From 29f588a91a202a6d515dfb7383ecacc25668b7f7 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Wed, 6 Feb 2013 01:09:27 +0100
Subject: [PATCH] Make building the demo app optional if SDL_image and/or
 libpng12 are not found.

---
 Makefile.in  |  7 ++++++-
 configure.ac | 11 ++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index f98bbfc..4656959 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -6,6 +6,7 @@ includedir = @includedir@
 libdir = @libdir@
 datarootdir = @datarootdir@
 datadir = @datadir@
+with_demo_app = @with_demo_app@
 
 CC=@CC@
 CXX=@CXX@
@@ -62,7 +63,11 @@ TESTS=effect_chain_test $(TESTED_INPUTS:=_test) $(TESTED_EFFECTS:=_test)
 LIB_OBJS=effect_util.o util.o widgets.o effect.o effect_chain.o init.o $(INPUTS:=.o) $(EFFECTS:=.o)
 
 # Default target:
-all: $(TESTS) demo
+all: libmovit.a $(TESTS)
+
+ifeq ($(with_demo_app),yes)
+all: demo
+endif
 
 # Google Test and other test library functions.
 TEST_OBJS = gtest-all.o gtest_sdl_main.o test_util.o
diff --git a/configure.ac b/configure.ac
index f044a17..d21b85a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7,10 +7,15 @@ AC_PROG_CXX
 PKG_CHECK_MODULES([Eigen3], [eigen3])
 PKG_CHECK_MODULES([GLEW], [glew])
 
-# These are only needed for the demo app.
+# Needed for unit tests and the demo app.
 PKG_CHECK_MODULES([SDL], [sdl])
-PKG_CHECK_MODULES([SDL_image], [SDL_image])
-PKG_CHECK_MODULES([libpng], [libpng12])
+
+# These are only needed for the demo app.
+with_demo_app=yes
+PKG_CHECK_MODULES([SDL_image], [SDL_image], [], [with_demo_app=no; AC_MSG_WARN([SDL_image not found, demo program will not be built])])
+PKG_CHECK_MODULES([libpng], [libpng12], [], [with_demo_app=no; AC_MSG_WARN([libpng12 not found, demo program will not be built])])
+
+AC_SUBST([with_demo_app])
 
 AC_CONFIG_FILES([Makefile movit.pc])
 AC_OUTPUT
-- 
2.39.2