OpenGL: remove use of GLEW MX

MX (Multiple conteXt) support was dropped from the GLEW 2.0 library to make core profile support cleaner.

Our WITH_GLEW_MX build option was OFF by default already; this commit removes the inactive code paths.

I'm working on a plan for multiple GPUs, contexts, resource sharing, etc. This commit gives us a cleaner starting point for that upcoming work.

Tested on Mac, will test on Linux & Windows immediately after pushing.

21 files changed, 12 insertions, 317 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 13171ac2780..c7209ed4819 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -466,7 +466,6 @@ endif()
 
 # OpenGL
 
-option(WITH_GLEW_MX             "Support multiple GLEW contexts (experimental)"                                                                     OFF )
 option(WITH_GLEW_ES             "Switches to experimental copy of GLEW that has support for OpenGL ES. (temporary option for development purposes)" OFF)
 option(WITH_GL_EGL              "Use the EGL OpenGL system library instead of the platform specific OpenGL system library (CGL, glX, or WGL)"       OFF)
 option(WITH_GL_PROFILE_COMPAT   "Support using the OpenGL 'compatibility' profile. (deprecated)"                                                    ON )
@@ -474,7 +473,6 @@ option(WITH_GL_PROFILE_CORE     "Support using the OpenGL 3.3+ 'core' profile."
 option(WITH_GL_PROFILE_ES20     "Support using OpenGL ES 2.0. (thru either EGL or the AGL/WGL/XGL 'es20' profile)"                                  OFF)
 
 mark_as_advanced(
-	WITH_GLEW_MX
 	WITH_GLEW_ES
 	WITH_GL_EGL
 	WITH_GL_PROFILE_COMPAT
@@ -1224,10 +1222,6 @@ endif()
 #-----------------------------------------------------------------------------
 # Configure GLEW
 
-if(WITH_GLEW_MX)
-	list(APPEND GL_DEFINITIONS -DWITH_GLEW_MX)
-endif()
-
 if(WITH_SYSTEM_GLEW)
 	find_package(GLEW)
 
@@ -1237,11 +1231,7 @@ if(WITH_SYSTEM_GLEW)
 		message(FATAL_ERROR "GLEW is required to build Blender. Install it or disable WITH_SYSTEM_GLEW.")
 	endif()
 
-	if(WITH_GLEW_MX)
-		set(BLENDER_GLEW_LIBRARIES ${GLEW_MX_LIBRARY})
-	else()
-		set(BLENDER_GLEW_LIBRARIES ${GLEW_LIBRARY})
-	endif()
+	set(BLENDER_GLEW_LIBRARIES ${GLEW_LIBRARY})
 else()
 	if(WITH_GLEW_ES)
 		set(GLEW_INCLUDE_PATH "${CMAKE_SOURCE_DIR}/extern/glew-es/include")
diff --git a/build_files/cmake/Modules/FindGLEW.cmake b/build_files/cmake/Modules/FindGLEW.cmake
index 2f098d5d9a4..3057237f3c6 100644
--- a/build_files/cmake/Modules/FindGLEW.cmake
+++ b/build_files/cmake/Modules/FindGLEW.cmake
@@ -9,7 +9,6 @@
 #
 # also defined,
 #  GLEW_LIBRARY, where to find the Glew library.
-#  GLEW_MX_LIBRARY, where to find the GlewMX library.
 
 #=============================================================================
 # Copyright 2014 Blender Foundation.
@@ -50,16 +49,6 @@ FIND_LIBRARY(GLEW_LIBRARY
     lib64 lib
   )
 
-
-FIND_LIBRARY(GLEW_MX_LIBRARY
-  NAMES
-    GLEWmx
-  HINTS
-    ${_glew_SEARCH_DIRS}
-  PATH_SUFFIXES
-    lib64 lib
-  )
-
 # handle the QUIETLY and REQUIRED arguments and set GLEW_FOUND to TRUE if 
 # all listed variables are TRUE
 INCLUDE(FindPackageHandleStandardArgs)
@@ -73,7 +62,6 @@ ENDIF(GLEW_FOUND)
 MARK_AS_ADVANCED(
   GLEW_INCLUDE_DIR
   GLEW_LIBRARY
-  GLEW_MX_LIBRARY
 )
 
