diff --git a/examples/shader/Shader.cpp b/examples/shader/Shader.cpp
index 0945497f4..bd5b134bf 100644
--- a/examples/shader/Shader.cpp
+++ b/examples/shader/Shader.cpp
@@ -130,16 +130,16 @@ int main()
     ShaderSelector globalShader(shaders, "nothing");
 
     // Do specific initializations
-    shaders["nothing"].SetTexture("texture", sf::Shader::CurrentTexture);
-    shaders["blur"].SetTexture("texture", sf::Shader::CurrentTexture);
+    shaders["nothing"].SetCurrentTexture("texture");
+    shaders["blur"].SetCurrentTexture("texture");
     shaders["blur"].SetParameter("offset", 0.f);
-    shaders["colorize"].SetTexture("texture", sf::Shader::CurrentTexture);
+    shaders["colorize"].SetCurrentTexture("texture");
     shaders["colorize"].SetParameter("color", 1.f, 1.f, 1.f);
-    shaders["edge"].SetTexture("texture", sf::Shader::CurrentTexture);
-    shaders["fisheye"].SetTexture("texture", sf::Shader::CurrentTexture);
-    shaders["wave"].SetTexture("texture", sf::Shader::CurrentTexture);
+    shaders["edge"].SetCurrentTexture("texture");
+    shaders["fisheye"].SetCurrentTexture("texture");
+    shaders["wave"].SetCurrentTexture("texture");
     shaders["wave"].SetTexture("wave", waveImage);
-    shaders["pixelate"].SetTexture("texture", sf::Shader::CurrentTexture);
+    shaders["pixelate"].SetCurrentTexture("texture");
 
     // Define a string for displaying the description of the current shader
     sf::Text shaderStr;
diff --git a/include/SFML/Graphics/Image.hpp b/include/SFML/Graphics/Image.hpp
index a447038df..1ef822d7e 100644
--- a/include/SFML/Graphics/Image.hpp
+++ b/include/SFML/Graphics/Image.hpp
@@ -29,6 +29,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/System/Resource.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <SFML/Graphics/Color.hpp>
 #include <SFML/Graphics/Rect.hpp>
 #include <string>
@@ -45,7 +46,7 @@ class RenderWindow;
 /// \brief Class for loading, manipulating and saving images
 ///
 ////////////////////////////////////////////////////////////
-class SFML_API Image : public Resource<Image>
+class SFML_API Image : public Resource<Image>, GlResource
 {
 public :
 
diff --git a/include/SFML/Graphics/Renderer.hpp b/include/SFML/Graphics/Renderer.hpp
index 40a13b4e0..b5fe0234a 100644
--- a/include/SFML/Graphics/Renderer.hpp
+++ b/include/SFML/Graphics/Renderer.hpp
@@ -30,6 +30,7 @@
 ////////////////////////////////////////////////////////////
 #include <SFML/Config.hpp>
 #include <SFML/System/NonCopyable.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <SFML/Graphics/Color.hpp>
 #include <SFML/Graphics/Drawable.hpp>
 #include <SFML/Graphics/Matrix3.hpp>
@@ -44,7 +45,7 @@ class Shader;
 /// \brief Handles the low-level rendering (states and geometry)
 ///
 ////////////////////////////////////////////////////////////
-class SFML_API Renderer : NonCopyable
+class SFML_API Renderer : GlResource, NonCopyable
 {
 public :
 
diff --git a/include/SFML/Graphics/Shader.hpp b/include/SFML/Graphics/Shader.hpp
index e49f34543..9f947e0e2 100644
--- a/include/SFML/Graphics/Shader.hpp
+++ b/include/SFML/Graphics/Shader.hpp
@@ -30,6 +30,7 @@
 ////////////////////////////////////////////////////////////
 #include <SFML/Config.hpp>
 #include <SFML/Graphics/Image.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <SFML/System/Vector2.hpp>
 #include <SFML/System/Vector3.hpp>
 #include <map>
@@ -44,7 +45,7 @@ class Renderer;
 /// \brief Pixel/fragment shader class
 ///
 ////////////////////////////////////////////////////////////
-class SFML_API Shader
+class SFML_API Shader : GlResource
 {
 public :
 
@@ -120,7 +121,7 @@ public :
     /// \param name Name of the parameter in the shader
     /// \param x    Value to assign
     ///
-    /// \see SetTexture
+    /// \see SetTexture, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetParameter(const std::string& name, float x);
@@ -141,7 +142,7 @@ public :
     /// \param x    First component of the value to assign
     /// \param y    Second component of the value to assign
     ///
-    /// \see SetTexture
+    /// \see SetTexture, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetParameter(const std::string& name, float x, float y);
@@ -163,7 +164,7 @@ public :
     /// \param y    Second component of the value to assign
     /// \param z    Third component of the value to assign
     ///
-    /// \see SetTexture
+    /// \see SetTexture, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetParameter(const std::string& name, float x, float y, float z);
@@ -186,7 +187,7 @@ public :
     /// \param z    Third component of the value to assign
     /// \param w    Fourth component of the value to assign
     ///
-    /// \see SetTexture
+    /// \see SetTexture, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetParameter(const std::string& name, float x, float y, float z, float w);
@@ -206,7 +207,7 @@ public :
     /// \param name   Name of the parameter in the shader
     /// \param vector Vector to assign
     ///
-    /// \see SetTexture
+    /// \see SetTexture, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetParameter(const std::string& name, const Vector2f& vector);
@@ -226,7 +227,7 @@ public :
     /// \param name   Name of the parameter in the shader
     /// \param vector Vector to assign
     ///
-    /// \see SetTexture
+    /// \see SetTexture, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetParameter(const std::string& name, const Vector3f& vector);
@@ -235,19 +236,18 @@ public :
     /// \brief Change a texture parameter of the shader
     ///
     /// \a name is the name of the texture to change in the shader.
-    /// To tell the shader to use the current texture of the object being
-    /// drawn, pass Shader::CurrentTexture.
+    /// This function maps an external image to the texture variable;
+    /// to use the current texture of the object being drawn, use
+    /// SetCurrentTexture instead.
     /// Example:
     /// \code
     /// // These are the variables in the pixel shader
-    /// uniform sampler2D current;
-    /// uniform sampler2D other;
+    /// uniform sampler2D texture;
     /// \endcode
     /// \code
     /// sf::Image image;
     /// ...
-    /// shader.SetParameter("current", sf::Shader::CurrentTexture);
-    /// shader.SetParameter("other", image);
+    /// shader.SetTexture("texture", image);
     /// \endcode
     /// It is important to note that \a texture must remain alive as long
     /// as the shader uses it, no copy is made internally.
@@ -255,11 +255,32 @@ public :
     /// \param name    Name of the texture in the shader
     /// \param texture Image to assign
     ///
-    /// \see SetParameter
+    /// \see SetParameter, SetCurrentTexture
     ///
     ////////////////////////////////////////////////////////////
     void SetTexture(const std::string& name, const Image& texture);
 
