"Basic" entity component system. Almost.

Escape-the-Dawn/Component.h

@@ -0,0 +1,14 @@
+#ifndef Component_h__
+#define Component_h__
+
+#include <memory>
+
+#include "Entity.h"
+#include "ComponentFactory.h"
+
+struct Component
+{
+	EntityID Entity;
+};
+
+#endif // Component_h__

Escape-the-Dawn/ComponentFactory.h

@@ -0,0 +1,50 @@
+#ifndef ComponentFactory_h__
+#define ComponentFactory_h__
+
+#include <string>
+#include <functional>
+#include <map>
+
+#include "Component.h"
+
+#define REGISTER_COMPONENT(NAME, TYPE) \
+	static ComponentRegistrar<TYPE> registrar(NAME);
+
+template<class T>
+class ComponentRegistrar
+{
+public:
+	ComponentRegistrar(std::string name)
+	{
+		ComponentFactory::Instance()->Register(name, [](void) -> std::shared_ptr<Component> { return new T() });
+	}
+};
+
+class ComponentFactory
+{
+public:
+	static ComponentFactory* Instance()
+	{
+		static ComponentFactory factory;
+		return &factory;
+	}
+
+	void Register(std::string name, std::function<std::shared_ptr<Component>(void)> factoryFunction)
+	{
+		m_FactoryFunctions[name] = factoryFunction;
+	}
+
+	std::shared_ptr<Component> Create(std::string name)
+	{
+		auto it = m_FactoryFunctions.find(name);
+		if (it != m_FactoryFunctions.end())
+			return it->second();
+		else
+			return nullptr;
+	}
+
+private:
+	std::map<std::string, std::function<std::shared_ptr<Component>(void)>> m_FactoryFunctions;
+};
+
+#endif // ComponentFactory_h__

Escape-the-Dawn/Components/Transform.h

@@ -0,0 +1,13 @@
+#include "Component.h"
+
+namespace Components
+{
+
+REGISTER_COMPONENT("Transform", Transform);
+struct Transform : Component
+{
+	float Position[3];
+};
+
+}
+

Escape-the-Dawn/Entity.h

@@ -0,0 +1 @@
+typedef unsigned int EntityID;

Escape-the-Dawn/Escape-the-Dawn.vcxproj

@@ -39,7 +39,7 @@
   </ImportGroup>
   <PropertyGroup Label="UserMacros" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
-    <IncludePath>$(SolutionDir)\Libraries;$(SolutionDir)\Libraries\glew-1.10.0\include;$(SolutionDir)\Libraries\glfw-3.0.4\include;$(SolutionDir)\Libraries\glm-0.9.5.2;$(IncludePath)</IncludePath>
+    <IncludePath>$(ProjectDir);$(SolutionDir)\Libraries;$(SolutionDir)\Libraries\glew-1.10.0\include;$(SolutionDir)\Libraries\glfw-3.0.4\include;$(SolutionDir)\Libraries\glm-0.9.5.2;$(IncludePath)</IncludePath>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <LibraryPath>$(SolutionDir)\Libraries\glew-1.10.0\lib\Debug\Win32;$(SolutionDir)\Libraries\glfw-3.0.4\lib\Debug;$(LibraryPath)</LibraryPath>
@@ -48,7 +48,7 @@
     <TargetName>$(ProjectName)-$(Configuration)</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
-    <IncludePath>$(SolutionDir)\Libraries;$(SolutionDir)\Libraries\glew-1.10.0\include;$(SolutionDir)\Libraries\glfw-3.0.4\include;$(SolutionDir)\Libraries\glm-0.9.5.2;$(IncludePath)</IncludePath>
+    <IncludePath>$(ProjectDir);$(SolutionDir)\Libraries;$(SolutionDir)\Libraries\glew-1.10.0\include;$(SolutionDir)\Libraries\glfw-3.0.4\include;$(SolutionDir)\Libraries\glm-0.9.5.2;$(IncludePath)</IncludePath>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LibraryPath>$(SolutionDir)\Libraries\glew-1.10.0\lib\Release\Win32;$(SolutionDir)\Libraries\glfw-3.0.4\lib\Release;$(LibraryPath)</LibraryPath>
@@ -90,8 +90,13 @@
     <ClCompile Include="main.cpp" />
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="Component.h" />
+    <ClInclude Include="ComponentFactory.h" />
+    <ClInclude Include="Components\Transform.h" />
+    <ClInclude Include="Entity.h" />
     <ClInclude Include="logging.h" />
     <ClInclude Include="glerror.h" />
+    <ClInclude Include="World.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

