CMake improvements for DLL version compilation; Wrapped ImGui::GetCurrentWindow() in GetCurrentWindowImpl() as a hack fix for DLL version usage; Changed singleton definition macros to make the singleton better suited for DLL usage; Introduced a new way to define an easy-to-access macro for singletons that is DLL-friendly.

Author: Azzinoth

CMakeLists.txt

@@ -7,6 +7,11 @@ set(CMAKE_CONFIGURATION_TYPES Debug Release)
 # set the project name
 project(VisualNodeSystem LANGUAGES CXX)
 
+option(VISUAL_NODE_SYSTEM_USE_EXTERNAL_IMGUI "Use an external ImGui library instead of compiling our own" OFF)
+option(VISUAL_NODE_SYSTEM_BUILD_SHARED_LIBS "Build VisualNodeSystem as a shared library" OFF)
+option(VISUAL_NODE_SYSTEM_USE_STATIC_RUNTIME "Use static runtime (/MT) instead of dynamic (/MD) for VisualNodeSystem" ON)
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
 # Turn on the ability to create folders to organize projects (.vcproj)
 # It creates "CMakePredefinedTargets" folder by default and adds CMake
 # defined projects like INSTALL.vcproj and ZERO_CHECK.vcproj
@@ -33,6 +38,7 @@ file(GLOB VisualNodeSystem_SRC
 	"VisualNodeSocket.h"
 	"VisualNodeCore.cpp"
 	"VisualNodeCore.h"
+	"VisualNodeSystemAPI.h"
 )
 
 # *************** THIRD_PARTY ***************
@@ -47,13 +53,29 @@ file(GLOB jsoncpp_SRC
 
 # *************** THIRD_PARTY END ***************
 
-add_library(VisualNodeSystem
-			${VisualNodeSystem_SRC}
+set(ALL_SOURCE_FILES "")
+list(APPEND ALL_SOURCE_FILES
+            ${VisualNodeSystem_SRC}
 			${VisualNodeArea_SRC}
 			# *************** THIRD_PARTY ***************
 			${jsoncpp_SRC}
 )
 
+if(VISUAL_NODE_SYSTEM_BUILD_SHARED_LIBS)
+    add_library(VisualNodeSystem SHARED ${ALL_SOURCE_FILES})   
+    target_compile_definitions(VisualNodeSystem PRIVATE VISUAL_NODE_SYSTEM_EXPORTS)
+    target_compile_definitions(VisualNodeSystem PUBLIC VISUAL_NODE_SYSTEM_SHARED)
+
+	# Some times /GL conflicts with WINDOWS_EXPORT_ALL_SYMBOLS
+	set_target_properties(VisualNodeSystem PROPERTIES COMPILE_OPTIONS "/GL-")
+	set_target_properties(VisualNodeSystem PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS ON)
+
+	# Disable C4251 warning
+	target_compile_options(VisualNodeSystem PRIVATE /wd4251)
+else()
+    add_library(VisualNodeSystem STATIC ${ALL_SOURCE_FILES})
+endif()
+
 source_group("Source Files" FILES ${VisualNodeSystem_SRC})
 source_group("Source Files/SubSystems/VisualNodeArea/" FILES ${VisualNodeArea_SRC})
 # *************** THIRD_PARTY ***************
@@ -67,6 +89,31 @@ set_property(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT V
 # Promt to give Dear ImGui path
 set(DEAR_IMGUI_INCLUDE_DIR "" CACHE PATH "Path to Dear ImGui directory.")
 
