add obsidian_lining option, clean up mapgen code

LICENSE.txt

@@ -1,6 +1,9 @@
+Note: voxelarea_iterator.lua is separately licensed under the LGPL, see that file for details.
+The rest of this mod is covered by:
+
 MIT License
 
-Copyright (c) 2017 FaceDeer
+Copyright (c) 2018 FaceDeer
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

config.lua

@@ -26,5 +26,6 @@ end
 setting("int", "spread", 400, "Approximate spacing between magma conduits")
 setting("bool", "remove_default_lava", true, "Removes default mapgen lava")
 setting("bool", "ameliorate_floods", true, "Ameliorate lava floods on the surface")
+setting("bool", "obsidian_lining", true, "Add an obsidian lining to magma conduits")
 setting("int", "upper_limit", 512, "Upper extent of magma conduits")
 setting("int", "lower_limit", -31000, "Lower extent of magma conduits")

init.lua

@@ -5,6 +5,7 @@ local modpath = minetest.get_modpath(minetest.get_current_modname())
 
 --load companion lua files
 dofile(modpath.."/config.lua")
+dofile(modpath.."/voxelarea_iterator.lua")
 
 if magma_conduits.config.remove_default_lava then
 	minetest.register_alias_force("mapgen_lava_source", "air") -- veins of lava are far more realistic
@@ -25,6 +26,7 @@ minetest.register_ore({
 		"default:stone_with_coal",
 		"default:stone_with_iron",
 		"default:stone_with_copper",
+		"default:stone_with_tin",
 		"default:stone_with_gold",
 		"default:stone_with_diamond",
 		"default:dirt",
@@ -52,31 +54,50 @@ minetest.register_ore({
 -------------------------------------------------------------------------------------------------
 -- Ameliorate lava floods on the surface world by removing lava that's poised to spill
 
-if not magma_conduits.config.ameliorate_floods then return end
+if not (magma_conduits.config.ameliorate_floods or magma_conduits.config.obsidian_lining) then return end
+
+local ameliorate_floods = magma_conduits.config.ameliorate_floods
+local obsidian_lining = magma_conduits.config.obsidian_lining
 
 local c_air = minetest.get_content_id("air")
 local c_lava = minetest.get_content_id("default:lava_source")
+local c_stone = minetest.get_content_id("default:stone")
+local c_obsidian = minetest.get_content_id("default:obsidian")
 
 local water_level = tonumber(minetest.get_mapgen_setting("water_level"))
 
-local is_adjacent_to_air = function(area, data, pos)
-	return (data[area:index(pos.x+1, pos.y, pos.z)] == c_air
-		or data[area:index(pos.x-1, pos.y, pos.z)] == c_air
-		or data[area:index(pos.x, pos.y, pos.z+1)] == c_air
-		or data[area:index(pos.x, pos.y, pos.z-1)] == c_air
-		or data[area:index(pos.x, pos.y-1, pos.z)] == c_air)
+local is_adjacent_to_air = function(area, data, x, y, z)
+	return (data[area:index(x+1, y, z)] == c_air
+		or data[area:index(x-1, y, z)] == c_air
+		or data[area:index(x, y, z+1)] == c_air
+		or data[area:index(x, y, z-1)] == c_air
+		or data[area:index(x, y-1, z)] == c_air)
 end
 
-magma_conduits.remove_unsupported_lava = function(area, data, vi)
+local remove_unsupported_lava
+remove_unsupported_lava = function(area, data, vi, x, y, z)
+	--if too far from water level, abort. Caverns are on their own.
+	if y < water_level or y > 512 or not area:contains(x, y, z) then return end
+
 	if data[vi] == c_lava then
-		local pos = area:position(vi)
-		if is_adjacent_to_air(area, data, pos) then
+		if is_adjacent_to_air(area, data, x, y, z) then
 			data[vi] = c_air
-			magma_conduits.remove_unsupported_lava(area, data, area:index(pos.x+1, pos.y, pos.z))
-			magma_conduits.remove_unsupported_lava(area, data, area:index(pos.x-1, pos.y, pos.z))
-			magma_conduits.remove_unsupported_lava(area, data, area:index(pos.x, pos.y, pos.z+1))
-			magma_conduits.remove_unsupported_lava(area, data, area:index(pos.x, pos.y, pos.z-1))
-			magma_conduits.remove_unsupported_lava(area, data, area:index(pos.x, pos.y+1, pos.z))
+			for pi, x2, y2, z2 in area:iter_xyz(x-1, y, z-1, x+1, y+1, z+1) do
+				if pi ~= vi and area:containsi(pi) then
+					remove_unsupported_lava(area, data, pi, x2, y2, z2)
+				end
+			end
+		end
+	end
+end
+
+local obsidianize = function(area, data, vi, x, y, z, minp, maxp)
+	if data[vi] == c_lava then
+		for pi in area:iter(math.max(x-1, minp.x), math.max(y-1, minp.y), math.max(z-1, minp.z),
+							math.min(x+1, maxp.x), math.min(y+1, maxp.y), math.min(z+1, maxp.z)) do
+			if data[pi] == c_stone then
+				data[pi] = c_obsidian
+			end
 		end
 	end
 end
@@ -85,33 +106,20 @@ local data = {}
 
