Add a transform component and propagation system

[libs/game.git] / source / game / transformpropagator.h

diff --git a/source/game/transformpropagator.h b/source/game/transformpropagator.h
new file mode 100644 (file)
index 0000000..3ac291b
--- /dev/null
+++ b/source/game/transformpropagator.h
@@ -0,0 +1,38 @@
+#ifndef MSP_GAME_TRANSFORMPROPAGATOR_H_
+#define MSP_GAME_TRANSFORMPROPAGATOR_H_
+
+#include "eventobserver.h"
+#include "handle.h"
+#include "system.h"
+
+namespace Msp::Game {
+
+class Entity;
+class Transform;
+
+class TransformPropagator: public System
+{
+private:
+       struct ParentedTransform
+       {
+               Handle<Transform> transform;
+               Handle<Transform> parent;
+       };
+
+       EventObserver observer;
+       std::vector<ParentedTransform> transforms;
+       bool transforms_dirty = true;
+
+public:
+       TransformPropagator(Stage &);
+
+       void tick(Time::TimeDelta) override;
+
+private:
+       void rebuild_transform_order();
+       void rebuild_transform_order(Handle<Entity>, Handle<Transform>);
+};
+
+} // namespace Msp::Game
+
+#endif