source/game/transformpropagator.cpp

   1 #include "transformpropagator.h"
   2 #include "events.h"
   3 #include "root.h"
   4 #include "stage.h"
   5 #include "transform.h"
   6
   7 using namespace std;
   8
   9 namespace Msp::Game {
  10
  11 TransformPropagator::TransformPropagator(Stage &s):
  12         System(s),
  13         observer(s.get_event_bus())
  14 {
  15         observer.observe<Events::EntityCreated>([this](auto &){ transforms_dirty = true; });
  16         observer.observe<Events::EntityDestroyed>([this](auto &){ transforms_dirty = true; });
  17 }
  18
  19 void TransformPropagator::tick(Time::TimeDelta)
  20 {
  21         if(transforms_dirty)
  22                 rebuild_transform_order();
  23
  24         for(const ParentedTransform &t: transforms)
  25                 t.transform->update_world_matrix(t.parent.get());
  26 }
  27
  28 void TransformPropagator::rebuild_transform_order()
  29 {
  30         transforms.clear();
  31         for(Handle<Entity> c: stage.get_root()->get_children())
  32                 rebuild_transform_order(c, nullptr);
  33 }
  34
  35 void TransformPropagator::rebuild_transform_order(Handle<Entity> entity, Handle<Transform> parent_trans)
  36 {
  37         if(Handle<Transform> trans = entity->get_transform())
  38         {
  39                 transforms.emplace_back(trans, parent_trans);
  40                 parent_trans = trans;
  41         }
  42
  43         for(Handle<Entity> c: entity->get_children())
  44                 rebuild_transform_order(c, parent_trans);
  45 }
  46
  47 } // namespace Msp::Game