 minetest.register_on_generated(function(minp, maxp, seed)
 	--if too far from water level, abort. Caverns are on their own.
-	if minp.y > 512 or maxp.y < water_level then
-		return
-	end
-		
-	--easy reference to commonly used values
-	local t_start = os.clock()
-	local x_max = maxp.x
-	local y_max = maxp.y
-	local z_max = maxp.z
-	local x_min = minp.x
-	local y_min = minp.y
-	local z_min = minp.z
-		
+--	if minp.y > 512 or maxp.y < water_level then
+--		return
+--	end
+	
 	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
 	local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
 	vm:get_data(data)
-		
-	for z = z_min, z_max do -- for each xy plane progressing northwards
-		--structure loop, hollows out the cavern
-		for y = y_min, y_max do -- for each x row progressing upwards
-			if y > water_level then
-				local vi = area:index(x_min, y, z) --current node index
-				for x = x_min, x_max do -- for each node do
-					magma_conduits.remove_unsupported_lava(area, data, vi)
-					vi = vi + 1
-				end
-			end
+	
+	for vi, x, y, z in area:iterp_xyz(minp, maxp) do
+		if ameliorate_floods then
+			remove_unsupported_lava(area, data, vi, x, y, z)
+		end
+		if obsidian_lining then
+			obsidianize(area, data, vi, x, y, z, minp, maxp)
 		end
 	end
 		

settingtypes.txt

@@ -2,4 +2,5 @@ magma_conduits_spread (Approximate spacing between magma conduits) int 400
 magma_conduits_upper_limit (Upper extent of magma conduits) int 512
 magma_conduits_lower_limit (Lower extent of magma conduits) int -31000
 magma_conduits_ameliorate_floods (Ameliorate lava floods on the surface) bool true
+magma_conduits_obsidian_lining (Adds an obsidian lining to magma conduits) bool true
 magma_conduits_remove_default_lava (Remove default mapgen lava) bool true

voxelarea_iterator.lua

@@ -0,0 +1,75 @@
+-- These functions are a minor modification of the voxel area iterator defined in the built in voxelarea.lua lua code.
+-- As such, this file is separately licened under the LGPL as follows:
+
+-- License of Minetest source code
+-------------------------------
+
+--Minetest
+--Copyright (C) 2010-2018 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+--This program is free software; you can redistribute it and/or modify
+--it under the terms of the GNU Lesser General Public License as published by
+--the Free Software Foundation; either version 2.1 of the License, or
+--(at your option) any later version.
+
+--This program is distributed in the hope that it will be useful,
+--but WITHOUT ANY WARRANTY; without even the implied warranty of
+--MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--GNU Lesser General Public License for more details.
+
+--You should have received a copy of the GNU Lesser General Public License along
+--with this program; if not, write to the Free Software Foundation, Inc.,
+--51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+function VoxelArea:iter_xyz(minx, miny, minz, maxx, maxy, maxz)
+	local i = self:index(minx, miny, minz) - 1
+	
+	local x = minx - 1 -- subtracting one because x gets incremented before it gets returned the first time.
+	local xrange = maxx - minx + 1
+	local nextaction = i + 1 + xrange
+
+	local y = 0
+	local yrange = maxy - miny + 1
+	local yreqstride = self.ystride - xrange
+
+	local z = 0
+	local zrange = maxz - minz + 1
+	local multistride = self.zstride - ((yrange - 1) * self.ystride + xrange)
+
+	return function()
+		-- continue i until it needs to jump
+		i = i + 1
+		x = x + 1
+		if i ~= nextaction then
+			return i, x, y+miny, z+minz
+		end
+
+		-- continue y until maxy is exceeded
+		y = y + 1
+		x = minx -- new line
+		if y ~= yrange then
+			-- set i to index(minx, miny + y, minz + z) - 1
+			i = i + yreqstride
+			nextaction = i + xrange
+			return i, x, y+miny, z+minz
+		end
+
+		-- continue z until maxz is exceeded
+		z = z + 1
+		if z == zrange then
+			-- cuboid finished, return nil
+			return
+		end
+
+		-- set i to index(minx, miny, minz + z) - 1
+		i = i + multistride
+
+		y = 0
+		nextaction = i + xrange
+		return i, x, y+miny, z+minz
+	end
+end
+
+function VoxelArea:iterp_xyz(minp, maxp)
+	return self:iter_xyz(minp.x, minp.y, minp.z, maxp.x, maxp.y, maxp.z)
+end