Added random number generator

Fixed typo in calculate camera
Removed some warning

code/game/impl/world.c

@@ -8,10 +8,10 @@ void UpdateWorld(F32 delta, World *world) {
 }
 
 void UpdateNPCs(F32 delta, World *world) {
-  for(int i = 0; i < world->npcCount; i++) {
+  for(U32 i = 0; i < world->npcCount; i++) {
     updateNPC(delta, &world->npcs[i], world);
   }
-} 
+}
 
 void ProcessEvents(SDL_Event *event, World *world) {
   PlayerUpdate(event, &world->player);