 UNSET(_glew_SEARCH_DIRS)
diff --git a/extern/glew-es/CMakeLists.txt b/extern/glew-es/CMakeLists.txt
index ba80d3f6120..ea25425df81 100644
--- a/extern/glew-es/CMakeLists.txt
+++ b/extern/glew-es/CMakeLists.txt
@@ -49,9 +49,4 @@ set(SRC
 
 add_definitions(${GL_DEFINITIONS})
 
-if(WITH_GLEW_MX)
-	add_definitions(-DGLEW_MX)
-endif()
-
-
 blender_add_lib(extern_glew_es "${SRC}" "${INC}" "${INC_SYS}")
diff --git a/extern/glew/CMakeLists.txt b/extern/glew/CMakeLists.txt
index 250127f088f..c9323fa12b2 100644
--- a/extern/glew/CMakeLists.txt
+++ b/extern/glew/CMakeLists.txt
@@ -48,8 +48,4 @@ set(SRC
 
 add_definitions(${GL_DEFINITIONS})
 
-if(WITH_GLEW_MX)
-	add_definitions(-DGLEW_MX)
-endif()
-
 blender_add_lib(extern_glew "${SRC}" "${INC}" "${INC_SYS}")
diff --git a/intern/cycles/blender/blender_sync.cpp b/intern/cycles/blender/blender_sync.cpp
index 3b071bf0e7d..5926b2a04a6 100644
--- a/intern/cycles/blender/blender_sync.cpp
+++ b/intern/cycles/blender/blender_sync.cpp
@@ -710,17 +710,8 @@ SessionParams BlenderSync::get_session_params(BL::RenderEngine& b_engine,
 		params.shadingsystem = SHADINGSYSTEM_OSL;
 	
 	/* color managagement */
-#ifdef GLEW_MX
-	/* When using GLEW MX we need to check whether we've got an OpenGL
-	 * context for current window. This is because command line rendering
-	 * doesn't have OpenGL context actually.
-	 */
-	if(glewGetContext() != NULL)
-#endif
-	{
-		params.display_buffer_linear = GLEW_ARB_half_float_pixel &&
-		                               b_engine.support_display_space_shader(b_scene);
-	}
+	params.display_buffer_linear = GLEW_ARB_half_float_pixel &&
+	                               b_engine.support_display_space_shader(b_scene);
 
 	if(b_engine.is_preview()) {
 		/* For preview rendering we're using same timeout as
diff --git a/intern/cycles/util/util_opengl.h b/intern/cycles/util/util_opengl.h
index 0b5462e0a09..7a8d5eec1f9 100644
--- a/intern/cycles/util/util_opengl.h
+++ b/intern/cycles/util/util_opengl.h
@@ -20,12 +20,6 @@
 /* OpenGL header includes, used everywhere we use OpenGL, to deal with
  * platform differences in one central place. */
 
-#ifdef WITH_GLEW_MX
-#  include "glew-mx.h"
-#else
-#  include <GL/glew.h>
-#  define mxCreateContext() glewInit()
-#  define mxMakeCurrentContext(x) (x)
-#endif
+#include <GL/glew.h>
 
 #endif /* __UTIL_OPENGL_H__ */
diff --git a/intern/cycles/util/util_view.cpp b/intern/cycles/util/util_view.cpp
index 10d86167921..7b453d123b8 100644
--- a/intern/cycles/util/util_view.cpp
+++ b/intern/cycles/util/util_view.cpp
@@ -252,7 +252,7 @@ void view_main_loop(const char *title, int width, int height,
 	glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);
 	glutCreateWindow(title);
 