+    ////////////////////////////////////////////////////////////
+    /// \brief Set the current object texture in the shader
+    ///
+    /// This function maps a shader texture variable to the
+    /// image of the object being drawn.
+    /// Example:
+    /// \code
+    /// // This is the variable in the pixel shader
+    /// uniform sampler2D current;
+    /// \endcode
+    /// \code
+    /// shader.SetCurrentTexture("current");
+    /// \endcode
+    ///
+    /// \param name Name of the texture in the shader
+    ///
+    /// \see SetParameter, SetTexture
+    ///
+    ////////////////////////////////////////////////////////////
+    void SetCurrentTexture(const std::string& name);
+
     ////////////////////////////////////////////////////////////
     /// \brief Bind the shader for rendering (activate it)
     ///
@@ -312,11 +333,6 @@ public :
     ////////////////////////////////////////////////////////////
     static bool IsAvailable();
 
-    ////////////////////////////////////////////////////////////
-    // Static member data
-    ////////////////////////////////////////////////////////////
-    static const Image CurrentTexture; ///< Special image representing the texture used by the object being drawn
-
 private :
 
     friend class Renderer;
@@ -394,12 +410,12 @@ private :
 /// \code
 /// shader.SetParameter("offset", 2.f);
 /// shader.SetParameter("color", 0.5f, 0.8f, 0.3f);
-/// shader.SetTexture("image", image); // image is a sf::Image
-/// shader.SetTexture("current", sf::Shader::CurrentTexture);
+/// shader.SetTexture("overlay", image); // image is a sf::Image
+/// shader.SetCurrentTexture("texture");
 /// \endcode
 ///
-/// Shader::CurrentTexture is a special value that represents
-/// the texture that the object being drawn is using.
+/// Shader::SetCurrentTexture maps the given texture variable
+/// to the current texture of the object being drawn.
 ///
 /// To apply a shader to a drawable, you must pass it as an
 /// additional parameter to the Draw function:
diff --git a/include/SFML/Window/Context.hpp b/include/SFML/Window/Context.hpp
index 9ec69c5ef..844d2c471 100644
--- a/include/SFML/Window/Context.hpp
+++ b/include/SFML/Window/Context.hpp
@@ -29,6 +29,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/Config.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <SFML/System/NonCopyable.hpp>
 
 
@@ -43,7 +44,7 @@ namespace priv
 /// \brief Class holding a valid drawing context
 ///
 ////////////////////////////////////////////////////////////
-class SFML_API Context : NonCopyable
+class SFML_API Context : GlResource, NonCopyable
 {
 public :
 
@@ -71,18 +72,6 @@ public :
     ////////////////////////////////////////////////////////////
     void SetActive(bool active);
 
-    ////////////////////////////////////////////////////////////
-    /// \brief Make the current thread's reference context active
-    ///
-    /// This function is meant to be called internally; it is used
-    /// to deactivate the current context by activating another one
-    /// (so that we still have an active context on the current thread).
-    ///
-    /// \return True if operation was successful, false otherwise
-    ///
-    ////////////////////////////////////////////////////////////
-    static bool SetReferenceActive();
-
 private :
 
     ////////////////////////////////////////////////////////////
diff --git a/include/SFML/Window/GlResource.hpp b/include/SFML/Window/GlResource.hpp
new file mode 100644
index 000000000..36e7ebd26
--- /dev/null
+++ b/include/SFML/Window/GlResource.hpp
@@ -0,0 +1,72 @@
+////////////////////////////////////////////////////////////
+//
+// SFML - Simple and Fast Multimedia Library
+// Copyright (C) 2007-2009 Laurent Gomila (laurent.gom@gmail.com)
+//
+// This software is provided 'as-is', without any express or implied warranty.
+// In no event will the authors be held liable for any damages arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it freely,
+// subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented;
+//    you must not claim that you wrote the original software.
+//    If you use this software in a product, an acknowledgment
+//    in the product documentation would be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such,
+//    and must not be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source distribution.
+//
+////////////////////////////////////////////////////////////
+
+#ifndef SFML_GLRESOURCE_HPP
+#define SFML_GLRESOURCE_HPP
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+#include <SFML/Config.hpp>
+
+
+namespace sf
+{
+////////////////////////////////////////////////////////////
+/// \brief Base class for classes that require an OpenGL context
+///
+////////////////////////////////////////////////////////////
+class SFML_API GlResource
+{
+protected :
+
+    ////////////////////////////////////////////////////////////
+    /// \brief Default constructor
+    ///
+    ////////////////////////////////////////////////////////////
+    GlResource();
+
+    ////////////////////////////////////////////////////////////
+    /// \brief Destructor
+    ///
+    ////////////////////////////////////////////////////////////
+    ~GlResource();
+
+    static void EnsureGlContext();
+};
+
+} // namespace sf
+
+
+#endif // SFML_GLRESOURCE_HPP
+
+////////////////////////////////////////////////////////////
+/// \class sf::GlResource
+/// \ingroup window
+///
+/// This class is for internal use only, it must be the base
+/// of every class that requires a valid OpenGL context in
+/// order to work.
+///
+////////////////////////////////////////////////////////////
diff --git a/include/SFML/Window/Window.hpp b/include/SFML/Window/Window.hpp
index 90959147f..726707bce 100644
--- a/include/SFML/Window/Window.hpp
+++ b/include/SFML/Window/Window.hpp
@@ -33,6 +33,7 @@
 #include <SFML/Window/VideoMode.hpp>
 #include <SFML/Window/WindowHandle.hpp>
 #include <SFML/Window/WindowStyle.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <SFML/System/Clock.hpp>
 #include <SFML/System/NonCopyable.hpp>
 #include <string>
@@ -52,7 +53,7 @@ class Event;
 /// \brief Window that serves as a target for OpenGL rendering
 ///
 ////////////////////////////////////////////////////////////
-class SFML_API Window : NonCopyable
+class SFML_API Window : GlResource, NonCopyable
 {
 public :
 
diff --git a/src/SFML/Graphics/Image.cpp b/src/SFML/Graphics/Image.cpp
index 972de13bc..66134a652 100644
--- a/src/SFML/Graphics/Image.cpp
+++ b/src/SFML/Graphics/Image.cpp
@@ -84,6 +84,8 @@ Image::~Image()
     // Destroy the OpenGL texture
     if (myTexture)
     {
+        EnsureGlContext();
+
         GLuint Texture = static_cast<GLuint>(myTexture);
         GLCheck(glDeleteTextures(1, &Texture));
     }
@@ -410,6 +412,8 @@ void Image::UpdatePixels(const Uint8* pixels)
 {
     if (pixels && myTexture)
     {
+        EnsureGlContext();
+
         GLint previous;
         GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
 
