hopefully fix #33

in OpenStarbound, players can place blocks with their own collision type. this can cause objects to override the collision type if the object has material spaces and a previous attempt at accounting for this led to that bug: giving object collision its own field in the server tile should fix this

source/base/StarAssets.cpp

@@ -681,7 +681,7 @@ ByteArray Assets::read(String const& path) const {
 Json Assets::checkPatchArray(String const& path, AssetSourcePtr const& source, Json const result, JsonArray const patchData, Maybe<Json> const external) const {
   auto externalRef = external.value();
   auto newResult = result;
-  for (auto const patch : patchData) {
+  for (auto const& patch : patchData) {
     switch(patch.type()) {
       case Json::Type::Array: // if the patch is an array, go down recursively until we get objects
         try {

source/game/StarWorldServer.cpp

@@ -1255,7 +1255,7 @@ void WorldServer::init(bool firstTime) {
   m_entityMessageResponses = {};
 
   m_collisionGenerator.init([=](int x, int y) {
-      return m_tileArray->tile({x, y}).collision;
+      return m_tileArray->tile({x, y}).getCollision();
     });
 
   m_tileEntityBreakCheckTimer = GameTimer(m_serverConfig.getFloat("tileEntityBreakCheckInterval"));
@@ -1505,21 +1505,20 @@ void WorldServer::updateTileEntityTiles(TileEntityPtr const& entity, bool removi
 
     ServerTile* tile = m_tileArray->modifyTile(pos);
     if (tile) {
-      bool updated = false;
+      tile->rootSource = {};
+      bool updatedTile = false;
       if (tile->foreground == materialSpace.material) {
         tile->foreground = EmptyMaterialId;
         tile->foregroundMod = NoModId;
-        tile->rootSource = {};
-        updated = true;
+        updatedTile = true;
       }
-      if (tile->collision == materialDatabase->materialCollisionKind(materialSpace.material)
-        && tile->updateCollision(materialSpace.prevCollision.value(CollisionKind::None))) {
+      if (tile->updateObjectCollision(CollisionKind::None)) {
         m_liquidEngine->visitLocation(pos);
         m_fallingBlocksAgent->visitLocation(pos);
         dirtyCollision(RectI::withSize(pos, { 1, 1 }));
-        updated = true;
+        updatedTile = true;
       }
-      if (updated)
+      if (updatedTile)
         queueTileUpdates(pos);
     }
   }
@@ -1533,35 +1532,27 @@ void WorldServer::updateTileEntityTiles(TileEntityPtr const& entity, bool removi
     for (auto const& materialSpace : newMaterialSpaces) {
       Vec2I pos = materialSpace.space + entity->tilePosition();
 
-      bool updated = false;
+      bool updatedTile = false;
       bool updatedCollision = false;
       ServerTile* tile = m_tileArray->modifyTile(pos);
-      if (tile && (tile->foreground == EmptyMaterialId || tile->foreground == materialSpace.material)) {
+      if (tile) {
+        if (tile->foreground == EmptyMaterialId) {
           tile->foreground = materialSpace.material;
           tile->foregroundMod = NoModId;
+          updatedTile = true;
+        }
         bool hadRoot = tile->rootSource.isValid();
         if (isRealMaterial(materialSpace.material))
           tile->rootSource = entity->tilePosition();
         auto& space = passedSpaces.emplaceAppend(materialSpace);
-        if (hadRoot)
-          space.prevCollision.emplace(tile->collision);
-        updatedCollision = tile->updateCollision(materialDatabase->materialCollisionKind(tile->foreground));
-        updated = true;
-      }
-      else if (tile && tile->collision < CollisionKind::Dynamic) {
-        bool hadRoot = tile->rootSource.isValid();
-        auto& space = passedSpaces.emplaceAppend(materialSpace);
-        if (hadRoot)
-          space.prevCollision.emplace(tile->collision);
-        updatedCollision = tile->updateCollision(materialDatabase->materialCollisionKind(materialSpace.material));
-        updated = true;
+        updatedTile |= updatedCollision = tile->updateObjectCollision(materialDatabase->materialCollisionKind(materialSpace.material));
       }
       if (updatedCollision) {
         m_liquidEngine->visitLocation(pos);
         m_fallingBlocksAgent->visitLocation(pos);
         dirtyCollision(RectI::withSize(pos, { 1, 1 }));
       }
-      if (updated)
+      if (updatedTile)
         queueTileUpdates(pos);
     }
     spaces.materials = std::move(passedSpaces);
@@ -1997,7 +1988,7 @@ void WorldServer::writeNetTile(Vec2I const& pos, NetTile& netTile) const {
   netTile.backgroundMod = tile.backgroundMod;
   netTile.backgroundModHueShift = tile.backgroundModHueShift;
   netTile.liquid = tile.liquid.netUpdate();
-  netTile.collision = tile.collision;
+  netTile.collision = tile.getCollision();
   netTile.blockBiomeIndex = tile.blockBiomeIndex;
   netTile.environmentBiomeIndex = tile.environmentBiomeIndex;
   netTile.dungeonId = tile.dungeonId;

