Add documentation and checks to SceneGraph

engine/SceneGraph.cpp

@@ -42,6 +42,9 @@ SceneGraph::SceneGraph()
 //-----------------------------------------------------------------------------
 int32_t SceneGraph::create_node(int32_t parent, const Vector3& pos, const Quaternion& rot)
 {
+	CE_ASSERT(parent >= -1, "Parent node must be >= -1");
+	CE_ASSERT(parent < (int32_t) m_local_poses.size(), "Parent node must be < child node");
+
 	Matrix4x4 pose(rot, pos);
 
 	m_world_poses.push_back(pose);
@@ -51,29 +54,36 @@ int32_t SceneGraph::create_node(int32_t parent, const Vector3& pos, const Quater
 	return m_local_poses.size() - 1;
 }
 
-//-----------------------------------------------------------------------------
-void SceneGraph::destroy_node(int32_t id)
-{
-	(void)id;
-}
-
 //-----------------------------------------------------------------------------
 void SceneGraph::link(int32_t child, int32_t parent)
 {
+	CE_ASSERT(child < (int32_t) m_parents.size(), "Child node does not exist");
+	CE_ASSERT(parent < (int32_t) m_parents.size(), "Parent node does not exist");
+	CE_ASSERT(parent < child, "Parent must be < child");
+
+	m_world_poses[child] = Matrix4x4::IDENTITY;
+	m_local_poses[child] = Matrix4x4::IDENTITY;
 	m_parents[child] = parent;
 }
 
 //-----------------------------------------------------------------------------
 void SceneGraph::unlink(int32_t child)
 {
-	// Copy world pose before unlinking from parent
-	m_local_poses[child] = m_world_poses[m_parents[child]];
-	m_parents[child] = -1;
+	CE_ASSERT(child < (int32_t) m_parents.size(), "Child node does not exist");
+
+	if (m_parents[child] != -1)
+	{
+		// Copy world pose before unlinking from parent
+		m_local_poses[child] = m_world_poses[child];
+		m_parents[child] = -1;
+	}
 }
 
 //-----------------------------------------------------------------------------
 void SceneGraph::set_local_position(int32_t node, const Vector3& pos)
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	Matrix4x4& local_pose = m_local_poses[node];
 	local_pose.set_translation(pos);
 }
@@ -81,6 +91,8 @@ void SceneGraph::set_local_position(int32_t node, const Vector3& pos)
 //-----------------------------------------------------------------------------
 void SceneGraph::set_local_rotation(int32_t node, const Quaternion& rot)
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	Matrix4x4& local_pose = m_local_poses[node];
 
 	Vector3 local_translation = local_pose.translation();
@@ -91,45 +103,67 @@ void SceneGraph::set_local_rotation(int32_t node, const Quaternion& rot)
 //-----------------------------------------------------------------------------
 void SceneGraph::set_local_pose(int32_t node, const Matrix4x4& pose)
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	m_local_poses[node] = pose;
 }
 
 //-----------------------------------------------------------------------------
 Vector3 SceneGraph::local_position(int32_t node) const
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	return m_local_poses[node].translation();
 }
 
 //-----------------------------------------------------------------------------
 Quaternion SceneGraph::local_rotation(int32_t /*node*/) const
 {
+	//CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	return Quaternion(Vector3(1, 0, 0), 0.0f);
 }
 
 //-----------------------------------------------------------------------------
 Matrix4x4 SceneGraph::local_pose(int32_t node) const
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	return m_local_poses[node];
 }
 
 //-----------------------------------------------------------------------------
 Vector3 SceneGraph::world_position(int32_t node) const
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	return m_world_poses[node].translation();
 }
 
 //-----------------------------------------------------------------------------
 Quaternion SceneGraph::world_rotation(int32_t /*node*/) const
 {
+	// CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	return Quaternion(Vector3(1, 0, 0), 0.0f);
 }
 
 //-----------------------------------------------------------------------------
 Matrix4x4 SceneGraph::world_pose(int32_t node) const
 {
+	CE_ASSERT(node < (int32_t) m_parents.size(), "Node does not exist");
+
 	return m_world_poses[node];
 }
 
+//-----------------------------------------------------------------------------
+void SceneGraph::clear()
+{
+	m_world_poses.clear();
+	m_local_poses.clear();
+	m_parents.clear();
+}
+
 //-----------------------------------------------------------------------------
 void SceneGraph::update()
 {

engine/SceneGraph.h

@@ -36,10 +36,21 @@ namespace crown
 struct SceneGraph
 {
 					SceneGraph();
+
+	/// Creates a new node with @a parent parent at position @a pos and rotation @a rot.
+	/// @note
+	/// The @a parent node must be either -1 (meaning no parent), or an index lesser
+	/// than the being created node.
 	int32_t			create_node(int32_t parent, const Vector3& pos, const Quaternion& rot);
-	void			destroy_node(int32_t id);
 
+	/// Links the @a child node to the @a parent node.
+	/// After the linking the @a child pose is reset to identity.
+	/// @note
+	/// The @a parent node must be either -1 (meaning no parent), or an index lesser than child
 	void			link(int32_t child, int32_t parent);
+
+	/// Unlinks the @a child node from its parent if it has any.
+	/// After unlinking, the @child local pose is set to its previous world pose.
 	void			unlink(int32_t child);
 
 	void			set_local_position(int32_t node, const Vector3& pos);
@@ -54,6 +65,10 @@ struct SceneGraph
 	Quaternion		world_rotation(int32_t node) const;
 	Matrix4x4		world_pose(int32_t node) const;
 
+	// Clears the content of the scene graph.
+	void			clear();
+
+	/// Transforms local poses to world poses.
 	void			update();
 
 public: