Only run the pkg-config line for Eigen3 once.

Also, print an error message if pkg-config has failed.

diff --git a/Makefile b/Makefile
index f7ba81e7c7c12a188b43ba6dc3e57464fd79b033..1ab3d9cce46d84d754060e2e207fa0a95a068f70 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,13 @@
 GTEST_DIR = /usr/src/gtest
 
 GTEST_DIR = /usr/src/gtest
 

+EIGEN_CXXFLAGS := $(shell pkg-config --cflags eigen3)
+ifeq ($(EIGEN_CXXFLAGS),)
+$(error Empty EIGEN_CXXFLAGS. You probably need to install Eigen3)
+endif
+

 CC=gcc
 CXX=g++
 CC=gcc
 CXX=g++

-CXXFLAGS=-Wall -g -I$(GTEST_DIR)/include $(shell pkg-config --cflags eigen3 )
+CXXFLAGS=-Wall -g -I$(GTEST_DIR)/include $(EIGEN_CXXFLAGS)

 LDFLAGS=-lSDL -lSDL_image -lGL -lrt -lpthread
 RANLIB=ranlib
 
 LDFLAGS=-lSDL -lSDL_image -lGL -lrt -lpthread
 RANLIB=ranlib