Merge pull request #1475 from aws-lumberyard-dev/nvsickle/ViewportInfoDpiScaling

Make IMGUI & viewport info scale with DPI

Code/Editor/RenderViewport.h

@@ -219,6 +219,7 @@ public:
     void SetFullScreenState(bool fullScreenState) override;
     bool CanToggleFullScreenState() const override;
     void ToggleFullScreenState() override;
+    float GetDpiScaleFactor() const override { return 1.0f; };
 
     void ConnectViewportInteractionRequestBus();
     void DisconnectViewportInteractionRequestBus();

Code/Framework/AzFramework/AzFramework/Windowing/NativeWindow.cpp

@@ -116,6 +116,11 @@ namespace AzFramework
         SetFullScreenState(!GetFullScreenState());
     }
 
+    float NativeWindow::GetDpiScaleFactor() const
+    {
+        return m_pimpl->GetDpiScaleFactor();
+    }
+
     /*static*/ bool NativeWindow::GetFullScreenStateOfDefaultWindow()
     {
         NativeWindowHandle defaultWindowHandle = nullptr;
@@ -228,4 +233,10 @@ namespace AzFramework
         return false;
     }
 
+    float NativeWindow::Implementation::GetDpiScaleFactor() const
+    {
+        // For platforms that aren't DPI-aware, we simply return a 1.0 ratio for no scaling
+        return 1.0f;
+    }
+
 } // namespace AzFramework

Code/Framework/AzFramework/AzFramework/Windowing/NativeWindow.h

@@ -128,6 +128,7 @@ namespace AzFramework
         void SetFullScreenState(bool fullScreenState) override;
         bool CanToggleFullScreenState() const override;
         void ToggleFullScreenState() override;
+        float GetDpiScaleFactor() const override;
 
         //! Get the full screen state of the default window.
         //! \return True if the default window is currently in full screen, false otherwise.
@@ -169,6 +170,7 @@ namespace AzFramework
             virtual bool GetFullScreenState() const;
             virtual void SetFullScreenState(bool fullScreenState);
             virtual bool CanToggleFullScreenState() const;
+            virtual float GetDpiScaleFactor() const;
 
         protected:
             uint32_t m_width = 0;

Code/Framework/AzFramework/AzFramework/Windowing/WindowBus.h

@@ -68,6 +68,11 @@ namespace AzFramework
 
         //! Toggle the full screen state of the window.
         virtual void ToggleFullScreenState() = 0;
+
+        //! Returns a scalar multiplier representing how many dots-per-inch this window has, compared
+        //! to a "standard" value of 96, the default for Windows in a DPI unaware setting. This can
+        //! be used to scale user interface elements to ensure legibility on high density displays.
+        virtual float GetDpiScaleFactor() const = 0;
     };
     using WindowRequestBus = AZ::EBus<WindowRequests>;
 
@@ -87,6 +92,9 @@ namespace AzFramework
         //! This is called once when the window is Activated and also called if the user resizes the window.
         virtual void OnWindowResized(uint32_t width, uint32_t height) { AZ_UNUSED(width); AZ_UNUSED(height); };
 
+        //! This is called if the window's underyling DPI scaling factor changes.
+        virtual void OnDpiScaleFactorChanged(float dpiScaleFactor) { AZ_UNUSED(dpiScaleFactor); }
+
         //! This is called when the window is deactivated from code or if the user closes the window.
         virtual void OnWindowClosed() {};
     };

Code/Framework/AzFramework/Platform/Windows/AzFramework/Windowing/NativeWindow_Windows.cpp

@@ -8,6 +8,7 @@
 #include <AzFramework/Input/Buses/Notifications/RawInputNotificationBus_Windows.h>
 #include <AzFramework/Windowing/NativeWindow.h>
 
+#include <AzCore/Module/DynamicModuleHandle.h>
 #include <AzCore/PlatformIncl.h>
 
 namespace AzFramework
@@ -17,7 +18,7 @@ namespace AzFramework
     {
     public:
         AZ_CLASS_ALLOCATOR(NativeWindowImpl_Win32, AZ::SystemAllocator, 0);
-        NativeWindowImpl_Win32() = default;
+        NativeWindowImpl_Win32();
         ~NativeWindowImpl_Win32() override;
 
