fltk14-devel: Modify option handling

- Explicitly enable nanosvg
- Add option "xdbe" for X11 double buffer extension

fltk14-devel/Makefile

@@ -22,6 +22,7 @@ TEST_TARGET=		test
 PTHREAD_OPTS+=		require
 GNU_CONFIGURE=		yes
 CONFIGURE_ARGS+=	--enable-libtool=${LIBTOOL:Q}
+CONFIGURE_ARGS+=	--enable-nanosvg
 CONFIGURE_ARGS+=	--enable-print
 CONFIGURE_ARGS+=	--enable-shared
 CONFIGURE_ARGS+=	--enable-threads
@@ -29,7 +30,7 @@ CONFIGURE_ARGS+=	--enable-xcursor
 CONFIGURE_ARGS+=	--enable-xfixes
 CONFIGURE_ARGS+=	--enable-xrender
 
-# Use pkgsrc versions of libraries, not package's bundled versions.
+# Use pkgsrc versions of libraries, not package's bundled versions
 CONFIGURE_ARGS+=	--disable-localjpeg
 CONFIGURE_ARGS+=	--disable-localpng
 CONFIGURE_ARGS+=	--disable-localzlib

fltk14-devel/options.mk

@@ -1,8 +1,8 @@
 # $NetBSD$
 
 PKG_OPTIONS_VAR=	PKG_OPTIONS.fltk14
-PKG_SUPPORTED_OPTIONS=	opengl pango xft2 xinerama
-PKG_SUGGESTED_OPTIONS=	opengl pango xft2 xinerama
+PKG_SUPPORTED_OPTIONS=	opengl pango xdbe xft2 xinerama
+PKG_SUGGESTED_OPTIONS=	opengl pango xdbe xft2 xinerama
 PLIST_VARS+=		opengl
 
 .include "../../mk/bsd.prefs.mk"
@@ -40,6 +40,17 @@ CONFIGURE_ARGS+=	--enable-pango
 CONFIGURE_ARGS+=	--disable-pango
 .endif
 
+# "xdbe" option: Use X11 double buffer extension
+# On older systems double buffering can be very slow. Disabling this option can
+# make the GUI more responsive. The drawback is potential flickering, e.g. in
+# a text field while a scrollbar is moved.
+# Note: This extension is implemented in X servers, no client library required.
+.if !empty(PKG_OPTIONS:Mxdbe)
+CONFIGURE_ARGS+=	--enable-xdbe
+.else
+CONFIGURE_ARGS+=	--disable-xdbe
+.endif
+
 # "xft2" option: Use client side font rendering for X11 backend
 # Disabling this option uses the original core X11 font system and removes all
 # font related dependencies (the X server is used for font rendering and client