diff --git a/.gitmodules b/.gitmodules
index 643371b..6d2aabf 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -16,3 +16,6 @@
 [submodule "external/libanm2"]
 	path = external/libanm2
 	url = https://github.com/shweetsstuff/libanm2
+[submodule "external/physfs"]
+	path = external/physfs
+	url = https://github.com/icculus/physfs
diff --git a/external/physfs b/external/physfs
new file mode 160000
index 0000000..d70c3fc
--- /dev/null
+++ b/external/physfs
@@ -0,0 +1 @@
+Subproject commit d70c3fcf06814f8608c8327d3e8136063ee0133d
diff --git a/src/canvas.h b/src/canvas.hpp
similarity index 100%
rename from src/canvas.h
rename to src/canvas.hpp
diff --git a/src/character.h b/src/character.hpp
similarity index 100%
rename from src/character.h
rename to src/character.hpp
diff --git a/src/cursor.h b/src/cursor.hpp
similarity index 100%
rename from src/cursor.h
rename to src/cursor.hpp
diff --git a/src/game_data.h b/src/game_data.hpp
similarity index 100%
rename from src/game_data.h
rename to src/game_data.hpp
diff --git a/src/item.h b/src/item.hpp
similarity index 100%
rename from src/item.h
rename to src/item.hpp
diff --git a/src/loader.h b/src/loader.hpp
similarity index 100%
rename from src/loader.h
rename to src/loader.hpp
diff --git a/src/resource/anm2.h b/src/resource/anm2.hpp
similarity index 100%
rename from src/resource/anm2.h
rename to src/resource/anm2.hpp
diff --git a/src/resource/audio.h b/src/resource/audio.hpp
similarity index 100%
rename from src/resource/audio.h
rename to src/resource/audio.hpp
diff --git a/src/resource/dialogue.h b/src/resource/dialogue.hpp
similarity index 100%
rename from src/resource/dialogue.h
rename to src/resource/dialogue.hpp
diff --git a/src/resource/font.h b/src/resource/font.hpp
similarity index 100%
rename from src/resource/font.h
rename to src/resource/font.hpp
diff --git a/src/resource/shader.h b/src/resource/shader.hpp
similarity index 100%
rename from src/resource/shader.h
rename to src/resource/shader.hpp
diff --git a/src/resource/texture.h b/src/resource/texture.hpp
similarity index 100%
rename from src/resource/texture.h
rename to src/resource/texture.hpp
diff --git a/src/resources.h b/src/resources.hpp
similarity index 100%
rename from src/resources.h
rename to src/resources.hpp
diff --git a/src/state.h b/src/state.hpp
similarity index 100%
rename from src/state.h
rename to src/state.hpp
diff --git a/src/types.h b/src/types.hpp
similarity index 100%
rename from src/types.h
rename to src/types.hpp
diff --git a/src/util/imgui_.h b/src/util/imgui_.hpp
similarity index 100%
rename from src/util/imgui_.h
rename to src/util/imgui_.hpp
diff --git a/src/util/map_.h b/src/util/map_.hpp
similarity index 100%
rename from src/util/map_.h
rename to src/util/map_.hpp
diff --git a/src/util/math_.h b/src/util/math_.hpp
similarity index 100%
rename from src/util/math_.h
rename to src/util/math_.hpp
diff --git a/src/util/string_.h b/src/util/string_.hpp
similarity index 100%
rename from src/util/string_.h
rename to src/util/string_.hpp
diff --git a/src/util/unordered_map_.h b/src/util/unordered_map_.hpp
similarity index 100%
rename from src/util/unordered_map_.h
rename to src/util/unordered_map_.hpp
diff --git a/src/util/vector_.h b/src/util/vector_.hpp
similarity index 100%
rename from src/util/vector_.h
rename to src/util/vector_.hpp
diff --git a/src/util/xml_.h b/src/util/xml_.hpp
similarity index 100%
rename from src/util/xml_.h
rename to src/util/xml_.hpp
diff --git a/src/window/chat.h b/src/window/chat.hpp
similarity index 100%
rename from src/window/chat.h
rename to src/window/chat.hpp
diff --git a/src/window/info.h b/src/window/info.hpp
similarity index 100%
rename from src/window/info.h
rename to src/window/info.hpp
diff --git a/src/window/inventory.h b/src/window/inventory.hpp
similarity index 100%
rename from src/window/inventory.h
rename to src/window/inventory.hpp
diff --git a/src/window/main_menu.h b/src/window/main_menu.hpp
similarity index 100%
rename from src/window/main_menu.h
rename to src/window/main_menu.hpp
diff --git a/src/window/play.h b/src/window/play.hpp
similarity index 100%
rename from src/window/play.h
rename to src/window/play.hpp
diff --git a/src/window/stats.h b/src/window/stats.hpp
similarity index 100%
rename from src/window/stats.h
rename to src/window/stats.hpp
diff --git a/src/window/text.h b/src/window/text.hpp
similarity index 100%
rename from src/window/text.h
rename to src/window/text.hpp