         // NativeWindow::Implementation overrides...
@@ -33,6 +34,7 @@ namespace AzFramework
         bool GetFullScreenState() const override;
         void SetFullScreenState(bool fullScreenState) override;
         bool CanToggleFullScreenState() const override { return true; }
+        float GetDpiScaleFactor() const override;
 
     private:
         static DWORD ConvertToWin32WindowStyleMask(const WindowStyleMasks& styleMasks);
@@ -49,6 +51,9 @@ namespace AzFramework
         RECT m_windowRectToRestoreOnFullScreenExit; //!< The position and size of the window to restore when exiting full screen.
         UINT m_windowStyleToRestoreOnFullScreenExit; //!< The style(s) of the window to restore when exiting full screen.
         bool m_isInBorderlessWindowFullScreenState = false; //!< Was a borderless window used to enter full screen state?
+
+        using GetDpiForWindowType = UINT(HWND hwnd);
+        GetDpiForWindowType* m_getDpiFunction = nullptr;
     };
 
     const char* NativeWindowImpl_Win32::s_defaultClassName = "O3DEWin32Class";
@@ -58,6 +63,15 @@ namespace AzFramework
         return aznew NativeWindowImpl_Win32();
     }
 
+    NativeWindowImpl_Win32::NativeWindowImpl_Win32()
+    {
+        // Attempt to load GetDpiForWindow from user32 at runtime, available on Windows 10+ versions >= 1607
+        if (auto user32module = AZ::DynamicModuleHandle::Create("user32"); user32module->Load(false))
+        {
+            m_getDpiFunction = user32module->GetFunction<GetDpiForWindowType*>("GetDpiForWindow");
+        }
+    }
+
     NativeWindowImpl_Win32::~NativeWindowImpl_Win32()
     {
         DestroyWindow(m_win32Handle);
@@ -237,6 +251,12 @@ namespace AzFramework
             // Send all other WM_SYSKEYDOWN messages to the default WndProc.
             break;
         }
+        case WM_DPICHANGED:
+        {
+            const float newScaleFactor = nativeWindowImpl->GetDpiScaleFactor();
+            WindowNotificationBus::Event(nativeWindowImpl->GetWindowHandle(), &WindowNotificationBus::Events::OnDpiScaleFactorChanged, newScaleFactor);
+            break;
+        }
         default:
             return DefWindowProc(hWnd, message, wParam, lParam);
             break;
@@ -330,6 +350,17 @@ namespace AzFramework
         }
     }
 
+    float NativeWindowImpl_Win32::GetDpiScaleFactor() const
+    {
+        constexpr UINT defaultDotsPerInch = 96;
+        UINT dotsPerInch = defaultDotsPerInch;
+        if (m_getDpiFunction)
+        {
+            dotsPerInch = m_getDpiFunction(m_win32Handle);
+        }
+        return aznumeric_cast<float>(dotsPerInch) / aznumeric_cast<float>(defaultDotsPerInch);
+    }
+
     void NativeWindowImpl_Win32::EnterBorderlessWindowFullScreen()
     {
         if (m_isInBorderlessWindowFullScreenState)

Code/LauncherUnified/launcher_generator.cmake

@@ -122,6 +122,8 @@ foreach(project_name project_path IN ZIP_LISTS LY_PROJECTS_TARGET_NAME LY_PROJEC
             FOLDER ${project_name}
     )
 
+    # After ensuring that we correctly support DPI scaling, this should be switched to "PerMonitor"
+    set_property(TARGET ${project_name}.GameLauncher APPEND PROPERTY VS_DPI_AWARE "OFF")
     if(LY_DEFAULT_PROJECT_PATH)
         set_property(TARGET ${project_name}.GameLauncher APPEND PROPERTY VS_DEBUGGER_COMMAND_ARGUMENTS "--project-path=\"${LY_DEFAULT_PROJECT_PATH}\"")
     endif()

Gems/Atom/RPI/Code/Include/Atom/RPI.Public/ViewportContext.h

@@ -65,9 +65,15 @@ namespace AZ
             ConstViewPtr GetDefaultView() const;
 
             //! Gets the current size of the viewport.
+            //! This value is cached and updated on-demand, so may be efficiently queried.
             AzFramework::WindowSize GetViewportSize() const;
 
