package/mesa3d: add a new option to enable GLX support

When switching to meson build system, enabling GLX support
require at least one DRI or Gallium dirver.

So add a dependency on BR2_PACKAGE_MESA3D_DRIVER for
BR2_PACKAGE_MESA3D_OPENGL_GLX option.

quoting the meson build system:
"dri based GLX requires at least one DRI driver." [1]
"Even when building just gallium drivers the user probably wants dri." [2]

[1] https://cgit.freedesktop.org/mesa/mesa/tree/meson.build?h=19.0#n340
[2] https://cgit.freedesktop.org/mesa/mesa/tree/meson.build?h=19.0#n266

Signed-off-by: Romain Naour <romain.naour@smile.fr>
[Bernd: moved x11 dependencies from glx condition to xorg7 condition to
 fix build error with enabled egl without glx
 BR2_PACKAGE_HAS_LIBGL needs to depend on BR2_PACKAGE_MESA3D_OPENGL_GLX]
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
[Arnout: small changes to Config.in help text and menus]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/mesa3d/Config.in

@@ -6,16 +6,7 @@ menuconfig BR2_PACKAGE_MESA3D
 	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL
 	select BR2_PACKAGE_LIBDRM
 	select BR2_PACKAGE_EXPAT
-	select BR2_PACKAGE_HAS_LIBGL if BR2_PACKAGE_XORG7
 	select BR2_PACKAGE_WAYLAND_PROTOCOLS if BR2_PACKAGE_WAYLAND
-	select BR2_PACKAGE_XORGPROTO if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_XLIB_LIBX11 if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_XLIB_LIBXEXT if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_XLIB_LIBXDAMAGE if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_XLIB_LIBXFIXES if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_XLIB_LIBXRANDR if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_XLIB_LIBXXF86VM if BR2_PACKAGE_XORG7
-	select BR2_PACKAGE_LIBXCB if BR2_PACKAGE_XORG7
 	select BR2_PACKAGE_ZLIB
 	help
 	  Mesa 3D, an open-source implementation of the OpenGL
@@ -281,7 +272,25 @@ comment "OSMesa classic requires dri (classic) swrast"
 
 if BR2_PACKAGE_MESA3D_DRIVER
 
-comment "Additional API Support"
+comment "OpenGL API Support"
+
+config BR2_PACKAGE_MESA3D_OPENGL_GLX
+	bool "OpenGL GLX"
+	depends on BR2_PACKAGE_XORG7
+	select BR2_PACKAGE_HAS_LIBGL
+	select BR2_PACKAGE_LIBXCB
+	select BR2_PACKAGE_XLIB_LIBX11
+	select BR2_PACKAGE_XLIB_LIBXDAMAGE
+	select BR2_PACKAGE_XLIB_LIBXEXT
+	select BR2_PACKAGE_XLIB_LIBXFIXES
+	select BR2_PACKAGE_XLIB_LIBXRANDR
+	select BR2_PACKAGE_XLIB_LIBXXF86VM
+	select BR2_PACKAGE_XORGPROTO
+	help
+	  Enable GLX graphic acceleration (OpenGL + X11).
+
+comment "OpenGL GLX support needs X11"
+	depends on !BR2_PACKAGE_XORG7
 
 config BR2_PACKAGE_MESA3D_OPENGL_EGL
 	bool "OpenGL EGL"
@@ -301,7 +310,7 @@ config BR2_PACKAGE_MESA3D_OPENGL_ES
 endif # BR2_PACKAGE_MESA3D_DRIVER
 
 config BR2_PACKAGE_PROVIDES_LIBGL
-	default "mesa3d" if BR2_PACKAGE_XORG7
+	default "mesa3d" if BR2_PACKAGE_MESA3D_OPENGL_GLX
 
 config BR2_PACKAGE_PROVIDES_LIBEGL
 	default "mesa3d" if BR2_PACKAGE_MESA3D_OPENGL_EGL

package/mesa3d/mesa3d.mk

@@ -72,16 +72,7 @@ MESA3D_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -mno-compact-eh"
 MESA3D_CONF_ENV += CXXFLAGS="$(TARGET_CXXFLAGS) -mno-compact-eh"
 endif
 
-ifeq ($(BR2_PACKAGE_XORG7),y)
-MESA3D_DEPENDENCIES += \
-	xlib_libX11 \
-	xlib_libXext \
-	xlib_libXdamage \
-	xlib_libXfixes \
-	xlib_libXrandr \
-	xlib_libXxf86vm \
-	xorgproto \
-	libxcb
+ifeq ($(BR2_PACKAGE_MESA3D_OPENGL_GLX),y)
 MESA3D_CONF_OPTS += --enable-glx --disable-mangling
 ifeq ($(BR2_PACKAGE_MESA3D_NEEDS_XA),y)
 MESA3D_CONF_OPTS += --enable-xa
@@ -170,7 +161,7 @@ MESA3D_CONF_OPTS += --enable-opengl --enable-dri
 MESA3D_CONF_OPTS += --disable-va
 
 # libGL is only provided for a full xorg stack
-ifeq ($(BR2_PACKAGE_XORG7),y)
+ifeq ($(BR2_PACKAGE_MESA3D_OPENGL_GLX),y)
 MESA3D_PROVIDES += libgl
 else
 define MESA3D_REMOVE_OPENGL_HEADERS
@@ -195,7 +186,16 @@ ifeq ($(BR2_PACKAGE_WAYLAND),y)
 MESA3D_DEPENDENCIES += wayland wayland-protocols
 MESA3D_PLATFORMS += wayland
 endif
-ifeq ($(BR2_PACKAGE_XORG7),y)
+ifeq ($(BR2_PACKAGE_MESA3D_OPENGL_GLX),y)
+MESA3D_DEPENDENCIES += \
+	xlib_libX11 \
+	xlib_libXext \
+	xlib_libXdamage \
+	xlib_libXfixes \
+	xlib_libXrandr \
+	xlib_libXxf86vm \
+	xorgproto \
+	libxcb
 MESA3D_PLATFORMS += x11
 endif