Mostly working spatical map with 2 level collision/space structure. Not the best implementation but this is the idea.

gui/main_ui.cpp

@@ -31,7 +31,8 @@ namespace gui {
   }
 
   DinkyECS::Entity MainUI::camera_aim() {
-    if($level.collision->occupied($rayview.aiming_at)) {
+    // what happens if there's two things at that spot
+    if($level.collision->something_there($rayview.aiming_at)) {
       return $level.collision->get($rayview.aiming_at);
     } else {
       return 0;

levelmanager.cpp

@@ -85,7 +85,7 @@ DinkyECS::Entity LevelManager::spawn_enemy(std::string named) {
     }
   }
 
-  level.collision->insert(entity_pos.location, entity_id);
+  level.collision->insert(entity_pos.location, entity_id, true);
 
   return entity_id;
 }

spatialmap.cpp

@@ -5,25 +5,43 @@ using namespace fmt;
 
 using DinkyECS::Entity;
 
-void SpatialMap::insert(Point pos, Entity ent) {
+void SpatialMap::insert(Point pos, Entity ent, bool has_collision) {
+  if(has_collision) {
     yes_collision.insert_or_assign(pos, ent);
+  } else {
+    no_collision.insert_or_assign(pos, ent);
+  }
 }
 
-void SpatialMap::remove(Point pos) {
+bool SpatialMap::remove(Point pos) {
+  if(yes_collision.contains(pos)) {
     yes_collision.erase(pos);
+    return true;
+  } else {
+    no_collision.erase(pos);
+    return false;
+  }
 }
 
 void SpatialMap::move(Point from, Point to, Entity ent) {
-  remove(from);
+  bool has_collision = remove(from);
-  insert(to, ent);
+  insert(to, ent, has_collision);
 }
 
 bool SpatialMap::occupied(Point at) const {
   return yes_collision.contains(at);
 }
 
+bool SpatialMap::something_there(Point at) const {
+  return yes_collision.contains(at) || no_collision.contains(at);
+}
+
 Entity SpatialMap::get(Point at) const {
+  if(yes_collision.contains(at)) {
     return yes_collision.at(at);
+  } else {
+    return no_collision.at(at);
+  }
 }
 
 /*
@@ -81,6 +99,7 @@ SortedEntities SpatialMap::distance_sorted(Point from, int max_dist) {
   SortedEntities sprite_distance;
 
   update_sorted(sprite_distance, yes_collision, from, max_dist);
+  update_sorted(sprite_distance, no_collision, from, max_dist);
 
   std::sort(sprite_distance.begin(), sprite_distance.end(), std::greater<>());
 

spatialmap.hpp

@@ -20,11 +20,14 @@ class SpatialMap {
   public:
     SpatialMap() {}
     PointEntityMap yes_collision;
+    PointEntityMap no_collision;
 
-    void insert(Point pos, DinkyECS::Entity obj);
+    void insert(Point pos, DinkyECS::Entity obj, bool has_collision);
     void move(Point from, Point to, DinkyECS::Entity ent);
-    void remove(Point pos);
+    // return value is whether the removed thing has collision
+    bool remove(Point pos);
     bool occupied(Point pos) const;
+    bool something_there(Point at) const;
     DinkyECS::Entity get(Point at) const;
     FoundEntities neighbors(Point position, bool diag=false) const;
 

systems.cpp

@@ -163,11 +163,10 @@ void System::distribute_loot(GameLevel &level, Position target_pos) {
     // BUG: inventory_count here isn't really used to remove it
     world.set<InventoryItem>(junk_entity, {inventory_count, entity_data});
     world.set<Position>(junk_entity, target_pos);
-    level.collision->insert(target_pos.location, junk_entity);
+    level.collision->insert(target_pos.location, junk_entity, false);
     level.world->send<Events::GUI>(Events::GUI::ENTITY_SPAWN, junk_entity, {});
   } else {
     dbc::log("DEAD BODY NOT IMPLEMENTED, for now just removing enemy");
-    level.collision->remove(target_pos.location);
     // BUG: should maybe add a component to the world for "dead thing no loot" that
     // has no collision or goes away after some kind of animation
     // Something like:
@@ -213,9 +212,11 @@ void System::death(GameLevel &level) {
     }
 
     auto pos = world.get<Position>(ent);
-    // NOTE: distribute loot is responsible for either removing or replacing
+
-    // the collision for this entity. It has to do this since it's determining
+    // need to remove _after_ getting the position
-    // if a junkpile goes there or nothing
+    level.collision->remove(pos.location);
+
+    // distribute_loot is then responsible for putting something there
     System::distribute_loot(level, pos);
 
