Fix GLEW deprecation errors

- Move `TGLWSIncludes.h` from the `inc` to the `src` directory
- Don't install the GLEW headers

Author: bellenot

builtins/glew/CMakeLists.txt

@@ -56,5 +56,3 @@ install(TARGETS GLEW
         LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
         ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
         )
-
-ROOT_INSTALL_HEADERS()

cmake/modules/RootMacros.cmake

@@ -811,7 +811,7 @@ function (ROOT_CXXMODULES_APPEND_TO_MODULEMAP library library_headers)
                         TIsAProxy.h TVirtualIsAProxy.h
                         DllImport.h ESTLType.h Varargs.h
                         ThreadLocalStorage.h
-                        TBranchProxyTemplate.h TGLWSIncludes.h
+                        TBranchProxyTemplate.h
                         snprintf.h strlcpy.h)
 
    # Deprecated header files.

graf3d/gl/CMakeLists.txt

@@ -194,6 +194,7 @@ ROOT_STANDARD_LIBRARY_PACKAGE(RGL
     src/TGLViewerEditor.cxx
     src/TGLVoxelPainter.cxx
     src/TGLWidget.cxx
+    src/TGLWSIncludes.h
     src/TH2GL.cxx
     src/TH3GL.cxx
     src/TKDEAdapter.cxx
@@ -224,6 +225,7 @@ target_include_directories(RGL PRIVATE
      ${OPENGL_INCLUDE_DIR}
      ${FTGL_INCLUDE_DIR}
      ${FREETYPE_INCLUDE_DIRS}
+     ${GLEW_INCLUDE_DIRS}
 )
 
 if(builtin_gl2ps)
@@ -232,9 +234,6 @@ else()
   target_include_directories(RGL PRIVATE ${GL2PS_INCLUDE_DIRS})
 endif()
 
-# Remove when not needed anymore in the ROOT 6.40 development cycle
-target_compile_definitions(RGL PRIVATE _ROOT_GL_BUILDS_ITSELF)
-
 if(MSVC AND builtin_glew)
   target_compile_definitions (RGL PRIVATE "GLEW_STATIC")
 endif()

graf3d/gl/inc/TGLWSIncludes.h

@@ -0,0 +1,31 @@
+// @(#)root/gl:$Id$
+// Authors:  Timur and Matevz, May 2008
+
+/*************************************************************************
+ * Copyright (C) 1995-2004, Rene Brun and Fons Rademakers.               *
+ * All rights reserved.                                                  *
+ *                                                                       *
+ * For the licensing terms see $ROOTSYS/LICENSE.                         *
+ * For the list of contributors see $ROOTSYS/README/CREDITS.             *
+ *************************************************************************/
+
+// Window-system specific GL includes.
+// Inclusion should only be necessary in in low-level system files.
+
+#ifndef ROOT_TGLWSIncludes
+
+#include "RConfigure.h"
+#include "TGLIncludes.h"
+
+#if defined(WIN32)
+#include <GL/wglew.h>
+#else
+#if defined(__APPLE__) && !defined(R__HAS_COCOA)
+#define GLEW_APPLE_GLX
+#endif
+#if !defined(R__HAS_COCOA)
+#include <GL/glxew.h>
+#endif
+#endif
+
+#endif