[Feature][Balance] Add critical captures, update shake probability to match gen 6 (#4791)

* Change shake probability to match Gen 6

* Add critical captures, update shake probability to gen 6

* Change IntegerHolder to NumberHolder

* Adjust dex count thresholds for multiplier

* Disable critical captures in fresh start runs

* Skip first shake check for critical captures

* Move shake check for crit captures to after first shake

* Use less insane catch formula

* Integer to number in bounceanim signature

* Use max crit catch dex multiplier in daily runs

* Adjust crit capture animation

---------

Co-authored-by: innerthunder <168692175+innerthunder@users.noreply.github.com>
Co-authored-by: NightKev <34855794+DayKev@users.noreply.github.com>

src/data/pokeball.ts

@@ -1,3 +1,4 @@
+import { NumberHolder } from "#app/utils";
 import { PokeballType } from "#enums/pokeball";
 import BattleScene from "../battle-scene";
 import i18next from "i18next";
@@ -82,11 +83,38 @@ export function getPokeballTintColor(type: PokeballType): number {
   }
 }
 
-export function doPokeballBounceAnim(scene: BattleScene, pokeball: Phaser.GameObjects.Sprite, y1: number, y2: number, baseBounceDuration: integer, callback: Function) {
+/**
+ * Gets the critical capture chance based on number of mons registered in Dex and modified {@link https://bulbapedia.bulbagarden.net/wiki/Catch_rate Catch rate}
+ * Formula from {@link https://www.dragonflycave.com/mechanics/gen-vi-vii-capturing Dragonfly Cave Gen 6 Capture Mechanics page}
+ * @param scene {@linkcode BattleScene} current BattleScene
+ * @param modifiedCatchRate the modified catch rate as calculated in {@linkcode AttemptCapturePhase}
+ * @returns the chance of getting a critical capture, out of 256
+ */
+export function getCriticalCaptureChance(scene: BattleScene, modifiedCatchRate: number): number {
+  if (scene.gameMode.isFreshStartChallenge()) {
+    return 0;
+  }
+  const dexCount = scene.gameData.getSpeciesCount(d => !!d.caughtAttr);
+  const catchingCharmMultiplier = new NumberHolder(1);
+  //scene.findModifier(m => m instanceof CriticalCatchChanceBoosterModifier)?.apply(catchingCharmMultiplier);
+  const dexMultiplier = scene.gameMode.isDaily || dexCount > 800 ? 2.5
+    : dexCount > 600 ? 2
+      : dexCount > 400 ? 1.5
+        : dexCount > 200 ? 1
+          : dexCount > 100 ? 0.5
+            : 0;
+  return Math.floor(catchingCharmMultiplier.value * dexMultiplier * Math.min(255, modifiedCatchRate) / 6);
+}
+
+export function doPokeballBounceAnim(scene: BattleScene, pokeball: Phaser.GameObjects.Sprite, y1: number, y2: number, baseBounceDuration: number, callback: Function, isCritical: boolean = false) {
   let bouncePower = 1;
   let bounceYOffset = y1;
   let bounceY = y2;
   const yd = y2 - y1;
+  const x0 = pokeball.x;
+  const x1 = x0 + 3;
+  const x2 = x0 - 3;
+  let critShakes = 4;
 
   const doBounce = () => {
     scene.tweens.add({
@@ -117,5 +145,40 @@ export function doPokeballBounceAnim(scene: BattleScene, pokeball: Phaser.GameOb
     });
   };
 
+  const doCritShake = () => {
+    scene.tweens.add({
+      targets: pokeball,
+      x: x2,
+      duration: 125,
+      ease: "Linear",
+      onComplete: () => {
+        scene.tweens.add({
+          targets: pokeball,
+          x: x1,
+          duration: 125,
+          ease: "Linear",
+          onComplete: () => {
+            critShakes--;
+            if (critShakes > 0) {
+              doCritShake();
+            } else {
+              scene.tweens.add({
+                targets: pokeball,
+                x: x0,
+                duration: 60,
+                ease: "Linear",
+                onComplete: () => scene.time.delayedCall(500, doBounce)
+              });
+            }
+          }
+        });
+      }
+    });
+  };
+
+  if (isCritical) {
+    scene.time.delayedCall(500, doCritShake);
+  } else {
     doBounce();
   }
+}

src/phases/attempt-capture-phase.ts

@@ -2,7 +2,7 @@ import { BattlerIndex } from "#app/battle";
 import BattleScene from "#app/battle-scene";
 import { PLAYER_PARTY_MAX_SIZE } from "#app/constants";
 import { SubstituteTag } from "#app/data/battler-tags";
-import { doPokeballBounceAnim, getPokeballAtlasKey, getPokeballCatchMultiplier, getPokeballTintColor } from "#app/data/pokeball";
+import { doPokeballBounceAnim, getPokeballAtlasKey, getPokeballCatchMultiplier, getPokeballTintColor, getCriticalCaptureChance } from "#app/data/pokeball";
 import { getStatusEffectCatchRateMultiplier } from "#app/data/status-effect";
 import { addPokeballCaptureStars, addPokeballOpenParticles } from "#app/field/anims";
 import { EnemyPokemon } from "#app/field/pokemon";
@@ -52,8 +52,10 @@ export class AttemptCapturePhase extends PokemonPhase {
     const catchRate = pokemon.species.catchRate;
     const pokeballMultiplier = getPokeballCatchMultiplier(this.pokeballType);
     const statusMultiplier = pokemon.status ? getStatusEffectCatchRateMultiplier(pokemon.status.effect) : 1;
-    const x = Math.round((((_3m - _2h) * catchRate * pokeballMultiplier) / _3m) * statusMultiplier);
+    const modifiedCatchRate = Math.round((((_3m - _2h) * catchRate * pokeballMultiplier) / _3m) * statusMultiplier);
-    const y = Math.round(65536 / Math.sqrt(Math.sqrt(255 / x)));
+    const shakeProbability = Math.round(65536 / Math.pow((255 / modifiedCatchRate), 0.1875)); // Formula taken from gen 6
+    const criticalCaptureChance = getCriticalCaptureChance(this.scene, modifiedCatchRate);
+    const isCritical = pokemon.randSeedInt(256) < criticalCaptureChance;
     const fpOffset = pokemon.getFieldPositionOffset();
 