+if(VISUAL_NODE_SYSTEM_BUILD_SHARED_LIBS)
+	if(VISUAL_NODE_SYSTEM_USE_EXTERNAL_IMGUI)
+		# Use external ImGui library
+		set(EXTERNAL_IMGUI_LIBRARY "" CACHE FILEPATH "Path to external ImGui library")
+		if(NOT EXTERNAL_IMGUI_LIBRARY)
+			message(FATAL_ERROR "EXTERNAL_IMGUI_LIBRARY must be set when VISUAL_NODE_SYSTEM_USE_EXTERNAL_IMGUI is ON")
+		endif()
+		target_link_libraries(VisualNodeSystem PRIVATE ${EXTERNAL_IMGUI_LIBRARY})
+	else()
+		# If we are building .dll we would need GLFW information.
+		set(VISUAL_NODE_SYSTEM_GLFW_INCLUDE_DIR "" CACHE PATH "Path to GLFW include directory.")
+		target_include_directories(VisualNodeSystem PRIVATE ${VISUAL_NODE_SYSTEM_GLFW_INCLUDE_DIR})
+		set(VISUAL_NODE_SYSTEM_GLFW_LIBRARY "" CACHE PATH "Path to GLFW library.")
+		target_link_libraries(VisualNodeSystem PRIVATE ${VISUAL_NODE_SYSTEM_GLFW_LIBRARY})
+
+		# Add Dear ImGui source files
+		file(GLOB IMGUI_SOURCES
+			"${DEAR_IMGUI_INCLUDE_DIR}/*.cpp"
+			"${DEAR_IMGUI_INCLUDE_DIR}/*.h"
+		)
+		target_sources(VisualNodeSystem PRIVATE ${IMGUI_SOURCES})
+		source_group("Source Files/ThirdParty/ImGui" FILES ${IMGUI_SOURCES})
+	endif()
+endif()
+
 include_directories(
 	${DEAR_IMGUI_INCLUDE_DIR}
 	${VISUAL_NODE_SYSTEM_THIRDPARTY_DIR}

GroupComment.h

@@ -7,7 +7,7 @@ namespace VisNodeSys
 #define GROUP_COMMENT_CAPTION_MAX_LENGHT 1024
 #define GROUP_COMMENT_TITLE_HEIGHT 30.0f
 
-	class GroupComment
+	class VISUAL_NODE_SYSTEM_API GroupComment
 	{
 	protected:
 		friend class NodeSystem;

SubSystems/VisualNodeArea/VisualNodeArea.cpp

@@ -641,17 +641,17 @@ std::vector<ConnectionSegment> NodeArea::GetConnectionSegments(const Connection*
 ImVec2 NodeArea::LocalToScreen(ImVec2 LocalPosition) const
 {
 	ImVec2 WindowPosition = ImVec2(0.0f, 0.0f);
-	if (ImGui::GetCurrentContext() != nullptr && ImGui::GetCurrentContext()->CurrentWindow != nullptr)
-		WindowPosition = ImGui::GetCurrentWindow()->Pos;
+	if (GetCurrentWindowImpl() != nullptr)
+		WindowPosition = GetCurrentWindowImpl()->Pos;
 
 	return WindowPosition + LocalPosition * Zoom + RenderOffset;
 }
 
 ImVec2 NodeArea::ScreenToLocal(ImVec2 ScreenPosition) const
 {
 	ImVec2 WindowPosition = ImVec2(0.0f, 0.0f);
-	if (ImGui::GetCurrentContext() != nullptr && ImGui::GetCurrentContext()->CurrentWindow != nullptr)
-		WindowPosition = ImGui::GetCurrentWindow()->Pos;
+	if (GetCurrentWindowImpl() != nullptr)
+		WindowPosition = GetCurrentWindowImpl()->Pos;
 
 	return (ScreenPosition - WindowPosition - RenderOffset) / Zoom;
 }
@@ -700,4 +700,13 @@ bool NodeArea::IsSecondRectInsideFirstOne(ImVec2 FirstRectMin, ImVec2 FirstRectS
 	}
 
 	return false;
+}
+
+ImGuiWindow* NodeArea::GetCurrentWindowImpl() const
+{
+	ImGuiContext* Context = ImGui::GetCurrentContext();
+	if (Context == nullptr)
+		return nullptr;
+
+	return Context->CurrentWindow;
 }

SubSystems/VisualNodeArea/VisualNodeArea.h

@@ -64,7 +64,7 @@ namespace VisNodeSys
 		bool bReduceTransparencyForUnconnectableSockets = true;
 	};
 
-	class NodeArea
+	class VISUAL_NODE_SYSTEM_API NodeArea
 	{
 		friend NodeSystem;
 	public:
@@ -336,5 +336,8 @@ namespace VisNodeSys
 
 		ImVec2 ScreenToLocal(ImVec2 ScreenPosition) const;
 		ImVec2 LocalToScreen(ImVec2 LocalPosition) const;
+
+		// TO DO: Here I am using internal ImGui functions. Need to find a way to avoid it.
+		ImGuiWindow* GetCurrentWindowImpl() const;
 	};
 }

