Cleaned up equipment stripping skills (#3493)

* Fixes #3476.
* Centralized all equipment stripping skills to skill_strip_equip.
* Updated success rates and durations to match official.
Thanks to @mrjnumber1!

src/map/skill.cpp

@@ -130,6 +130,7 @@ int overbrand_brandish_nounit_pos;
 static char dir_ka = -1; // Holds temporary direction to the target for SR_KNUCKLEARROW
 
 //Early declaration
+bool skill_strip_equip(struct block_list *src, struct block_list *target, uint16 skill_id, uint16 skill_lv);
 int skill_block_check(struct block_list *bl, enum sc_type type, uint16 skill_id);
 static int skill_check_unit_range (struct block_list *bl, int x, int y, uint16 skill_id, uint16 skill_lv);
 static int skill_check_unit_range2 (struct block_list *bl, int x, int y, uint16 skill_id, uint16 skill_lv, bool isNearNPC);
@@ -1529,9 +1530,7 @@ int skill_additional_effect(struct block_list* src, struct block_list *bl, uint1
 		sc_start(src,bl,SC_FLING,100, sd?sd->spiritball_old:5,skill_get_time(skill_id,skill_lv));
 		break;
 	case GS_DISARM:
-		rate = sstatus->dex / (4 * (7 - skill_lv)) + sstatus->luk / (4 * (6 - skill_lv));
-		rate = rate + status_get_lv(src) - (tstatus->agi * rate / 100) - tstatus->luk - status_get_lv(bl);
-		skill_strip_equip(src,bl, EQP_WEAPON, rate, skill_lv, skill_get_time(skill_id,skill_lv));
+		skill_strip_equip(src, bl, skill_id, skill_lv);
 		clif_skill_nodamage(src,bl,skill_id,skill_lv,1);
 		break;
 	case NPC_EVILLAND:
@@ -1563,15 +1562,10 @@ int skill_additional_effect(struct block_list* src, struct block_list *bl, uint1
 		sc_start4(src,bl,SC_BURNING,100,skill_lv,1000,src->id,0,skill_get_time(skill_id,skill_lv));
 		break;
 	case WL_EARTHSTRAIN:
-		{
-			uint16 i;
-			const int pos[5] = { EQP_WEAPON, EQP_HELM, EQP_SHIELD, EQP_ARMOR, EQP_ACC };
+		if (dmg_lv != ATK_DEF) // Only strip if we make a successful hit.
+			break;
 
-			if (dmg_lv != ATK_DEF) // Only strip if we make a successful hit.
-				break;
-			for (i = 0; i < skill_lv; i++)
-					skill_strip_equip(src, bl, pos[i], 5 * skill_lv, skill_lv, skill_get_time2(skill_id, skill_lv));
-		}
+		skill_strip_equip(src, bl, skill_id, skill_lv);
 		break;
 	case WL_JACKFROST:
 	case NPC_JACKFROST:
@@ -2623,32 +2617,135 @@ int skill_break_equip(struct block_list *src, struct block_list *bl, unsigned sh
 	return where; //Return list of pieces broken.
 }
 