-	mxMakeCurrentContext(mxCreateContext());
+	glewInit();
 
 	view_reshape(width, height);
 
diff --git a/intern/ghost/intern/GHOST_Context.cpp b/intern/ghost/intern/GHOST_Context.cpp
index f69f2181ef7..fc7193ae99b 100644
--- a/intern/ghost/intern/GHOST_Context.cpp
+++ b/intern/ghost/intern/GHOST_Context.cpp
@@ -143,11 +143,7 @@ bool win32_chk(bool result, const char *file, int line, const char *text)
 
 void GHOST_Context::initContextGLEW()
 {
-	mxDestroyContext(m_mxContext); // no-op if m_mxContext is NULL
-
-	mxMakeCurrentContext(mxCreateContext());
-
-	m_mxContext = mxGetCurrentContext();
+	GLEW_CHK(glewInit());
 }
 
 
diff --git a/intern/ghost/intern/GHOST_Context.h b/intern/ghost/intern/GHOST_Context.h
index 18d36c40e9c..8776fa4764f 100644
--- a/intern/ghost/intern/GHOST_Context.h
+++ b/intern/ghost/intern/GHOST_Context.h
@@ -50,15 +50,13 @@ public:
 	 */
 	GHOST_Context(bool stereoVisual, GHOST_TUns16 numOfAASamples)
 	    : m_stereoVisual(stereoVisual),
-	      m_numOfAASamples(numOfAASamples),
-	      m_mxContext(NULL)
+	      m_numOfAASamples(numOfAASamples)
 	{}
 
 	/**
 	 * Destructor.
 	 */
 	virtual ~GHOST_Context() {
-		mxDestroyContext(m_mxContext);
 	}
 
 	/**
@@ -128,19 +126,12 @@ public:
 protected:
 	void initContextGLEW();
 
-	inline void activateGLEW() const {
-		mxMakeCurrentContext(m_mxContext);
-	}
-
 	bool m_stereoVisual;
 
 	GHOST_TUns16 m_numOfAASamples;
 
 	static void initClearGL();
 
-private:
-	MXContext *m_mxContext;
-
 #ifdef WITH_CXX_GUARDEDALLOC
 	MEM_CXX_CLASS_ALLOC_FUNCS("GHOST:GHOST_Context")
 #endif
diff --git a/intern/ghost/intern/GHOST_ContextCGL.h b/intern/ghost/intern/GHOST_ContextCGL.h
index 8186eaa759d..6dcc4da0f0a 100644
--- a/intern/ghost/intern/GHOST_ContextCGL.h
+++ b/intern/ghost/intern/GHOST_ContextCGL.h
@@ -34,10 +34,6 @@
 
 #include "GHOST_Context.h"
 
-//#define cglewGetContext() cglewContext
-//#include <GL/cglew.h>
-//extern "C" CGLEWContext *cglewContext;
-
 #ifndef GHOST_OPENGL_CGL_CONTEXT_FLAGS
 #define GHOST_OPENGL_CGL_CONTEXT_FLAGS 0
 #endif
@@ -120,14 +116,7 @@ public:
 	 */
 	GHOST_TSuccess updateDrawingContext();
 
-//protected:
-//	inline void activateCGLEW() const {
-//		cglewContext = m_cglewContext;
-//	}
-
 private:
-	//void initContextCGLEW()
-
 	/** The openGL view */
 	NSOpenGLView *m_openGLView;
 
@@ -136,8 +125,6 @@ private:
 
 	bool m_coreProfile;
 
-	//static CGLEWContext *s_cglewContext;
-
 	const bool m_debug;
 
 	/** The first created OpenGL context (for sharing display lists) */
diff --git a/intern/ghost/intern/GHOST_ContextCGL.mm b/intern/ghost/intern/GHOST_ContextCGL.mm
index f6adb362470..03af3cc497e 100644
--- a/intern/ghost/intern/GHOST_ContextCGL.mm
+++ b/intern/ghost/intern/GHOST_ContextCGL.mm
@@ -159,9 +159,6 @@ GHOST_TSuccess GHOST_ContextCGL::activateDrawingContext()
 	if (m_openGLContext != nil) {
 		NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
 		[m_openGLContext makeCurrentContext];
-
-		activateGLEW();
-
 		[pool drain];
 		return GHOST_kSuccess;
 	}
diff --git a/intern/ghost/intern/GHOST_ContextEGL.cpp b/intern/ghost/intern/GHOST_ContextEGL.cpp
index 520aa0fffb2..a591d9b7583 100644
--- a/intern/ghost/intern/GHOST_ContextEGL.cpp
+++ b/intern/ghost/intern/GHOST_ContextEGL.cpp
@@ -42,11 +42,6 @@
 #include <cstring>
 
