--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Platforms/Sdl/SdlOpenGLContext.cpp	Sat Jan 29 12:47:32 2022 +0100
@@ -0,0 +1,131 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2022 Osimis S.A., Belgium
+ * Copyright (C) 2021-2022 Sebastien Jodogne, ICTEAM UCLouvain, Belgium
+ *
+ * This program 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.
+ *
+ * This program 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 "SdlOpenGLContext.h"
+#include "../../../OrthancStone/Sources/StoneException.h"
+
+#if ORTHANC_ENABLE_SDL == 1
+
+#if !defined(ORTHANC_ENABLE_GLEW)
+#  error Macro ORTHANC_ENABLE_GLEW must be defined
+#endif
+
+#if ORTHANC_ENABLE_GLEW == 1
+#  include <GL/glew.h>
+#endif
+
+#include <Logging.h>
+#include <OrthancException.h>
+
+#include <boost/thread/mutex.hpp>
+
+namespace OrthancStone
+{
+  SdlOpenGLContext::SdlOpenGLContext(const char* title,
+                                     unsigned int width,
+                                     unsigned int height,
+                                     bool allowDpiScaling) 
+    : window_(title, width, height, true /* enable OpenGL */, allowDpiScaling)
+    , context_(NULL)
+  {
+    context_ = SDL_GL_CreateContext(window_.GetObject());
+    
+    if (context_ == NULL)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError,
+                                      "Cannot initialize OpenGL");
+    }
+
+#if ORTHANC_ENABLE_GLEW == 1
+    // The initialization function of glew (i.e. "glewInit()") can
+    // only be called once an OpenGL is setup.
+    // https://stackoverflow.com/a/45033669/881731
+    {
+      static boost::mutex  mutex_;
+      static bool          isGlewInitialized_ = false;
+  
+      boost::mutex::scoped_lock lock(mutex_);
+
+      if (!isGlewInitialized_)
+      {
+        LOG(INFO) << "Initializing glew";
+        
+        GLenum err = glewInit();
+        if (GLEW_OK != err)
+        {
+          LOG(ERROR) << glewGetErrorString(err);
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError,
+                                          "Cannot initialize glew");
+        }
+
+        isGlewInitialized_ = true;
+      }
+    }    
+#endif
+  }
+
+  
+  SdlOpenGLContext::~SdlOpenGLContext()
+  {
+    SDL_GL_DeleteContext(context_);
+  }
+
+  void SdlOpenGLContext::MakeCurrent()
+  {
+    if (SDL_GL_MakeCurrent(window_.GetObject(), context_) != 0)
+    {
+      const char* errText = SDL_GetError();
+      std::stringstream ss;
+      ss << "Cannot set current OpenGL context. SDL error text: " << errText;
+      std::string errStr = ss.str();
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError, errStr.c_str());
+    }
+
+    // This makes our buffer swap synchronized with the monitor's vertical refresh
+    SDL_GL_SetSwapInterval(1);
+  }
+
+  
+  void SdlOpenGLContext::SwapBuffer()
+  {
+    // Swap our buffer to display the current contents of buffer on screen
+    SDL_GL_SwapWindow(window_.GetObject());
+  }
+
+  
+  unsigned int SdlOpenGLContext::GetCanvasWidth() const
+  {
+    int w = 0;
+    SDL_GL_GetDrawableSize(window_.GetObject(), &w, NULL);
+    return static_cast<unsigned int>(w);
+  }
+
+  
+  unsigned int SdlOpenGLContext::GetCanvasHeight() const
+  {
+    int h = 0;
+    SDL_GL_GetDrawableSize(window_.GetObject(), NULL, &h);
+    return static_cast<unsigned int>(h);
+  }
+}
+
+#endif