@@ -468,6 +472,8 @@ void Image::SetSmooth(bool smooth)
 
         if (myTexture)
         {
+            EnsureGlContext();
+
             GLint previous;
             GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
 
@@ -535,6 +541,8 @@ FloatRect Image::GetTexCoords(const IntRect& rect) const
 ////////////////////////////////////////////////////////////
 unsigned int Image::GetMaximumSize()
 {
+    EnsureGlContext();
+
     GLint size;
     GLCheck(glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size));
 
@@ -565,6 +573,8 @@ Image& Image::operator =(const Image& right)
 ////////////////////////////////////////////////////////////
 unsigned int Image::GetValidSize(unsigned int size)
 {
+    EnsureGlContext();
+
     // Make sure that GLEW is initialized
     priv::EnsureGlewInit();
 
@@ -613,6 +623,8 @@ bool Image::CreateTexture(unsigned int width, unsigned int height)
     myTextureWidth  = textureWidth;
     myTextureHeight = textureHeight;
 
+    EnsureGlContext();
+
     // Create the OpenGL texture if it doesn't exist yet
     if (!myTexture)
     {
@@ -645,6 +657,8 @@ void Image::EnsureTextureUpdate() const
     {
         if (myTexture && !myPixels.empty())
         {
+            EnsureGlContext();
+
             GLint previous;
             GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
 
@@ -666,6 +680,8 @@ void Image::EnsureArrayUpdate() const
 {
     if (!myArrayUpdated)
     {
+        EnsureGlContext();
+
         // Save the previous texture
         GLint previous;
         GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
diff --git a/src/SFML/Graphics/Linux/RenderImageImplPBuffer.cpp b/src/SFML/Graphics/Linux/RenderImageImplPBuffer.cpp
index 059411c8c..e68d14ae0 100644
--- a/src/SFML/Graphics/Linux/RenderImageImplPBuffer.cpp
+++ b/src/SFML/Graphics/Linux/RenderImageImplPBuffer.cpp
@@ -49,6 +49,8 @@ myHeight (0)
 ////////////////////////////////////////////////////////////
 RenderImageImplPBuffer::~RenderImageImplPBuffer()
 {
+    EnsureGlContext();
+
     if (myContext)
         glXDestroyContext(myDisplay, myContext);
 
@@ -56,20 +58,18 @@ RenderImageImplPBuffer::~RenderImageImplPBuffer()
         glXDestroyGLXPbufferSGIX(myDisplay, myPBuffer);
 
     XCloseDisplay(myDisplay);
-
-    // This is to make sure that another valid context is made
-    // active after we destroy the P-Buffer's one
-    Context::SetReferenceActive();
 }
 
 
 ////////////////////////////////////////////////////////////
 bool RenderImageImplPBuffer::IsSupported()
 {
+    EnsureGlContext();
+
     // Make sure that GLEW is initialized
     EnsureGlewInit();
 
-    return glxewIsSupported("GLX_SGIX_pbuffer");
+    return GLXEW_SGIX_pbuffer && GLXEW_SGIX_fbconfig;
 }
 
 
@@ -182,7 +182,9 @@ bool RenderImageImplPBuffer::Activate(bool active)
         // To deactivate the P-Buffer's context, we actually activate
         // another one so that we make sure that there is always an
         // active context for subsequent graphics operations
-        return Context::SetReferenceActive();
+        // @odo fixme
+        //return Context::SetReferenceActive();
+        return true;
     }
 }
 
@@ -190,17 +192,14 @@ bool RenderImageImplPBuffer::Activate(bool active)
 ////////////////////////////////////////////////////////////
 void RenderImageImplPBuffer::UpdateTexture(unsigned int textureId)
 {
-    if (Activate(true))
-    {
-        GLint previous;
-        GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
+    GLint previous;
+    GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
 
-        // Copy the rendered pixels to the image
-        GLCheck(glBindTexture(GL_TEXTURE_2D, textureId));
-        GLCheck(glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, myWidth, myHeight));
+    // Copy the rendered pixels to the image
+    GLCheck(glBindTexture(GL_TEXTURE_2D, textureId));
+    GLCheck(glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, myWidth, myHeight));
 
-        GLCheck(glBindTexture(GL_TEXTURE_2D, previous));
-    }
+    GLCheck(glBindTexture(GL_TEXTURE_2D, previous));
 }
 
 } // namespace priv
diff --git a/src/SFML/Graphics/Linux/RenderImageImplPBuffer.hpp b/src/SFML/Graphics/Linux/RenderImageImplPBuffer.hpp
index 78956fcc9..d092ff9e1 100644
--- a/src/SFML/Graphics/Linux/RenderImageImplPBuffer.hpp
+++ b/src/SFML/Graphics/Linux/RenderImageImplPBuffer.hpp
@@ -29,6 +29,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/Graphics/RenderImageImpl.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <GL/glew.h>
 #include <GL/glxew.h>
 #include <X11/Xlib.h>
@@ -42,7 +43,7 @@ namespace priv
 /// \brief Specialization of RenderImageImpl using GLX P-Buffers
 ///
 ////////////////////////////////////////////////////////////
-class RenderImageImplPBuffer : public RenderImageImpl
+class RenderImageImplPBuffer : public RenderImageImpl, GlResource
 {
 public :
 
diff --git a/src/SFML/Graphics/OSX/RenderImageImplPBuffer.cpp b/src/SFML/Graphics/OSX/RenderImageImplPBuffer.cpp
index 4b193e48f..3e8ab4176 100644
--- a/src/SFML/Graphics/OSX/RenderImageImplPBuffer.cpp
+++ b/src/SFML/Graphics/OSX/RenderImageImplPBuffer.cpp
@@ -66,16 +66,14 @@ RenderImageImplPBuffer::~RenderImageImplPBuffer()
         << aglGetError()
         << std::endl;
     }
-
-    // This is to make sure that another valid context is made
-    // active after we destroy the P-Buffer's one
-    Context::SetReferenceActive();
 }
 
