feat: add enchantsConflict and enchantApplies to Enchant

core/src/Enchant.cpp

@@ -156,3 +156,145 @@ int enchantMaxCost(EnchantKind kind, int level) {
     }
 }
 
+bool enchantsConflict(EnchantKind a, EnchantKind b) {
+    if (a == b) return false;
+    if (isProtectionFamily(a) && isProtectionFamily(b)) return true;
+    if (isDamageFamily(a) && isDamageFamily(b)) return true;
+    if ((a == EnchantKind::SilkTouch && b == EnchantKind::Fortune) ||
+        (a == EnchantKind::Fortune && b == EnchantKind::SilkTouch))
+        return true;
+    if ((a == EnchantKind::SilkTouch && b == EnchantKind::Looting) ||
+        (a == EnchantKind::Looting && b == EnchantKind::SilkTouch))
+        return true;
+    if ((a == EnchantKind::Infinity && b == EnchantKind::Mending) ||
+        (a == EnchantKind::Mending && b == EnchantKind::Infinity))
+        return true;
+    return false;
+}
+
+bool enchantApplies(EnchantKind kind, Enchantment::Target target) {
+    if (target == Enchantment::Target::Book) return true;
+    switch (kind) {
+        case EnchantKind::Unbreaking:
+        case EnchantKind::Mending:
+            return true;
+        case EnchantKind::Protection:
+        case EnchantKind::FireProtection:
+        case EnchantKind::BlastProtection:
+        case EnchantKind::ProjectileProtection:
+        case EnchantKind::Thorns:
+            return isArmourTarget(target);
+        case EnchantKind::FeatherFalling:
+            return target == Enchantment::Target::Boots;
+        case EnchantKind::Respiration:
+        case EnchantKind::AquaAffinity:
+            return target == Enchantment::Target::Helmet;
+        case EnchantKind::Knockback:
+        case EnchantKind::FireAspect:
+        case EnchantKind::Looting:
+            return target == Enchantment::Target::Sword;
+        case EnchantKind::Sharpness:
+        case EnchantKind::Smite:
+        case EnchantKind::BaneOfArthropods:
+            return target == Enchantment::Target::Sword || target == Enchantment::Target::Axe;
+        case EnchantKind::Efficiency:
+        case EnchantKind::SilkTouch:
+        case EnchantKind::Fortune:
+            return isDiggerTarget(target);
+        case EnchantKind::Power:
+        case EnchantKind::Punch:
+        case EnchantKind::Flame:
+        case EnchantKind::Infinity:
+            return target == Enchantment::Target::Bow;
+        default:
+            return false;
+    }
+}
+
+int enchantabilityOf(ItemId item) {
+    if (!isTool(item)) return 0;
+    switch (itemInfo(item).toolTier) {
+        case ToolTier::Wood:    return 15;
+        case ToolTier::Stone:   return 5;
+        case ToolTier::Iron:    return 14;
+        case ToolTier::Gold:    return 22;
+        case ToolTier::Diamond: return 10;
+        default:                return 0;
+    }
+}
+
+Enchantment::Target enchantTargetOf(ItemId item) {
+    switch (itemInfo(item).toolType) {
+        case ToolType::Sword:   return Enchantment::Target::Sword;
+        case ToolType::Axe:     return Enchantment::Target::Axe;
+        case ToolType::Pickaxe: return Enchantment::Target::Pickaxe;
+        case ToolType::Shovel:  return Enchantment::Target::Shovel;
+        default:                return Enchantment::Target::Book;
+    }
+}
+
+int EnchantSet::levelOf(EnchantKind kind) const {
+    for (const Enchantment& entry : entries) {
+        if (entry.kind == kind) return entry.level;
+    }
+    return 0;
+}
+
+bool EnchantSet::conflictsWith(EnchantKind kind) const {
+    for (const Enchantment& entry : entries) {
+        if (enchantsConflict(entry.kind, kind)) return true;
+    }
+    return false;
+}
+
+bool addEnchant(EnchantSet& set, EnchantKind kind, int level) {
+    if (level < 1 || level > maxEnchantLevel(kind)) return false;
+    if (set.conflictsWith(kind)) return false;
+    for (Enchantment& entry : set.entries) {
+        if (entry.kind != kind) continue;
+        if (level <= entry.level) return false;
+        entry.level = level;
+        return true;
+    }
+    set.entries.push_back({kind, level});
+    return true;
+}
+
+bool removeEnchant(EnchantSet& set, EnchantKind kind) {
+    std::size_t before = set.entries.size();
+    set.entries.erase(std::remove_if(set.entries.begin(), set.entries.end(),
+                                     [kind](const Enchantment& e) { return e.kind == kind; }),
+                      set.entries.end());
+    return set.entries.size() != before;
+}
+
+int bookshelfCount(const World& world, const Vec3i& tablePos) {
+    int found = 0;
+    for (int dx = -2; dx <= 2; ++dx) {
+        for (int dz = -2; dz <= 2; ++dz) {
+            if (std::max(std::abs(dx), std::abs(dz)) != 2) continue;
+            int stepX = dx > 0 ? 1 : (dx < 0 ? -1 : 0);
+            int stepZ = dz > 0 ? 1 : (dz < 0 ? -1 : 0);
+            for (int dy = 0; dy <= 1; ++dy) {
+                Block shelf = world.blockAt(tablePos.x + dx, tablePos.y + dy, tablePos.z + dz);
+                if (shelf != Block::Bookshelf) continue;
+                Block blocker =
+                    world.blockAt(tablePos.x + stepX, tablePos.y + dy, tablePos.z + stepZ);
+                if (isOpaque(blocker)) continue;
+                ++found;
+            }
+        }
+    }
+    return std::min(found, maxBookshelfPower);
+}
+
+EnchantSet rollEnchantments(Enchantment::Target target, int enchantability, int enchantLevel,
+                            uint32_t& rng) {
+    EnchantSet chosen;
+    if (enchantLevel < 1) return chosen;
+
+    int bonus = enchantability / 4 + 1;
+    int modified = enchantLevel + rollBelow(rng, bonus) + rollBelow(rng, bonus) + 1;
+    float spread = 1.0f + (unitFloat(rng) + unitFloat(rng) - 1.0f) * 0.15f;
+    modified = std::max(1, static_cast<int>(std::lround(static_cast<float>(modified) * spread)));
+