source/game/StarWorldTiles.cpp

@@ -26,7 +26,7 @@ bool WorldTile::isColliding(CollisionSet const& collisionSet) const {
 
 VersionNumber const ServerTile::CurrentSerializationVersion = 418;
 
-ServerTile::ServerTile() {}
+ServerTile::ServerTile() : objectCollision(CollisionKind::None) {}
 
 ServerTile::ServerTile(ServerTile const& serverTile) : WorldTile() {
   *this = serverTile;
@@ -37,7 +37,7 @@ ServerTile& ServerTile::operator=(ServerTile const& serverTile) {
 
   liquid = serverTile.liquid;
   rootSource = serverTile.rootSource;
-
+  objectCollision = serverTile.objectCollision;
   return *this;
 }
 
@@ -109,6 +109,25 @@ bool ServerTile::updateCollision(CollisionKind kind) {
   return false;
 }
 
+bool ServerTile::updateObjectCollision(CollisionKind kind) {
+  if (objectCollision != kind) {
+    objectCollision = kind;
+    collisionCacheDirty = true;
+    collisionCache.clear();
+    return true;
+  }
+  return false;
+}
+
+CollisionKind ServerTile::getCollision() const {
+  CollisionKind kind = collision;
+  if (objectCollision != CollisionKind::None
+      && (objectCollision != CollisionKind::Platform || kind == CollisionKind::None)) {
+    kind = objectCollision;
+  }
+  return kind;
+}
+
 PredictedTile::operator bool() const {
   return
      background

source/game/StarWorldTiles.hpp

@@ -69,12 +69,20 @@ struct ServerTile : public WorldTile {
   // Updates collision, clears cache, and if the collision kind does not
   // support liquid destroys it.
   bool updateCollision(CollisionKind kind);
+  // Used for setting the second collision kind calculated by object material spaces.
+  bool updateObjectCollision(CollisionKind kind);
+
+  // Calculates the actually-used collision kind based on the tile and object collision kinds.
+  CollisionKind getCollision() const;
 
   LiquidStore liquid;
 
   // If set, a plant or object is rooted to the tile and tile damage
   // should be redirected to this position
   Maybe<Vec2I> rootSource;
+
+  // Do not serialize - calculated at runtime
+  CollisionKind objectCollision;
 };
 typedef TileSectorArray<ServerTile, WorldSectorSize> ServerTileSectorArray;
 typedef shared_ptr<ServerTileSectorArray> ServerTileSectorArrayPtr;

source/game/interfaces/StarTileEntity.hpp

@@ -17,7 +17,6 @@ struct MaterialSpace {
 
   Vec2I space;
   MaterialId material;
-  Maybe<CollisionKind> prevCollision; //exclude from ==
 };
 
 DataStream& operator<<(DataStream& ds, MaterialSpace const& materialSpace);