 
-#ifdef WITH_GLEW_MX
-EGLEWContext *eglewContext = NULL;
-#endif
-
-
 #define CASE_CODE_RETURN_STR(code) case code: return #code;
 
 static const char *get_egl_error_enum_string(EGLenum error)
@@ -168,13 +163,8 @@ static bool egl_chk(bool result, const char *file = NULL, int line = 0, const ch
 
 static inline bool bindAPI(EGLenum api)
 {
-#ifdef WITH_GLEW_MX
-	if (eglewContext != NULL)
-#endif
-	{
-		if (EGLEW_VERSION_1_2) {
-			return (EGL_CHK(eglBindAPI(api)) == EGL_TRUE);
-		}
+	if (EGLEW_VERSION_1_2) {
+		return (EGL_CHK(eglBindAPI(api)) == EGL_TRUE);
 	}
 
 	return false;
@@ -238,9 +228,6 @@ GHOST_ContextEGL::GHOST_ContextEGL(
       m_surface(EGL_NO_SURFACE),
       m_display(EGL_NO_DISPLAY),
       m_swap_interval(1),
-#ifdef WITH_GLEW_MX
-      m_eglewContext(NULL),
-#endif
       m_sharedContext(choose_api(api, s_gl_sharedContext, s_gles_sharedContext, s_vg_sharedContext)),
       m_sharedCount  (choose_api(api, s_gl_sharedCount,   s_gles_sharedCount,   s_vg_sharedCount))
 {
@@ -252,7 +239,6 @@ GHOST_ContextEGL::GHOST_ContextEGL(
 GHOST_ContextEGL::~GHOST_ContextEGL()
 {
 	if (m_display != EGL_NO_DISPLAY) {
-		activateEGLEW();
 
 		bindAPI(m_api);
 
@@ -276,10 +262,6 @@ GHOST_ContextEGL::~GHOST_ContextEGL()
 			EGL_CHK(::eglDestroySurface(m_display, m_surface));
 
 		EGL_CHK(::eglTerminate(m_display));
-
-#ifdef WITH_GLEW_MX
-		delete m_eglewContext;
-#endif
 	}
 }
 
@@ -321,9 +303,6 @@ GHOST_TSuccess GHOST_ContextEGL::getSwapInterval(int &intervalOut)
 GHOST_TSuccess GHOST_ContextEGL::activateDrawingContext()
 {
 	if (m_display) {
-		activateEGLEW();
-		activateGLEW();
-
 		bindAPI(m_api);
 
 		return EGL_CHK(::eglMakeCurrent(m_display, m_surface, m_surface, m_context)) ? GHOST_kSuccess : GHOST_kFailure;
@@ -336,14 +315,6 @@ GHOST_TSuccess GHOST_ContextEGL::activateDrawingContext()
 
 void GHOST_ContextEGL::initContextEGLEW()
 {
-#ifdef WITH_GLEW_MX
-	eglewContext = new EGLEWContext;
-	memset(eglewContext, 0, sizeof(EGLEWContext));
-
-	delete m_eglewContext;
-	m_eglewContext = eglewContext;
-#endif
-
 	if (GLEW_CHK(eglewInit(m_display)) != GLEW_OK)
 		fprintf(stderr, "Warning! EGLEW failed to initialize properly.\n");
 }
diff --git a/intern/ghost/intern/GHOST_ContextEGL.h b/intern/ghost/intern/GHOST_ContextEGL.h
index 70c26c940fc..6dfb177f26d 100644
--- a/intern/ghost/intern/GHOST_ContextEGL.h
+++ b/intern/ghost/intern/GHOST_ContextEGL.h
@@ -34,17 +34,8 @@
 
 #include "GHOST_Context.h"
 
-#ifdef WITH_GLEW_MX
-#  define eglewGetContext() eglewContext
-#endif
-
 #include <GL/eglew.h>
 
