Fix abuse of array2D<>

- Add copy c'tor and assignment to `array2D<>`
- Use `std::vector<>` instead of smart pointer to array
- Constify a bit
- Make use of `rtengine::max(...)`

rtengine/array2D.h

@@ -64,8 +64,7 @@ constexpr unsigned int ARRAY2D_BYREFERENCE = 2;
 
 
 template<typename T>
-class array2D :
-    public rtengine::NonCopyable
+class array2D
 {
 
 private:
@@ -125,6 +124,25 @@ public:
         }
     }
 
+    array2D(const array2D& other) :
+        width(other.width),
+        buffer(other.buffer)
+    {
+        initRows(other.rows.size());
+    }
+
+    array2D& operator =(const array2D& other)
+    {
+        if (this != &other) {
+            free();
+            width = other.width;
+            buffer = other.buffer;
+            initRows(other.rows.size());
+        }
+
+        return *this;
+    }
+
     void fill(const T val, bool multiThread = false)
     {
         const ssize_t height = rows.size();