-            // SceneNotificationBus interface
+            //! Gets the screen DPI scaling factor.
+            //! This value is cached and updated on-demand, so may be efficiently queried.
+            //! \see AzFramework::WindowRequests::GetDpiScaleFactor
+            float GetDpiScalingFactor() const;
+
+            // SceneNotificationBus interface overrides...
             //! Ensures our default view remains set when our scene's render pipelines are modified.
             void OnRenderPipelineAdded(RenderPipelinePtr pipeline) override;
             //! Ensures our default view remains set when our scene's render pipelines are modified.
@@ -75,15 +81,22 @@ namespace AZ
             //! OnBeginPrepareRender is forwarded to our RenderTick notification to allow subscribers to do rendering.
             void OnBeginPrepareRender() override;
 
-            //WindowNotificationBus interface
-            //! Used to fire a notification when our window resizes
+            // WindowNotificationBus interface overrides...
+            //! Used to fire a notification when our window resizes.
             void OnWindowResized(uint32_t width, uint32_t height) override;
+            //! Used to fire a notification when our window DPI changes.
+            void OnDpiScaleFactorChanged(float dpiScaleFactor) override;
 
             using SizeChangedEvent = AZ::Event<AzFramework::WindowSize>;
             //! Notifies consumers when the viewport size has changed.
             //! Alternatively, connect to ViewportContextNotificationsBus and listen to ViewportContextNotifications::OnViewportSizeChanged.
             void ConnectSizeChangedHandler(SizeChangedEvent::Handler& handler);
 
+            using ScalarChangedEvent = AZ::Event<float>;
+            //! Notifies consumers when the viewport DPI scaling ratio has changed.
+            //! Alternatively, connect to ViewportContextNotificationsBus and listen to ViewportContextNotifications::OnViewportDpiScalingChanged.
+            void ConnectDpiScalingFactorChangedHandler(ScalarChangedEvent::Handler& handler);
+
             using MatrixChangedEvent = AZ::Event<const AZ::Matrix4x4&>;
             //! Notifies consumers when the view matrix has changed.
             void ConnectViewMatrixChangedHandler(MatrixChangedEvent::Handler& handler);
@@ -106,7 +119,7 @@ namespace AZ
             //! Notifies consumers when this ViewportContext is about to be destroyed.
             void ConnectAboutToBeDestroyedHandler(ViewportIdEvent::Handler& handler);
 
-            // ViewportRequestBus interface
+            // ViewportRequestBus interface overrides...
             //! Gets the current camera's view matrix.
             const AZ::Matrix4x4& GetCameraViewMatrix() const override;
             //! Sets the current camera's view matrix.
@@ -130,8 +143,10 @@ namespace AZ
             WindowContextSharedPtr m_windowContext;
             ViewPtr m_defaultView;
             AzFramework::WindowSize m_viewportSize;
+            float m_viewportDpiScaleFactor = 1.0f;
 
             SizeChangedEvent m_sizeChangedEvent;
+            ScalarChangedEvent m_dpiScalingFactorChangedEvent;
             MatrixChangedEvent m_viewMatrixChangedEvent;
             MatrixChangedEvent::Handler m_onViewMatrixChangedHandler;
             MatrixChangedEvent m_projectionMatrixChangedEvent;

Gems/Atom/RPI/Code/Include/Atom/RPI.Public/ViewportContextBus.h

@@ -105,8 +105,10 @@ namespace AZ
         class ViewportContextNotifications
         {
         public:
-            //! Called when the underlying native window size changes for a given viewport context name.
+            //! Called when the underlying native window size changes for a given viewport context.
             virtual void OnViewportSizeChanged(AzFramework::WindowSize size){AZ_UNUSED(size);}
+            //! Called when the window DPI scaling changes for a given viewport context.
+            virtual void OnViewportDpiScalingChanged(float dpiScale){AZ_UNUSED(dpiScale);}
             //! Called when the active view for a given viewport context name changes.
             virtual void OnViewportDefaultViewChanged(AZ::RPI::ViewPtr view){AZ_UNUSED(view);}
             //! Called when the viewport is to be rendered.

Gems/Atom/RPI/Code/Include/Atom/RPI.Public/ViewportContextManager.h

@@ -51,6 +51,7 @@ namespace AZ
             {
                 AZStd::weak_ptr<ViewportContext> context;
                 ViewportContext::SizeChangedEvent::Handler sizeChangedHandler;
+                ViewportContext::ScalarChangedEvent::Handler dpiScalingChangedHandler;
             };
 
             // ViewportContextManager is a singleton owned solely by RPISystem, which is tagged as a friend