 
 ////////////////////////////////////////////////////////////
 bool RenderImageImplPBuffer::IsSupported()
 {
+    EnsureGlContext();
+
     const GLubyte* strExt = glGetString(GL_EXTENSIONS);
     GLboolean isSupported = gluCheckExtension((const GLubyte*)"GL_APPLE_pixel_buffer", strExt);
     
@@ -164,21 +162,24 @@ bool RenderImageImplPBuffer::Create(unsigned int width, unsigned int height, uns
 ////////////////////////////////////////////////////////////
 bool RenderImageImplPBuffer::Activate(bool active)
 {
-    if (active) {
-        if (!myContext || !myPBuffer) { // Not created yet.
+    if (active)
+    {
+        if (!myContext || !myPBuffer) // Not created yet.
             return false;
-        }
         
-        if (aglGetCurrentContext() == myContext) {
+        if (aglGetCurrentContext() == myContext)
             return true;
-        } else {
+        else
             return aglSetCurrentContext(myContext);
-        }
-    } else {
+    }
+    else
+    {
         // To deactivate the P-Buffer's context, we actually activate
         // another one so that we make sure that there is always an
         // active context for subsequent graphics operations
-        return Context::SetReferenceActive();
+        // @todo fixme
+        // return Context::SetReferenceActive();
+        return true;
     }
 }
 
@@ -186,17 +187,14 @@ bool RenderImageImplPBuffer::Activate(bool active)
 ////////////////////////////////////////////////////////////
 void RenderImageImplPBuffer::UpdateTexture(unsigned int textureId)
 {
-    if (Activate(true))
-    {
-        GLint previous;
-        GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
+    GLint previous;
+    GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
 
-        // Copy the rendered pixels to the image
-        GLCheck(glBindTexture(GL_TEXTURE_2D, textureId));
-        GLCheck(glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, myWidth, myHeight));
+    // Copy the rendered pixels to the image
+    GLCheck(glBindTexture(GL_TEXTURE_2D, textureId));
+    GLCheck(glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, myWidth, myHeight));
 
-        GLCheck(glBindTexture(GL_TEXTURE_2D, previous));
-    }
+    GLCheck(glBindTexture(GL_TEXTURE_2D, previous));
 }
 
 } // namespace priv
diff --git a/src/SFML/Graphics/OSX/RenderImageImplPBuffer.hpp b/src/SFML/Graphics/OSX/RenderImageImplPBuffer.hpp
index a4b3572c3..192eb9a10 100644
--- a/src/SFML/Graphics/OSX/RenderImageImplPBuffer.hpp
+++ b/src/SFML/Graphics/OSX/RenderImageImplPBuffer.hpp
@@ -30,6 +30,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/Graphics/RenderImageImpl.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <GL/glew.h>
 #include <AGL/agl.h>
 
@@ -41,7 +42,7 @@ namespace priv
 /// \brief Specialization of RenderImageImpl using AGL P-Buffers
 ///
 ////////////////////////////////////////////////////////////
-class RenderImageImplPBuffer : public RenderImageImpl
+class RenderImageImplPBuffer : public RenderImageImpl, GlResource
 {
 public :
 
diff --git a/src/SFML/Graphics/RenderImage.cpp b/src/SFML/Graphics/RenderImage.cpp
index b2a5ed648..3c1770eb9 100644
--- a/src/SFML/Graphics/RenderImage.cpp
+++ b/src/SFML/Graphics/RenderImage.cpp
@@ -44,6 +44,7 @@ myRenderImage(NULL)
 ////////////////////////////////////////////////////////////
 RenderImage::~RenderImage()
 {
+    SetActive(false);
     delete myRenderImage;
 }
 
@@ -117,7 +118,7 @@ bool RenderImage::SetActive(bool active)
 void RenderImage::Display()
 {
     // Update the target image
-    if (myRenderImage)
+    if (SetActive(true))
     {
         myRenderImage->UpdateTexture(myImage.myTexture);
 
diff --git a/src/SFML/Graphics/RenderImageImplFBO.cpp b/src/SFML/Graphics/RenderImageImplFBO.cpp
index 4d5b7cdf1..f3fe9f36c 100644
--- a/src/SFML/Graphics/RenderImageImplFBO.cpp
+++ b/src/SFML/Graphics/RenderImageImplFBO.cpp
@@ -47,6 +47,8 @@ myDepthBuffer(0)
 ////////////////////////////////////////////////////////////
 RenderImageImplFBO::~RenderImageImplFBO()
 {
+    EnsureGlContext();
+
     // Destroy the depth buffer
     if (myDepthBuffer)
     {
@@ -66,6 +68,8 @@ RenderImageImplFBO::~RenderImageImplFBO()
 ////////////////////////////////////////////////////////////
 bool RenderImageImplFBO::IsSupported()
 {
+    EnsureGlContext();
+
     // Make sure that GLEW is initialized
     priv::EnsureGlewInit();
 
@@ -76,6 +80,9 @@ bool RenderImageImplFBO::IsSupported()
 ////////////////////////////////////////////////////////////
 bool RenderImageImplFBO::Create(unsigned int width, unsigned int height, unsigned int textureId, bool depthBuffer)
 {
+    // Activate the render-image's context
+    myContext.SetActive(true);
+
     // Create the framebuffer object
     GLuint frameBuffer = 0;
     GLCheck(glGenFramebuffersEXT(1, &frameBuffer));
diff --git a/src/SFML/Graphics/RenderImageImplFBO.hpp b/src/SFML/Graphics/RenderImageImplFBO.hpp
index ae6512158..0a4d3e02f 100644
--- a/src/SFML/Graphics/RenderImageImplFBO.hpp
+++ b/src/SFML/Graphics/RenderImageImplFBO.hpp
@@ -30,6 +30,7 @@
 ////////////////////////////////////////////////////////////
 #include <SFML/Graphics/RenderImageImpl.hpp>
 #include <SFML/Window/Context.hpp>
+#include <SFML/Window/GlResource.hpp>
 
 
 namespace sf
@@ -41,7 +42,7 @@ namespace priv
 ///        Frame Buffer Object OpenGL extension
 ///
 ////////////////////////////////////////////////////////////
-class RenderImageImplFBO : public RenderImageImpl
+class RenderImageImplFBO : public RenderImageImpl, GlResource
 {
 public :
 
diff --git a/src/SFML/Graphics/Shader.cpp b/src/SFML/Graphics/Shader.cpp
index df7035e98..8e7be3fe0 100644
--- a/src/SFML/Graphics/Shader.cpp
+++ b/src/SFML/Graphics/Shader.cpp
@@ -35,12 +35,6 @@
 
