update makefile with additional sources

Makefile.am

@@ -20,7 +20,12 @@ moddir=$(prefix)/share/guile/site/$(GUILE_EFFECTIVE_VERSION)
 godir=$(libdir)/guile/$(GUILE_EFFECTIVE_VERSION)/site-ccache
 
 SOURCES = 					\
-  game/main.scm
+  game/model/level.scm \
+  game/model/hero.scm \
+  game/render/level.scm \
+  game/render/hero.scm \
+  game/main.scm 
+
 
 EXTRA_DIST = 					\
   $(SOURCES)					\

game/render/hero.scm

@@ -21,8 +21,8 @@
 
 (define (hero-sprite hero)
   (let* ((x (inexact->exact (floor (vec2-x (hero-position hero)))))
-         (x-offset (remainder x 8))
-         (hero-index (+ hero-walk-offset x-offset)))
+         (animation-frame (remainder x 8))
+         (hero-index (+ hero-walk-offset animation-frame)))
     (texture-atlas-ref hero-atlas hero-index)))
 
 (define (render-hero hero)