-int skill_strip_equip(struct block_list *src,struct block_list *bl, unsigned short where, int rate, int lv, int time)
+/**
+ * Strip equipment from a target
+ * @param src: Source of call
+ * @param target: Target to strip
+ * @param skill_id: Skill used
+ * @param skill_lv: Skill level used
+ * @return True on successful strip or false otherwise
+ */
+bool skill_strip_equip(struct block_list *src, struct block_list *target, uint16 skill_id, uint16 skill_lv)
 {
-	struct status_change *sc;
+	nullpo_retr(false, src);
+	nullpo_retr(false, target);
+
+	struct status_change *tsc = status_get_sc(target);
+
+	if (!tsc || tsc->option&OPTION_MADOGEAR) // Mado Gear cannot be divested [Ind]
+		return false;
+
 	const int pos[5]             = {EQP_WEAPON, EQP_SHIELD, EQP_ARMOR, EQP_HELM, EQP_ACC};
 	const enum sc_type sc_atk[5] = {SC_STRIPWEAPON, SC_STRIPSHIELD, SC_STRIPARMOR, SC_STRIPHELM, SC__STRIPACCESSORY};
 	const enum sc_type sc_def[5] = {SC_CP_WEAPON, SC_CP_SHIELD, SC_CP_ARMOR, SC_CP_HELM, SC_NONE};
-	int i;
+	struct status_data *sstatus = status_get_status_data(src), *tstatus = status_get_status_data(target);
+	int rate, time, location;
+
+	switch (skill_id) { // Rate
+		case RG_STRIPWEAPON:
+		case RG_STRIPARMOR:
+		case RG_STRIPSHIELD:
+		case RG_STRIPHELM:
+		case GC_WEAPONCRUSH:
+			rate = 50 * (skill_lv + 1) + 2 * (sstatus->dex - tstatus->dex);
+			break;
+		case ST_FULLSTRIP: {
+			int min_rate = 50 + 20 * skill_lv;
+
+			rate = min_rate + 2 * (sstatus->dex - tstatus->dex);
+			rate = max(min_rate, rate);
+			break;
+		}
+		case GS_DISARM:
+			rate = sstatus->dex / (4 * (7 - skill_lv)) + sstatus->luk / (4 * (6 - skill_lv));
+			rate = rate + status_get_lv(src) - (tstatus->agi * rate / 100) - tstatus->luk - status_get_lv(target);
+			break;
+		case WL_EARTHSTRAIN: {
+			int job_lv = 0;
+
+			if (src->type == BL_PC)
+				job_lv = ((TBL_PC*)src)->status.job_level;
+			rate = 6 * skill_lv + job_lv / 4 + sstatus->dex / 10;
+			break;
+		}
+		case SC_STRIPACCESSARY:
+			rate = 12 + 2 * skill_lv;
+			break;
+		default:
+			return false;
+	}
 
 	if (rnd()%100 >= rate)
-		return 0;
+		return false;
 
-	sc = status_get_sc(bl);
-	if (!sc || sc->option&OPTION_MADOGEAR ) //Mado Gear cannot be divested [Ind]
-		return 0;
+	switch (skill_id) { // Duration
+		case SC_STRIPACCESSARY:
+		case GS_DISARM:
+			time = skill_get_time(skill_id, skill_lv);
+			break;
+		case WL_EARTHSTRAIN:
+		case RG_STRIPWEAPON:
+		case RG_STRIPARMOR:
+		case RG_STRIPSHIELD:
+		case RG_STRIPHELM:
+		case GC_WEAPONCRUSH:
+		case ST_FULLSTRIP:
+			if (skill_id == WL_EARTHSTRAIN)
+				time = skill_get_time2(skill_id, skill_lv);
+			else
+				time = skill_get_time(skill_id, skill_lv);
+
+			if (target->type == BL_PC)
+				time += skill_lv + 500 * (sstatus->dex - tstatus->dex);
+			else {
+				time += 15000;
+				time += skill_lv + 500 * (sstatus->dex - tstatus->dex);
+			}
+			break;
+	}
+
+	switch (skill_id) { // Location
+		case GC_WEAPONCRUSH:
+		case RG_STRIPWEAPON:
+		case GS_DISARM:
+			location = EQP_WEAPON;
+			break;
+		case RG_STRIPARMOR:
+			location = EQP_ARMOR;
+			break;
+		case RG_STRIPSHIELD:
+			location = EQP_SHIELD;
+			break;
+		case RG_STRIPHELM:
+			location = EQP_HELM;
+			break;
+		case ST_FULLSTRIP:
+			location = EQP_WEAPON|EQP_SHIELD|EQP_ARMOR|EQP_HELM;
+			break;
+		case SC_STRIPACCESSARY:
+			location = EQP_ACC;
+			break;
+		case WL_EARTHSTRAIN:
+			location = EQP_SHIELD|EQP_ARMOR|EQP_HELM;
+			if (skill_lv >= 4)
+				location |= EQP_WEAPON;
+			if (skill_lv >= 5)
+				location |= EQP_ACC;
+			break;
+	}
 