 namespace sf
 {
-////////////////////////////////////////////////////////////
-// Static member data
-////////////////////////////////////////////////////////////
-const Image Shader::CurrentTexture;
-
-
 ////////////////////////////////////////////////////////////
 Shader::Shader() :
 myShaderProgram (0),
@@ -66,6 +60,8 @@ myFragmentShader(copy.myFragmentShader)
 ////////////////////////////////////////////////////////////
 Shader::~Shader()
 {
+    EnsureGlContext();
+
     // Destroy effect program
     if (myShaderProgram)
         GLCheck(glDeleteObjectARB(myShaderProgram));
@@ -109,6 +105,8 @@ void Shader::SetParameter(const std::string& name, float x)
 {
     if (myShaderProgram)
     {
+        EnsureGlContext();
+
         // Enable program
         GLhandleARB program = glGetHandleARB(GL_PROGRAM_OBJECT_ARB);
         GLCheck(glUseProgramObjectARB(myShaderProgram));
@@ -131,6 +129,8 @@ void Shader::SetParameter(const std::string& name, float x, float y)
 {
     if (myShaderProgram)
     {
+        EnsureGlContext();
+
         // Enable program
         GLhandleARB program = glGetHandleARB(GL_PROGRAM_OBJECT_ARB);
         GLCheck(glUseProgramObjectARB(myShaderProgram));
@@ -153,6 +153,8 @@ void Shader::SetParameter(const std::string& name, float x, float y, float z)
 {
     if (myShaderProgram)
     {
+        EnsureGlContext();
+
         // Enable program
         GLhandleARB program = glGetHandleARB(GL_PROGRAM_OBJECT_ARB);
         GLCheck(glUseProgramObjectARB(myShaderProgram));
@@ -175,6 +177,8 @@ void Shader::SetParameter(const std::string& name, float x, float y, float z, fl
 {
     if (myShaderProgram)
     {
+        EnsureGlContext();
+
         // Enable program
         GLhandleARB program = glGetHandleARB(GL_PROGRAM_OBJECT_ARB);
         GLCheck(glUseProgramObjectARB(myShaderProgram));
@@ -211,16 +215,9 @@ void Shader::SetTexture(const std::string& name, const Image& texture)
 {
     if (myShaderProgram)
     {
-        // Check if there is a texture unit available
-        GLint maxUnits;
-        GLCheck(glGetIntegerv(GL_MAX_TEXTURE_COORDS_ARB, &maxUnits));
-        if (myTextures.size() + 1 >= static_cast<std::size_t>(maxUnits))
-        {
-            Err() << "Impossible to use texture \"" << name << "\" for shader: all available texture units are used" << std::endl;
-            return;
-        }
+        EnsureGlContext();
 
-        // Make sure the given name is a valid variable in the effect
+        // Find the location of the variable in the shader
         int location = glGetUniformLocationARB(myShaderProgram, name.c_str());
         if (location == -1)
         {
@@ -228,11 +225,41 @@ void Shader::SetTexture(const std::string& name, const Image& texture)
             return;
         }
 
-        // Store the texture for later use
-        if (&texture != &CurrentTexture)
+        // Store the location -> texture mapping
+        TextureTable::iterator it = myTextures.find(location);
+        if (it == myTextures.end())
+        {
+            // New entry, make sure there are enough texture units
+            GLint maxUnits;
+            GLCheck(glGetIntegerv(GL_MAX_TEXTURE_COORDS_ARB, &maxUnits));
+            if (myTextures.size() + 1 >= static_cast<std::size_t>(maxUnits))
+            {
+                Err() << "Impossible to use texture \"" << name << "\" for shader: all available texture units are used" << std::endl;
+                return;
+            }
+
             myTextures[location] = &texture;
+        }
         else
-            myCurrentTexture = location;
+        {
+            // Location already used, just replace the texture
+            it->second = &texture;
+        }
+    }
+}
+
+
+////////////////////////////////////////////////////////////
+void Shader::SetCurrentTexture(const std::string& name)
+{
+    if (myShaderProgram)
+    {
+        EnsureGlContext();
+
+        // Find the location of the variable in the shader
+        int myCurrentTexture = glGetUniformLocationARB(myShaderProgram, name.c_str());
+        if (myCurrentTexture == -1)
+            Err() << "Texture \"" << name << "\" not found in shader" << std::endl;
     }
 }
 
@@ -242,6 +269,8 @@ void Shader::Bind() const
 {
     if (myShaderProgram)
     {
+        EnsureGlContext();
+
         // Enable the program
         GLCheck(glUseProgramObjectARB(myShaderProgram));
 
@@ -258,6 +287,8 @@ void Shader::Bind() const
 ////////////////////////////////////////////////////////////
 void Shader::Unbind() const
 {
+    EnsureGlContext();
+
     GLCheck(glUseProgramObjectARB(0));
 }
 
@@ -279,6 +310,8 @@ Shader& Shader::operator =(const Shader& right)
 ////////////////////////////////////////////////////////////
 bool Shader::IsAvailable()
 {
+    EnsureGlContext();
+
     // Make sure that GLEW is initialized
     priv::EnsureGlewInit();
 
@@ -292,6 +325,8 @@ bool Shader::IsAvailable()
 ////////////////////////////////////////////////////////////
 bool Shader::CompileProgram()
 {
+    EnsureGlContext();
+
     // First make sure that we can use shaders
     if (!IsAvailable())
     {
@@ -300,9 +335,6 @@ bool Shader::CompileProgram()
         return false;
     }
 
-    // Make sure that GLEW is initialized (extra safety -- it is already done in IsAvailable())
-    priv::EnsureGlewInit();
-
     // Destroy the shader if it was already created
     if (myShaderProgram)
         GLCheck(glDeleteObjectARB(myShaderProgram));
@@ -398,7 +430,7 @@ void Shader::BindTextures() const
         GLCheck(glUniform1iARB(it->first, index));
         GLCheck(glActiveTextureARB(GL_TEXTURE0_ARB + index));
         it->second->Bind();
-        it++;
+        ++it;
     }
 
     // Make sure that the texture unit which is left active is the number 0
diff --git a/src/SFML/Graphics/Win32/RenderImageImplPBuffer.cpp b/src/SFML/Graphics/Win32/RenderImageImplPBuffer.cpp
index 32dbd78c0..8ab750309 100644
--- a/src/SFML/Graphics/Win32/RenderImageImplPBuffer.cpp
+++ b/src/SFML/Graphics/Win32/RenderImageImplPBuffer.cpp
@@ -50,6 +50,8 @@ myHeight       (0)
 ////////////////////////////////////////////////////////////
 RenderImageImplPBuffer::~RenderImageImplPBuffer()
 {
+    EnsureGlContext();
+
     if (myContext)
         wglDeleteContext(myContext);
 