     const pokeballAtlasKey = getPokeballAtlasKey(this.pokeballType);
@@ -61,17 +63,19 @@ export class AttemptCapturePhase extends PokemonPhase {
     this.pokeball.setOrigin(0.5, 0.625);
     this.scene.field.add(this.pokeball);
 
-    this.scene.playSound("se/pb_throw");
+    this.scene.playSound("se/pb_throw", isCritical ? { rate: 0.2 } : undefined); // Crit catch throws are higher pitched
     this.scene.time.delayedCall(300, () => {
       this.scene.field.moveBelow(this.pokeball as Phaser.GameObjects.GameObject, pokemon);
     });
 
     this.scene.tweens.add({
+      // Throw animation
       targets: this.pokeball,
       x: { value: 236 + fpOffset[0], ease: "Linear" },
       y: { value: 16 + fpOffset[1], ease: "Cubic.easeOut" },
       duration: 500,
       onComplete: () => {
+        // Ball opens
         this.pokeball.setTexture("pb", `${pokeballAtlasKey}_opening`);
         this.scene.time.delayedCall(17, () => this.pokeball.setTexture("pb", `${pokeballAtlasKey}_open`));
         this.scene.playSound("se/pb_rel");
@@ -80,30 +84,33 @@ export class AttemptCapturePhase extends PokemonPhase {
         addPokeballOpenParticles(this.scene, this.pokeball.x, this.pokeball.y, this.pokeballType);
 
         this.scene.tweens.add({
+          // Mon enters ball
           targets: pokemon,
           duration: 500,
           ease: "Sine.easeIn",
           scale: 0.25,
           y: 20,
           onComplete: () => {
+            // Ball closes
             this.pokeball.setTexture("pb", `${pokeballAtlasKey}_opening`);
             pokemon.setVisible(false);
             this.scene.playSound("se/pb_catch");
             this.scene.time.delayedCall(17, () => this.pokeball.setTexture("pb", `${pokeballAtlasKey}`));
 
             const doShake = () => {
+              // After the overall catch rate check, the game does 3 shake checks before confirming the catch.
               let shakeCount = 0;
               const pbX = this.pokeball.x;
               const shakeCounter = this.scene.tweens.addCounter({
                 from: 0,
                 to: 1,
-                repeat: 4,
+                repeat: isCritical ? 2 : 4, // Critical captures only perform 1 shake check
                 yoyo: true,
                 ease: "Cubic.easeOut",
                 duration: 250,
                 repeatDelay: 500,
                 onUpdate: t => {
-                  if (shakeCount && shakeCount < 4) {
+                  if (shakeCount && shakeCount < (isCritical ? 2 : 4)) {
                     const value = t.getValue();
                     const directionMultiplier = shakeCount % 2 === 1 ? 1 : -1;
                     this.pokeball.setX(pbX + value * 4 * directionMultiplier);
@@ -114,13 +121,18 @@ export class AttemptCapturePhase extends PokemonPhase {
                   if (!pokemon.species.isObtainable()) {
                     shakeCounter.stop();
                     this.failCatch(shakeCount);
-                  } else if (shakeCount++ < 3) {
+                  } else if (shakeCount++ < (isCritical ? 1 : 3)) {
-                    if (pokeballMultiplier === -1 || pokemon.randSeedInt(65536) < y) {
+                    // Shake check (skip check for critical or guaranteed captures, but still play the sound)
+                    if (pokeballMultiplier === -1 || isCritical || modifiedCatchRate >= 255 || pokemon.randSeedInt(65536) < shakeProbability) {
                       this.scene.playSound("se/pb_move");
                     } else {
                       shakeCounter.stop();
                       this.failCatch(shakeCount);
                     }
+                  } else if (isCritical && pokemon.randSeedInt(65536) >= shakeProbability) {
+                    // Above, perform the one shake check for critical captures after the ball shakes once
+                    shakeCounter.stop();
+                    this.failCatch(shakeCount);
                   } else {
                     this.scene.playSound("se/pb_lock");
                     addPokeballCaptureStars(this.scene, this.pokeball);
@@ -153,7 +165,8 @@ export class AttemptCapturePhase extends PokemonPhase {
               });
             };
 
-            this.scene.time.delayedCall(250, () => doPokeballBounceAnim(this.scene, this.pokeball, 16, 72, 350, doShake));
+            // Ball bounces (handled in pokemon.ts)
+            this.scene.time.delayedCall(250, () => doPokeballBounceAnim(this.scene, this.pokeball, 16, 72, 350, doShake, isCritical));
           }
         });
       }