+ // If a parent node exists, we'll become it.
+ //TODO: Generate a new parent node if none exists, and work out when to change child_type
+ // away from QTC_UNKNOWN
+ if (m_document.GetQuadTree().nodes[m_current_quadtree_node].parent != QUADTREE_EMPTY)
+ {
+ m_bounds = TransformFromQuadChild(m_bounds, m_document.GetQuadTree().nodes[m_current_quadtree_node].child_type);
+ m_current_quadtree_node = m_document.GetQuadTree().nodes[m_current_quadtree_node].parent;
+ }
+ }
+
+ // If we have a parent... (This prevents some crashes, but should disappear.)
+ if (m_document.GetQuadTree().nodes[m_current_quadtree_node].parent != QUADTREE_EMPTY)
+ {
+ // If the current node is off the left-hand side of the screen...
+ while (m_bounds.x > 1)
+ {
+ //... the current node becomes the node to its right.
+ m_bounds = Rect(m_bounds.x - 1, m_bounds.y, m_bounds.w, m_bounds.h);
+ m_current_quadtree_node = m_document.GetQuadTree().GetNeighbour(m_current_quadtree_node, 1, 0, &m_document);
+ }
+ while (m_bounds.y > 1)
+ {
+ m_bounds = Rect(m_bounds.x, m_bounds.y - 1, m_bounds.w, m_bounds.h);
+ m_current_quadtree_node = m_document.GetQuadTree().GetNeighbour(m_current_quadtree_node, 0, 1, &m_document);
+ }
+ while (m_bounds.x < 0)
+ {
+ m_bounds = Rect(m_bounds.x + 1, m_bounds.y, m_bounds.w, m_bounds.h);
+ m_current_quadtree_node = m_document.GetQuadTree().GetNeighbour(m_current_quadtree_node, -1, 0, &m_document);
+ }
+ while (m_bounds.y < 0)
+ {
+ m_bounds = Rect(m_bounds.x, m_bounds.y + 1, m_bounds.w, m_bounds.h);
+ m_current_quadtree_node = m_document.GetQuadTree().GetNeighbour(m_current_quadtree_node, 0, -1, &m_document);
+ }
+ }
+
+ // Recurse into a node if we are completely within it. (If we're okay with having an invalid frame or two, we can remove this.)
+ if (ContainedInQuadChild(m_bounds, QTC_TOP_LEFT))
+ {
+ if (m_document.GetQuadTree().nodes[m_current_quadtree_node].top_left == QUADTREE_EMPTY)
+ {
+ // We want to reparent into a child node, but none exist. Get the document to create one.
+ m_document.GenQuadChild(m_current_quadtree_node, QTC_TOP_LEFT);
+ m_render_dirty = true;
+ }