Gems/Atom/RPI/Code/Source/RPI.Public/ViewportContext.cpp

@@ -28,6 +28,10 @@ namespace AZ
                 m_viewportSize,
                 nativeWindow,
                 &AzFramework::WindowRequestBus::Events::GetClientAreaSize);
+            AzFramework::WindowRequestBus::EventResult(
+                m_viewportDpiScaleFactor,
+                nativeWindow,
+                &AzFramework::WindowRequestBus::Events::GetDpiScaleFactor);
             AzFramework::WindowNotificationBus::Handler::BusConnect(nativeWindow);
             AzFramework::ViewportRequestBus::Handler::BusConnect(id);
 
@@ -148,11 +152,21 @@ namespace AZ
             return m_viewportSize;
         }
 
+        float ViewportContext::GetDpiScalingFactor() const
+        {
+            return m_viewportDpiScaleFactor;
+        }
+
         void ViewportContext::ConnectSizeChangedHandler(SizeChangedEvent::Handler& handler)
         {
             handler.Connect(m_sizeChangedEvent);
         }
 
+        void ViewportContext::ConnectDpiScalingFactorChangedHandler(ScalarChangedEvent::Handler& handler)
+        {
+            handler.Connect(m_dpiScalingFactorChangedEvent);
+        }
+
         void ViewportContext::ConnectViewMatrixChangedHandler(MatrixChangedEvent::Handler& handler)
         {
             handler.Connect(m_viewMatrixChangedEvent);
@@ -289,5 +303,11 @@ namespace AZ
                 m_sizeChangedEvent.Signal(m_viewportSize);
             }
         }
+
+        void ViewportContext::OnDpiScaleFactorChanged(float dpiScaleFactor)
+        {
+            m_viewportDpiScaleFactor = dpiScaleFactor;
+            m_dpiScalingFactorChangedEvent.Signal(dpiScaleFactor);
+        }
     } // namespace RPI
 } // namespace AZ

Gems/Atom/RPI/Code/Source/RPI.Public/ViewportContextManager.cpp

@@ -55,16 +55,28 @@ namespace AZ
                 auto onSizeChanged = [this, viewportId](AzFramework::WindowSize size)
                 {
                     // Ensure we emit OnViewportSizeChanged with the correct name.
-                    auto viewportContext = this->GetViewportContextById(viewportId);
+                    auto viewportContext = GetViewportContextById(viewportId);
                     if (viewportContext)
                     {
                         ViewportContextNotificationBus::Event(viewportContext->GetName(), &ViewportContextNotificationBus::Events::OnViewportSizeChanged, size);
                     }
                     ViewportContextIdNotificationBus::Event(viewportId, &ViewportContextIdNotificationBus::Events::OnViewportSizeChanged, size);
                 };
+                auto onDpiScalingChanged = [this, viewportId](float dpiScalingFactor)
+                {
+                    // Ensure we emit OnViewportDpiScalingChanged with the correct name.
+                    auto viewportContext = GetViewportContextById(viewportId);
+                    if (viewportContext)
+                    {
+                        ViewportContextNotificationBus::Event(viewportContext->GetName(), &ViewportContextNotificationBus::Events::OnViewportDpiScalingChanged, dpiScalingFactor);
+                    }
+                    ViewportContextIdNotificationBus::Event(viewportId, &ViewportContextIdNotificationBus::Events::OnViewportDpiScalingChanged, dpiScalingFactor);
+                };
                 viewportContext->m_name = contextName;
                 viewportData.sizeChangedHandler = ViewportContext::SizeChangedEvent::Handler(onSizeChanged);
+                viewportData.dpiScalingChangedHandler = ViewportContext::ScalarChangedEvent::Handler(onDpiScalingChanged);
                 viewportContext->ConnectSizeChangedHandler(viewportData.sizeChangedHandler);
+                viewportContext->ConnectDpiScalingFactorChangedHandler(viewportData.dpiScalingChangedHandler);
                 ViewPtrStack& associatedViews = GetOrCreateViewStackForContext(contextName);
                 viewportContext->SetDefaultView(associatedViews.back());
                 onSizeChanged(viewportContext->GetViewportSize());
@@ -176,6 +188,7 @@ namespace AZ
             UpdateViewForContext(newContextName);
             // Ensure anyone listening on per-name viewport size updates gets notified.
             ViewportContextNotificationBus::Event(newContextName, &ViewportContextNotificationBus::Events::OnViewportSizeChanged, viewportContext->GetViewportSize());
+            ViewportContextNotificationBus::Event(newContextName, &ViewportContextNotificationBus::Events::OnViewportDpiScalingChanged, viewportContext->GetDpiScalingFactor());
         }
 
         void ViewportContextManager::EnumerateViewportContexts(AZStd::function<void(ViewportContextPtr)> visitorFunction)

Gems/Atom/Tools/AtomToolsFramework/Code/Include/AtomToolsFramework/Viewport/RenderViewportWidget.h

@@ -113,6 +113,7 @@ namespace AtomToolsFramework
         void SetFullScreenState(bool fullScreenState) override;
         bool CanToggleFullScreenState() const override;
         void ToggleFullScreenState() override;
+        float GetDpiScaleFactor() const override;
 
     protected:
         // AzFramework::InputChannelEventListener ...