@@ -58,16 +60,14 @@ RenderImageImplPBuffer::~RenderImageImplPBuffer()
         wglReleasePbufferDCARB(myPBuffer, myDeviceContext);
         wglDestroyPbufferARB(myPBuffer);
     }
-
-    // This is to make sure that another valid context is made
-    // active after we destroy the P-Buffer's one
-    Context::SetReferenceActive();
 }
 
 
 ////////////////////////////////////////////////////////////
 bool RenderImageImplPBuffer::IsSupported()
 {
+    EnsureGlContext();
+
     // Make sure that GLEW is initialized
     priv::EnsureGlewInit();
 
@@ -171,7 +171,9 @@ bool RenderImageImplPBuffer::Activate(bool active)
         // To deactivate the P-Buffer's context, we actually activate
         // another one so that we make sure that there is always an
         // active context for subsequent graphics operations
-        return Context::SetReferenceActive();
+        // @todo fix
+        //return Context::SetReferenceActive();
+        return true;
     }
 }
 
@@ -179,17 +181,14 @@ bool RenderImageImplPBuffer::Activate(bool active)
 ////////////////////////////////////////////////////////////
 void RenderImageImplPBuffer::UpdateTexture(unsigned int textureId)
 {
-    if (Activate(true))
-    {
-        GLint previous;
-        GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
+    GLint previous;
+    GLCheck(glGetIntegerv(GL_TEXTURE_BINDING_2D, &previous));
 
-        // Copy the rendered pixels to the image
-        GLCheck(glBindTexture(GL_TEXTURE_2D, textureId));
-        GLCheck(glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, myWidth, myHeight));
+    // Copy the rendered pixels to the image
+    GLCheck(glBindTexture(GL_TEXTURE_2D, textureId));
+    GLCheck(glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, myWidth, myHeight));
 
-        GLCheck(glBindTexture(GL_TEXTURE_2D, previous));
-    }
+    GLCheck(glBindTexture(GL_TEXTURE_2D, previous));
 }
 
 } // namespace priv
diff --git a/src/SFML/Graphics/Win32/RenderImageImplPBuffer.hpp b/src/SFML/Graphics/Win32/RenderImageImplPBuffer.hpp
index 80ab3572b..b137dce92 100644
--- a/src/SFML/Graphics/Win32/RenderImageImplPBuffer.hpp
+++ b/src/SFML/Graphics/Win32/RenderImageImplPBuffer.hpp
@@ -29,6 +29,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/Graphics/RenderImageImpl.hpp>
+#include <SFML/Window/GlResource.hpp>
 #include <GL/glew.h>
 #include <GL/wglew.h>
 
@@ -41,7 +42,7 @@ namespace priv
 /// \brief Specialization of RenderImageImpl using WGL P-Buffers
 ///
 ////////////////////////////////////////////////////////////
-class RenderImageImplPBuffer : public RenderImageImpl
+class RenderImageImplPBuffer : public RenderImageImpl, GlResource
 {
 public :
 
diff --git a/src/SFML/Window/CMakeLists.txt b/src/SFML/Window/CMakeLists.txt
index ba306d76a..9e942344b 100644
--- a/src/SFML/Window/CMakeLists.txt
+++ b/src/SFML/Window/CMakeLists.txt
@@ -8,6 +8,8 @@ set(SRC
     ${INCROOT}/Context.hpp
     ${SRCROOT}/GlContext.cpp
     ${SRCROOT}/GlContext.hpp
+    ${SRCROOT}/GlResource.cpp
+    ${INCROOT}/GlResource.hpp
     ${INCROOT}/ContextSettings.hpp
     ${INCROOT}/Event.hpp
     ${SRCROOT}/Input.cpp
@@ -51,24 +53,24 @@ else() # MACOSX
     set(SRC
         ${SRC}
         ${SRCROOT}/OSX/cpp_objc_conversion.h
-        ${SRCROOT}/OSX/cpp_objc_conversion.mm
-        ${SRCROOT}/OSX/cg_sf_conversion.hpp
+        ${SRCROOT}/OSX/cpp_objc_conversion.mm
+        ${SRCROOT}/OSX/cg_sf_conversion.hpp
         ${SRCROOT}/OSX/cg_sf_conversion.cpp
         ${SRCROOT}/OSX/Joystick.cpp
-        ${SRCROOT}/OSX/Joystick.hpp
-        ${SRCROOT}/OSX/SFApplication.h
-        ${SRCROOT}/OSX/SFApplication.m
-        ${SRCROOT}/OSX/SFContext.hpp
-        ${SRCROOT}/OSX/SFContext.mm
-        ${SRCROOT}/OSX/SFOpenGLView.h
-        ${SRCROOT}/OSX/SFOpenGLView.mm
-        ${SRCROOT}/OSX/SFWindow.h
-        ${SRCROOT}/OSX/SFWindow.m
-        ${SRCROOT}/OSX/SFWindowController.h
-        ${SRCROOT}/OSX/SFWindowController.mm
-        ${SRCROOT}/OSX/VideoModeImpl.cpp
-        ${SRCROOT}/OSX/WindowImplCocoa.hpp
-        ${SRCROOT}/OSX/WindowImplCocoa.mm
+        ${SRCROOT}/OSX/Joystick.hpp
+        ${SRCROOT}/OSX/SFApplication.h
+        ${SRCROOT}/OSX/SFApplication.m
+        ${SRCROOT}/OSX/SFContext.hpp
+        ${SRCROOT}/OSX/SFContext.mm
+        ${SRCROOT}/OSX/SFOpenGLView.h
+        ${SRCROOT}/OSX/SFOpenGLView.mm
+        ${SRCROOT}/OSX/SFWindow.h
+        ${SRCROOT}/OSX/SFWindow.m
+        ${SRCROOT}/OSX/SFWindowController.h
+        ${SRCROOT}/OSX/SFWindowController.mm
+        ${SRCROOT}/OSX/VideoModeImpl.cpp
+        ${SRCROOT}/OSX/WindowImplCocoa.hpp
+        ${SRCROOT}/OSX/WindowImplCocoa.mm
         ${SRCROOT}/OSX/WindowImplDelegateProtocol.h
     )
 endif()
@@ -84,8 +86,8 @@ set(WINDOW_EXT_LIBS ${OPENGL_gl_LIBRARY})
 if(WINDOWS)
     set(WINDOW_EXT_LIBS ${WINDOW_EXT_LIBS} winmm gdi32)
 elseif(LINUX)
-    set(WINDOW_EXT_LIBS ${WINDOW_EXT_LIBS} ${X11_X11_LIB} ${X11_Xrandr_LIB})
-elseif(MACOSX)
+    set(WINDOW_EXT_LIBS ${WINDOW_EXT_LIBS} ${X11_X11_LIB} ${X11_Xrandr_LIB})
+elseif(MACOSX)
     set(WINDOW_EXT_LIBS ${WINDOW_EXT_LIBS} "-framework Foundation -framework AppKit")
 endif()
 
diff --git a/src/SFML/Window/Context.cpp b/src/SFML/Window/Context.cpp
index feb46a09e..220a0cfe6 100644
--- a/src/SFML/Window/Context.cpp
+++ b/src/SFML/Window/Context.cpp
@@ -54,11 +54,4 @@ void Context::SetActive(bool active)
 }
 
