Make merchants spawn with stacks of stackable items.

CHANGELOG.md

@@ -37,6 +37,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Retiered most sceptres and staves
 - Loot tables can now recursively reference loot tables
 - "max_sfx_channels" default now set to 30
+- Merchants now have stacks of stackable items instead of just one per slot
 
 ### Removed
 

common/src/comp/inventory/loadout_builder.rs

@@ -595,10 +595,28 @@ impl LoadoutBuilder {
                             *i = Some(Item::new_from_asset_expect(&item_id));
                         }
                     }
+                    let mut rng = rand::thread_rng();
+                    let mut item_with_amount = |item_id: &str, amount: &mut f32| {
+                        if *amount > 0.0 {
+                            let mut item = Item::new_from_asset_expect(&item_id);
+                            if *amount > 1.0 && item.is_stackable() {
+                                let n = rng.gen_range(0..amount.min(100.0) as u32).max(1);
+                                item.set_amount(n).unwrap_or_else(|_| {
+                                    panic!("{} should be stackable (n={})", item_id, n)
+                                });
+                                *amount -= n as f32;
+                            } else {
+                                *amount -= 1.0;
+                            }
+                            Some(item)
+                        } else {
+                            None
+                        }
+                    };
                     let mut bag2 = Item::new_from_asset_expect(
                         "common.items.armor.misc.bag.reliable_backpack",
                     );
-                    let ingredients = economy
+                    let mut ingredients = economy
                         .map(|e| e.unconsumed_stock.get(&Good::Ingredients))
                         .flatten()
                         .copied()
@@ -608,27 +626,32 @@ impl LoadoutBuilder {
                         if let Some(item_id) =
                             TradePricing::random_item(Good::Ingredients, ingredients)
                         {
-                            *i = Some(Item::new_from_asset_expect(&item_id));
+                            *i = item_with_amount(&item_id, &mut ingredients);
                         }
                     }
                     let mut bag3 = Item::new_from_asset_expect(
                         "common.items.armor.misc.bag.reliable_backpack",
                     );
-                    let food = economy
+                    // TODO: currently econsim spends all its food on population, resulting in none
+                    // for the players to buy; the `.max` is temporary to ensure that there's some
+                    // food for sale at every site, to be used until we have some solution like NPC
+                    // houses as a limit on econsim population growth
+                    let mut food = economy
                         .map(|e| e.unconsumed_stock.get(&Good::Food))
                         .flatten()
                         .copied()
                         .unwrap_or_default()
+                        .max(10000.0)
                         / 10.0;
                     for i in bag3.slots_mut() {
                         if let Some(item_id) = TradePricing::random_item(Good::Food, food) {
-                            *i = Some(Item::new_from_asset_expect(&item_id));
+                            *i = item_with_amount(&item_id, &mut food);
                         }
                     }
                     let mut bag4 = Item::new_from_asset_expect(
                         "common.items.armor.misc.bag.reliable_backpack",
                     );
-                    let potions = economy
+                    let mut potions = economy
                         .map(|e| e.unconsumed_stock.get(&Good::Potions))
                         .flatten()
                         .copied()
@@ -636,7 +659,7 @@ impl LoadoutBuilder {
                         / 10.0;
                     for i in bag4.slots_mut() {
                         if let Some(item_id) = TradePricing::random_item(Good::Potions, potions) {
-                            *i = Some(Item::new_from_asset_expect(&item_id));
+                            *i = item_with_amount(&item_id, &mut potions);
                         }
                     }
                     LoadoutBuilder::new()