Properly destroy modules on exit;

src/audio/audio.c

@@ -31,9 +31,10 @@ void lovrAudioInit() {
   state.device = device;
   state.context = context;
   vec_init(&state.sources);
-
   vec3_set(state.position, 0, 0, 0);
   quat_set(state.orientation, 0, 0, 0, -1);
+
+  atexit(lovrAudioDestroy);
 }
 
 void lovrAudioDestroy() {

src/event/event.c

@@ -18,6 +18,7 @@ void lovrEventInit() {
   vec_init(&state.events);
   lovrEventAddPump(glfwPollEvents);
   glfwSetWindowCloseCallback(window, onClose);
+  atexit(lovrEventDestroy);
 }
 
 void lovrEventDestroy() {

src/filesystem/filesystem.c

@@ -2,6 +2,7 @@
 #include "util.h"
 #include <physfs.h>
 #include <stdio.h>
+#include <stdlib.h>
 #ifdef __APPLE__
 #include <mach-o/dyld.h>
 #elif _WIN32
@@ -21,6 +22,7 @@ void lovrFilesystemInit(const char* arg0) {
 
   state.gameSource = NULL;
   state.identity = NULL;
+  atexit(lovrFilesystemDestroy);
 }
 
 void lovrFilesystemDestroy() {

src/graphics/graphics.c

@@ -29,6 +29,7 @@ void lovrGraphicsInit() {
   vec_init(&state.shapeIndices);
   state.depthTest = -1;
   lovrGraphicsReset();
+  atexit(lovrGraphicsDestroy);
 }
 
 void lovrGraphicsDestroy() {

src/headset/headset.c

@@ -10,6 +10,14 @@ void lovrHeadsetInit() {
   if (headset) {
     lovrEventAddPump(lovrHeadsetPoll);
   }
+
+  atexit(lovrHeadsetDestroy);
+}
+
+void lovrHeadsetDestroy() {
+  if (headset) {
+    headset->destroy(headset);
+  }
 }
 
 void lovrHeadsetPoll() {

src/headset/headset.h

@@ -32,6 +32,7 @@ typedef struct {
 typedef vec_t(Controller*) vec_controller_t;
 
 typedef struct {
+  void (*destroy)(void* headset);
   char (*isPresent)(void* headset);
   void (*poll)(void* headset);
   const char* (*getType)(void* headset);
@@ -61,6 +62,7 @@ typedef struct {
 #endif
 
 void lovrHeadsetInit();
+void lovrHeadsetDestroy();
 void lovrHeadsetPoll();
 char lovrHeadsetIsPresent();
 const char* lovrHeadsetGetType();

src/headset/vive.c

@@ -61,6 +61,7 @@ Headset* viveInit() {
   if (!vive) return NULL;
 
   Headset* headset = (Headset*) vive;
+  headset->destroy = viveDestroy;
   headset->poll = vivePoll;
   headset->isPresent = viveIsPresent;
   headset->getType = viveGetType;