Remove references about using FTGL

FTGL has been constantly undermaintained (and currently has no maintainer)
and was never used by libcaca. It was added back in 9752e82 (Jul 2008)
'to be used later'. In 2025 it is safe to assume 'later' won't happen
in this case.

caca/Makefile.am

@@ -92,9 +92,9 @@ libx11_plugin_la_LDFLAGS = -no-undefined -module -no-version
 libx11_plugin_la_LIBADD = libcaca.la $(X11_LIBS)
 
 libgl_plugin_la_SOURCES = driver/gl.c
-libgl_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(GL_CFLAGS) #$(FTGL_CFLAGS)
+libgl_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(GL_CFLAGS)
 libgl_plugin_la_LDFLAGS = -no-undefined -module -no-version
-libgl_plugin_la_LIBADD = libcaca.la $(GL_LIBS) #$(FTGL_LIBS)
+libgl_plugin_la_LIBADD = libcaca.la $(GL_LIBS)
 else
 driver_source += driver/x11.c driver/gl.c
 endif

configure.ac

@@ -257,9 +257,7 @@ if test "${enable_gl}" != "no"; then
   elif test "${enable_gl}" = "yes"; then
     AC_MSG_ERROR([cannot find OpenGL+FreeGLUT development files])
   fi
-  PKG_CHECK_MODULES(FTGL, ftgl >= 2.1.3, [FTGL="yes"], [FTGL="no"])
 fi
-AM_CONDITIONAL(USE_FTGL, test "${FTGL}" = "yes")
 
 if test "${enable_cocoa}" != "no"; then
   ac_cv_my_have_cocoa="no"
@@ -364,8 +362,8 @@ if test "${enable_plugins}" = "yes"; then
   AC_DEFINE(USE_PLUGINS, 1, Define to 1 to activate plugins)
   CACA_LIBS="${CACA_LIBS} -ldl"
 else
-  CACA_CFLAGS="${CACA_CFLAGS} ${X11_CFLAGS} ${GL_CFLAGS} ${FTGL_CFLAGS}"
-  CACA_LIBS="${CACA_LIBS} ${X11_LIBS} ${GL_LIBS} ${FTGL_LIBS}"
+  CACA_CFLAGS="${CACA_CFLAGS} ${X11_CFLAGS} ${GL_CFLAGS}"
+  CACA_LIBS="${CACA_LIBS} ${X11_LIBS} ${GL_LIBS}"
 fi
 AM_CONDITIONAL(USE_PLUGINS, test "${ac_cv_my_have_plugins}" = "yes")