added ptrdiff_t definition on windows

git-svn-id: https://glew.svn.sourceforge.net/svnroot/glew/trunk/glew@197 783a27ee-832a-0410-bc00-9f386506c6dd

auto/src/glew_gl.c

@@ -70,6 +70,7 @@ static GLuint _glewInit ()
       GLEW_VERSION_1_2 = GL_TRUE;
       GLEW_VERSION_1_3 = GL_TRUE;
       GLEW_VERSION_1_4 = GL_TRUE;
+      GLEW_VERSION_1_5 = GL_TRUE;
     }
     if (s[2] == '4')
     {

auto/src/glew_pre.h

@@ -124,19 +124,15 @@
 #    define _WCHAR_T_DEFINED
 #  endif
 #endif
-
-/*
- * FIXME: the definition of ptrdiff_t is needed here, it's found in
- * stddef.h.
- *
- * Since Windows doesn't actually _run_ on anything but PCs this will do
- * for now.
- *
- * What does the compiler define when the target is a 64 bit platform
- * anyway?  WIN64?
- */
-
-typedef int                     ptrdiff_t;
+/* <stddef.h> */
+#ifndef _PTRDIFF_T_DEFINED
+#  ifdef  _WIN64
+typedef __int64 ptrdiff_t;
+#  else
+typedef _W64 int ptrdiff_t;
+#  endif
+#  define _PTRDIFF_T_DEFINED
+#endif
 
 #ifndef GLAPI
 #  if defined(__CYGWIN__) || defined(__MINGW32__)