3 files changed, 21 insertions, 7 deletions

diff --git a/anglerange.cpp b/anglerange.cpp
index c62f760..99e6718 100644
--- a/anglerange.cpp
+++ b/anglerange.cpp
@@ -144,7 +144,7 @@ bool anglerange::isinside(const angleclass &val) const
     }
 }
 
-anglerange anglerange::overlap(const anglerange &other)
+anglerange anglerange::overlap(const anglerange &other) const
 {
     //storage for the return value:
     anglerange retval; //anglerange constructor without arguments: emtpy range [0:0]
@@ -239,7 +239,7 @@ anglerange anglerange::overlap(const anglerange &other)
     return(retval);
 }
 
-anglerange anglerange::combine(const anglerange &other)
+anglerange anglerange::combine(const anglerange &other) const
 {
     anglerange retval;
     retval.setsorttype(sortby); //return value inherits current sorttype.
diff --git a/anglerange.h b/anglerange.h
index 6d6d286..f0c9eec 100644
--- a/anglerange.h
+++ b/anglerange.h
@@ -77,11 +77,13 @@ public:
 
     //this function calculates the overlap between this anglerange and another one, returning it as
     //a new anglerange.
-    anglerange overlap(const anglerange &other);
+    anglerange overlap(const anglerange &other) const;
 
     //this function does the opposite of overlap: Both ranges are combined into one bigger range.
     //if they are disjoint, an empty range is given back.
-    anglerange combine(const anglerange &other);
+    anglerange combine(const anglerange &other) const;
+
+    //a subtract function is not possible at this level, as single angle ranges could get disjoint by it.
 
     bool operator<(const anglerange &other) const;
     bool operator>(const anglerange &other) const;
diff --git a/angleset.cpp b/angleset.cpp
index fc759b8..24d5b62 100644
--- a/angleset.cpp
+++ b/angleset.cpp
@@ -114,9 +114,10 @@ void angleset::add(const anglerange &value)
     //this means: we *should not reuse* this function for adding anglesets.
     if(!value.isempty())
     {
+        consistent=false;
         storage.push_back(value);
         storage.back().setsorttype(anglerange::SRT_LOWER);
-        combine();
+        //combine();
     }
 }
 
@@ -125,14 +126,16 @@ void angleset::add(const angleset &value)
     storage.reserve(storage.size()+value.storage.size());
     storage.insert(storage.end(),value.storage.begin(),value.storage.end());
     //if value is a valid angleset, sort order is set to SRT_LOWER for all fields.
-    combine();
+    consistent=false;
+    //combine();
 }
 
 void angleset::add(const double &lower, const double &upper)
 {
     storage.push_back(anglerange(lower,upper));
     storage.back().setsorttype(anglerange::SRT_LOWER);
-    combine();
+    consistent=false;
+    //combine();
 }
 
 
@@ -164,25 +167,34 @@ angleset angleset::overlap(const angleset &other)
                     retval.add(overlap(i));
                 }
                 );
+    if(!other.consistent)
+        retval.combine();
     return(retval);
 }
 
 std::vector<anglerange> angleset::getranges()
 {
+    if(!consistent)
+        combine();
     return storage;
 }
 
 const std::vector<anglerange>& angleset::getrangesref()
 {
+    if(!consistent)
+        combine();
     return storage;
 }
 
 void angleset::clear()
 {
     storage.clear();
+    consistent=true;
 }
 
 void angleset::sort()
 {
+    if(!consistent)
+        combine();
     std::sort(storage.begin(),storage.end());
 }