diablo2d/js/game/loot.js

/* ============================================================
 * Diablo2D — loot.js : drops, gold, pickups
 * ============================================================ */
'use strict';
window.D2 = window.D2 || {};
(function (D2) {

  const rnd = Math.random;

  function goldFindMult(player) {
    return 1 + ((player.stats && player.stats.goldFind) || 0) / 100;
  }

  function magicFindOf(player) {
    return (player.stats && player.stats.magicFind) || 0;
  }

  /** main drop routine when a monster dies */
  function dropFor(game, m) {
    const p = game.player;
    const DC = D2.BAL.dropChances;
    const x = m.x, y = m.y;

    /* --- gold --- */
    let goldChance = DC.gold + (m.isElite ? 0.4 : 0) + (m.isBoss ? 1 : 0);
    if (m.isBoss) goldChance = 1;
    if (rnd() < goldChance) {
      let amount = D2.BAL.goldDropBase(m.level) * goldFindMult(p);
      if (m.isElite) amount *= 2.6;
      if (m.isBoss) amount *= 7;
      amount = Math.max(1, Math.round(amount));
      const piles = m.isBoss ? 4 : amount > 40 ? 2 : 1;
      for (let i = 0; i < piles; i++) {
        game.pickups.push(new D2.entities.Pickup('gold',
          x + (rnd() - .5) * 0.8, y + (rnd() - .5) * 0.8,
          { amount: Math.max(1, Math.round(amount / piles)) }));
      }
    }

    /* --- potions --- */
    const potChance = (DC.potionHp + DC.potionMp) * (m.isElite ? 1.8 : 1);
    if (rnd() < potChance || m.isBoss) {
      const type = rnd() < 0.62 ? 'hp' : 'mp';
      game.pickups.push(new D2.entities.Pickup('potion',
        x + (rnd() - .5) * .6, y + (rnd() - .5) * .6, { potionType: type }));
    }
    if (m.isBoss) {
      game.pickups.push(new D2.entities.Pickup('potion', x + .5, y, { potionType: 'hp' }));
      game.pickups.push(new D2.entities.Pickup('potion', x - .5, y, { potionType: 'mp' }));
    }

    /* --- gear --- */
    let gearChance = DC.gear + (m.isElite ? DC.gearEliteBonus : 0);
    if (m.isBoss) gearChance = DC.gearBoss;
    const rolls = m.isBoss ? 4 : 1;
    for (let i = 0; i < rolls; i++) {
      if (rnd() >= gearChance && !(m.isBoss && i === 0)) continue;
      const opts = {
        magicFind: magicFindOf(p),
        elite: m.isElite,
        boss: m.isBoss,
        slot: rnd() < 0.55 ? undefined :
          D2.Items.SLOTS[(rnd() * D2.Items.SLOTS.length) | 0],
      };
      if (m.isBoss && i === 0) {
        /* guaranteed flagship drop: legendary 40%, else rare */
        opts.rarity = rnd() < 0.4 ? 'legendary' : 'rare';
      }
      const item = D2.Items.rollItem(Math.max(1, m.level), opts);
      if (item) {
        game.pickups.push(new D2.entities.Pickup('item',
          x + (rnd() - .5) * 1.2, y + (rnd() - .5) * 1.2, { item }));
        if (item.rarity === 'legendary') {
          game.sfx('legendary');
          game.toast('✦ ' + item.name, 'gold');
          game.addLight(x, y, 3, '#ef8f34', 0.9, 2.5);
        } else if (item.rarity === 'rare') {
          game.sfx('pickup');
        }
      }
    }
  }

  /** barrels / urns / chests */
  function rollPropLoot(game, x, y, propType) {
    if (propType === 'shrine' || String(propType).startsWith('npc_')) return;

    if (propType === 'chest') {
      /* chests are generous */
      const n = 1 + (rnd() < 0.4 ? 1 : 0);
      for (let i = 0; i < n; i++) {
        const item = D2.Items.rollItem(Math.max(1, game.monsterLevel()),
          { magicFind: magicFindOf(game.player) + 15 });
        if (item) game.pickups.push(new D2.entities.Pickup('item', x + (rnd() - .5), y + (rnd() - .5) * .6, { item }));
      }
      const g = Math.round(D2.BAL.goldDropBase(game.monsterLevel()) * 2 * goldFindMult(game.player));
      game.pickups.push(new D2.entities.Pickup('gold', x, y + .3, { amount: g }));
      game.sfx('coin');
      return;
    }

    /* barrels & urns */
    if (rnd() < 0.45) {
      const amount = Math.max(1, Math.round(D2.BAL.goldDropBase(Math.max(1, game.monsterLevel() - 2)) * 0.5 * goldFindMult(game.player)));
      game.pickups.push(new D2.entities.Pickup('gold', x, y, { amount }));
    } else if (rnd() < 0.14) {
      game.pickups.push(new D2.entities.Pickup('potion', x, y, {
        potionType: rnd() < 0.65 ? 'hp' : 'mp'
      }));
    } else if (rnd() < 0.05) {
      const item = D2.Items.rollItem(Math.max(1, game.monsterLevel() - 1));
      if (item) game.pickups.push(new D2.entities.Pickup('item', x, y, { item }));
    }
  }

  /** collect a pickup; returns true if consumed */
  function collect(game, pk) {
    const p = game.player;
    switch (pk.kind) {
      case 'gold': {
        p.gold += pk.amount;
        game.sfx('coin', { vol: .35 });
        return true;
      }
      case 'potion': {
        if (p.potions[pk.potionType] >= D2.BAL.potionStackMax) return false;
        p.potions[pk.potionType]++;
        game.sfx('pickup', { vol: .3 });
        return true;
      }
      case 'item': {
        if (p.inventory.length >= 40) {
          game.toast(D2.i18n.t('msg.inventory_full'), 'bad');
          return false;
        }
        p.inventory.push(pk.item);
        game.sfx(pk.item.rarity === 'legendary' ? 'legendary' : 'pickup', { vol: .45 });
        if (pk.item.rarity === 'magic' || pk.item.rarity === 'rare' || pk.item.rarity === 'legendary') {
          game.toast(pk.item.name, pk.item.rarity === 'legendary' ? 'gold' : '');
        }
        if (D2.ui) D2.ui.refreshInventory();
        return true;
      }
    }
    return false;
  }

  D2.loot = { dropFor, rollPropLoot, collect };
})(window.D2);