-#ifdef WITH_GLEW_MX
-extern "C" EGLEWContext *eglewContext;
-#endif
-
-
 #ifndef GHOST_OPENGL_EGL_CONTEXT_FLAGS
 #define GHOST_OPENGL_EGL_CONTEXT_FLAGS 0
 #endif
@@ -116,13 +107,6 @@ public:
 	 */
 	GHOST_TSuccess getSwapInterval(int &intervalOut);
 
-protected:
-	inline void activateEGLEW() const {
-#ifdef WITH_GLEW_MX
-		eglewContext = m_eglewContext;
-#endif
-	}
-
 private:
 	void initContextEGLEW();
 
@@ -143,10 +127,6 @@ private:
 
 	EGLint m_swap_interval;
 
-#ifdef WITH_GLEW_MX
-	EGLEWContext *m_eglewContext;
-#endif
-
 	EGLContext &m_sharedContext;
 	EGLint     &m_sharedCount;
 
diff --git a/intern/ghost/intern/GHOST_ContextGLX.cpp b/intern/ghost/intern/GHOST_ContextGLX.cpp
index 60cdce83602..a89b23fe486 100644
--- a/intern/ghost/intern/GHOST_ContextGLX.cpp
+++ b/intern/ghost/intern/GHOST_ContextGLX.cpp
@@ -48,10 +48,6 @@ static GLuint _glewStrLen(const GLubyte *s);
 static GLboolean _glewSearchExtension(const char *name, const GLubyte *start, const GLubyte *end);
 #endif
 
-#ifdef WITH_GLEW_MX
-GLXEWContext *glxewContext = NULL;
-#endif
-
 GLXContext GHOST_ContextGLX::s_sharedContext = None;
 int        GHOST_ContextGLX::s_sharedCount   = 0;
 
@@ -79,10 +75,6 @@ GHOST_ContextGLX::GHOST_ContextGLX(
       m_contextFlags(contextFlags),
       m_contextResetNotificationStrategy(contextResetNotificationStrategy),
       m_context(None)
-#ifdef WITH_GLEW_MX
-      ,
-      m_glxewContext(NULL)
-#endif
 {
 	assert(m_window  != 0);
 	assert(m_display != NULL);
@@ -109,11 +101,6 @@ GHOST_ContextGLX::~GHOST_ContextGLX()
 				::glXDestroyContext(m_display, m_context);
 			}
 		}
-
-#ifdef WITH_GLEW_MX
-		if (m_glxewContext)
-			delete m_glxewContext;
-#endif
 	}
 }
 
@@ -129,9 +116,6 @@ GHOST_TSuccess GHOST_ContextGLX::swapBuffers()
 GHOST_TSuccess GHOST_ContextGLX::activateDrawingContext()
 {
 	if (m_display) {
-		activateGLXEW();
-		activateGLEW();
-
 		return ::glXMakeCurrent(m_display, m_window, m_context) ? GHOST_kSuccess : GHOST_kFailure;
 	}
 	else {
@@ -141,15 +125,6 @@ GHOST_TSuccess GHOST_ContextGLX::activateDrawingContext()
 
 void GHOST_ContextGLX::initContextGLXEW()
 {
-#ifdef WITH_GLEW_MX
-	glxewContext = new GLXEWContext;
-	memset(glxewContext, 0, sizeof(GLXEWContext));
-
-	if (m_glxewContext)
-		delete m_glxewContext;
-	m_glxewContext = glxewContext;
-#endif
-
 	initContextGLEW();
 }
 
diff --git a/intern/ghost/intern/GHOST_ContextGLX.h b/intern/ghost/intern/GHOST_ContextGLX.h
index f0f010d1942..6547a0bd00a 100644
--- a/intern/ghost/intern/GHOST_ContextGLX.h
+++ b/intern/ghost/intern/GHOST_ContextGLX.h
@@ -34,16 +34,8 @@
 
 #include "GHOST_Context.h"
 
-#ifdef WITH_GLEW_MX
-#  define glxewGetContext() glxewContext
-#endif
-
 #include <GL/glxew.h>
 
