Fix bug in randomSFixed

Pharap · web-flow · commit d622c1b0b46f · 2017-10-03T14:45:49.000+01:00
Fixes bug that caused `randomSFixed(inclusiveLowerBound, exclusiveUpperBound)` to return values beyond its boundaries.
diff --git a/src/FixedPoints/Utils.h b/src/FixedPoints/Utils.h
@@ -203,7 +203,7 @@ template< unsigned Integer, unsigned Fraction >
 UFixed<Integer, Fraction> randomUFixed(const UFixed<Integer, Fraction> & inclusiveLowerBound, const UFixed<Integer, Fraction> & exclusiveUpperBound)
 {
 	using InternalType = typename UFixed<Integer, Fraction>::InternalType;
-	return UFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random() % exclusiveUpperBound.getInternal());
+	return UFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + (FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random() % (exclusiveUpperBound.getInternal() - inclusiveLowerBound.getInternal())));
 }
 
 //
@@ -228,6 +228,7 @@ template< unsigned Integer, unsigned Fraction >
 SFixed<Integer, Fraction> randomSFixed(const SFixed<Integer, Fraction> & inclusiveLowerBound, const SFixed<Integer, Fraction> & exclusiveUpperBound)
 {
 	using InternalType = typename SFixed<Integer, Fraction>::InternalType;
-	return SFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random() % exclusiveUpperBound.getInternal());
+	auto value = FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random();
+	return SFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + (abs(value) % (exclusiveUpperBound.getInternal() - inclusiveLowerBound.getInternal())));
 }
 FIXED_POINTS_END_NAMESPACE

Original file line number	Diff line number	Diff line change
`@@ -203,7 +203,7 @@ template< unsigned Integer, unsigned Fraction >`
`203`	`203`	`UFixed<Integer, Fraction> randomUFixed(const UFixed<Integer, Fraction> & inclusiveLowerBound, const UFixed<Integer, Fraction> & exclusiveUpperBound)`
`204`	`204`	`{`
`205`	`205`	`using InternalType = typename UFixed<Integer, Fraction>::InternalType;`
`206`		`- return UFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random() % exclusiveUpperBound.getInternal());`
	`206`	`+ return UFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + (FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random() % (exclusiveUpperBound.getInternal() - inclusiveLowerBound.getInternal())));`
`207`	`207`	`}`
`208`	`208`
`209`	`209`	`//`
`@@ -228,6 +228,7 @@ template< unsigned Integer, unsigned Fraction >`
`228`	`228`	`SFixed<Integer, Fraction> randomSFixed(const SFixed<Integer, Fraction> & inclusiveLowerBound, const SFixed<Integer, Fraction> & exclusiveUpperBound)`
`229`	`229`	`{`
`230`	`230`	`using InternalType = typename SFixed<Integer, Fraction>::InternalType;`
`231`		`- return SFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random() % exclusiveUpperBound.getInternal());`
	`231`	`+ auto value = FIXED_POINTS_DETAILS::RandomHelper<InternalType>::Random();`
	`232`	`+ return SFixed<Integer, Fraction>::fromInternal(inclusiveLowerBound.getInternal() + (abs(value) % (exclusiveUpperBound.getInternal() - inclusiveLowerBound.getInternal())));`
`232`	`233`	`}`
`233`	`234`	`FIXED_POINTS_END_NAMESPACE`