-Updated Contrast Enhancement test

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9238 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: ersts

tests/src/core/testcontrastenhancements.cpp

@@ -23,6 +23,7 @@
 #include <qgscliptominmaxenhancement.h>
 #include <qgscontrastenhancement.h>
 #include <qgslinearminmaxenhancement.h>
+#include <qgslinearminmaxenhancementwithclip.h>
 
 /** \ingroup UnitTests
  * This is a unit test for the ContrastEnhancements contrast enhancement classes.
@@ -36,7 +37,8 @@ class TestContrastEnhancements: public QObject
     void init() {};// will be called before each testfunction is executed.
     void cleanup() {};// will be called after every testfunction.
 
-    void minMaxEnhancementTest();
+    void clipMinMaxEnhancementTest();
+    void linearMinMaxEnhancementWithClipTest();
     void linearMinMaxEnhancementTest();
   private:
     QString mReport;
@@ -63,20 +65,42 @@ void TestContrastEnhancements::cleanupTestCase()
 }
 
 
-void TestContrastEnhancements::minMaxEnhancementTest()
+void TestContrastEnhancements::clipMinMaxEnhancementTest()
 {
+  //Clips 0 < x < 10, 240 < X < 256
+  //Stretch no stretch is applied
   QgsClipToMinMaxEnhancement myEnhancement(QgsContrastEnhancement::QGS_Byte, 10.0, 240.0);
+  // Original pixel value 0.0 Should be out of range thus clipped
   QVERIFY(!myEnhancement.isValueInDisplayableRange(0.0));
-  QVERIFY(10.0 == myEnhancement.enhanceValue(0.0)) ; 
-  QVERIFY(250.0 == myEnhancement.enhanceValue(240.0)) ; 
+  //Original pixel value of 10.0 should be scaled to 10.0
+  QVERIFY(10.0 == myEnhancement.enhanceValue(10.0)) ;
+  //Original pixel value of 240 should be scaled to 240 
+  QVERIFY(240.0 == myEnhancement.enhanceValue(240.0)) ; 
 }
+
+void TestContrastEnhancements::linearMinMaxEnhancementWithClipTest()
+{
+  //First clips 0 < x < 10, 240 < X < 256
+  //Then stretch 10 = 0, 240 = 255 linearly distribute values 10 -> 240 between 0 -> 255
+  QgsLinearMinMaxEnhancementWithClip myEnhancement(QgsContrastEnhancement::QGS_Byte, 10.0, 240.0);
+  // Original pixel value 0.0 Should be out of range thus clipped
+  QVERIFY(!myEnhancement.isValueInDisplayableRange(0.0));
+  //Original pixel value of 10.0 should be scaled to 0.0
+  QVERIFY(0.0 == myEnhancement.enhanceValue(10.0)) ;
+  //Original pixel value of 240 should be scaled to 255 
+  QVERIFY(255.0 == myEnhancement.enhanceValue(240.0)) ;
+}
+
 void TestContrastEnhancements::linearMinMaxEnhancementTest()
 {
+  //Stretch 10 = 0, 240 = 255 linearly distribute values 10 -> 240 between 0 -> 255
   QgsLinearMinMaxEnhancement myEnhancement(QgsContrastEnhancement::QGS_Byte, 10.0, 240.0);
   //0 should be scaled to 10 and not clipped
   QVERIFY(myEnhancement.isValueInDisplayableRange(0.0));
-  QVERIFY(10.0 == myEnhancement.enhanceValue(0.0)) ; 
-  QVERIFY(250.0 == myEnhancement.enhanceValue(240.0)) ; 
+  //Original pixel value of 10.0 should be scaled to 0.0
+  QVERIFY(0.0 == myEnhancement.enhanceValue(10.0)) ;
+  //Original pixel value of 240 should be scaled to 255 
+  QVERIFY(255.0 == myEnhancement.enhanceValue(240.0)) ;
 }
 QTEST_MAIN( TestContrastEnhancements )
 #include "moc_testcontrastenhancements.cxx"