Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/png/render_to_png_async.cpp

@@ -0,0 +1,54 @@
+// 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/.
+#include "render_to_png_async.h"
+#include "../opengl/gl.h"
+#include <igl_stb_image.h>
+
+static IGL_INLINE bool render_to_png_async_helper(
+  unsigned char * img, int width, int height,
+  const std::string png_file,
+  const bool alpha,
+  const bool fast)
+{
+  //img->flip();
+  if(!alpha)
+  {
+    for(int i = 0;i<width;i++)
+    for(int j = 0;j<height;j++)
+    {
+      img[4*(i+j*width)+3] = 255;
+    }
+  }
+
+  bool ret = igl::stbi_write_png(png_file.c_str(), width, height, 4, img, width*sizeof(unsigned char));
+  delete [] img;
+  return ret;
+}
+
+IGL_INLINE std::thread igl::png::render_to_png_async(
+  const std::string png_file,
+  const int width,
+  const int height,
+  const bool alpha,
+  const bool fast)
+{
+  // Part that should serial
+  unsigned char * data = new unsigned char[width*height];
+  glReadPixels(
+    0,
+    0,
+    width,
+    height,
+    GL_RGBA,
+    GL_UNSIGNED_BYTE,
+    data);
+  // Part that should be asynchronous
+  std::thread t(render_to_png_async_helper,data,width,height,png_file,alpha,fast);
+  t.detach();
+  return t;
+}