Escape-the-Dawn/Escape-the-Dawn.vcxproj.filters

@@ -13,6 +13,9 @@
       <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
       <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
     </Filter>
+    <Filter Include="Header Files\Components">
+      <UniqueIdentifier>{9af04489-86da-41b7-aaba-12d5b6653660}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="main.cpp">
@@ -26,5 +29,20 @@
     <ClInclude Include="logging.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="World.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="Component.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="Entity.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="Components\Transform.h">
+      <Filter>Header Files\Components</Filter>
+    </ClInclude>
+    <ClInclude Include="ComponentFactory.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

Escape-the-Dawn/World.h

@@ -0,0 +1,81 @@
+#include <stack>
+#include <unordered_map>
+#include <vector>
+#include <string>
+
+#include "Entity.h"
+#include "Component.h"
+#include "Components/Transform.h"
+
+class World
+{
+public:
+	World()
+	{
+		m_LastEntityID = 0;
+	}
+
+	EntityID CreateEntity(EntityID parent = 0)
+	{
+		EntityID newEntity = GenerateEntityID();
+		m_SceneGraph.insert(std::pair<EntityID, EntityID>(newEntity, parent));
+		return newEntity;
+	}
+
+	void RemoveEntity(EntityID entity)
+	{
+		m_SceneGraph.erase(entity);
+		RecycleEntityID(entity);
+	}
+
+	bool ValidEntity(EntityID entity)
+	{
+		return m_SceneGraph.find(entity) != m_SceneGraph.end();
+	}
+
+	EntityID GetEntityParent(EntityID entity)
+	{
+		auto it = m_SceneGraph.find(entity);
+		return it == m_SceneGraph.end() ? 0 : it->second;
+	}
+
+	std::shared_ptr<Component> AddComponent(EntityID entity, std::string componentType)
+	{
+		std::shared_ptr<Component> component = ComponentFactory::Instance()->Create(componentType);
+		m_ComponentsOfType[componentType].push_back(component);
+		m_EntityComponents[entity][componentType] = component;
+	}
+
+	/*std::vector<EntityID> GetEntityChildren(EntityID entity)
+	{
+		std::vector<EntityID> children;
+		auto range = m_SceneGraph.equal_range(entity);
+		for (auto it = range.first; it != range.second; ++it)
+			children.push_back(it->second);
+		return children;
+	}*/
+
+private:
+	EntityID m_LastEntityID;
+	std::stack<EntityID> m_RecycledEntityIDs;
+	// A map of child entities to parent entities
+	std::unordered_map<EntityID, EntityID> m_SceneGraph; 
+	std::unordered_map<std::string, std::vector<std::shared_ptr<Component>>> m_ComponentsOfType;
+	std::unordered_map<EntityID, std::map<std::string, std::shared_ptr<Component>>> m_EntityComponents;
+
+	EntityID GenerateEntityID()
+	{
+		if (!m_RecycledEntityIDs.empty()) {
+			EntityID id = m_RecycledEntityIDs.top();
+			m_RecycledEntityIDs.pop();
+			return id;
+		} else {
+			return ++m_LastEntityID;
+		}
+	}
+
+	void RecycleEntityID(EntityID id)
+	{
+		m_RecycledEntityIDs.push(id);
+	}
+};