add pausing and stepping

Editor/src/Editor/EditorLayer.cpp

@@ -42,7 +42,9 @@ namespace Hazel
     	m_CheckerBoardTexture = Texture2D::Create("assets/textures/Checkerboard.png");
 
     	m_IconPlay = Texture2D::Create("Resources/Icons/PlayButton.png");
-    	m_IconStop = Texture2D::Create("Resources/Icons/PauseButton.png");
+    	m_IconPause = Texture2D::Create("Resources/Icons/PauseButton.png");
+    	m_IconStep = Texture2D::Create("Resources/Icons/StepButton.png");
+    	m_IconStop = Texture2D::Create("Resources/Icons/StopButton.png");
     	m_IconSimulate = Texture2D::Create("Resources/Icons/SimulateButton.png");
 
     	m_EditorScene = CreateRef<Scene>();
@@ -76,12 +78,13 @@ namespace Hazel
     	// reset Renderer Draw Stats
     	Renderer2D::ResetStats();
 
+		m_ActiveScene->OnViewportResize((uint32_t)m_ViewPortSize.x, (uint32_t)m_ViewPortSize.y);
+
     	if (const auto& spec = m_FrameBuffer->GetSpecification();
     		spec.Width != m_ViewPortSize.x || spec.Height != m_ViewPortSize.y)
     	{
 		    m_FrameBuffer->Resize((uint32_t)m_ViewPortSize.x, (uint32_t)m_ViewPortSize.y);
 		    m_CameraController.OnResize(m_ViewPortSize.x, m_ViewPortSize.y);
-
     		m_EditorCamera.SetViewPortSize(m_ViewPortSize.x, m_ViewPortSize.y);
 	    }
 
@@ -594,6 +597,10 @@ namespace Hazel
     	m_SceneHierachyPanel.SetContext(m_ActiveScene);
     }
 
+    void EditorLayer::OnScenePause()
+    {
+    }
+
     void EditorLayer::OnSceneSimulation()
     {
     	if (m_SceneState == SceneState::Simulate)
@@ -684,6 +691,12 @@ namespace Hazel
     	ImGui::SetCursorPosX(ImGui::GetWindowContentRegionMax().x * 0.5f - size * 0.5f);
     	ImGui::SetCursorPosX(ImGui::GetWindowContentRegionMax().x * 0.5f - (size * 0.5f));
 
+    	bool hasPlayButton = m_SceneState == SceneState::Play || m_SceneState == SceneState::Edit;
+    	bool hasSimulateButton = m_SceneState == SceneState::Simulate || m_SceneState == SceneState::Edit;
+    	bool hasPauseButton = m_SceneState != SceneState::Edit;
+
+    	if (hasPlayButton)
+    	{
 			Ref<Texture2D> icon = (m_SceneState == SceneState::Edit || m_SceneState == SceneState::Simulate)? m_IconPlay : m_IconStop;
 			if (ImGui::ImageButton("toolbar-play-edit", icon->GetRendererID(), ImVec2{size, size}, ImVec2{0, 0}, ImVec2{1, 1}))
 			{
@@ -692,9 +705,13 @@ namespace Hazel
 				else if (m_SceneState == SceneState::Play)
 					OnSceneStop();
 			}
+    	}
 
-    	ImGui::SameLine();
+    	if (hasSimulateButton)
 	    {
+    		if (hasPlayButton)
+    			ImGui::SameLine();
+
 		    Ref<Texture2D> icon = (m_SceneState == SceneState::Edit || m_SceneState == SceneState::Play)? m_IconSimulate : m_IconStop;
 		    if (ImGui::ImageButton("toolbar-simulate", icon->GetRendererID(), ImVec2{size, size}, ImVec2{0, 0}, ImVec2{1, 1}))
 		    {
@@ -705,6 +722,32 @@ namespace Hazel
 		    }
 	    }
 
+    	if (hasPauseButton)
+    	{
+    		bool isPaused = m_ActiveScene->IsPaused();
+    		ImGui::SameLine();
+    		{
+    			Ref<Texture2D> icon = m_IconPause;
+    			if (ImGui::ImageButton("toolbar-pause", icon->GetRendererID(), ImVec2{size, size}, ImVec2{0, 0}, ImVec2{1, 1}))
+    			{
+    				m_ActiveScene->SetPaused(!isPaused);
+    			}
+    		}
+
+    		if (isPaused)
+    		{
+    			ImGui::SameLine();
+    			{
+    				Ref<Texture2D> icon = m_IconStep;
+    				if (ImGui::ImageButton("toolbar-step", icon->GetRendererID(), ImVec2{size, size}, ImVec2{0, 0}, ImVec2{1, 1}))
+    				{
+    					m_ActiveScene->Step();
+    				}
+
+    			}
+    		}
+    	}
+
     	ImGui::PopStyleVar(2);
     	ImGui::PopStyleColor(3);
 		ImGui::End();

Editor/src/Editor/EditorLayer.h

@@ -29,6 +29,7 @@ namespace Hazel
         void OnScenePlay();
         void OnSceneSimulation();
         void OnSceneStop();
+        void OnScenePause();
 
 
         void SaveSceneAs() const;
@@ -84,7 +85,7 @@ namespace Hazel
 
         SceneState m_SceneState = SceneState::Edit;
 
-        Ref<Texture2D> m_IconPlay, m_IconStop, m_IconSimulate;
+        Ref<Texture2D> m_IconPlay, m_IconPause, m_IconStep, m_IconStop, m_IconSimulate;
     };
 }
 

Hazel/src/Hazel/Scene/Scene.cpp

@@ -143,6 +143,11 @@ namespace Hazel
     }
 
 
+    void Scene::Step(const int frames)
+    {
+        m_StepFrame = frames;
+    }
+
     void Scene::OnPhysics2DStart()
     {
         b2WorldDef worldDef = b2DefaultWorldDef();
@@ -284,6 +289,8 @@ namespace Hazel
     }
 
     void Scene::OnUpdateRuntime(TimeStep& ts)
+    {
+        if (!m_IsPaused || m_StepFrame-- > 0)
         {
             // Update scripts
             {
@@ -330,6 +337,7 @@ namespace Hazel
                     transform.Rotation.z    = angle;
                 }
             }
+        }
 
         // Renderer 2D
         Camera*   mainCamera = nullptr;
@@ -379,6 +387,8 @@ namespace Hazel
     }
 
     void Scene::OnUpdateSimulation(TimeStep& ts, const EditorCamera& camera)
+    {
+        if (!m_IsPaused || m_StepFrame-- > 0)
         {
             // Physics
             {
@@ -400,6 +410,7 @@ namespace Hazel
                     transform.Rotation.z    = angle;
                 }
             }
+        }
 
         // Render
         RenderScene(camera);

Hazel/src/Hazel/Scene/Scene.h

@@ -49,6 +49,10 @@ namespace Hazel
         Entity GetEntityByUUID(UUID uuid);
 
         bool IsRunning() const {return m_IsRunning; }
+        bool IsPaused() const {return m_IsPaused; }
+
+        void SetPaused(const bool pause) {m_IsPaused = pause; }
+        void Step(int frames = 1);
 
         template<typename... Components>
         auto GetAllEntitiesWith()
@@ -73,6 +77,8 @@ namespace Hazel
         b2WorldId* m_PhysicsWorld = nullptr;
 
         bool m_IsRunning = false;
+        bool m_IsPaused = false;
+        int m_StepFrame = 0;
 
         std::unordered_map<UUID, entt::entity> m_EnttMap;