Started refactoring. Put player walk logic in a designated sound system.

src/Game/Systems/SoundSystem.cpp

@@ -0,0 +1,73 @@
+#include "Game/Systems/SoundSystem.h"
+
+SoundSystem::SoundSystem(World* world, EventBroker* eventbroker)
+    : System(world, eventbroker)
+    , PureSystem("SoundEmitter")
+    , ImpureSystem()
+    , SoundManager(world, eventbroker, true)
+{
+    m_World = world;
+    m_EventBroker = eventbroker;
+    EVENT_SUBSCRIBE_MEMBER(m_EPlayerSpawned, &SoundSystem::OnPlayerSpawned);
+}
+
+void SoundSystem::UpdateComponent(EntityWrapper& entity, ComponentWrapper& cComponent, double dt)
+{
+    
+}
+
+void SoundSystem::Update(double dt)
+{
+    SoundManager::Update(dt);
+    playerStep(dt);
+}
+
+void SoundSystem::playerStep(double dt)
+{
+    if (!m_LocalPlayer.Valid()) {
+        return;
+    }
+    if (m_LocalPlayer.ID == EntityID_Invalid) {
+        return;
+    }
+
+    m_TimeSinceLastFootstep += dt;
+    glm::vec3 vel = (glm::vec3)m_World->GetComponent(m_LocalPlayer.ID, "Physics")["Velocity"];
+    float playerSpeed = glm::length(vel);
+    bool isAirborne = vel.y != 0;
+    if (playerSpeed > 1 && !isAirborne) {
+        // Player is walking
+        if (m_TimeSinceLastFootstep * std::min<float>(playerSpeed, 2) > m_PlayerFootstepInterval) {
+            // Create footstep sound
+            Events::PlaySoundOnEntity e;
+            e.EmitterID = createChildEmitter();
+            if (m_LeftFoot) {
+                e.FilePath = "Audio/footstep/footstep2.wav";
+            } else {
+                e.FilePath = "Audio/footstep/footstep3.wav";
+            }
+            m_LeftFoot = !m_LeftFoot;
+            m_EventBroker->Publish(e);
+            m_TimeSinceLastFootstep = 0;
+        }
+    }
+}
+
+bool SoundSystem::OnPlayerSpawned(const Events::PlayerSpawned &e)
+{
+    if (e.PlayerID == -1) { // Local player
+        m_World->AttachComponent(e.Player.ID, "Listener");
+        m_LocalPlayer = e.Player;
+        Events::PlaySoundOnEntity event;
+        event.EmitterID = createChildEmitter();
+        event.FilePath = "Audio/announcer/go.wav";
+        m_EventBroker->Publish(event);
+        // TEMP: starts bgm
+//         {
+//             Events::PlayBackgroundMusic ev;
+//             ev.FilePath = "Audio/bgm/ambient.wav";
+//             m_EventBroker->Publish(ev);
+//         }
+    }
+    return true;
+}