Bubberstation/code/game/objects/explosion.dm

//TODO: Flash range does nothing currently

//A very crude linear approximatiaon of pythagoras theorem.
/proc/cheap_pythag(var/dx, var/dy)
	dx = abs(dx); dy = abs(dy);
	if(dx>=dy)	return dx + (0.5*dy)	//The longest side add half the shortest side approximates the hypotenuse
	else		return dy + (0.5*dx)

proc/trange(var/Dist=0,var/turf/Center=null)//alternative to range (ONLY processes turfs and thus less intensive)
	if(Center==null) return

	//var/x1=((Center.x-Dist)<1 ? 1 : Center.x-Dist)
	//var/y1=((Center.y-Dist)<1 ? 1 : Center.y-Dist)
	//var/x2=((Center.x+Dist)>world.maxx ? world.maxx : Center.x+Dist)
	//var/y2=((Center.y+Dist)>world.maxy ? world.maxy : Center.y+Dist)

	var/turf/x1y1 = locate(((Center.x-Dist)<1 ? 1 : Center.x-Dist),((Center.y-Dist)<1 ? 1 : Center.y-Dist),Center.z)
	var/turf/x2y2 = locate(((Center.x+Dist)>world.maxx ? world.maxx : Center.x+Dist),((Center.y+Dist)>world.maxy ? world.maxy : Center.y+Dist),Center.z)
	return block(x1y1,x2y2)


proc/explosion(turf/epicenter, devastation_range, heavy_impact_range, light_impact_range, flash_range, adminlog = 1, ignorecap = 0, flame_range = 0 ,silent = 0)
	src = null	//so we don't abort once src is deleted
	epicenter = get_turf(epicenter)

	// Archive the uncapped explosion for the doppler array
	var/orig_dev_range = devastation_range
	var/orig_heavy_range = heavy_impact_range
	var/orig_light_range = light_impact_range

	if(!ignorecap)
		// Clamp all values to MAX_EXPLOSION_RANGE
		devastation_range = min (MAX_EX_DEVESTATION_RANGE, devastation_range)
		heavy_impact_range = min (MAX_EX_HEAVY_RANGE, heavy_impact_range)
		light_impact_range = min (MAX_EX_LIGHT_RANGE, light_impact_range)
		flash_range = min (MAX_EX_FLASH_RANGE, flash_range)
		flame_range = min (MAX_EX_FLAME_RANGE, flame_range)

	spawn(0)
		var/start = world.timeofday
		if(!epicenter) return

		var/max_range = max(devastation_range, heavy_impact_range, light_impact_range, flame_range)

		if(adminlog)
			message_admins("Explosion with size ([devastation_range], [heavy_impact_range], [light_impact_range], [flame_range]) in area [epicenter.loc.name] ([epicenter.x],[epicenter.y],[epicenter.z])")
			log_game("Explosion with size ([devastation_range], [heavy_impact_range], [light_impact_range], [flame_range]) in area [epicenter.loc.name] ([epicenter.x],[epicenter.y],[epicenter.z])")

		// Play sounds; we want sounds to be different depending on distance so we will manually do it ourselves.
		// Stereo users will also hear the direction of the explosion!

		// Calculate far explosion sound range. Only allow the sound effect for heavy/devastating explosions.
		// 3/7/14 will calculate to 80 + 35

		var/far_dist = 0
		far_dist += heavy_impact_range * 5
		far_dist += devastation_range * 20

		if(!silent)
			var/frequency = get_rand_frequency()
			for(var/mob/M in player_list)
				// Double check for client
				if(M && M.client)
					var/turf/M_turf = get_turf(M)
					if(M_turf && M_turf.z == epicenter.z)
						var/dist = get_dist(M_turf, epicenter)
						// If inside the blast radius + world.view - 2
						if(dist <= round(max_range + world.view - 2, 1))
							M.playsound_local(epicenter, get_sfx("explosion"), 100, 1, frequency, falloff = 5) // get_sfx() is so that everyone gets the same sound
						// You hear a far explosion if you're outside the blast radius. Small bombs shouldn't be heard all over the station.
						else if(dist <= far_dist)
							var/far_volume = Clamp(far_dist, 30, 50) // Volume is based on explosion size and dist
							far_volume += (dist <= far_dist * 0.5 ? 50 : 0) // add 50 volume if the mob is pretty close to the explosion
							M.playsound_local(epicenter, 'sound/effects/explosionfar.ogg', far_volume, 1, frequency, falloff = 5)

		//postpone processing for a bit
		var/postponeCycles = max(round(devastation_range/8),1)
		SSlighting.postpone(postponeCycles)
		SSmachine.postpone(postponeCycles)

		if(heavy_impact_range > 1)
			var/datum/effect/system/explosion/E = new/datum/effect/system/explosion()
			E.set_up(epicenter)
			E.start()

		var/x0 = epicenter.x
		var/y0 = epicenter.y
		var/z0 = epicenter.z

		for(var/turf/T in trange(max_range, epicenter))

			var/dist = cheap_pythag(T.x - x0,T.y - y0)
			var/flame_dist = 0
			var/throw_dist = dist

			if(dist < flame_range)
				flame_dist = 1

			if(dist < devastation_range)		dist = 1
			else if(dist < heavy_impact_range)	dist = 2
			else if(dist < light_impact_range)	dist = 3
			else 								dist = 0

			//------- TURF FIRES -------

			if(T)
				if(flame_dist && prob(40) && !istype(T, /turf/space) && !T.density)
					PoolOrNew(/obj/effect/hotspot, T) //Mostly for ambience!
				if(dist > 0)
					T.ex_act(dist)

			//--- THROW ITEMS AROUND ---

			var/throw_dir = get_dir(epicenter,T)
			for(var/obj/item/I in T)
				spawn(0) //Simultaneously not one at a time
					if(I)
						var/throw_range = rand(throw_dist, max_range)
						var/turf/throw_at = get_ranged_target_turf(I, throw_dir, throw_range)
						I.throw_speed = 4 //Temporarily change their throw_speed for embedding purposes (Reset when it finishes throwing, regardless of hitting anything)
						I.throw_at(throw_at, throw_range, 2)//Throw it at 2 speed, this is purely visual anyway.


		var/took = (world.timeofday-start)/10
		//You need to press the DebugGame verb to see these now....they were getting annoying and we've collected a fair bit of data. Just -test- changes  to explosion code using this please so we can compare
		if(Debug2)	world.log << "## DEBUG: Explosion([x0],[y0],[z0])(d[devastation_range],h[heavy_impact_range],l[light_impact_range]): Took [took] seconds."

		//Machines which report explosions.
		for(var/i,i<=doppler_arrays.len,i++)
			var/obj/machinery/doppler_array/Array = doppler_arrays[i]
			if(Array)
				Array.sense_explosion(x0,y0,z0,devastation_range,heavy_impact_range,light_impact_range,took,orig_dev_range,orig_heavy_range,orig_light_range)

	return 1



proc/secondaryexplosion(turf/epicenter, range)
	for(var/turf/tile in trange(range, epicenter))
		tile.ex_act(2)