From f5371ae83fceffb04d08c736cf3362432aad0408 Mon Sep 17 00:00:00 2001
From: Evan Debenham <Evan@ShatteredPixel.com>
Date: Fri, 5 May 2023 13:10:09 -0400
Subject: [PATCH] v2.1.0: fixed interactions with grim and damage reducing
 effects

---
 .../shatteredpixeldungeon/actors/Char.java    | 17 +++++++
 .../items/weapon/enchantments/Grim.java       | 46 ++++++++++---------
 2 files changed, 42 insertions(+), 21 deletions(-)

diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/Char.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/Char.java
index 823075264..7669eb895 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/Char.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/Char.java
@@ -78,6 +78,7 @@ import com.shatteredpixel.shatteredpixeldungeon.actors.mobs.Elemental;
 import com.shatteredpixel.shatteredpixeldungeon.actors.mobs.Tengu;
 import com.shatteredpixel.shatteredpixeldungeon.actors.mobs.npcs.MirrorImage;
 import com.shatteredpixel.shatteredpixeldungeon.actors.mobs.npcs.PrismaticImage;
+import com.shatteredpixel.shatteredpixeldungeon.effects.particles.ShadowParticle;
 import com.shatteredpixel.shatteredpixeldungeon.items.Heap;
 import com.shatteredpixel.shatteredpixeldungeon.items.Item;
 import com.shatteredpixel.shatteredpixeldungeon.items.armor.glyphs.AntiMagic;
@@ -736,6 +737,22 @@ public abstract class Char extends Actor {
 		shielded -= dmg;
 		HP -= dmg;
 
+		if (HP > 0 && buff(Grim.GrimTracker.class) != null){
+
+			float finalChance = buff(Grim.GrimTracker.class).maxChance;
+			finalChance *= (float)Math.pow( ((HT - HP) / (float)HT), 2);
+
+			if (Random.Float() < finalChance) {
+				dmg += HP;
+				HP = 0;
+
+				sprite.emitter().burst( ShadowParticle.UP, 5 );
+				if (!isAlive() && buff(Grim.GrimTracker.class).qualifiesForBadge){
+					Badges.validateGrimWeapon();
+				}
+			}
+		}
+
 		if (HP < 0 && src instanceof Char && alignment == Alignment.ENEMY){
 			if (((Char) src).buff(Kinetic.KineticTracker.class) != null){
 				int dmgToAdd = -HP;
diff --git a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/enchantments/Grim.java b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/enchantments/Grim.java
index acf8a2ff0..372ffbe5b 100644
--- a/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/enchantments/Grim.java
+++ b/core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/weapon/enchantments/Grim.java
@@ -21,14 +21,13 @@
 
 package com.shatteredpixel.shatteredpixeldungeon.items.weapon.enchantments;
 
-import com.shatteredpixel.shatteredpixeldungeon.Badges;
+import com.shatteredpixel.shatteredpixeldungeon.actors.Actor;
 import com.shatteredpixel.shatteredpixeldungeon.actors.Char;
+import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Buff;
 import com.shatteredpixel.shatteredpixeldungeon.actors.hero.Hero;
-import com.shatteredpixel.shatteredpixeldungeon.effects.particles.ShadowParticle;
 import com.shatteredpixel.shatteredpixeldungeon.items.weapon.Weapon;
 import com.shatteredpixel.shatteredpixeldungeon.sprites.ItemSprite;
 import com.shatteredpixel.shatteredpixeldungeon.sprites.ItemSprite.Glowing;
-import com.watabou.utils.Random;
 
 public class Grim extends Weapon.Enchantment {
 	
@@ -39,27 +38,16 @@ public class Grim extends Weapon.Enchantment {
 
 		int level = Math.max( 0, weapon.buffedLvl() );
 
-		int enemyHealth = defender.HP - damage;
-		if (enemyHealth <= 0) return damage; //no point in proccing if they're already dead.
-
-		//scales from 0 - 50% based on how low hp the enemy is, plus 5% per level
+		//scales from 0 - 50% based on how low hp the enemy is, plus 0-5% per level
 		float maxChance = 0.5f + .05f*level;
-		float chanceMulti = (float)Math.pow( ((defender.HT - enemyHealth) / (float)defender.HT), 2);
-		float chance = maxChance * chanceMulti;
+		maxChance *= procChanceMultiplier(attacker);
 
-		chance *= procChanceMultiplier(attacker);
+		//we defer logic using an actor here so we can know the true final damage
+		//see Char.damage
+		Buff.affect(defender, GrimTracker.class).maxChance = maxChance;
 
-		if (Random.Float() < chance) {
-			
-			defender.damage( defender.HP, this );
-			defender.sprite.emitter().burst( ShadowParticle.UP, 5 );
-			
-			if (!defender.isAlive() && attacker instanceof Hero
-				//this prevents unstable from triggering grim achievement
-				&& weapon.hasEnchant(Grim.class, attacker)) {
-				Badges.validateGrimWeapon();
-			}
-			
+		if (attacker instanceof Hero && weapon.hasEnchant(Grim.class, attacker)){
+			defender.buff(GrimTracker.class).qualifiesForBadge = true;
 		}
 
 		return damage;
@@ -70,4 +58,20 @@ public class Grim extends Weapon.Enchantment {
 		return BLACK;
 	}
 
+	public static class GrimTracker extends Buff {
+
+		{
+			actPriority = Actor.VFX_PRIO;
+		}
+
+		public float maxChance;
+		public boolean qualifiesForBadge;
+
+		@Override
+		public boolean act() {
+			detach();
+			return true;
+		}
+	};
+
 }