-	for (i = 0; i < ARRAYLENGTH(pos); i++) {
-		if (where&pos[i] && sc_def[i] > SC_NONE && sc->data[sc_def[i]])
-			where&=~pos[i];
+	for (uint8 i = 0; i < ARRAYLENGTH(pos); i++) {
+		if (location&pos[i] && sc_def[i] > SC_NONE && tsc->data[sc_def[i]])
+			location &=~ pos[i];
 	}
-	if (!where) return 0;
+	if (!location)
+		return false;
 
-	for (i = 0; i < ARRAYLENGTH(pos); i++) {
-		if (where&pos[i] && !sc_start(src,bl, sc_atk[i], 100, lv, time))
-			where&=~pos[i];
+	for (uint8 i = 0; i < ARRAYLENGTH(pos); i++) {
+		if (location&pos[i] && !sc_start(src, target, sc_atk[i], 100, skill_lv, time))
+			location &=~ pos[i];
 	}
-	return where?1:0;
+	return location ? true : false;
 }
 
 /**
@@ -7594,53 +7691,7 @@ int skill_castend_nodamage_id (struct block_list *src, struct block_list *bl, ui
 	case ST_FULLSTRIP:
 	case GC_WEAPONCRUSH:
 	case SC_STRIPACCESSARY: {
-		unsigned short location = 0;
-		int d = 0;
-
-		//Rate in percent
-		if ( skill_id == ST_FULLSTRIP ) {
-			i = 5 + 2*skill_lv + (sstatus->dex - tstatus->dex)/5;
-		} else if( skill_id == SC_STRIPACCESSARY ) {
-			i = 12 + 2 * skill_lv + (sstatus->dex - tstatus->dex)/5;
-		} else {
-			i = 5 + 5*skill_lv + (sstatus->dex - tstatus->dex)/5;
-		}
-
-		if (i < 5) i = 5; //Minimum rate 5%
-
-		//Duration in ms
-		if( skill_id == GC_WEAPONCRUSH){
-			d = skill_get_time(skill_id,skill_lv);
-			if(bl->type == BL_PC)
-				d += skill_lv * 15 + (sstatus->dex - tstatus->dex);
-			else
-				d += skill_lv * 30 + (sstatus->dex - tstatus->dex) / 2;
-		}else
-			d = skill_get_time(skill_id,skill_lv) + (sstatus->dex - tstatus->dex)*500;
-
-		if (d < 0) d = 0; //Minimum duration 0ms
-
-		switch (skill_id) {
-		case RG_STRIPWEAPON:
-		case GC_WEAPONCRUSH:
-			location = EQP_WEAPON;
-			break;
-		case RG_STRIPSHIELD:
-			location = EQP_SHIELD;
-			break;
-		case RG_STRIPARMOR:
-			location = EQP_ARMOR;
-			break;
-		case RG_STRIPHELM:
-			location = EQP_HELM;
-			break;
-		case ST_FULLSTRIP:
-			location = EQP_WEAPON|EQP_SHIELD|EQP_ARMOR|EQP_HELM;
-			break;
-		case SC_STRIPACCESSARY:
-			location = EQP_ACC;
-			break;
-		}
+		bool i;
 
 		//Special message when trying to use strip on FCP [Jobbie]
 		if( sd && skill_id == ST_FULLSTRIP && tsc && tsc->data[SC_CP_WEAPON] && tsc->data[SC_CP_HELM] && tsc->data[SC_CP_ARMOR] && tsc->data[SC_CP_SHIELD])
@@ -7649,8 +7700,7 @@ int skill_castend_nodamage_id (struct block_list *src, struct block_list *bl, ui
 			break;
 		}
 
-		//Attempts to strip at rate i and duration d
-		if( (i = skill_strip_equip(src,bl, location, i, skill_lv, d)) || (skill_id != ST_FULLSTRIP && skill_id != GC_WEAPONCRUSH ) )
+		if( (i = skill_strip_equip(src, bl, skill_id, skill_lv)) || (skill_id != ST_FULLSTRIP && skill_id != GC_WEAPONCRUSH ) )
 			clif_skill_nodamage(src,bl,skill_id,skill_lv,i);
 
 		//Nothing stripped.