Merge pull request #944 from troussil/DSLGetPointBug

bug fixed in method getPoint of ArithmeticalDSL
DGtal-team · Feb 10, 2015 · b4f8b7b · b4f8b7b
2 parents 53cac2c + 0a5a8a3
commit b4f8b7b
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diff --git a/ChangeLog.md b/ChangeLog.md
@@ -61,6 +61,9 @@
  (Tristan Roussillon, [#939](https:/DGtal-team/DGtal/pull/939))
  - Fixing DSS based length estimator on open curves. (David
  Coeurjolly, [#941](https:/DGtal-team/DGtal/pull/941))
+ - Fix bug of method ArithmeticalDSL::getPoint with negative values
+ of positions as input arguments.
+ (Tristan Roussillon, [#944](https:/DGtal-team/DGtal/pull/944))
  - Fix Bezout Vector computation (Isabelle Sivignon, [#948](https:/DGtal-team/DGtal/pull/948))
 
 # DGtal 0.8

diff --git a/src/DGtal/geometry/curves/ArithmeticalDSL.h b/src/DGtal/geometry/curves/ArithmeticalDSL.h
@@ -480,13 +480,15 @@ namespace DGtal
  /**
  * Returns the unique point of the DSL located at position zero
  * in O(1). 
+ * @pre the arithmetical thickness is not equal to zero
  * @return the point of the DSL located at position zero
  */
  Point getPoint() const;
 
  /**
  * Returns the unique point of the DSL located at position @a aPosition
  * in O(1). 
+ * @pre the arithmetical thickness is not equal to zero
  * @param aPosition position of the returned point
  * @return the point of the DSL located at position @a aPosition
  */

diff --git a/src/DGtal/geometry/curves/ArithmeticalDSL.ih b/src/DGtal/geometry/curves/ArithmeticalDSL.ih
@@ -312,11 +312,14 @@ inline
 typename DGtal::ArithmeticalDSL<TCoordinate, TInteger, adjacency>::Point
 DGtal::ArithmeticalDSL<TCoordinate, TInteger, adjacency>::getPoint() const
 {
+ ASSERT( omega() != NumberTraits<Integer>::ZERO );
+
  Integer shiftRemainder = omega(); 
- Integer q0 = myLowerBound / shiftRemainder;
- if (myLowerBound > (q0 * shiftRemainder))
- q0++; 
- Point origin = toCoordinate(q0) * myShift;
+ Integer q = ( myLowerBound / shiftRemainder ); 
+ if ( (myLowerBound >= NumberTraits<Integer>::ZERO)
+ &&(myLowerBound != (q * shiftRemainder)) )
+ q++; 
+ Point origin = toCoordinate(q) * myShift;
 
  ASSERT( position(origin) == NumberTraits<Position>::ZERO ); 
  ASSERT( isInDSL(origin) ); 
@@ -330,13 +333,16 @@ inline
 typename DGtal::ArithmeticalDSL<TCoordinate, TInteger, adjacency>::Point
 DGtal::ArithmeticalDSL<TCoordinate, TInteger, adjacency>::getPoint(const Position& aPosition) const
 {
- //point of position 0 lying in the DSL
- Point origin = getPoint(); 
+ ASSERT( omega() != NumberTraits<Integer>::ZERO );
 
- //point of position aPosition
- Integer q = ( (myLowerBound - (remainder(origin) + static_cast<Integer>(aPosition) * remainder( mySteps.first ))) 
- / omega() ); 
- Point res = origin + ( aPosition * mySteps.first + toCoordinate(q) * myShift ); 
+ Integer shiftRemainder = omega();
+ Point startingPoint = static_cast<Coordinate>(aPosition) * mySteps.first;
+ Integer bound = (myLowerBound-remainder(startingPoint)); 
+ Integer q = ( bound / shiftRemainder ); 
+ if ( (bound >= NumberTraits<Integer>::ZERO)
+ &&(bound != (q * shiftRemainder)) )
+ q++; 
+ Point res = startingPoint + (toCoordinate(q) * myShift);
 
  ASSERT( position(res) == aPosition ); 
  ASSERT( isInDSL(res) );

diff --git a/src/DGtal/geometry/doc/moduleArithDSSReco.dox b/src/DGtal/geometry/doc/moduleArithDSSReco.dox
@@ -183,6 +183,7 @@ We list below the main methods of ArithmeticalDSL:
  - ArithmeticalDSL::remainder()
  - ArithmeticalDSL::isInDSL() (called in ArithmeticalDSL::operator())
  - ArithmeticalDSL::position()
+ - ArithmeticalDSL::getPoint()
  - ArithmeticalDSL::before()
  - ArithmeticalDSL::beforeOrEqual()
 

diff --git a/tests/geometry/curves/testArithmeticalDSL.cpp b/tests/geometry/curves/testArithmeticalDSL.cpp
@@ -175,6 +175,21 @@ bool mainTest()
  nb++; 
  trace.info() << "(" << nbok << "/" << nb << ") "
  << std::endl;
+
+ if ( (dsl7.getPoint() == Point(0,0)) 
+ &&(DSL(5,8,dsl7.omega()-1).getPoint() == Point(0,0)+dsl.shift())
+ &&(DSL(5,8,dsl7.omega()).getPoint() == Point(0,0)+dsl.shift())
+ &&(DSL(5,8,dsl7.omega()+1).getPoint() == Point(0,0)+2*dsl.shift())
+ &&(DSL(5,8,-dsl7.omega()+1).getPoint() == Point(0,0))
+ &&(DSL(5,8,-dsl7.omega()).getPoint() == Point(0,0)-dsl.shift())
+ &&(DSL(5,8,-dsl7.omega()-1).getPoint() == Point(0,0)-dsl.shift())
+ )
+ nbok++; 
+ nb++; 
+
+ trace.info() << "(" << nbok << "/" << nb << ") "
+ << std::endl;
+
 
  trace.endBlock();
 
@@ -201,7 +216,8 @@ bool rangeTest(const DSL& dsl)
  trace.beginBlock ( "Range/Iterator services..." );
  trace.info() << dsl << std::endl; 
 
- Point first = dsl.getPoint(); 
+ Point origin = dsl.getPoint();
+ Point first = Point(origin[0]-dsl.b(), origin[1]-dsl.a());
  Point last = Point(first[0]+dsl.b(), first[1]+dsl.a()); 
  trace.info() << "from " << first << " to " << last << std::endl;