</p> * - * <p> - * The signs of the numerator and the denominator may be flipped such that the denominator - * is always 0. - * </p> + * <p>The signs of the numerator and the denominator may be flipped such that the denominator + * is always positive.</p> + * + * <p>A rational value with a 0-denominator may be constructed, but will have similar semantics + * as float NaN and INF values. The int getter functions return 0 in this case.</p> * * @param numerator the numerator of the rational * @param denominator the denominator of the rational - * - * @throws IllegalArgumentException if the denominator is 0 */ public Rational(int numerator, int denominator) { - if (denominator == 0) { - throw new IllegalArgumentException("Argument 'denominator' is 0"); - } - if (denominator < 0) { numerator = -numerator; denominator = -denominator; @@ -55,6 +50,9 @@ public final class Rational { * Gets the numerator of the rational. */ public int getNumerator() { + if (mDenominator == 0) { + return 0; + } return mNumerator; } @@ -65,22 +63,41 @@ public final class Rational { return mDenominator; } + private boolean isNaN() { + return mDenominator == 0 && mNumerator == 0; + } + + private boolean isInf() { + return mDenominator == 0 && mNumerator > 0; + } + + private boolean isNegInf() { + return mDenominator == 0 && mNumerator < 0; + } + /** * <p>Compare this Rational to another object and see if they are equal.</p> * * <p>A Rational object can only be equal to another Rational object (comparing against any other * type will return false).</p> * - * <p>A Rational object is considered equal to another Rational object if and only if their - * reduced forms have the same numerator and denominator.</p> + * <p>A Rational object is considered equal to another Rational object if and only if one of + * the following holds</p>: + * <ul><li>Both are NaN</li> + * <li>Both are infinities of the same sign</li> + * <li>Both have the same numerator and denominator in their reduced form</li> + * </ul> * * <p>A reduced form of a Rational is calculated by dividing both the numerator and the * denominator by their greatest common divisor.</p> * * <pre> - * (new Rational(1, 2)).equals(new Rational(1, 2)) == true // trivially true - * (new Rational(2, 3)).equals(new Rational(1, 2)) == false // trivially false - * (new Rational(1, 2)).equals(new Rational(2, 4)) == true // true after reduction + * (new Rational(1, 2)).equals(new Rational(1, 2)) == true // trivially true + * (new Rational(2, 3)).equals(new Rational(1, 2)) == false // trivially false + * (new Rational(1, 2)).equals(new Rational(2, 4)) == true // true after reduction + * (new Rational(0, 0)).equals(new Rational(0, 0)) == true // NaN.equals(NaN) + * (new Rational(1, 0)).equals(new Rational(5, 0)) == true // both are +infinity + * (new Rational(1, 0)).equals(new Rational(-1, 0)) == false // +infinity != -infinity * </pre> * * @param obj a reference to another object @@ -91,13 +108,17 @@ public final class Rational { public boolean equals(Object obj) { if (obj == null) { return false; - } - if (this == obj) { - return true; - } - if (obj instanceof Rational) { + } else if (obj instanceof Rational) { Rational other = (Rational) obj; - if(mNumerator == other.mNumerator && mDenominator == other.mDenominator) { + if (mDenominator == 0 || other.mDenominator == 0) { + if (isNaN() && other.isNaN()) { + return true; + } else if (isInf() && other.isInf() || isNegInf() && other.isNegInf()) { + return true; + } else { + return false; + } + } else if (mNumerator == other.mNumerator && mDenominator == other.mDenominator) { return true; } else { int thisGcd = gcd(); @@ -117,7 +138,25 @@ public final class Rational { @Override public String toString() { - return mNumerator + "/" + mDenominator; + if (isNaN()) { + return "NaN"; + } else if (isInf()) { + return "Infinity"; + } else if (isNegInf()) { + return "-Infinity"; + } else { + return mNumerator + "/" + mDenominator; + } + } + + /** + * <p>Convert to a floating point representation.</p> + * + * @return The floating point representation of this rational number. + * @hide + */ + public float toFloat() { + return (float) mNumerator / (float) mDenominator; } @Override diff --git a/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/RationalTest.java b/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/RationalTest.java index 926719c..9621f92 100644 --- a/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/RationalTest.java +++ b/media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/unit/RationalTest.java @@ -50,12 +50,20 @@ public class RationalTest extends junit.framework.TestCase { assertEquals(1, r.getNumerator()); assertEquals(2, r.getDenominator()); - // Dividing by zero is not allowed - try { - r = new Rational(1, 0); - fail("Expected Rational constructor to throw an IllegalArgumentException"); - } catch(IllegalArgumentException e) { - } + // Infinity. + r = new Rational(1, 0); + assertEquals(0, r.getNumerator()); + assertEquals(0, r.getDenominator()); + + // Negative infinity. + r = new Rational(-1, 0); + assertEquals(0, r.getNumerator()); + assertEquals(0, r.getDenominator()); + + // NaN. + r = new Rational(0, 0); + assertEquals(0, r.getNumerator()); + assertEquals(0, r.getDenominator()); } @SmallTest @@ -110,5 +118,34 @@ public class RationalTest extends junit.framework.TestCase { assertEquals(moreComplicated, moreComplicated2); assertEquals(moreComplicated2, moreComplicated); + Rational nan = new Rational(0, 0); + Rational nan2 = new Rational(0, 0); + assertTrue(nan.equals(nan)); + assertTrue(nan.equals(nan2)); + assertTrue(nan2.equals(nan)); + assertFalse(nan.equals(r)); + assertFalse(r.equals(nan)); + + // Infinities of the same sign are equal. + Rational posInf = new Rational(1, 0); + Rational posInf2 = new Rational(2, 0); + Rational negInf = new Rational(-1, 0); + Rational negInf2 = new Rational(-2, 0); + assertEquals(posInf, posInf); + assertEquals(negInf, negInf); + assertEquals(posInf, posInf2); + assertEquals(negInf, negInf2); + + // Infinities aren't equal to anything else. + assertFalse(posInf.equals(negInf)); + assertFalse(negInf.equals(posInf)); + assertFalse(negInf.equals(r)); + assertFalse(posInf.equals(r)); + assertFalse(r.equals(negInf)); + assertFalse(r.equals(posInf)); + assertFalse(posInf.equals(nan)); + assertFalse(negInf.equals(nan)); + assertFalse(nan.equals(posInf)); + assertFalse(nan.equals(negInf)); } -}
\ No newline at end of file +} |