--Red Rings v1 - Made by Nightwolf
--Inspired by "OMG THE RED RINGS" Sonic 1 hack made by Fiz

freeslot("MT_EVILRING","S_ERNG")

local rrenable = CV_RegisterVar({
	name = "redrings_enable",
	defaultvalue = "Yes",
	flags = CV_NETVAR,
	PossibleValue = CV_YesNo,
	func = function() end
})

local supermode = CV_RegisterVar({
	name = "redrings_difficulty",
	defaultvalue = tostring(0),
	flags = CV_NETVAR,
	PossibleValue = {MIN = 0, MAX = 6},
	func = function() end
})
//Difficulty settings
//0 - rings only bounce up and down
//1 - rings can bounce horizontally
//2 - rings will fall in a weird way and they can bounce horizontally
//3 - rings WILL always bounce horizontally and will fall in a weird way
//4 - nearby rings will change their horizontal speed to try to face you
//5 - nearby rings will change their both speeds to try to face you
//6 - like 5 but rings can turn into any enemy they touch (1/16 chance)

local function ringtargeting(actor,maxdist)
	if not actor.target then
		P_LookForPlayers(actor,maxdist,true)
		actor.momx = P_RandomRange(-64,64)*FRACUNIT
		actor.momy = P_RandomRange(-64,64)*FRACUNIT
	else
		local dist = R_PointToDist2(actor.x,actor.y,actor.target.x,actor.target.y)
		if dist < maxdist and P_CheckSight(actor,actor.target) then
			local angle = R_PointToAngle2(actor.x,actor.y,actor.target.x,actor.target.y)
			actor.momx = P_RandomRange(32,64)*cos(angle)
			actor.momy = P_RandomRange(32,64)*sin(angle)
			if supermode.value > 4 then
				actor.momz = FixedDiv(actor.target.z-actor.z,dist)
			end
		else
			actor.target = nil
		end
	end
end

addHook("MobjCollide",function(thing,tmthing)
	if not tmthing.redrset or supermode.value < 6 then return nil end
	if not (thing.flags & MF_ENEMY) or thing.type == MT_PLAYER then return nil end
	if P_RandomChance(FRACUNIT/16) then
		P_SpawnMobj(tmthing.x,tmthing.y,tmthing.z,thing.type)
		tmthing.state = S_NULL
		return nil
	end
end)

--Red Ring Action
function A_EvilRedRing(actor)
	--Remove red rings in special stages
	if G_IsSpecialStage(gamemap) then
		actor.state = S_NULL
		return
	end
	--Red ring setup (only once)
	if not actor.redrset then
		actor.flags = MF_SLIDEME|MF_RUNSPAWNFUNC|MF_PAIN
		actor.speed = 38*FRACUNIT
		actor.radius = 16*FRACUNIT
		actor.height = 24*FRACUNIT
		actor.deathstate = S_SPRK1
		actor.redrset = true
		actor.color = SKINCOLOR_RED
		actor.momz = -1*FRACUNIT
		if actor.ceilingz - actor.floorz < 96*FRACUNIT
			actor.state = S_NULL
			return
		end
	end
	if supermode.value == 6 then
		ringtargeting(actor,1024*FRACUNIT)
	elseif supermode.value > 1 then
		if actor.z == actor.floorz
			A_ZThrust(actor,20,(1<<16)+0)
			if supermode.value == 3 then
				actor.momx = P_RandomRange(-64,64)*FRACUNIT
				actor.momy = P_RandomRange(-64,64)*FRACUNIT
			elseif supermode.value > 3 then
				ringtargeting(actor,512*FRACUNIT)
			end
		end
		if actor.momz < 0
			actor.momz = P_RandomRange(-50,0)*FRACUNIT
		end
		if supermode.value > 2 and actor.momx == 0 and actor.momy == 0 then
			actor.momx = P_RandomRange(-64,64)*FRACUNIT
			actor.momy = P_RandomRange(-64,64)*FRACUNIT
		end
	else
		--Push rings upwards if they're on the floor
		if actor.z == actor.floorz
			A_ZThrust(actor,20,(1<<16)+1)
		end
		--Set Z Momentum to -5*FRACUNIT if rings are falling down
		if actor.momz < 0
			actor.momz = -5*FRACUNIT
		end
		if supermode.value == 1 or supermode.value == 2 then return end
		--Remove horizontal momentum
		if actor.momx != 0 or actor.momy != 0
			actor.momx = 0
			actor.momy = 0
		end
	end
end

--Red ring (MT_EVILRING) definition
mobjinfo[MT_EVILRING] = {
	doomednum = 300,
	spawnstate = S_ERNG,
	spawnhealth = 1000,
	seestate = S_NULL,
	seesound = sfx_None,
	reactiontime = MT_FLINGRING,
	attacksound = sfx_None,
	painstate = S_NULL,
	painchance = 0,
	painsound = sfx_None,
	meleestate = S_NULL,
	missilestate = S_NULL,
	deathstate = S_SPRK1,
	xdeathstate = S_NULL,
	deathsound = sfx_itemup,
	speed = 38*FRACUNIT,
	radius = 16*FRACUNIT,
	height = 24*FRACUNIT,
	dispoffset = 0,
	mass = 100,
	damage = 0,
	activesound = sfx_None,
	flags = MF_SLIDEME|MF_RUNSPAWNFUNC|MF_PAIN,
	raisestate = S_NULL
}

--Red ring main state (S_ERNG)
states[S_ERNG] = {
	sprite = SPR_RRNG,
	frame = 0,
	tics = 1,
	action = A_EvilRedRing,
	var1 = 0,
	var2 = 0,
	nextstate = S_ERNG
}

addHook("PlayerThink", function(p)
	if rrenable.value == 0 then return end
	if gamemap != nil
		--Bonus type > 0 --> Boss (bonustype == 1) or ERZ3 Boss (bonustype == 2)
		if mapheaderinfo[gamemap].bonustype > 0
			--If on boss level, limit ring count to 1
			if p.rings > 1
				p.rings = 1
			end
			return
		end
	end
	--If not on boss level, take all rings from player
	if p.rings > 0
		p.rings = 0
	end
end)

--If not in netgame give player 1 second of invincibility after (re)spawn
--This was added to prevent rings from killing you constantly after respawn
addHook("PlayerSpawn", function(p)
	if rrenable.value == 1 and netgame == false then
		p.powers[pw_flashing] = TICRATE
	end
end)

addHook("MobjThinker",function(mo)
	if mo.redringdeletelater then
		P_SpawnMobj(mo.x,mo.y,mo.z,MT_EVILRING)
		mo.state = S_NULL
	end
end)

addHook("MobjSpawn",function(mo)
	if rrenable.value == 0 then return nil end
	if mo.type == MT_RING or mo.flags & MF_MONITOR then
		mo.redringdeletelater = true
	elseif mo.type == MT_FLINGRING then
		mo.state = S_SPRK1
	end
end)