Do not try to link with liblol-bullet if Bullet was disabled.

build/autotools/m4/lol-conf.m4

@@ -252,7 +252,7 @@ dnl  How to use the Lol Engine outside this tree
 LOL_CFLAGS="$LOL_CFLAGS $SDL_CFLAGS $GL_CFLAGS $EGL_CFLAGS $LIBPNG_CFLAGS"
 LOL_LIBS="$LOL_LIBS $SDL_LIBS $GL_LIBS $EGL_LIBS $LIBPNG_LIBS $D3D_LIBS"
 LOL_DEPS="${LOL_DEPS} \$(lol_builddir)/src/liblol-core.a"
-LOL_DEPS="${LOL_DEPS} \$(lol_builddir)/src/3rdparty/liblol-bullet.a"
+LOL_BULLET_DEPS="${LOL_BULLET_DEPS} \$(lol_builddir)/src/3rdparty/liblol-bullet.a"
 LOL_LUA_DEPS="${LOL_LUA_DEPS} \$(lol_builddir)/src/3rdparty/liblol-lua.a"
 
 dnl  How to use the Lol Engine inside this tree
@@ -266,6 +266,7 @@ dnl  Extra flags
 AC_SUBST(LOL_CFLAGS)
 AC_SUBST(LOL_LIBS)
 AC_SUBST(LOL_DEPS)
+AC_SUBST(LOL_BULLET_DEPS)
 AC_SUBST(LOL_LUA_DEPS)
 
 AC_SUBST(AM_CFLAGS)

doc/samples/Makefile.am

@@ -37,7 +37,7 @@ btphystest_SOURCES = \
     front_camera_sprite.lolfx
 btphystest_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/src/3rdparty/bullet3/src \
     -DHAVE_PHYS_USE_BULLET
-btphystest_DEPENDENCIES = @LOL_DEPS@
+btphystest_DEPENDENCIES = @LOL_DEPS@ @LOL_BULLET_DEPS@
 btphystest_LDFLAGS = $(AM_LDFLAGS)
 if LOL_USE_EMSCRIPTEN
 btphystest_LDFLAGS += \