allow to (multi) select scrap

src/lib/sim/EntityHitTest.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include <vector>
+
+#include <QPoint>
 #include <QVector2D>
 
 #include "entt/entity/entity.hpp"
@@ -7,3 +10,12 @@
 class EntityAdmin;
 
 entt::entity entityAtWorldPos(EntityAdmin& admin, QVector2D worldPos);
+
+// Returns the nearest scrap pile whose center is within the scrap pick radius of
+// worldPos, or entt::null if none (REQ-UI-SCRAP-CLICK-SELECT). Scrap is picked only
+// after actors: entityAtWorldPos never returns scrap (scrap has no HealthComponent).
+entt::entity scrapAtWorldPos(EntityAdmin& admin, QVector2D worldPos);
+
+// Returns every scrap pile whose position falls within the inclusive tile rectangle
+// spanned by tileA and tileB, in any corner order (REQ-UI-SCRAP-MULTI-SELECT).
+std::vector<entt::entity> scrapInBox(EntityAdmin& admin, QPoint tileA, QPoint tileB);