Adds strains framework (tgstation#15790)

Co-authored-by: TiviPlus <[email protected]>

code/__DEFINES/mobs.dm

@@ -520,6 +520,7 @@ GLOBAL_LIST_INIT(xenoupgradetiers, list(XENO_UPGRADE_BASETYPE, XENO_UPGRADE_INVA
 #define CASTE_DO_NOT_ANNOUNCE_DEATH (1<<14) // xenos with this flag wont be announced to hive when dying
 #define CASTE_STAGGER_RESISTANT (1<<15) //Resistant to some forms of stagger, such as projectiles
 #define CASTE_HAS_WOUND_MASK (1<<16) //uses an alpha mask for wounded states
+#define CASTE_EXCLUDE_STRAINS (1<<17) // denotes castes/basetypes that should be excluded from being evoable as a strain
 
 // Xeno defines that affect evolution, considering making a new var for these
 #define CASTE_LEADER_TYPE (1<<16) //Whether we are a leader type caste, such as the queen, shrike or ?king?, and is affected by queen ban and playtime restrictions

code/__DEFINES/traits.dm

@@ -264,6 +264,7 @@
 //regress and caste swap UI
 #define TRAIT_CASTE_SWAP "caste_swap"
 #define TRAIT_REGRESSING "regressing"
+#define TRAIT_STRAIN_SWAP "strain swap"
 
 ///Pauses campaign mission timer
 #define CAMPAIGN_MISSION_TIMER_PAUSED "campaign_mission_timer_paused"

code/_globalvars/bitfields.dm

@@ -377,7 +377,8 @@ GLOBAL_LIST_INIT(bitfields, list(
 		"CASTE_PLASMADRAIN_IMMUNE" = CASTE_PLASMADRAIN_IMMUNE,
 		"CASTE_NOT_IN_BIOSCAN" = CASTE_NOT_IN_BIOSCAN,
 		"CASTE_DO_NOT_ANNOUNCE_DEATH" = CASTE_DO_NOT_ANNOUNCE_DEATH,
-		"CASTE_STAGGER_RESISTANT" = CASTE_STAGGER_RESISTANT
+		"CASTE_STAGGER_RESISTANT" = CASTE_STAGGER_RESISTANT,
+		"CASTE_EXCLUDE_STRAINS" = CASTE_EXCLUDE_STRAINS,
 	),
 	"can_flags" = list(
 		"CASTE_CAN_HOLD_FACEHUGGERS" = CASTE_CAN_HOLD_FACEHUGGERS,

code/modules/mob/living/carbon/xenomorph/castes/hunter/castedatum_hunter.dm

@@ -111,7 +111,7 @@
 	sunder_recover = 1
 
 	// *** Flags *** //
-	caste_flags = CASTE_INNATE_HEALING|CASTE_INNATE_PLASMA_REGEN|CASTE_HIDE_IN_STATUS
+	caste_flags = CASTE_INNATE_HEALING|CASTE_INNATE_PLASMA_REGEN|CASTE_HIDE_IN_STATUS|CASTE_EXCLUDE_STRAINS
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED|CASTE_CAN_BE_GIVEN_PLASMA|CASTE_CAN_BE_LEADER|CASTE_CAN_HEAL_WITHOUT_QUEEN
 
 	// *** Defense *** //

code/modules/mob/living/carbon/xenomorph/evo_datum.dm

@@ -1,3 +1,5 @@
+//! TODO: this needs a refactor/UI rewor at some point, we've probably bolted too much onto this over time
+
 /// Empty datum parent for use as evolution panel entrance.
 /datum/evolution_panel
 	// Empty
@@ -39,7 +41,7 @@
 			"type_path" = caste.type,
 			"name" = caste.display_name,
 			"abilities" = list(),
-			"instant_evolve" = (caste.caste_flags & CASTE_INSTANT_EVOLUTION || (HAS_TRAIT(xeno, TRAIT_CASTE_SWAP) || HAS_TRAIT(xeno, TRAIT_REGRESSING))),
+			"instant_evolve" = (caste.caste_flags & CASTE_INSTANT_EVOLUTION || (HAS_TRAIT(xeno, TRAIT_STRAIN_SWAP) || HAS_TRAIT(xeno, TRAIT_CASTE_SWAP) || HAS_TRAIT(xeno, TRAIT_REGRESSING))),
 		)
 		for(var/ability in caste.actions)
 			var/datum/action/ability/xeno_action/xeno_ability = ability
@@ -86,3 +88,4 @@
 	. = ..()
 	REMOVE_TRAIT(user, TRAIT_CASTE_SWAP, TRAIT_CASTE_SWAP)
 	REMOVE_TRAIT(user, TRAIT_REGRESSING, TRAIT_REGRESSING)
+	REMOVE_TRAIT(user, TRAIT_STRAIN_SWAP, TRAIT_STRAIN_SWAP)

code/modules/mob/living/carbon/xenomorph/evolution.dm

@@ -16,14 +16,27 @@
 	set desc = "Change into another caste in the same tier."
 	set category = "Alien"
 