SubSystems/VisualNodeArea/VisualNodeAreaRendering.cpp

@@ -288,18 +288,18 @@ void NodeArea::Render()
 	ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, 0));
 	ImGui::PushStyleColor(ImGuiCol_ChildBg, Settings.Style.Grid.GridBackgroundColor);
 
-	const ImVec2 CurrentPosition = ImGui::GetCurrentWindow()->Pos + Position;
+	const ImVec2 CurrentPosition = GetCurrentWindowImpl()->Pos + Position;
 	ImGui::SetNextWindowPos(CurrentPosition);
 
 	if (bFillWindow)
 	{
-		auto NodeAreaParentWindow = ImGui::GetCurrentWindow();
+		auto NodeAreaParentWindow = GetCurrentWindowImpl();
 		SetSize(NodeAreaParentWindow->Size - ImVec2(2, 2));
 	}
 
 	ImGui::BeginChild("Nodes area", GetSize(), true, ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoMove);
 
-	NodeAreaWindow = ImGui::GetCurrentWindow();
+	NodeAreaWindow = GetCurrentWindowImpl();
 	CurrentDrawList = ImGui::GetWindowDrawList();
 
 	RenderGrid(CurrentPosition);
@@ -701,7 +701,7 @@ ImVec2 NodeArea::GetRenderedViewCenter() const
 	}
 	else
 	{
-		return (ImGui::GetCurrentWindow()->Size / 2.0f - RenderOffset) / Zoom;
+		return (GetCurrentWindowImpl()->Size / 2.0f - RenderOffset) / Zoom;
 	}
 }
 
@@ -851,7 +851,7 @@ void NodeArea::RenderGroupComment(GroupComment* GroupComment)
 	if (!GroupComment->bLastFrameRenameEditWasVisiable)
 	{
 		ImGui::SetKeyboardFocusHere(0);
-		ImGui::SetFocusID(ImGui::GetID("##newCommentEditor"), ImGui::GetCurrentWindow());
+		ImGui::SetFocusID(ImGui::GetID("##newCommentEditor"), GetCurrentWindowImpl());
 		ImGui::SetItemDefaultFocus();
 		GroupComment->bLastFrameRenameEditWasVisiable = true;
 
@@ -864,7 +864,7 @@ void NodeArea::RenderGroupComment(GroupComment* GroupComment)
 		ImGui::SetCursorScreenPos(CaptionPosition + TextOffset);
 		ImGui::SetNextItemWidth(GroupComment->GetSize().x * Zoom - TextOffset.x * 4.0f);
 		if (ImGui::InputText("##newCommentEditor", GroupComment->GroupCommentRename, IM_ARRAYSIZE(GroupComment->GroupCommentRename), ImGuiInputTextFlags_EnterReturnsTrue) ||
-			ImGui::IsMouseClicked(0) && !ImGui::IsItemHovered() || ImGui::GetFocusID() != ImGui::GetID("##newCommentEditor"))
+			ImGui::IsMouseClicked(0) && !ImGui::IsItemHovered() || !ImGui::IsItemFocused())
 		{
 			GroupComment->bIsRenamingActive = false;
 			GroupComment->SetCaption(GroupComment->GroupCommentRename);

VisualNode.h

@@ -23,7 +23,7 @@ namespace VisNodeSys
 		EXECUTE = 4
 	};
 
-	class Node
+	class VISUAL_NODE_SYSTEM_API Node
 	{
 	protected:
 		friend class NodeSystem;

VisualNodeCore.cpp

@@ -1,7 +1,12 @@
 #include "VisualNodeCore.h"
 using namespace VisNodeSys;
 
-NodeCore* NodeCore::Instance = nullptr;
+#ifdef VISUAL_NODE_SYSTEM_SHARED
+extern "C" __declspec(dllexport) void* GetNodeCore()
+{
+	return NodeCore::GetInstancePointer();
+}
+#endif
 
 NodeCore::NodeCore() {}
 NodeCore::~NodeCore() {}

VisualNodeCore.h

@@ -27,38 +27,46 @@
 
 #include "jsoncpp/json/json.h"
 
