explosion.dm

var/datum/explosions/controller/the_controller = new

/datum/explosions/controller
	var/list/datum/explosions/explosion/to_process = list()
	var/list/datum/explosions/explosion/being_processed = list()

	var/explosion_step = 0



/datum/explosions/controller/proc/make_explosion()
	explosion_step = 0
	for (var/datum/explosions/explosion/X in to_process)
		X.calculate_all()
	for (var/datum/explosions/explosion/X in to_process)
		X.merge()
	for (var/datum/explosions/explosion/X in to_process)
		being_processed += X
		to_process -= X
	do_explosion()

/datum/explosions/controller/proc/do_explosion()
	var/started_at = explosion_step
	var/still_going = 1
	spawn while (still_going)
		still_going = 0
		var/list/list/datum/explosions/data/sorted = list()
		for (var/datum/explosions/explosion/EXP in being_processed)
			if (EXP.affected.len)
				still_going = 1
				for (var/datum/explosions/data/D in EXP.affected)
					sorted[round(get_dist(D.old_turf,EXP.ground_center))] += D
		if (still_going)
			explosion_step++
			for (var/datum/explosions/data/D in sorted[explosion_step - started_at])
				D.affected.ex_act(D.power)




/datum/explosions/controller/proc/add(datum/explosions/explosion/exp)
	exp.taken_place_at = explosion_step
	to_process += exp
	spawn(0)	do_explosion()

//
// 3,7,14,35 - ideal explosion
// 14 is max. radius
// Therefore 21% of radius is max destruction.
// Therefore 50% of radius is heavy destruction
// The rest is light destruction
//

#define MAX_DESTRUCTION .21
#define HEV_DESTRUCTION .50
#define LIG_DESTRUCTION 1.0

datum/explosions/explosion
	var/turf/ground_center
	var/list/datum/explosions/data/affected = list()
	var/atom/movable/ray = new
	var/taken_place_at = 0
	var/initial_radius = 0
	var/maxi_radius = 0
	var/heav_radius = 0
	var/ligh_radius = 0

	New(turf/loc, power)
		if (loc)
			ground_center = loc
			initial_radius = power
			maxi_radius = initial_radius * MAX_DESTRUCTION
			heav_radius = initial_radius * HEV_DESTRUCTION
			ligh_radius = initial_radius * LIG_DESTRUCTION
			if (the_controller)
				the_controller.to_process += src

//
// By casting rays calculate which tiles are affected.
// If one of tiles are affected by different waves - use the strongest one.
//
datum/explosions/data
	var/atom/affected
	var/turf/old_turf
	var/power = 0
	New (what, power, datum/explosions/explosion/callback)
		src.affected = what
		src.old_turf = get_turf(what)
		src.power = power

datum/explosions/explosion/proc/calculate_all()
	var/list/turf/borders = range(initial_radius, ground_center) - range(initial_radius-1, ground_center)

	for (var/turf/target in borders)
		calculate_trace(ground_center, target, initial_radius)

datum/explosions/explosion/proc/calculate_trace(atom/target, initial)
	ray.loc = ground_center
	var/remain_force = initial
	do
		if (target)
			step_to(ray,target)
			var/resistance = 0
			for (var/atom/A in get_turf(ray))
				if ( (isobj(A) || isturf(A) ) && A != ray)	resistance += A:explosion_resistance
			remain_force -= resistance
			for (var/atom/A in get_turf(ray))
				affected += new (A, calc_exact(remain_force), src)
	while (remain_force > 0 || ray.loc != get_turf(target))
	return 0

datum/explosions/explosion/proc/calculate_power(atom/target, initial)
	ray.loc = ground_center
	var/remain_force = initial
	do
		if (target)
			step_to(ray,target)
			var/resistance = 0
			for (var/atom/A in get_turf(ray))
				if ( (isobj(A) || isturf(A) ) && A != ray)	resistance += A:explosion_resistance
			remain_force -= resistance
	while (remain_power > 0 || ray.loc != get_turf(target))
	return calc_exact (remain_power)

datum/explosions/explosion/proc/calc_exact(force)
	if (force >= initial_radius - maxi_radius)	return 1
	if (force >= initial_radius - heav_radius)	return 2
	if (force >= initial_radius - ligh_radius)	return 3
	return 0

datum/explosions/explosion/proc/merge()
	for (var/datum/explosions/data/chosen in affected)
		for (var/datum/explosions/data/second in affected)
			if (chosen != second && chosen.old_turf == second.old_turf)
				if (second.power > chosen.power)
					second.power = chosen.power
					affected -= chosen
					del(chosen)
				else
					affected -= second
					del(second)