add rare big webs to the chasms, to give them a unique feature

chasms/init.lua

@@ -4,6 +4,8 @@ local maxy = tonumber(minetest.settings:get("chasms_maxy")) or -50
 local miny = tonumber(minetest.settings:get("chasms_miny")) or -2500
 local falloff = tonumber(minetest.settings:get("chasms_falloff")) or 100
 
+local web_probability = 0.1 -- the chance that a given mapblock will have webbing criss-crossing the chasm
+
 local chasms_threshold = tonumber(minetest.settings:get("chasms_threshold")) or 0.9
 local np_chasms_default = {
 	offset = 0,
@@ -61,12 +63,44 @@ local get_intensity = function(y)
 end
 
 local c_air = minetest.get_content_id("air")
+local c_web
+
+local big_webs_path = minetest.get_modpath("big_webs")
+if big_webs_path then
+	c_web = minetest.get_content_id("big_webs:webbing")
+end
+
+local z_displace = 10000
 
 minetest.register_on_generated(function(minp, maxp, seed)
 	if minp.y >= maxy or maxp.y <= miny then
 		return
 	end
 	
+	-- build a set of web patterns
+	local webs
+	if big_webs_path then
+		local seed = math.random()*10000000
+		math.randomseed(minp.y + z_displace*minp.z) -- use consistent seeds across the x axis
+		if math.random() < web_probability then
+			webs = {}
+			for count = 1, math.random(10,30) do
+				local width = math.random(5, 20)
+				local direction_vertical = math.random() > 0.5
+				local web_y = math.random(minp.y+8, maxp.y-8)
+				local web_z = math.random(minp.z+8, maxp.z-8)
+				for i = -math.floor(width/2), math.ceil(width/2) do
+					if direction_vertical then
+						webs[(web_y+i) + web_z*z_displace] = true
+					else
+						webs[web_y + (web_z+i)*z_displace] = true
+					end
+				end
+			end
+		end
+		math.randomseed(seed)
+	end
+	
 	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
 	vm:get_data(data)
 
@@ -83,9 +117,19 @@ minetest.register_on_generated(function(minp, maxp, seed)
 		local waver = math.min(math.max(math.floor(waver_data[i]+0.5), -waver_strength), waver_strength)
 		local intensity = get_intensity(y)
 		if chasm_data[chasm_area:index(x+waver, y, z)]*intensity > chasms_threshold then
-			data[i] = c_air
+			if webs then
+				if webs[y + z*z_displace] and math.random() < 0.85 then -- random holes in the web
+					data[i] = c_web
+					minetest.get_node_timer({x=x,y=y,z=z}):start(1) -- this timer will check for unsupported webs
+				else
+					data[i] = c_air
+				end
+			else
+				data[i] = c_air
+			end
 		end
 	end
+	
 	vm:set_data(data)
 	vm:calc_lighting()
 	vm:write_to_map()

chasms/mod.conf

@@ -1,3 +1,3 @@
 name=chasms
 depends=mapgen_helper
-optional_depends=df_caverns
+optional_depends=df_caverns, big_webs