contracts: use quadratic formula for scaling building cost

BibliothecaDAO · Sep 27, 2024 · 527aac6 · 527aac6
1 parent fec7fb3
commit 527aac6
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Showing 7 changed files with 21 additions and 12 deletions.
diff --git a/contracts/src/models/buildings.cairo b/contracts/src/models/buildings.cairo
@@ -594,12 +594,21 @@ impl BuildingCustomImpl of BuildingCustomTrait {
                 break;
             }
 
+            // calculate cost of building based on the formula:
+            // Cost = Base + (Base * Rate * (N - 1)²)
+            // Where:
+            //  Base = The cost of the first building
+            //  Rate = How quickly the cost goes up (a small number like 0.1 or 0.2)
+            //  N = Which number building this is (1st, 2nd, 3rd, etc.)
+            //
             let resource_cost: ResourceCost = get!(world, (building_config.resource_cost_id, index), ResourceCost);
             let mut resource = ResourceCustomImpl::get(world, (self.outer_entity_id, resource_cost.resource_type));
-            let additional_cost = PercentageImpl::get(
-                resource_cost.amount, building_general_config.cost_scale_percent.into()
+            let percentage_additional_cost = PercentageImpl::get(
+                resource_cost.amount, building_general_config.base_cost_percent_increase.into()
             );
-            let total_cost = resource_cost.amount + ((building_quantity.value.into() - 1) * additional_cost);
+            let scale_factor = building_quantity.value - 1;
+            let total_cost = resource_cost.amount
+                + (scale_factor.into() * scale_factor.into() * percentage_additional_cost);
             resource.burn(total_cost);
             resource.save(world);
             index += 1;

diff --git a/contracts/src/models/config.cairo b/contracts/src/models/config.cairo
@@ -350,7 +350,7 @@ pub struct BuildingGeneralConfig {
     #[key]
     config_id: ID,
     // cost scale percent
-    cost_scale_percent: u16,
+    base_cost_percent_increase: u16,
 }
 
 

diff --git a/contracts/src/systems/config/contracts.cairo b/contracts/src/systems/config/contracts.cairo
@@ -107,7 +107,7 @@ trait ITroopConfig {
 
 #[dojo::interface]
 trait IBuildingConfig {
-    fn set_building_general_config(ref world: IWorldDispatcher, cost_scale_percent: u16);
+    fn set_building_general_config(ref world: IWorldDispatcher, base_cost_percent_increase: u16);
     fn set_building_config(
         ref world: IWorldDispatcher,
         building_category: BuildingCategory,
@@ -529,10 +529,10 @@ mod config_systems {
 
     #[abi(embed_v0)]
     impl BuildingConfigCustomImpl of super::IBuildingConfig<ContractState> {
-        fn set_building_general_config(ref world: IWorldDispatcher, cost_scale_percent: u16) {
+        fn set_building_general_config(ref world: IWorldDispatcher, base_cost_percent_increase: u16) {
             assert_caller_is_admin(world);
 
-            set!(world, BuildingGeneralConfig { config_id: WORLD_CONFIG_ID, cost_scale_percent });
+            set!(world, BuildingGeneralConfig { config_id: WORLD_CONFIG_ID, base_cost_percent_increase });
         }
 
         fn set_building_config(

diff --git a/sdk/packages/eternum/src/config/index.ts b/sdk/packages/eternum/src/config/index.ts
@@ -76,7 +76,7 @@ export const setBuildingCategoryPopConfig = async (account: Account, provider: E
 export const setBuildingGeneralConfig = async (account: Account, provider: EternumProvider) => {
   const tx = await provider.set_building_general_config({
     signer: account,
-    cost_scale_percent: BUILDING_FIXED_COST_SCALE_PERCENT,
+    base_cost_percent_increase: BUILDING_FIXED_COST_SCALE_PERCENT,
   });
 
   console.log(`Configuring building general config ${tx.statusReceipt}...`);

diff --git a/sdk/packages/eternum/src/constants/global.ts b/sdk/packages/eternum/src/constants/global.ts
@@ -102,7 +102,7 @@ export const ONE_MONTH = 2628000;
 
 // Buildings
 export const BASE_POPULATION_CAPACITY = 5;
-export const BUILDING_FIXED_COST_SCALE_PERCENT = 1_000; // 1_000/10_000 = 10%
+export const BUILDING_FIXED_COST_SCALE_PERCENT = 5_000; // 5_000/10_000 = 50%
 // Points
 export const HYPERSTRUCTURE_POINTS_PER_CYCLE = 10;
 export const HYPERSTRUCTURE_POINTS_ON_COMPLETION = 2_000_000; // about the amount of points generated by the structure in 2 days

diff --git a/sdk/packages/eternum/src/provider/index.ts b/sdk/packages/eternum/src/provider/index.ts
@@ -879,12 +879,12 @@ export class EternumProvider extends EnhancedDojoProvider {
   }
 
   public async set_building_general_config(props: SystemProps.SetBuildingGeneralConfigProps) {
-    const { cost_scale_percent, signer } = props;
+    const { base_cost_percent_increase, signer } = props;
 
     return await this.executeAndCheckTransaction(signer, {
       contractAddress: getContractByName(this.manifest, `${NAMESPACE}-config_systems`),
       entrypoint: "set_building_general_config",
-      calldata: [cost_scale_percent],
+      calldata: [base_cost_percent_increase],
     });
   }
 

diff --git a/sdk/packages/eternum/src/types/provider.ts b/sdk/packages/eternum/src/types/provider.ts
@@ -445,7 +445,7 @@ export interface SetBuildingCategoryPopConfigProps extends SystemSigner {
 }
 
 export interface SetBuildingGeneralConfigProps extends SystemSigner {
-  cost_scale_percent: num.BigNumberish;
+  base_cost_percent_increase: num.BigNumberish;
 }
 
 export interface SetPopulationConfigProps extends SystemSigner {