+#include "VisualNodeSystemAPI.h"
+
 namespace VisNodeSys
 {
-#define SINGLETON_PUBLIC_PART(CLASS_NAME)  \
-static CLASS_NAME& getInstance()           \
-{										   \
-	if (!Instance)                         \
-		Instance = new CLASS_NAME();       \
-	return *Instance;				       \
-}                                          \
-										   \
-~CLASS_NAME();
 
-#define SINGLETON_PRIVATE_PART(CLASS_NAME) \
-static CLASS_NAME* Instance;               \
-CLASS_NAME();                              \
-CLASS_NAME(const CLASS_NAME &);            \
-void operator= (const CLASS_NAME &);
+#define SINGLETON_PUBLIC_PART(CLASS_NAME)		\
+    static CLASS_NAME& GetInstance()			\
+    {											\
+		static CLASS_NAME* Instance = nullptr;	\
+        if (!Instance)							\
+            Instance = new CLASS_NAME();		\
+        return *Instance;						\
+    }											\
+												\
+	static CLASS_NAME* GetInstancePointer()		\
+	{											\
+		return &GetInstance();					\
+	}
+
+#define SINGLETON_PRIVATE_PART(CLASS_NAME)	\
+    CLASS_NAME();							\
+	~CLASS_NAME();							\
+    CLASS_NAME(const CLASS_NAME &);			\
+    void operator= (const CLASS_NAME &);
+
 
 #define FE_MAP_TO_STR_VECTOR(map)          \
-std::vector<std::string> result;           \
-auto iterator = map.begin();               \
-while (iterator != map.end())              \
-{                                          \
-	result.push_back(iterator->first);     \
-	iterator++;                            \
-}                                          \
-                                           \
-return result;
+	std::vector<std::string> result;       \
+	auto iterator = map.begin();           \
+	while (iterator != map.end())          \
+	{                                      \
+		result.push_back(iterator->first); \
+		iterator++;                        \
+	}                                      \
+										   \
+	return result;
 
 #define VISUAL_NODE_SYSTEM_VERSION "0.1.0"
 
-	class NodeCore
+	class VISUAL_NODE_SYSTEM_API NodeCore
 	{
 		SINGLETON_PRIVATE_PART(NodeCore)
 
@@ -93,5 +101,10 @@ return result;
 		std::string Base64Decode(std::string const& EncodedString);
 	};
 
-#define NODE_CORE VisNodeSys::NodeCore::getInstance()
+#ifdef VISUAL_NODE_SYSTEM_SHARED
+	extern "C" __declspec(dllexport) void* GetNodeCore();
+	#define NODE_CORE (*static_cast<VisNodeSys::NodeCore*>(VisNodeSys::GetNodeCore()))
+#else
+	#define NODE_CORE VisNodeSys::NodeCore::GetInstance()
+#endif
 }

VisualNodeFactory.cpp

@@ -1,7 +1,12 @@
 #include "VisualNodeFactory.h"
 using namespace VisNodeSys;
 
-NodeFactory* NodeFactory::Instance = nullptr;
+#ifdef VISUAL_NODE_SYSTEM_SHARED
+extern "C" __declspec(dllexport) void* GetNodeFactory()
+{
+    return NodeFactory::GetInstancePointer();
+}
+#endif
 
 NodeFactory::NodeFactory() {}
 NodeFactory::~NodeFactory() {}

VisualNodeFactory.h

@@ -4,7 +4,7 @@
 
 namespace VisNodeSys
 {
-    class NodeFactory
+    class VISUAL_NODE_SYSTEM_API NodeFactory
     {
         SINGLETON_PRIVATE_PART(NodeFactory)
 
@@ -19,5 +19,10 @@ namespace VisNodeSys
         Node* CopyNode(const std::string& Type, const Node& Node) const;
     };
 
-#define NODE_FACTORY VisNodeSys::NodeFactory::getInstance()
+#ifdef VISUAL_NODE_SYSTEM_SHARED
+    extern "C" __declspec(dllexport) void* GetNodeFactory();
+    #define NODE_FACTORY (*static_cast<VisNodeSys::NodeFactory*>(VisNodeSys::GetNodeFactory()))
+#else
+    #define NODE_FACTORY VisNodeSys::NodeFactory::GetInstance()
+#endif
 }