1 files changed, 96 insertions, 0 deletions
diff --git a/libdimensionxx/png.cpp b/libdimensionxx/png.cpp
new file mode 100644
index 0000000..14b8c4d
--- /dev/null
+++ b/libdimensionxx/png.cpp
@@ -0,0 +1,96 @@
+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Library is distributed in the hope that it will be      *
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+#include "dimensionxx.hpp"
+#include "../libdimension-png/dimension-png.h"
+
+namespace Dimension
+{
+  PNG_Canvas::~PNG_Canvas()
+  {
+    if (m_ostr && !m_written) {
+      try {
+        write();
+      } catch (...) {
+        dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                    "Writing canvas to PNG failed in PNG_Canvas destructor.");
+      }
+    }
+  }
+
+  void PNG_Canvas::write()
+  {
+    if (m_written) {
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Attempt to write canvas to PNG twice.");
+      return;
+    }
+
+    if (!m_ostr) {
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Attempt to write canvas to PNG without an output stream.");
+      return;
+    }      
+
+    FILE* file = fcookie(*m_ostr);
+    if (!file) {
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Couldn't create C++/C IO interface when writing canvas"
+                  " to PNG.");
+      return;
+    }      
+
+    if (dmnsn_png_write_canvas(m_canvas, file)) {
+      fclose(file);
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Writing canvas to PNG failed.");
+      return;
+    }
+
+    fclose(file);
+    m_written = true;
+  }
+
+  void PNG_Canvas::read()
+  {
+    if (!m_istr) {
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Attempt to read canvas from PNG without an input stream.");
+      return;
+    }      
+
+    FILE* file = fcookie(*m_istr);
+    if (!file) {
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Couldn't create C++/C IO interface when reading canvas"
+                  " from PNG.");
+      return;
+    }      
+
+    if (!(m_canvas = dmnsn_png_read_canvas(file))) {
+      fclose(file);
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM,
+                  "Reading canvas from PNG failed.");
+      return;
+    }
+
+    fclose(file);
+  }
+}