added MexStream.h

Former-commit-id: 1ff7beed480695e119dd707a635201a21cffbb65

include/igl/matlab/MexStream.h

@@ -0,0 +1,53 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#ifndef IGL_MEX_STREAM_H
+#define IGL_MEX_STREAM_H
+#include <iostream>
+namespace igl
+{
+  // http://stackoverflow.com/a/249008/148668
+  
+  // Class to implement "cout" for mex files to print to the matlab terminal
+  // window.
+  //
+  // Insert at the beginning of mexFunction():
+  //  MexStream mout;
+  //  std::streambuf *outbuf = std::cout.rdbuf(&mout); 
+  //  ...
+  //  ALWAYS restore original buffer to avoid memory leak problems in matlab
+  //  std::cout.rdbuf(outbuf);
+  //
+  class MexStream : public std::streambuf
+  {
+    public:
+    protected:
+      inline virtual std::streamsize xsputn(const char *s, std::streamsize n); 
+      inline virtual int overflow(int c = EOF);
+  }; 
+}
+
+// Implementation 
+#include <mex.h>
+inline std::streamsize igl::MexStream::xsputn(
+  const char *s, 
+  std::streamsize n) 
+{
+  mexPrintf("%.*s",n,s);
+  mexEvalString("drawnow;"); // to dump string.
+  return n;
+}
+
+inline int igl::MexStream::overflow(int c) 
+{
+    if (c != EOF) {
+      mexPrintf("%.1s",&c);
+      mexEvalString("drawnow;"); // to dump string.
+    }
+    return 1;
+}
+#endif