-#ifdef WITH_GLEW_MX
-extern "C" GLXEWContext *glxewContext;
-#endif
-
 
 #ifndef GHOST_OPENGL_GLX_CONTEXT_FLAGS
 /* leave as convenience define for the future */
@@ -117,13 +109,6 @@ public:
 	 */
 	GHOST_TSuccess getSwapInterval(int &intervalOut);
 
-protected:
-	inline void activateGLXEW() const {
-#ifdef WITH_GLEW_MX
-		glxewContext = m_glxewContext;
-#endif
-	}
-
 private:
 	void initContextGLXEW();
 
@@ -140,10 +125,6 @@ private:
 
 	GLXContext m_context;
 
-#ifdef WITH_GLEW_MX
-	GLXEWContext *m_glxewContext;
-#endif
-
 	/** The first created OpenGL context (for sharing display lists) */
 	static GLXContext s_sharedContext;
 	static int        s_sharedCount;
diff --git a/intern/ghost/intern/GHOST_ContextSDL.cpp b/intern/ghost/intern/GHOST_ContextSDL.cpp
index 39627fac899..7a02e9743c3 100644
--- a/intern/ghost/intern/GHOST_ContextSDL.cpp
+++ b/intern/ghost/intern/GHOST_ContextSDL.cpp
@@ -97,8 +97,6 @@ GHOST_TSuccess GHOST_ContextSDL::swapBuffers()
 GHOST_TSuccess GHOST_ContextSDL::activateDrawingContext()
 {
 	if (m_context) {
-		activateGLEW();
-
 		return SDL_GL_MakeCurrent(m_window, m_context) ? GHOST_kSuccess : GHOST_kFailure;
 	}
 	else {
diff --git a/intern/ghost/intern/GHOST_ContextWGL.cpp b/intern/ghost/intern/GHOST_ContextWGL.cpp
index 39ef63fa723..f861631a94e 100644
--- a/intern/ghost/intern/GHOST_ContextWGL.cpp
+++ b/intern/ghost/intern/GHOST_ContextWGL.cpp
@@ -40,10 +40,6 @@
 #include <vector>
 
 
-#ifdef WITH_GLEW_MX
-WGLEWContext *wglewContext = NULL;
-#endif
-
 HGLRC GHOST_ContextWGL::s_sharedHGLRC = NULL;
 int   GHOST_ContextWGL::s_sharedCount = 0;
 
@@ -82,10 +78,6 @@ GHOST_ContextWGL::GHOST_ContextWGL(
       m_alphaBackground(alphaBackground),
       m_contextResetNotificationStrategy(contextResetNotificationStrategy),
       m_hGLRC(NULL)
-#ifdef WITH_GLEW_MX
-      ,
-      m_wglewContext(NULL)
-#endif
 #ifndef NDEBUG
       ,
       m_dummyVendor(NULL),
@@ -116,10 +108,6 @@ GHOST_ContextWGL::~GHOST_ContextWGL()
 		}
 	}
 
-#ifdef WITH_GLEW_MX
-	delete m_wglewContext;
-#endif
-
 #ifndef NDEBUG
 	free((void*)m_dummyRenderer);
 	free((void*)m_dummyVendor);
@@ -158,7 +146,6 @@ GHOST_TSuccess GHOST_ContextWGL::getSwapInterval(int &intervalOut)
 GHOST_TSuccess GHOST_ContextWGL::activateDrawingContext()
 {
 	if (WIN32_CHK(::wglMakeCurrent(m_hDC, m_hGLRC))) {
-		activateGLEW();
 		return GHOST_kSuccess;
 	}
 	else {
@@ -338,15 +325,6 @@ void GHOST_ContextWGL::initContextWGLEW(PIXELFORMATDESCRIPTOR &preferredPFD)
 
 	int iPixelFormat;
 
-
-#ifdef WITH_GLEW_MX
-	wglewContext = new WGLEWContext;
-	memset(wglewContext, 0, sizeof(WGLEWContext));
-
-	delete m_wglewContext;
-	m_wglewContext = wglewContext;
-#endif
-
 	SetLastError(NO_ERROR);
 
 	prevHDC = ::wglGetCurrentDC();
@@ -385,13 +363,8 @@ void GHOST_ContextWGL::initContextWGLEW(PIXELFORMATDESCRIPTOR &preferredPFD)
 	if (!WIN32_CHK(::wglMakeCurrent(dummyHDC, dummyHGLRC)))
 		goto finalize;
 
