1 files changed, 108 insertions, 2 deletions
diff --git a/src/SFML/Window/Context.cpp b/src/SFML/Window/Context.cpp
index 0ec500a..2d51bbc 100644
--- a/src/SFML/Window/Context.cpp
+++ b/src/SFML/Window/Context.cpp
@@ -1,7 +1,7 @@
 ////////////////////////////////////////////////////////////
 //
 // SFML - Simple and Fast Multimedia Library
-// Copyright (C) 2007-2015 Laurent Gomila (laurent@sfml-dev.org)
+// Copyright (C) 2007-2016 Laurent Gomila (laurent@sfml-dev.org)
 //
 // 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.
@@ -27,7 +27,32 @@
 ////////////////////////////////////////////////////////////
 #include <SFML/Window/Context.hpp>
 #include <SFML/Window/GlContext.hpp>
+#include <SFML/System/ThreadLocalPtr.hpp>
+#include <SFML/OpenGL.hpp>
+#include <algorithm>
+#include <vector>
+#include <string>
 
+#if defined(SFML_SYSTEM_WINDOWS)
+
+    typedef const GLubyte* (APIENTRY *glGetStringiFuncType)(GLenum, GLuint);
+
+#else
+
+    typedef const GLubyte* (*glGetStringiFuncType)(GLenum, GLuint);
+
+#endif
+
+#if !defined(GL_NUM_EXTENSIONS)
+    #define GL_NUM_EXTENSIONS 0x821D
+#endif
+
+
+namespace
+{
+    // This per-thread variable holds the current context for each thread
+    sf::ThreadLocalPtr<sf::Context> currentContext(NULL);
+}
 
 namespace sf
 {
@@ -42,6 +67,7 @@ Context::Context()
 ////////////////////////////////////////////////////////////
 Context::~Context()
 {
+    setActive(false);
     delete m_context;
 }
 
@@ -49,7 +75,26 @@ Context::~Context()
 ////////////////////////////////////////////////////////////
 bool Context::setActive(bool active)
 {
-    return m_context->setActive(active);
+    bool result = m_context->setActive(active);
+
+    if (result)
+        currentContext = (active ? this : NULL);
+
+    return result;
+}
+
+
+////////////////////////////////////////////////////////////
+const ContextSettings& Context::getSettings() const
+{
+    return m_context->getSettings();
+}
+
+
+////////////////////////////////////////////////////////////
+const Context* Context::getActiveContext()
+{
+    return currentContext;
 }
 
 
@@ -61,6 +106,67 @@ GlFunctionPointer Context::getFunction(const char* name)
 
 
 ////////////////////////////////////////////////////////////
+bool Context::isExtensionAvailable(const char* name)
+{
+    static std::vector<std::string> extensions;
+    static bool loaded = false;
+
+    if (!loaded)
+    {
+        const Context* context = getActiveContext();
+
+        if (!context)
+            return false;
+
+        const char* extensionString = NULL;
+
+        if(context->getSettings().majorVersion < 3)
+        {
+            // Try to load the < 3.0 way
+            extensionString = reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
+
+            do
+            {
+                const char* extension = extensionString;
+
+                while(*extensionString && (*extensionString != ' '))
+                    extensionString++;
+
+                extensions.push_back(std::string(extension, extensionString));
+            }
+            while (*extensionString++);
+        }
+        else
+        {
+            // Try to load the >= 3.0 way
+            glGetStringiFuncType glGetStringiFunc = NULL;
+            glGetStringiFunc = reinterpret_cast<glGetStringiFuncType>(getFunction("glGetStringi"));
+
+            if (glGetStringiFunc)
+            {
+                int numExtensions = 0;
+                glGetIntegerv(GL_NUM_EXTENSIONS, &numExtensions);
+
+                if (numExtensions)
+                {
+                    for (unsigned int i = 0; i < static_cast<unsigned int>(numExtensions); ++i)
+                    {
+                        extensionString = reinterpret_cast<const char*>(glGetStringiFunc(GL_EXTENSIONS, i));
+
+                        extensions.push_back(extensionString);
+                    }
+                }
+            }
+        }
+
+        loaded = true;
+    }
+
+    return std::find(extensions.begin(), extensions.end(), name) != extensions.end();
+}
+
+
+////////////////////////////////////////////////////////////
 Context::Context(const ContextSettings& settings, unsigned int width, unsigned int height)
 {
     m_context = priv::GlContext::create(settings, width, height);