gnu: gegl: Add optional dependencies.

* gnu/packages/gimp.scm (gegl)[inputs]: Add gdk-pixbuf, gexiv2, jasper,
libnsgif, libraw, librsvg, libspiro, libtiff, libwebp, maxflow, openexr,
poppler, sdl2.

Signed-off-by: Liliana Marie Prikler <liliana.prikler@gmail.com>

gnu/packages/gimp.scm

@@ -39,6 +39,7 @@
   #:use-module (gnu packages base)
   #:use-module (gnu packages build-tools)
   #:use-module (gnu packages documentation)
+  #:use-module (gnu packages fontutils)
   #:use-module (gnu packages graphviz)
   #:use-module (gnu packages pkg-config)
   #:use-module (gnu packages glib)
@@ -50,11 +51,13 @@
   #:use-module (gnu packages compression)
   #:use-module (gnu packages xml)
   #:use-module (gnu packages linux)
+  #:use-module (gnu packages maths)
   #:use-module (gnu packages ncurses)
   #:use-module (gnu packages patchutils)
   #:use-module (gnu packages pdf)
   #:use-module (gnu packages photo)
   #:use-module (gnu packages python)
+  #:use-module (gnu packages sdl)
   #:use-module (gnu packages web)
   #:use-module (gnu packages xorg))
 
@@ -247,10 +250,24 @@ provided, as well as a framework to add new color models and data types.")
        ("glib" ,glib)
        ("json-glib" ,json-glib)))
     (inputs
+     ;; All inputs except libjpeg and libpng are optional.
      `(("cairo" ,cairo)
-       ("pango" ,pango)
+       ("gdk-pixbuf" ,gdk-pixbuf)
+       ("gexiv2" ,gexiv2)
+       ("jasper" ,jasper)
+       ("libjpeg" ,libjpeg-turbo)
+       ("libnsgif" ,libnsgif)
        ("libpng" ,libpng)
-       ("libjpeg" ,libjpeg-turbo)))
+       ("libraw" ,libraw)
+       ("librsvg" ,librsvg)
+       ("libspiro" ,libspiro)
+       ("libtiff" ,libtiff)
+       ("libwebp" ,libwebp)
+       ("maxflow" ,maxflow)
+       ("openexr" ,openexr)
+       ("pango" ,pango)
+       ("poppler" ,poppler)
+       ("sdl2" ,sdl2)))
     (native-inputs
      `(("glib" ,glib "bin")             ; for gtester
        ("gobject-introspection" ,gobject-introspection)