From d7d3da6935b0f36a4477d7d9e49a28ca6d5962eb Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Wed, 16 Sep 2015 11:37:03 +0100
Subject: [PATCH] image - add iterator interface

---
 include/mapnik/image.hpp      |  8 ++++++++
 include/mapnik/image_impl.hpp | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/mapnik/image.hpp b/include/mapnik/image.hpp
index 7165e0c61..9ebdfc3b2 100644
--- a/include/mapnik/image.hpp
+++ b/include/mapnik/image.hpp
@@ -72,6 +72,8 @@ class image
 public:
     using pixel = T;
     using pixel_type = typename T::type;
+    using iterator = pixel_type*;
+    using const_iterator = pixel_type const*;
     static constexpr image_dtype dtype = T::id;
     static constexpr std::size_t pixel_size = sizeof(pixel_type);
 private:
@@ -110,6 +112,12 @@ public:
     void set(pixel_type const& t);
     pixel_type const* data() const;
     pixel_type* data();
+    // simple iterator inteface
+    const_iterator begin() const;
+    const_iterator end() const;
+    iterator begin();
+    iterator end();
+    //
     unsigned char const* bytes() const;
     unsigned char* bytes();
     pixel_type const* get_row(std::size_t row) const;
diff --git a/include/mapnik/image_impl.hpp b/include/mapnik/image_impl.hpp
index 2be52933f..b1fbfa966 100644
--- a/include/mapnik/image_impl.hpp
+++ b/include/mapnik/image_impl.hpp
@@ -226,6 +226,20 @@ inline unsigned char* image<T>::bytes()
     return buffer_.data();
 }
 
+// iterator interface
+template <typename T>
+inline typename image<T>::iterator image<T>::begin() { return pData_; }
+
+template <typename T>
+inline typename image<T>::iterator image<T>::end() { return pData_ + dimensions_.width() * dimensions_.height(); }
+
+template <typename T>
+inline typename image<T>::const_iterator image<T>::begin() const { return pData_; }
+
+template <typename T>
+inline typename image<T>::const_iterator image<T>::end() const{ return pData_ + dimensions_.width() * dimensions_.height(); }
+
+
 template <typename T>
 inline typename image<T>::pixel_type const* image<T>::get_row(std::size_t row) const
 {