From 0332bed0045c8b0fe3fe06e6bcb8137973c3789b Mon Sep 17 00:00:00 2001
From: ExMix <rahuba.youri@gmail.com>
Date: Wed, 13 Mar 2013 11:45:53 +0300
Subject: [PATCH] Support png writer for gil::view. Work only for
 Texture<RGBA8Traits>

---
 coding/lodepng.cpp            | 17 ++++++++---------
 coding/lodepng.hpp            |  3 ++-
 coding/lodepng_io.hpp         |  8 ++++----
 coding/lodepng_io_private.hpp |  8 ++++----
 coding/writer.hpp             | 28 ++++++++++++++++++++++++++++
 5 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/coding/lodepng.cpp b/coding/lodepng.cpp
index dd07351236..a1db3ec190 100644
--- a/coding/lodepng.cpp
+++ b/coding/lodepng.cpp
@@ -4265,15 +4265,14 @@ namespace LodePNG
   }
   
   /*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-//  void saveFile(const std::vector<unsigned char>& buffer, const std::string& filename)
-//  {
-//    size_t const sz = buffer.size();
-//    if (sz > 0)
-//    {
-//      FileWriter writer(filename);
-//      writer.Write(&buffer[0], sz);
-//    }
-//  }
+  void saveFile(const std::vector<unsigned char>& buffer, WriterPtr<Writer> &writer)
+  {
+    size_t const sz = buffer.size();
+    if (sz > 0)
+    {
+      writer.Write(&buffer[0], sz);
+    }
+  }
   
 //#endif /*LODEPNG_COMPILE_DISK*/
   
diff --git a/coding/lodepng.hpp b/coding/lodepng.hpp
index d6c906e912..a9a4f8f532 100644
--- a/coding/lodepng.hpp
+++ b/coding/lodepng.hpp
@@ -31,6 +31,7 @@ freely, subject to the following restrictions:
 #include <string.h>
 
 #include "reader.hpp"
+#include "writer.hpp"
 
 /* ////////////////////////////////////////////////////////////////////////// */
 /* Code Sections                                                              */
@@ -491,7 +492,7 @@ namespace LodePNG
 //#ifdef LODEPNG_COMPILE_DISK
   //free functions allowing to load and save a file from/to harddisk
   void loadFile(std::vector<unsigned char>& buffer, ReaderPtr<Reader> & reader);
-//  void saveFile(const std::vector<unsigned char>& buffer, const std::string& filename);
+  void saveFile(const std::vector<unsigned char>& buffer, WriterPtr<Writer> & writer);
 //#endif //LODEPNG_COMPILE_DISK
   
 } //namespace LodePNG
diff --git a/coding/lodepng_io.hpp b/coding/lodepng_io.hpp
index f6254e4c62..23b7787e70 100644
--- a/coding/lodepng_io.hpp
+++ b/coding/lodepng_io.hpp
@@ -193,18 +193,18 @@ struct lodepng_write_support {
 /// Triggers a compile assert if the view color space and channel depth are not supported by the PNG library or by the I/O extension.
 /// Throws std::ios_base::failure if it fails to create the file.
 template <typename View>
-inline void lodepng_write_view(const char* filename,const View& view) {
+inline void lodepng_write_view(WriterPtr<Writer> & writer,const View& view) {
     BOOST_STATIC_ASSERT(lodepng_write_support<View>::is_supported);
-    detail::lodepng_writer m(filename);
+    detail::lodepng_writer m(writer);
     m.apply(view);
 }
 
 /// \ingroup LODEPNG_IO
 /// \brief Saves the view to a png file specified by the given png image file name.
-template <typename View>
+/*template <typename View>
 inline void lodepng_write_view(const std::string& filename,const View& view) {
     lodepng_write_view(filename.c_str(),view);
-}
+}*/
 
 } }  // namespace boost::gil
 
diff --git a/coding/lodepng_io_private.hpp b/coding/lodepng_io_private.hpp
index 88e9ab741f..72e2732aaf 100644
--- a/coding/lodepng_io_private.hpp
+++ b/coding/lodepng_io_private.hpp
@@ -369,16 +369,16 @@ public:
 };
 
 
-class lodepng_writer : public file_mgr {
+class lodepng_writer /*: public file_mgr */{
 protected:
 
     LodePNG::Encoder m_encoder;
-    std::string m_fileName;
+    WriterPtr<Writer> & m_writer;
 
     void init() {}
 
 public:
-    lodepng_writer(const char* filename) : file_mgr(filename, "wb"), m_fileName(filename) { init(); }
+    lodepng_writer(WriterPtr<Writer> & writer) : /*file_mgr(filename, "wb"), m_fileName(filename)*/ m_writer(writer) { init(); }
 
     template <typename View>
     void apply(const View& view)
@@ -418,7 +418,7 @@ public:
           view.height()
       );
 
-//      LodePNG::saveFile(buffer, m_fileName);
+      LodePNG::saveFile(buffer, m_writer);
    }
 };
 
diff --git a/coding/writer.hpp b/coding/writer.hpp
index 2f300b2ffe..528d0f28da 100644
--- a/coding/writer.hpp
+++ b/coding/writer.hpp
@@ -3,6 +3,7 @@
 #include "../base/base.hpp"
 #include "../base/exception.hpp"
 #include "../std/algorithm.hpp"
+#include "../std/shared_ptr.hpp"
 #include "../std/memcpy.hpp"
 #include "../std/string.hpp"
 #include "../std/vector.hpp"
@@ -115,6 +116,33 @@ private:
 #endif
 };
 
+template<typename WriterT>
+class WriterPtr
+{
+public:
+  WriterPtr(WriterT * p = 0) : m_p(p) {}
+
+  void Seek(int64_t pos)
+  {
+    m_p->Seek(pos);
+  }
+
+  int64_t Pos() const
+  {
+    return m_p->Pos();
+  }
+
+  void Write(void const * p, size_t size)
+  {
+    m_p->Write(p, size);
+  }
+
+  WriterT * GetPtr() const { return m_p.get(); }
+
+protected:
+  shared_ptr<WriterT> m_p;
+};
+
 template <typename WriterT>
 class WriterSink
 {