title: This makefile does not update object files
body: <p>I generated a makefile out of a codeblocks project (written in c++11), so I can use Atom as IDE. But it does not update the object files when I i.e. change the default constructors parameter in the header file, which is really annoying. It just links the existing object files again. But even if I make a little change to the .cpp file, it recompiles the object without recognizing the changes in the header file. The only quick fix I found is to delete the object file manually, so it really generates it completely new. The header part I currently often change looks like this:</p>
  
  <pre><code>VRParticles(): VRParticles(123){}
  </code></pre>
  
  <p>The whole makefile is available here (generated using cbp2make): <a href="https://github.com/Pfeil/polyvr/blob/master/Makefile" rel="nofollow">https://github.com/Pfeil/polyvr/blob/master/Makefile</a>
  (Please note that I am just a fairly new contributor and not responsible for the way this is programmed ;) )</p>
  
  <p>I use the makefile mostly with one of those two commands:</p>
  
  <pre><code>make -j 3 build_debug
  make debug
  </code></pre>
  
  <p>Note that everything compiles fine when I delete VRParticles.o or do <code>make clean</code> and <code>make debug</code>.</p>
  
  <p>Please note that my experience with makefiles is very low. The makefile basically works like this (remember the link to the full version above):</p>
  
  <pre><code>OBJ_DEBUG = # all object files
  
  build_debug: before_debug out_debug after_debug
  
  debug: before_build build_debug after_build
  
  out_debug: before_debug $(OBJ_DEBUG) $(DEP_DEBUG)
      $(LD) $(LIBDIR_DEBUG) -o $(OUT_DEBUG) $(OBJ_DEBUG)  $(LDFLAGS_DEBUG) $(LIB_DEBUG)
  
  $(OBJDIR_DEBUG)/src/addons/Bullet/Particles/VRParticles.o: src/addons/Bullet/Particles/VRParticles.cpp
      $(CXX) $(CFLAGS_DEBUG) $(INC_DEBUG) -c src/addons/Bullet/Particles/VRParticles.cpp -o $(OBJDIR_DEBUG)/src/addons/Bullet/Particles/VRParticles.o
  </code></pre>
  
  <p>I'd really like give more information, but I have no idea what else could be important, so please ask if you need more. My question basically is how I need to modify the makefile (I guess this file contains the issue) so the object files get updated if needed. Without recompiling everything.</p>
  
  <p>I'm on Linux (Ubuntu 14.04 LTS).</p>