Fix histogram merging (#28)

HBPVIS · Mar 17, 2017 · afa2a02 · afa2a02
1 parent d571c47
commit afa2a02
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Showing 2 changed files with 21 additions and 5 deletions.
diff --git a/lexis/render/Histogram.cpp b/lexis/render/Histogram.cpp
@@ -28,19 +28,18 @@ Histogram& Histogram::operator+=( const Histogram& histogram )
         return *this;
     }
 
-    if( histogram.getBins().size() != getBins().size() ||
-        histogram.getMin() != getMin() ||
-        histogram.getMax() != getMax( ))
-    {
+    if( histogram.getBins().size() != getBins().size( ))
         throw std::runtime_error( "Addition of incompatible histograms" );
-    }
 
     const uint64_t* srcBins = histogram.getBins().data();
 
     uint64_t* bins = getBins().data();
     for( size_t i = 0; i < getBins().size(); ++i )
         bins[ i ] += srcBins[ i ];
 
+    setMin( std::min( getMin(), histogram.getMin()));
+    setMax( std::max( getMax(), histogram.getMax()));
+
     return *this;
 }
 

diff --git a/tests/render/histogram.cpp b/tests/render/histogram.cpp
@@ -65,3 +65,20 @@ BOOST_AUTO_TEST_CASE( sampleCurve )
     BOOST_CHECK_EQUAL_COLLECTIONS( sampleRange.begin(), sampleRange.end(),
                                    expectedRange.begin(), expectedRange.end( ));
 }
+
+BOOST_AUTO_TEST_CASE( mergeDifferentRange )
+{
+    lexis::render::Histogram histogram1;
+    histogram1.setBins( { 10, 5, 0, 5 } );
+    histogram1.setMin(1);
+    histogram1.setMax(5);
+
+    lexis::render::Histogram histogram2;
+    histogram2.setBins( { 1, 2, 3, 4 } );
+    histogram2.setMin(0);
+    histogram2.setMax(4);
+
+    histogram1 += histogram2;
+    BOOST_CHECK_EQUAL( histogram1.getMin(), 0 );
+    BOOST_CHECK_EQUAL( histogram1.getMax(), 5 );
+}