mesa opengl (gles2) need GL/gl.h too
Building latest VLC under Gentoo (MESA from git too) I found: GLES2 (and GLES1 IMHO must too) option required GL/gl.h too (at least for GL_VERTEX_ARRAY). I use next patch (but IMHO there are *nix/mesa only, just FYI):
--- a/modules/video_output/opengl.h +++ b/modules/video_output/opengl.h @@ -37,12 +37,11 @@ #define VLCGL_TEXTURE_COUNT 1
#if !defined (APPLE) +# include <GL/gl.h>
if USE_OPENGL_ES == 2
include <GLES2/gl2.h>
elif USE_OPENGL_ES == 1
include <GLES/gl.h>
-# else -# include <GL/gl.h>
endif
#else