fix integer overflow in mapgen (#11641)

[dragonfireclient.git] / src / mapgen / mapgen.cpp

diff --git a/src/mapgen/mapgen.cpp b/src/mapgen/mapgen.cpp
index 0094608ec6803e945edadd4ea6c196279b46da0d..1f2ac491e952331e41aac3249760d5d18be5c3f7 100644 (file)
--- a/src/mapgen/mapgen.cpp
+++ b/src/mapgen/mapgen.cpp
@@ -58,6 +58,7 @@ FlagDesc flagdesc_mapgen[] = {
        {"light",       MG_LIGHT},
        {"decorations", MG_DECORATIONS},
        {"biomes",      MG_BIOMES},
+       {"ores",        MG_ORES},
        {NULL,          0}
 };
 
@@ -106,8 +107,8 @@ STATIC_ASSERT(
 //// Mapgen
 ////
 
-Mapgen::Mapgen(int mapgenid, MapgenParams *params, EmergeManager *emerge) :
-       gennotify(emerge->gen_notify_on, &emerge->gen_notify_on_deco_ids)
+Mapgen::Mapgen(int mapgenid, MapgenParams *params, EmergeParams *emerge) :
+       gennotify(emerge->gen_notify_on, emerge->gen_notify_on_deco_ids)
 {
        id           = mapgenid;
        water_level  = params->water_level;
@@ -156,7 +157,7 @@ const char *Mapgen::getMapgenName(MapgenType mgtype)
 
 
 Mapgen *Mapgen::createMapgen(MapgenType mgtype, MapgenParams *params,
-       EmergeManager *emerge)
+       EmergeParams *emerge)
 {
        switch (mgtype) {
        case MAPGEN_CARPATHIAN:
@@ -217,7 +218,7 @@ void Mapgen::getMapgenNames(std::vector<const char *> *mgnames, bool include_hid
 void Mapgen::setDefaultSettings(Settings *settings)
 {
        settings->setDefault("mg_flags", flagdesc_mapgen,
-                MG_CAVES | MG_DUNGEONS | MG_LIGHT | MG_DECORATIONS | MG_BIOMES);
+                MG_CAVES | MG_DUNGEONS | MG_LIGHT | MG_DECORATIONS | MG_BIOMES | MG_ORES);
 
        for (int i = 0; i < (int)MAPGEN_INVALID; ++i) {
                MapgenParams *params = createMapgenParams((MapgenType)i);
@@ -237,32 +238,13 @@ u32 Mapgen::getBlockSeed(v3s16 p, s32 seed)
 
 u32 Mapgen::getBlockSeed2(v3s16 p, s32 seed)
 {
-       u32 n = 1619 * p.X + 31337 * p.Y + 52591 * p.Z + 1013 * seed;
+       // Multiply by unsigned number to avoid signed overflow (UB)
+       u32 n = 1619U * p.X + 31337U * p.Y + 52591U * p.Z + 1013U * seed;
        n = (n >> 13) ^ n;
        return (n * (n * n * 60493 + 19990303) + 1376312589);
 }
 
 
-// Returns Y one under area minimum if not found
-s16 Mapgen::findGroundLevelFull(v2s16 p2d)
-{
-       const v3s16 &em = vm->m_area.getExtent();
-       s16 y_nodes_max = vm->m_area.MaxEdge.Y;
-       s16 y_nodes_min = vm->m_area.MinEdge.Y;
-       u32 i = vm->m_area.index(p2d.X, y_nodes_max, p2d.Y);
-       s16 y;
-
-       for (y = y_nodes_max; y >= y_nodes_min; y--) {
-               MapNode &n = vm->m_data[i];
-               if (ndef->get(n).walkable)
-                       break;
-
-               VoxelArea::add_y(em, i, -1);
-       }
-       return (y >= y_nodes_min) ? y : y_nodes_min - 1;
-}
-
-
 // Returns -MAX_MAP_GENERATION_LIMIT if not found
 s16 Mapgen::findGroundLevel(v2s16 p2d, s16 ymin, s16 ymax)
 {
@@ -585,7 +567,7 @@ void Mapgen::spreadLight(const v3s16 &nmin, const v3s16 &nmax)
 //// MapgenBasic
 ////
 
-MapgenBasic::MapgenBasic(int mapgenid, MapgenParams *params, EmergeManager *emerge)
+MapgenBasic::MapgenBasic(int mapgenid, MapgenParams *params, EmergeParams *emerge)
        : Mapgen(mapgenid, params, emerge)
 {
        this->m_emerge = emerge;
@@ -614,7 +596,8 @@ MapgenBasic::MapgenBasic(int mapgenid, MapgenParams *params, EmergeManager *emer
        this->heightmap = new s16[csize.X * csize.Z];
 
        //// Initialize biome generator
-       biomegen = m_bmgr->createBiomeGen(BIOMEGEN_ORIGINAL, params->bparams, csize);
+       biomegen = emerge->biomegen;
+       biomegen->assertChunkSize(csize);
        biomemap = biomegen->biomemap;
 
        //// Look up some commonly used content
@@ -640,8 +623,9 @@ MapgenBasic::MapgenBasic(int mapgenid, MapgenParams *params, EmergeManager *emer
 
 MapgenBasic::~MapgenBasic()
 {
-       delete biomegen;
        delete []heightmap;
+
+       delete m_emerge; // destroying EmergeParams is our responsibility
 }
 
 
@@ -974,32 +958,20 @@ void MapgenBasic::generateDungeons(s16 max_stone_y)
 ////
 
 GenerateNotifier::GenerateNotifier(u32 notify_on,
-       std::set<u32> *notify_on_deco_ids)
+       const std::set<u32> *notify_on_deco_ids)
 {
        m_notify_on = notify_on;
        m_notify_on_deco_ids = notify_on_deco_ids;
 }
 
 
-void GenerateNotifier::setNotifyOn(u32 notify_on)
-{
-       m_notify_on = notify_on;
-}
-
-
-void GenerateNotifier::setNotifyOnDecoIds(std::set<u32> *notify_on_deco_ids)
-{
-       m_notify_on_deco_ids = notify_on_deco_ids;
-}
-
-
 bool GenerateNotifier::addEvent(GenNotifyType type, v3s16 pos, u32 id)
 {
        if (!(m_notify_on & (1 << type)))
                return false;
 
        if (type == GENNOTIFY_DECORATION &&
-               m_notify_on_deco_ids->find(id) == m_notify_on_deco_ids->end())
+               m_notify_on_deco_ids->find(id) == m_notify_on_deco_ids->cend())
                return false;
 
        GenNotifyEvent gne;
@@ -1047,10 +1019,11 @@ MapgenParams::~MapgenParams()
 
 void MapgenParams::readParams(const Settings *settings)
 {
-       std::string seed_str;
-       const char *seed_name = (settings == g_settings) ? "fixed_map_seed" : "seed";
+       // should always be used via MapSettingsManager
+       assert(settings != g_settings);
 
-       if (settings->getNoEx(seed_name, seed_str)) {
+       std::string seed_str;
+       if (settings->getNoEx("seed", seed_str)) {
                if (!seed_str.empty())
                        seed = read_seed(seed_str.c_str());
                else