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         declare_dependency<Transform>(CHAINED_UPDATE);
  16
  17         observer.observe<Events::EntityCreated>([this](auto &){ transforms_dirty = true; });
  18         observer.observe<Events::EntityDestroyed>([this](auto &){ transforms_dirty = true; });
  19 }
  20
  21 void TransformPropagator::tick(Time::TimeDelta)
  22 {
  23         if(transforms_dirty)
  24                 rebuild_transform_order();
  25
  26         for(const ParentedTransform &t: transforms)
  27                 t.transform->update_world_matrix(t.parent.get());
  28 }
  29
  30 void TransformPropagator::rebuild_transform_order()
  31 {
  32         transforms.clear();
  33         for(Handle<Entity> c: stage.get_root()->get_children())
  34                 rebuild_transform_order(c, nullptr);
  35 }
  36
  37 void TransformPropagator::rebuild_transform_order(Handle<Entity> entity, Handle<Transform> parent_trans)
  38 {
  39         if(Handle<Transform> trans = entity->get_transform())
  40         {
  41                 transforms.emplace_back(trans, parent_trans);
  42                 parent_trans = trans;
  43         }
  44
  45         for(Handle<Entity> c: entity->get_children())
  46                 rebuild_transform_order(c, parent_trans);
  47 }
  48
  49 } // namespace Msp::Game