optional_depends  xorg-libs                  \
                  "--with-x"                \
                  "--without-x"             \
                  "for X11 support"         &&

optional_depends  OPENGL                    \
                  "--enable-opengl"         \
                  "--disable-opengl"        \
                  "OpenGL support"          &&

optional_depends  tiff                      \
                  "--enable-tiff"           \
                  "--disable-tiff"          \
                  "for TIFF image support"  &&

optional_depends  libpng                   \
                  "--enable-png"           \
                  "--disable-png"          \
                  "for PNG image support"  &&

optional_depends  libmng                   \
                  "--enable-mng"           \
                  "--disable-mng"          \
                  "for MNG image support"  &&

optional_depends  JPEG                      \
                  "--enable-jpeg"           \
                  "--disable-jpeg"          \
                  "for JPEG image support"  &&

optional_depends  GIFLIB                   \
                  "--enable-gif"           \
                  "--disable-gif"          \
                  "for GIF image support"  &&

optional_depends  lcms                         \
                  "--enable-lcms"              \
                  "--disable-lcms"             \
                  "for LCMS color management"  &&

optional_depends  allegro                             \
                  "--enable-allegro"                  \
                  "--disable-allegro"                 \
                  "for allegro game library support"  &&

optional_depends  sdl                \
                  "--enable-sdl"     \
                  "--disable-sdl"    \
                  "for SDL support"