-	if(world.time - (GLOB.key_to_time_of_caste_swap[key] ? GLOB.key_to_time_of_caste_swap[key] : -INFINITY) < 9000) //casteswap timer, 15 minutes
+	if(world.time - (GLOB.key_to_time_of_caste_swap[key] ? GLOB.key_to_time_of_caste_swap[key] : -INFINITY) < (15 MINUTES))
 		to_chat(src, span_warning("Your caste swap timer is not done yet."))
 		return
 
 	SStgui.close_user_uis(src, GLOB.evo_panel)
 	ADD_TRAIT(src, TRAIT_CASTE_SWAP, TRAIT_CASTE_SWAP)
 	GLOB.evo_panel.ui_interact(src)
 
+/mob/living/carbon/xenomorph/verb/strain_swap()
+	set name = "Strain Swap"
+	set desc = "Change into a strain of your current caste."
+	set category = "Alien"
+
+	if(world.time - (GLOB.key_to_time_of_caste_swap[key] ? GLOB.key_to_time_of_caste_swap[key] : -INFINITY) < (5 MINUTES)) // yes this is shared
+		to_chat(src, span_warning("Your caste swap timer is not done yet."))
+		return
+
+	SStgui.close_user_uis(src, GLOB.evo_panel)
+	ADD_TRAIT(src, TRAIT_STRAIN_SWAP, TRAIT_STRAIN_SWAP)
+	GLOB.evo_panel.ui_interact(src)
+
 /mob/living/carbon/xenomorph/verb/regress()
 	set name = "Regress"
 	set desc = "Regress into a lower form."
@@ -36,6 +49,8 @@
 ///Creates a list of possible /datum/xeno_caste options for a caste based on their tier.
 /mob/living/carbon/xenomorph/proc/get_evolution_options()
 	. = list()
+	if(HAS_TRAIT(src, TRAIT_STRAIN_SWAP))
+		return xeno_caste.get_strain_options()
 	if(HAS_TRAIT(src, TRAIT_CASTE_SWAP))
 		switch(tier)
 			if(XENO_TIER_ZERO, XENO_TIER_FOUR)

code/modules/mob/living/carbon/xenomorph/xeno_defines.dm

@@ -245,6 +245,30 @@
 		current_type = initial(current_type.parent_type)
 	return current_type
 
+/// basetype = list(strain1, strain2)
+GLOBAL_LIST_INIT(strain_list, init_glob_strain_list())
+/proc/init_glob_strain_list()
+	var/list/strain_list = list()
+	for(var/datum/xeno_caste/root_caste AS in GLOB.xeno_caste_datums)
+		if(root_caste.parent_type != /datum/xeno_caste)
+			continue
+		strain_list[root_caste] = list()
+		for(var/datum/xeno_caste/typepath AS in subtypesof(root_caste))
+			if(typepath::upgrade != XENO_UPGRADE_BASETYPE)
+				continue
+			if(typepath::caste_flags & CASTE_EXCLUDE_STRAINS)
+				continue
+			strain_list[root_caste] += typepath
+	return strain_list
+
+///returns a list of strains(xeno castedatum paths) that this caste can currently evolve to
+/datum/xeno_caste/proc/get_strain_options()
+	var/datum/xeno_caste/root_type = type
+	while(initial(root_type.parent_type) != /datum/xeno_caste)
+		root_type = root_type::parent_type
+	var/list/options = GLOB.strain_list[root_type]
+	return options?.Copy()
+
 /mob/living/carbon/xenomorph
 	name = "Drone"
 	desc = "What the hell is THAT?"

code/modules/unit_tests/xeno_logical_scaling.dm

@@ -1,16 +1,15 @@
 /datum/unit_test/xeno_logical_scaling/Run()
 	var/list/by_xeno = list()
-	for(var/i in subtypesof(/datum/xeno_caste))
-		var/datum/xeno_caste/caste = i
+	for(var/datum/xeno_caste/caste AS in subtypesof(/datum/xeno_caste))
 		var/typepath = initial(caste.caste_type_path)
 		var/upgrade = initial(caste.upgrade)
 		if(isnull(typepath))
-			Fail("[i] has a null caste_type_path")
+			Fail("[caste] has a null caste_type_path")
 			continue
-		if(upgrade == "basetype")
+		if(upgrade == XENO_UPGRADE_BASETYPE)
 			continue
 		if(isnull(upgrade))
-			Fail("[i] has a null upgrade")
+			Fail("[caste] has a null upgrade")
 			continue
 		if(!("[typepath]" in by_xeno))
 			by_xeno["[typepath]"] = list()