-#ifdef WITH_GLEW_MX
-	if (GLEW_CHK(wglewInit()) != GLEW_OK)
-		fprintf(stderr, "Warning! WGLEW failed to initialize properly.\n");
-#else
 	if (GLEW_CHK(glewInit()) != GLEW_OK)
 		fprintf(stderr, "Warning! Dummy GLEW/WGLEW failed to initialize properly.\n");
-#endif
 
 	// the following are not technially WGLEW, but they also require a context to work
 
@@ -828,8 +801,6 @@ GHOST_TSuccess GHOST_ContextWGL::initializeDrawingContext()
 		return GHOST_kFailure;
 	}
 
-	activateWGLEW();
-
 	if (WGLEW_ARB_create_context) {
 		int profileBitCore   = m_contextProfileMask & WGL_CONTEXT_CORE_PROFILE_BIT_ARB;
 		int profileBitCompat = m_contextProfileMask & WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
diff --git a/intern/ghost/intern/GHOST_ContextWGL.h b/intern/ghost/intern/GHOST_ContextWGL.h
index 99efcc5ebd7..a07cc1b6301 100644
--- a/intern/ghost/intern/GHOST_ContextWGL.h
+++ b/intern/ghost/intern/GHOST_ContextWGL.h
@@ -36,16 +36,8 @@
 
 #include "GHOST_Context.h"
 
-#ifdef WITH_GLEW_MX
-#define wglewGetContext() wglewContext
-#endif
-
 #include <GL/wglew.h>
 
-#ifdef WITH_GLEW_MX 
-extern "C" WGLEWContext *wglewContext;
-#endif
-
 #ifndef GHOST_OPENGL_WGL_RESET_NOTIFICATION_STRATEGY
 #define GHOST_OPENGL_WGL_RESET_NOTIFICATION_STRATEGY 0
 #endif
@@ -113,13 +105,6 @@ public:
 	 */
 	GHOST_TSuccess getSwapInterval(int &intervalOut);
 
-protected:
-	inline void activateWGLEW() const {
-#ifdef WITH_GLEW_MX 
-		wglewContext = m_wglewContext;
-#endif
-	}
-
 private:
 	int choose_pixel_format(
 	        bool stereoVisual,
@@ -163,10 +148,6 @@ private:
 	const int m_contextResetNotificationStrategy;
 
 	HGLRC m_hGLRC;
-
-#ifdef WITH_GLEW_MX 
-	WGLEWContext *m_wglewContext;
-#endif
 	
 #ifndef NDEBUG
 	const char *m_dummyVendor;
diff --git a/intern/glew-mx/glew-mx.h b/intern/glew-mx/glew-mx.h
index 813e95958b5..86f48a1068d 100644
--- a/intern/glew-mx/glew-mx.h
+++ b/intern/glew-mx/glew-mx.h
@@ -49,12 +49,6 @@
 #ifndef __GLEW_MX_H__
 #define __GLEW_MX_H__
 
-#ifdef WITH_GLEW_MX
-/* glew itself expects this */
-#  define GLEW_MX 1
-#  define glewGetContext() (&(_mx_context->glew_context))
-#endif
-
 #include <GL/glew.h>
 
 
@@ -62,23 +56,6 @@
 extern "C" {
 #endif
 
-/* MXContext is used instead of GLEWContext directly so that
-   extending what data is held by a context is easier.
- */
-typedef struct MXContext {
-#ifdef WITH_GLEW_MX
-	GLEWContext glew_context;
-#endif
-
-	int reserved; /* structs need at least one member */
-
-} MXContext;
-
-#ifdef WITH_GLEW_MX
-extern MXContext *_mx_context;
-#endif
-
-
 #include "intern/symbol-binding.h"
 
 
@@ -89,12 +66,6 @@ extern MXContext *_mx_context;
 #  include "intern/gl-deprecated.h"
 #endif
 
