[MIRROR] Makes gas visuals send less assets [MDB IGNORE] (#25213)

* Makes gas visuals send less assets (#78955)

![Discord_2023-10-12_13-21-06](https://github.com/tgstation/tgstation/assets/1234602/e13cb015-dd94-48d9-a593-4258609049d1)

~~I'll see how this works out for the downstream, if it improves the
situation for them I'll check the profiler to see how much it affects
performance.~~

This reduces assets that need to be sent to the client, how much is hard
to tell but a downstream that was having issues due to it got reduced
issues when testing with this. Server side costs are roughly equivalent
now that I switched to using a straight color in the color matrix
filter.

* Makes gas visuals send less assets

---------

Co-authored-by: Emmett Gaines <[email protected]>

code/__HELPERS/colors.dm

@@ -17,6 +17,18 @@
 
 	return final_color
 
+/// Given a color in the format of "#RRGGBB" or "#RRGGBBAA", gives back a 4 entry list with the number values of each
+/proc/split_color(color)
+	var/list/output = list()
+	output += hex2num(copytext(color, 2, 4))
+	output += hex2num(copytext(color, 4, 6))
+	output += hex2num(copytext(color, 6, 8))
+	if(length(color) == 9)
+		output += hex2num(copytext(color, 8, 10))
+	else
+		output += 255
+	return output
+
 ///Returns a random color picked from a list, has 2 modes (0 and 1), mode 1 doesn't pick white, black or gray
 /proc/random_colour(mode = 0)
 	switch(mode)

code/modules/atmospherics/machinery/datum_pipeline.dm

@@ -325,20 +325,18 @@
 	if(gas_visuals[icon_file])
 		return gas_visuals[icon_file]
 
-	var/obj/effect/abstract/new_overlay = new
+	var/obj/effect/abstract/gas_visual/new_overlay = new
 	new_overlay.icon = icon_file
-	new_overlay.appearance_flags = RESET_COLOR | KEEP_APART
-	new_overlay.vis_flags = VIS_INHERIT_ICON_STATE | VIS_INHERIT_LAYER | VIS_INHERIT_PLANE | VIS_INHERIT_ID
-	new_overlay.color = gasmix_color
+	new_overlay.ChangeColor(gasmix_color)
 
 	gas_visuals[icon_file] = new_overlay
 	return new_overlay
 
 /// Called when the gasmix color has changed and the gas visuals need to be updated.
 /datum/pipeline/proc/UpdateGasVisuals()
 	for(var/icon/source as anything in gas_visuals)
-		var/obj/effect/abstract/overlay = gas_visuals[source]
-		animate(overlay, time=5, color=gasmix_color)
+		var/obj/effect/abstract/gas_visual/overlay = gas_visuals[source]
+		overlay.ChangeColor(gasmix_color)
 
 /// After updating, this proc handles looking at the new gas mixture and blends the colors together according to percentage of the gas mix.
 /datum/pipeline/proc/CalculateGasmixColor(datum/gas_mixture/source)
@@ -370,3 +368,24 @@
 	if(gasmix_color != current_color)
 		gasmix_color = current_color
 		UpdateGasVisuals()
+
+/obj/effect/abstract/gas_visual
+	appearance_flags  = RESET_COLOR | KEEP_APART
+	vis_flags = VIS_INHERIT_ICON_STATE | VIS_INHERIT_LAYER | VIS_INHERIT_PLANE | VIS_INHERIT_ID
+	var/current_color
+	var/color_filter
+
+/obj/effect/abstract/gas_visual/Initialize(mapload)
+	. = ..()
+	color_filter = filter(type="color", color=matrix())
+	filters += color_filter
+	color_filter = filters[filters.len]
+	if(current_color)
+		animate(color_filter, color=current_color, time=5)
+
+/obj/effect/abstract/gas_visual/proc/ChangeColor(new_color)
+	current_color = new_color
+	if(isnull(color_filter))
+		// Called before init
+		return
+	animate(color_filter, time=5, color=new_color)