From 193246e5339d83499657120d924a280f90171e0d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Sun, 7 Oct 2012 23:55:00 +0200
Subject: [PATCH] Private (implementation-only) OpenGL state tracker.

---
 src/CMakeLists.txt           |  2 ++
 src/Context.cpp              |  5 +++++
 src/Context.h                | 12 ++++++++++++
 src/Implementation/State.cpp | 25 +++++++++++++++++++++++++
 src/Implementation/State.h   | 31 +++++++++++++++++++++++++++++++
 5 files changed, 75 insertions(+)
 create mode 100644 src/Implementation/State.cpp
 create mode 100644 src/Implementation/State.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e2e867e56..6f1d45eaa 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -37,6 +37,8 @@ set(Magnum_SRCS
     Timeline.cpp
     TypeTraits.cpp
 
+    Implementation/State.cpp
+
     Trade/AbstractImporter.cpp
     Trade/MeshData2D.cpp
     Trade/MeshData3D.cpp)
diff --git a/src/Context.cpp b/src/Context.cpp
index 3a46b7638..92247c051 100644
--- a/src/Context.cpp
+++ b/src/Context.cpp
@@ -21,6 +21,7 @@
 
 #include "Buffer.h"
 #include "Extensions.h"
+#include "Implementation/State.h"
 
 using namespace std;
 
@@ -193,12 +194,16 @@ Context::Context() {
     CORRADE_ASSERT(!_current, "Context: Another context currently active", );
     _current = this;
 
+    /* Initialize state tracker */
+    _state = new Implementation::State;
+
     /* Initialize functionality based on current OpenGL version and extensions */
     Buffer::initializeContextBasedFunctionality(this);
 }
 
 Context::~Context() {
     CORRADE_ASSERT(_current == this, "Context: Cannot destroy context which is not currently active", );
+    delete _state;
     _current = nullptr;
 }
 
diff --git a/src/Context.h b/src/Context.h
index 820b998e5..3ac3de27e 100644
--- a/src/Context.h
+++ b/src/Context.h
@@ -28,6 +28,12 @@
 
 namespace Magnum {
 
+#ifndef DOXYGEN_GENERATING_OUTPUT
+namespace Implementation {
+    class State;
+}
+#endif
+
 /** @brief OpenGL version */
 enum class Version: GLint {
     None = 0,                       /**< @brief Unspecified */
@@ -202,6 +208,10 @@ class MAGNUM_EXPORT Context {
             return _version >= extension._coreVersion || (_version >= extension._requiredVersion && extensionStatus[extension._index]);
         }
 
+        #ifndef DOXYGEN_GENERATING_OUTPUT
+        inline Implementation::State* state() { return _state; }
+        #endif
+
     private:
         static Context* _current;
 
@@ -211,6 +221,8 @@ class MAGNUM_EXPORT Context {
 
         std::bitset<128> extensionStatus;
         std::vector<Extension> _supportedExtensions;
+
+        Implementation::State* _state;
 };
 
 }
diff --git a/src/Implementation/State.cpp b/src/Implementation/State.cpp
new file mode 100644
index 000000000..2fb89de2d
--- /dev/null
+++ b/src/Implementation/State.cpp
@@ -0,0 +1,25 @@
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum 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 version 3 for more details.
+*/
+
+#include "State.h"
+
+namespace Magnum { namespace Implementation {
+
+State::State() {}
+
+State::~State() {
+}
+
+}}
diff --git a/src/Implementation/State.h b/src/Implementation/State.h
new file mode 100644
index 000000000..8a070d47d
--- /dev/null
+++ b/src/Implementation/State.h
@@ -0,0 +1,31 @@
+#ifndef Magnum_Implementation_State_h
+#define Magnum_Implementation_State_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum 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 version 3 for more details.
+*/
+
+#include "Magnum.h"
+
+namespace Magnum { namespace Implementation {
+
+class BufferState;
+
+struct State {
+    State();
+    ~State();
+};
+
+}}
+
+#endif