-
-MXContext *mxCreateContext     (void);
-MXContext *mxGetCurrentContext (void);
-void       mxMakeCurrentContext(MXContext *ctx);
-void       mxDestroyContext    (MXContext *ctx);
-
 GLenum glew_chk(GLenum error, const char *file, int line, const char *text);
 
 #ifndef NDEBUG
diff --git a/intern/glew-mx/intern/glew-mx.c b/intern/glew-mx/intern/glew-mx.c
index 6fbb1a7a2e2..9db2d233085 100644
--- a/intern/glew-mx/intern/glew-mx.c
+++ b/intern/glew-mx/intern/glew-mx.c
@@ -84,61 +84,3 @@ GLenum glew_chk(GLenum error, const char *file, int line, const char *text)
 
 	return error;
 }
-
-
-#ifdef WITH_GLEW_MX
-MXContext *_mx_context = NULL;
-#endif
-
-
-MXContext *mxCreateContext(void)
-{
-#ifdef WITH_GLEW_MX
-	MXContext* new_ctx = calloc(1, sizeof(MXContext));
-
-	if (new_ctx != NULL) {
-		MXContext* cur_ctx = _mx_context;
-		_mx_context = new_ctx;
-		GLEW_CHK(glewInit());
-		_mx_context = cur_ctx;
-	}
-
-	return new_ctx;
-#else
-	GLEW_CHK(glewInit());
-	return NULL;
-#endif
-}
-
-
-MXContext *mxGetCurrentContext(void)
-{
-#ifdef WITH_GLEW_MX
-	return _mx_context;
-#else
-	return NULL;
-#endif
-}
-
-
-void mxMakeCurrentContext(MXContext *ctx)
-{
-#ifdef WITH_GLEW_MX
-	_mx_context = ctx;
-#else
-	(void)ctx;
-#endif
-}
-
-
-void mxDestroyContext(MXContext *ctx)
-{
-#ifdef WITH_GLEW_MX
-	if (_mx_context == ctx)
-		_mx_context = NULL;
-
-	free(ctx);
-#else
-	(void)ctx;
-#endif
-}
diff --git a/source/blender/gpu/intern/gpu_debug.c b/source/blender/gpu/intern/gpu_debug.c
index eeeb6e0ab33..9adc6b89067 100644
--- a/source/blender/gpu/intern/gpu_debug.c
+++ b/source/blender/gpu/intern/gpu_debug.c
@@ -161,21 +161,21 @@ void gpu_debug_init(void)
 		fprintf(stderr, "Using %s\n", GLEW_VERSION_4_3 ? "OpenGL 4.3 debug facilities" : "KHR_debug extension");
 		glEnable(GL_DEBUG_OUTPUT);
 		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
-		glDebugMessageCallback((GLDEBUGPROC)gpu_debug_proc, mxGetCurrentContext());
+		glDebugMessageCallback((GLDEBUGPROC)gpu_debug_proc, NULL);
 		glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, NULL, GL_TRUE);
 		GPU_string_marker(success);
 	}
 	else if (GLEW_ARB_debug_output) {
 		fprintf(stderr, "Using ARB_debug_output extension\n");
 		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
-		glDebugMessageCallbackARB((GLDEBUGPROCARB)gpu_debug_proc, mxGetCurrentContext());
+		glDebugMessageCallbackARB((GLDEBUGPROCARB)gpu_debug_proc, NULL);
 		glDebugMessageControlARB(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, NULL, GL_TRUE);
 		GPU_string_marker(success);
 	}
 #  if LEGACY_DEBUG
 	else if (GLEW_AMD_debug_output) {
 		fprintf(stderr, "Using AMD_debug_output extension\n");
-		glDebugMessageCallbackAMD(gpu_debug_proc_amd, mxGetCurrentContext());
+		glDebugMessageCallbackAMD(gpu_debug_proc_amd, NULL);
 		glDebugMessageEnableAMD(GL_DONT_CARE, GL_DONT_CARE, 0, NULL, GL_TRUE);
 		GPU_string_marker(success);
 	}