 
-////////////////////////////////////////////////////////////
-bool Context::SetReferenceActive()
-{
-    return priv::GlContext::SetReferenceActive();
-}
-
-
 } // namespace sf
diff --git a/src/SFML/Window/GlContext.cpp b/src/SFML/Window/GlContext.cpp
index 882a49a6a..8b7af3abb 100644
--- a/src/SFML/Window/GlContext.cpp
+++ b/src/SFML/Window/GlContext.cpp
@@ -27,9 +27,13 @@
 ////////////////////////////////////////////////////////////
 #include <SFML/Window/GlContext.hpp>
 #include <SFML/System/ThreadLocalPtr.hpp>
+#include <SFML/System/Mutex.hpp>
+#include <SFML/System/Lock.hpp>
 #include <SFML/OpenGL.hpp>
 #include <SFML/Window/glext/glext.h>
+#include <vector>
 #include <cstdlib>
+#include <cassert>
 
 
 #if defined(SFML_SYSTEM_WINDOWS)
@@ -55,16 +59,29 @@
 ////////////////////////////////////////////////////////////
 namespace
 {
-    // This thread-local variable will hold the "global" context for each thread
-    sf::ThreadLocalPtr<sf::priv::GlContext> threadContext(NULL);
+    // This per-thread variable holds the current context for each thread
+    sf::ThreadLocalPtr<sf::priv::GlContext> currentContext = NULL;
 
-    // Now we create two global contexts.
-    // The first one is the reference context: it will be shared with every other
-    // context, and it can't be activated if we want the sharing operation to always succeed.
-    // That's why we need the second context: this one will be activated and used
-    // in the main thread whenever there's no other context (window) active.
-    ContextType referenceContext(NULL);
-    ContextType defaultContext(&referenceContext);
+    // The hidden, inactive context that will be shared with all other contexts
+    ContextType* sharedContext = NULL;
+
+    // Internal contexts
+    sf::ThreadLocalPtr<sf::priv::GlContext> internalContext = NULL;
+    std::vector<sf::priv::GlContext*> internalContexts;
+    sf::Mutex internalContextsMutex;
+
+    // Retrieve the internal context for the current thread
+    sf::priv::GlContext* GetInternalContext()
+    {
+        if (!internalContext)
+        {
+            internalContext = sf::priv::GlContext::New();
+            sf::Lock lock(internalContextsMutex);
+            internalContexts.push_back(internalContext);
+        }
+
+        return internalContext;
+    }
 }
 
 
@@ -72,17 +89,58 @@ namespace sf
 {
 namespace priv
 {
+////////////////////////////////////////////////////////////
+void GlContext::Initialize()
+{
+    // Create the shared context
+    sharedContext = new ContextType(NULL);
+
+    // This call makes sure that:
+    // - the shared context is inactive (it must never be)
+    // - another valid context is activated in the current thread
+    sharedContext->SetActive(false);
+}
+
+
+////////////////////////////////////////////////////////////
+void GlContext::Cleanup()
+{
+    // Destroy the shared context
+    delete sharedContext;
+    sharedContext = NULL;
+
+    // Destroy the internal contexts
+    sf::Lock lock(internalContextsMutex);
+    for (std::vector<GlContext*>::iterator it = internalContexts.begin(); it != internalContexts.end(); ++it)
+        delete *it;
+    internalContexts.clear();
+}
+
+
+////////////////////////////////////////////////////////////
+void GlContext::EnsureContext()
+{
+    // If there's no active context on the current thread, activate an internal one
+    if (!currentContext)
+        GetInternalContext()->SetActive(true);
+}
+
+
 ////////////////////////////////////////////////////////////
 GlContext* GlContext::New()
 {
-    return new ContextType(&referenceContext);
+    return new ContextType(sharedContext);
 }
 
 
 ////////////////////////////////////////////////////////////
 GlContext* GlContext::New(const WindowImpl* owner, unsigned int bitsPerPixel, const ContextSettings& settings)
 {
-    ContextType* context = new ContextType(&referenceContext, owner, bitsPerPixel, settings);
+    // Make sure that there's an active context (context creation may need extensions, and thus a valid context)
+    EnsureContext();
+
+    // Create the context
+    GlContext* context = new ContextType(sharedContext, owner, bitsPerPixel, settings);
 
     // Enable antialiasing if needed
     if (context->GetSettings().AntialiasingLevel > 0)
@@ -95,15 +153,8 @@ GlContext* GlContext::New(const WindowImpl* owner, unsigned int bitsPerPixel, co
 ////////////////////////////////////////////////////////////
 GlContext::~GlContext()
 {
-    if (threadContext == this)
-    {
-        threadContext = NULL;
-    }
-    else if (threadContext)
-    {
-        // Don't call this->SetActive(false), it would lead to a pure virtual function call
-        threadContext->SetActive(true);
-    }
+    // Deactivate the context before killing it
+    SetActive(false);
 }
 
 
@@ -119,42 +170,40 @@ bool GlContext::SetActive(bool active)
 {
     if (active)
     {
-        // Activate the context
-        if (MakeCurrent())
+        if (this != currentContext)
         {
-            // If this is the first context to be activated on this thread, make
-            // it the reference context for the whole thread.
-            // referenceContext must *not* be the threadContext of the main thread
-            if (!threadContext && (this != &referenceContext))
-                threadContext = this;
-
+            // Activate the context
+            if (MakeCurrent())
+            {
+                // Set it as the new current context for this thread
+                currentContext = this;
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+        else
+        {
+            // This context is already the active one on this thread, don't do anything
             return true;
         }
     }
     else
     {
-        // Deactivate the context
-        if (threadContext && (threadContext != this))
+        if (this == currentContext)
         {
-            // To deactivate the context, we actually activate another one
-            // so that we make sure that there is always an active context
-            // for subsequent graphics operations
-            return threadContext->SetActive(true);
+            // To deactivate the context, we actually activate another one so that we make
+            // sure that there is always an active context for subsequent graphics operations
+            return GetInternalContext()->SetActive(true);
+        }
+        else
+        {
+            // This context is not the active one on this thread, don't do anything
+            return true;
         }
     }
-
-    // If we got there then something failed
-    return false;
-}
-
-
-////////////////////////////////////////////////////////////
-bool GlContext::SetReferenceActive()
-{
-    if (threadContext)
-        return threadContext->SetActive(true);
-    else
-        return false;
 }
 
 
diff --git a/src/SFML/Window/GlContext.hpp b/src/SFML/Window/GlContext.hpp
index 9c4226740..db7b44fb1 100644
--- a/src/SFML/Window/GlContext.hpp
+++ b/src/SFML/Window/GlContext.hpp
@@ -47,6 +47,36 @@ class GlContext : NonCopyable
 {
 public :
 
