libdeng2: Added de::wrap template for wrapping inside a range

skyjake · Feb 5, 2013 · 3104ccc · 3104ccc
1 parent 065b56b
commit 3104ccc
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/doomsday/libdeng2/include/de/math.h b/doomsday/libdeng2/include/de/math.h
@@ -69,6 +69,15 @@ inline Type clamp(Type const &low, Type const &value, Type const &high) {
     return min(max(value, low), high);
 }
 
+/// Wrap value within range [low, high).
+template <typename Type>
+Type wrap(Type value, Type const &low, Type const &high) {
+    Type const range = high - low;
+    while(value < low) value += range;
+    while(value >= high) value -= range;
+    return value;
+}
+
 inline dint32 floor(dfloat const &value) {
     return dint32(std::floor(value));
 }

diff --git a/doomsday/libshell/src/lineeditwidget.cpp b/doomsday/libshell/src/lineeditwidget.cpp
@@ -256,9 +256,8 @@ struct LineEditWidget::Instance
             String const base = wordBehindCursor();
 
             // Go to next suggestion.
-            completion.ordinal += (forwardCycle? 1 : -1);
-            if(completion.ordinal < 0) completion.ordinal += suggestions.size();
-            if(completion.ordinal >= suggestions.size()) completion.ordinal -= suggestions.size();
+            completion.ordinal = de::wrap(completion.ordinal + (forwardCycle? 1 : -1),
+                                          0, suggestions.size());
             String comp = suggestions[completion.ordinal];
             comp.remove(0, base.size());