     world.destroy(ent);
@@ -454,7 +455,7 @@ bool System::drop_item(GameLevel& level, Entity item) {
 
     if(map.can_move(pos.location) && !collision.occupied(pos.location)) {
       world.set<Position>(item, pos);
-      collision.insert(pos.location, item);
+      collision.insert(pos.location, item, false);
       // BUG: really there should be another system that handles loot->inv moves
       if(player_inv.has(item)) player_inv.remove(item);
       level.world->send<Events::GUI>(Events::GUI::ENTITY_SPAWN, item, {});

tests/spatialmap.cpp

@@ -23,8 +23,8 @@ TEST_CASE("confirm basic collision operations", "[collision]") {
   Entity enemy = world.entity();
 
   SpatialMap collider;
-  collider.insert({11,11}, player);
+  collider.insert({11,11}, player, true);
-  collider.insert({21,21}, enemy);
+  collider.insert({21,21}, enemy, true);
 
   { // not found
     auto [found, nearby] = collider.neighbors({1,1});
@@ -43,7 +43,7 @@ TEST_CASE("confirm basic collision operations", "[collision]") {
     REQUIRE(nearby.empty());
   }
 
-  collider.insert({11,11}, player); // setup for the move test
+  collider.insert({11,11}, player, true); // setup for the move test
   { // moving, not found
     collider.move({11,11}, {12, 12}, player);
     auto [found, nearby] = collider.neighbors({10,10}, true);
@@ -72,10 +72,10 @@ TEST_CASE("confirm multiple entities moving", "[collision]") {
   Entity e3 = world.entity();
 
   SpatialMap collider;
-  collider.insert({11,11}, player);
+  collider.insert({11,11}, player, true);
-  collider.insert({10,10}, e2);
+  collider.insert({10,10}, e2, true);
-  collider.insert({11,10}, e3);
+  collider.insert({11,10}, e3, true);
-  collider.insert({21,21}, e1);
+  collider.insert({21,21}, e1, true);
 
   EntityList nearby = require_found(collider, {11,11}, false, 1);
   REQUIRE(nearby[0] == e3);
@@ -95,10 +95,10 @@ TEST_CASE("test edge cases that might crash", "[collision]") {
   Entity enemy = world.entity();
 
   SpatialMap collider;
-  collider.insert({0,0}, player);
+  collider.insert({0,0}, player, true);
 
   Point enemy_at = {1, 0};
-  collider.insert(enemy_at, enemy);
+  collider.insert(enemy_at, enemy, true);
 
   EntityList nearby = require_found(collider, {0,0}, true, 1);
 
@@ -118,10 +118,10 @@ TEST_CASE("check all diagonal works", "[collision]") {
 
   SpatialMap collider;
   Point player_at = {1,1};
-  collider.insert(player_at, player);
+  collider.insert(player_at, player, true);
 
   Point enemy_at = {1, 0};
-  collider.insert(enemy_at, enemy);
+  collider.insert(enemy_at, enemy, true);
 
   for(size_t x = 0; x <= 2; x++) {
     for(size_t y = 0; y <= 2; y++) {
@@ -150,7 +150,7 @@ TEST_CASE("confirm can iterate through all", "[spatialmap-sort]") {
       size_t y = Random::uniform<size_t>(0, 251);
 
       Entity ent = world.entity();
-      collider.insert({x,y}, ent);
+      collider.insert({x,y}, ent, true);
     }
 
     auto sprite_distance = collider.distance_sorted(player, 1000);

worldbuilder.cpp

@@ -91,15 +91,20 @@ DinkyECS::Entity WorldBuilder::configure_entity_in_map(DinkyECS::World &world, j
   // NOTE: aiming_at is set by the rayview since it knows that
   world.set<Position>(item, {pos.x, pos.y});
 
-  if(entity_data["inventory_count"] > 0) {
+  // BUG: See #72, but this will change to a setting for collision
+  int inv_count = entity_data.contains("inventory_count") ? (int)entity_data["inventory_count"] : 0;
+  bool has_collision = true;
+
+  if(inv_count > 0) {
     world.set<InventoryItem>(item, {entity_data["inventory_count"], entity_data});
+    has_collision = false;
   }
 
   if(entity_data.contains("components")) {
     components::configure_entity(world, item, entity_data["components"]);
   }
 
-  $collision->insert(pos, item);
+  $collision->insert(pos, item, has_collision);
 
   return item;
 }