+    ////////////////////////////////////////////////////////////
+    /// \brief Perform the global initialization
+    ///
+    /// This function is called once, before the very first OpenGL
+    /// resource is created. It makes sure that everything is ready
+    /// for contexts to work properly.
+    /// Note: this function doesn't need to be thread-safe, as it
+    /// can be called only once.
+    ///
+    ////////////////////////////////////////////////////////////
+    static void Initialize();
+
+    ////////////////////////////////////////////////////////////
+    /// \brief Perform the global cleanup
+    ///
+    /// This function is called after the very last OpenGL resource
+    /// is destroyed. It makes sure that everything that was
+    /// created by Initialize() is properly released.
+    /// Note: this function doesn't need to be thread-safe, as it
+    /// can be called only once.
+    ///
+    ////////////////////////////////////////////////////////////
+    static void Cleanup();
+
+    ////////////////////////////////////////////////////////////
+    /// \brief Ensures that an OpenGL context is active in the current thread
+    ///
+    ////////////////////////////////////////////////////////////
+    static void EnsureContext();
+
     ////////////////////////////////////////////////////////////
     /// \brief Create a new context, not associated to a window
     ///
@@ -129,18 +159,6 @@ public :
     ////////////////////////////////////////////////////////////
     virtual void EnableVerticalSync(bool enabled) = 0;
 
-    ////////////////////////////////////////////////////////////
-    /// \brief Make the current thread's reference context active
-    ///
-    /// This function is meant to be called internally; it is used
-    /// to deactivate the current context by activating another one
-    /// (so that we still have an active context on the current thread).
-    ///
-    /// \return True if operation was successful, false otherwise
-    ///
-    ////////////////////////////////////////////////////////////
-    static bool SetReferenceActive();
-
 protected :
 
     ////////////////////////////////////////////////////////////
diff --git a/src/SFML/Window/GlResource.cpp b/src/SFML/Window/GlResource.cpp
new file mode 100644
index 000000000..d06a8fc98
--- /dev/null
+++ b/src/SFML/Window/GlResource.cpp
@@ -0,0 +1,89 @@
+////////////////////////////////////////////////////////////
+//
+// SFML - Simple and Fast Multimedia Library
+// Copyright (C) 2007-2009 Laurent Gomila (laurent.gom@gmail.com)
+//
+// This software is provided 'as-is', without any express or implied warranty.
+// In no event will the authors be held liable for any damages arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it freely,
+// subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented;
+//    you must not claim that you wrote the original software.
+//    If you use this software in a product, an acknowledgment
+//    in the product documentation would be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such,
+//    and must not be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source distribution.
+//
+////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+#include <SFML/Window/GlResource.hpp>
+#include <SFML/Window/GlContext.hpp>
+#include <SFML/System/Mutex.hpp>
+#include <SFML/System/Lock.hpp>
+
+
+////////////////////////////////////////////////////////////
+// Private data
+////////////////////////////////////////////////////////////
+namespace
+{
+    // OpenGL resources counter and its mutex
+    unsigned long count = 0;
+    bool initialized = false;
+    sf::Mutex mutex;
+}
+
+
+namespace sf
+{
+////////////////////////////////////////////////////////////
+GlResource::GlResource()
+{
+    {
+        // Protect from concurrent access
+        Lock lock(mutex);
+
+        // If this is the very first resource, trigger the global context initialization
+        if (count == 0)
+            priv::GlContext::Initialize();
+
+        // Increment the resources counter
+        count++;
+    }
+
+    // Now make sure that there is an active OpenGL context in the current thread
+    priv::GlContext::EnsureContext();
+}
+
+
+////////////////////////////////////////////////////////////
+GlResource::~GlResource()
+{
+    // Protect from concurrent access
+    Lock lock(mutex);
+
+    // Decrement the resources counter
+    count--;
+
+    // If there's no more resource alive, we can trigger the global context cleanup
+    if (count == 0)
+        priv::GlContext::Cleanup();
+}
+
+
+////////////////////////////////////////////////////////////
+void GlResource::EnsureGlContext()
+{
+    priv::GlContext::EnsureContext();
+}
+
+} // namespace sf
diff --git a/src/SFML/Window/Linux/GlxContext.cpp b/src/SFML/Window/Linux/GlxContext.cpp
index 52c9e0a4b..f441cbcfc 100644
--- a/src/SFML/Window/Linux/GlxContext.cpp
+++ b/src/SFML/Window/Linux/GlxContext.cpp
@@ -116,17 +116,7 @@ GlxContext::~GlxContext()
 ////////////////////////////////////////////////////////////
 bool GlxContext::MakeCurrent()
 {
-    if (myContext)
-    {
-        if (glXGetCurrentContext() != myContext)
-            return glXMakeCurrent(myDisplay, myWindow, myContext) != 0;
-        else
-            return true;
-    }
-    else
-    {
-        return false;
-    }
+    return myContext && glXMakeCurrent(myDisplay, myWindow, myContext);
 }
 
 
diff --git a/src/SFML/Window/Win32/WglContext.cpp b/src/SFML/Window/Win32/WglContext.cpp
index da7a1dc60..3a65fb4fe 100644
--- a/src/SFML/Window/Win32/WglContext.cpp
+++ b/src/SFML/Window/Win32/WglContext.cpp
@@ -107,17 +107,7 @@ WglContext::~WglContext()
 ////////////////////////////////////////////////////////////
 bool WglContext::MakeCurrent()
 {
-    if (myDeviceContext && myContext)
-    {
-        if (wglGetCurrentContext() != myContext)
-            return wglMakeCurrent(myDeviceContext, myContext) != 0;
-        else
-            return true;
-    }
-    else
-    {
-        return false;
-    }
+    return myDeviceContext && myContext && wglMakeCurrent(myDeviceContext, myContext);
 }