Gems/Atom/Tools/AtomToolsFramework/Code/Source/Viewport/RenderViewportWidget.cpp

@@ -540,4 +540,9 @@ namespace AtomToolsFramework
     {
         // The RenderViewportWidget does not currently support full screen.
     }
+
+    float RenderViewportWidget::GetDpiScaleFactor() const
+    {
+        return aznumeric_cast<float>(devicePixelRatioF());
+    }
 } //namespace AtomToolsFramework

Gems/AtomLyIntegration/AtomViewportDisplayInfo/Code/Source/AtomViewportDisplayInfoSystemComponent.cpp

@@ -155,9 +155,9 @@ namespace AZ::Render
 
         m_drawParams.m_drawViewportId = viewportContext->GetId();
         auto viewportSize = viewportContext->GetViewportSize();
-        m_drawParams.m_position = AZ::Vector3(viewportSize.m_width, 0.0f, 1.0f) + AZ::Vector3(r_topRightBorderPadding);
+        m_drawParams.m_position = AZ::Vector3(viewportSize.m_width, 0.0f, 1.0f) + AZ::Vector3(r_topRightBorderPadding) * viewportContext->GetDpiScalingFactor();
         m_drawParams.m_color = AZ::Colors::White;
-        m_drawParams.m_scale = AZ::Vector2(0.7f);
+        m_drawParams.m_scale = AZ::Vector2(BaseFontSize * viewportContext->GetDpiScalingFactor());
         m_drawParams.m_hAlign = AzFramework::TextHorizontalAlignment::Right;
         m_drawParams.m_monospace = false;
         m_drawParams.m_depthTest = false;

Gems/AtomLyIntegration/AtomViewportDisplayInfo/Code/Source/AtomViewportDisplayInfoSystemComponent.h

@@ -60,6 +60,8 @@ namespace AZ
             void DrawPassInfo();
             void DrawFramerate();
 
+            static constexpr float BaseFontSize = 0.7f;
+
             AZStd::string m_rendererDescription;
             AzFramework::TextDrawParameters m_drawParams;
             AzFramework::FontDrawInterface* m_fontDrawInterface = nullptr;

Gems/AtomLyIntegration/ImguiAtom/Code/Source/ImguiAtomSystemComponent.cpp

@@ -50,7 +50,8 @@ namespace AZ
         {
             ImGui::OtherActiveImGuiRequestBus::Handler::BusConnect();
 
-            auto atomViewportRequests = AZ::Interface<AZ::RPI::ViewportContextRequestsInterface>::Get();
+            auto atomViewportRequests = AZ::RPI::ViewportContextRequests::Get();
+            AZ_Assert(atomViewportRequests, "AtomViewportContextRequests interface not found!");
             const AZ::Name contextName = atomViewportRequests->GetDefaultViewportContextName();
             AZ::RPI::ViewportContextNotificationBus::Handler::BusConnect(contextName);
 
@@ -105,10 +106,20 @@ namespace AZ
                 // Let our ImguiAtomSystemComponent know once we successfully connect and update the viewport size.
                 if (!m_initialized)
                 {
+                    auto atomViewportRequests = AZ::RPI::ViewportContextRequests::Get();
+                    auto defaultViewportContext = atomViewportRequests->GetDefaultViewportContext();
+                    OnViewportDpiScalingChanged(defaultViewportContext->GetDpiScalingFactor());
                     m_initialized = true;
                 }
             });
-#endif
+#endif //define(IMGUI_ENABLED)
+        }
+
+        void ImguiAtomSystemComponent::OnViewportDpiScalingChanged(float dpiScale)
+        {
+#if defined(IMGUI_ENABLED)
+            ImGui::ImGuiManagerBus::Broadcast(&ImGui::ImGuiManagerBus::Events::SetDpiScalingFactor, dpiScale);
+#endif //define(IMGUI_ENABLED)
         }
     }
 }

