Adapted Escape the Dawn engine.

src/Systems/TransformSystem.cpp

@@ -0,0 +1,48 @@
+#include "PrecompiledHeader.h"
+#include "TransformSystem.h"
+#include "World.h"
+
+//void Systems::TransformSystem::UpdateEntity(double dt, EntityID entity, EntityID parent)
+//{
+//	if (parent == 0)
+//		return;
+//
+//	auto transform = m_World->GetComponent<Components::Transform>(entity, "Transform");
+//	auto parentTransform = m_World->GetComponent<Components::Transform>(parent, "Transform");
+//
+//	transform->Position = parentTransform->Position + transform->RelativePosition;
+//}
+
+glm::vec3 Systems::TransformSystem::AbsolutePosition(EntityID entity)
+{
+	glm::vec3 absPosition;
+	glm::quat accumulativeOrientation;
+
+	do
+	{
+		auto transform = m_World->GetComponent<Components::Transform>(entity, "Transform");
+		//absPosition += transform->Position;
+		entity = m_World->GetEntityParent(entity);
+		auto transform2 = m_World->GetComponent<Components::Transform>(entity, "Transform");
+		if (entity != 0)
+			absPosition += transform2->Orientation * transform->Position;
+		else
+			absPosition += transform->Position;
+	} while (entity != 0);
+
+	return absPosition * accumulativeOrientation;
+}
+
+glm::quat Systems::TransformSystem::AbsoluteOrientation(EntityID entity) 
+{
+	glm::quat absOrientation;
+
+	do
+	{
+		auto transform = m_World->GetComponent<Components::Transform>(entity, "Transform");
+		absOrientation *= transform->Orientation;
+		entity = m_World->GetEntityParent(entity);
+	} while (entity != 0);
+
+	return absOrientation;
+}