Gems/AtomLyIntegration/ImguiAtom/Code/Source/ImguiAtomSystemComponent.h

@@ -51,6 +51,7 @@ namespace AZ
             // ViewportContextNotificationBus overrides...
             void OnRenderTick() override;
             void OnViewportSizeChanged(AzFramework::WindowSize size) override;
+            void OnViewportDpiScalingChanged(float dpiScale) override;
 
             DebugConsole m_debugConsole;
             bool m_initialized = false;

Gems/ImGui/Code/Include/ImGuiBus.h

@@ -86,6 +86,8 @@ namespace ImGui
         virtual void SetImGuiRenderResolution(const ImVec2& res) = 0;
         virtual void OverrideRenderWindowSize(uint32_t width, uint32_t height) = 0;
         virtual void RestoreRenderWindowSizeToDefault() = 0;
+        virtual void SetDpiScalingFactor(float dpiScalingFactor) = 0;
+        virtual float GetDpiScalingFactor() const = 0;
         virtual void Render() = 0;
     };
 

Gems/ImGui/Code/Source/ImGuiManager.cpp

@@ -277,6 +277,20 @@ void ImGui::ImGuiManager::RestoreRenderWindowSizeToDefault()
     InitWindowSize();
 }
 
+void ImGui::ImGuiManager::SetDpiScalingFactor(float dpiScalingFactor)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    // Set the global font scale to size our UI to the scaling factor
+    // Note: Currently we use the default, 13px fixed-size IMGUI font, so this can get somewhat blurry
+    io.FontGlobalScale = dpiScalingFactor;
+}
+
+float ImGui::ImGuiManager::GetDpiScalingFactor() const
+{
+    ImGuiIO& io = ImGui::GetIO();
+    return io.FontGlobalScale;
+}
+
 void ImGuiManager::Render()
 {
     if (m_clientMenuBarState == DisplayState::Hidden && m_editorWindowState == DisplayState::Hidden)

Gems/ImGui/Code/Source/ImGuiManager.h

@@ -57,6 +57,8 @@ namespace ImGui
         void SetImGuiRenderResolution(const ImVec2& res) override { m_renderResolution = res; }
         void OverrideRenderWindowSize(uint32_t width, uint32_t height) override;
         void RestoreRenderWindowSizeToDefault() override;
+        void SetDpiScalingFactor(float dpiScalingFactor) override;
+        float GetDpiScalingFactor() const override;
         void Render() override;
         // -- ImGuiManagerBus Interface -------------------------------------------------------------------
 
@@ -82,7 +84,7 @@ namespace ImGui
         DisplayState m_editorWindowState = DisplayState::Hidden;
 
         // ImGui Resolution Settings
-        ImGuiResolutionMode m_resolutionMode = ImGuiResolutionMode::MatchToMaxRenderResolution;
+        ImGuiResolutionMode m_resolutionMode = ImGuiResolutionMode::MatchRenderResolution;
         ImVec2 m_renderResolution = ImVec2(1920.0f, 1080.0f);
         ImVec2 m_lastRenderResolution;
         AzFramework::WindowSize m_windowSize = AzFramework::WindowSize(1920, 1080);

Tools/LyTestTools/ly_test_tools/log/log_monitor.py

@@ -133,7 +133,7 @@ class LogMonitor(object):
         except AssertionError:  # Raised by waiter when timeout is reached.
             logger.warning(f"Timeout of '{timeout}' seconds was reached, log lines may not have been found")
             # exception will be raised below by _validate_results with failure analysis
-
+        finally:
             logger.info("Python log output:\n" + self.py_log)
             logger.info(
                 "Finished log monitoring for '{}' seconds, validating results.\n"
@@ -265,12 +265,21 @@ class LogMonitor(object):
             self.unexpected_lines_found = unexpected_lines_found
             self.expected_lines_not_found = expected_lines_not_found
 
+        exception_info = None
+
         # To avoid race conditions, we will check *before reading*
         # If in the mean time the file is closed, we will make sure we read everything by issuing an extra call
         # by returning the previous alive state
         process_runing = self.launcher.is_alive() 
         for line in log:
             line = line[:-1]  # remove /n
+            try:
                 process_line(line)
+            except LogMonitorException as e:
+                if exception_info is None:
+                    exception_info = e.args
+
+        if exception_info is not None:
+            raise LogMonitorException(*exception_info)
 
         return not process_runing  # Will loop until the process ends