From f57ce0896226414c081e960b9d0e38d0898ab38b Mon Sep 17 00:00:00 2001
From: Splizard <quentin@squeezedoranges.com>
Date: Wed, 20 Mar 2013 11:08:16 +1300
Subject: [PATCH] Change to L-systems for treegen.

---
 mapgen.lua | 87 +++++++++++++++++++++++++++---------------------------
 1 file changed, 43 insertions(+), 44 deletions(-)

diff --git a/mapgen.lua b/mapgen.lua
index cd4cb69..d76ea0f 100644
--- a/mapgen.lua
+++ b/mapgen.lua
@@ -1,15 +1,38 @@
+local pine_tree = {
+	axiom="TABff",
+	rules_a="[&T+f+ff+ff+ff+f]GA",
+	rules_b="[&T+f+Gf+Gf+Gf]GB",
+	trunk="default:tree",
+	leaves="snow:needles",
+	angle=90,
+	iterations=1,
+	random_level=0,
+	trunk_type="single",
+	thin_branches=true,
+}
+local xmas_tree = {
+	axiom="TABff",
+	rules_a="[&T+f+ff+ff+ff+f]GA",
+	rules_b="[&T+f+Gf+Gf+Gf]GB",
+	trunk="default:tree",
+	leaves="snow:needles_decorated",
+	angle=90,
+	iterations=1,
+	random_level=0,
+	trunk_type="single",
+	thin_branches=true,
+}
+
 --Makes pine tree
 function snow.make_pine(pos,snow,xmas)
 	local env = minetest.env
 	local perlin1 = env:get_perlin(112,3, 0.5, 150)
 	local try_node = function(pos, node)
 		local n = env:get_node(pos).name
-		if  n == "air" or n == "snow:needles" or n == "default:leaves" or n == "snow:sapling_pine" or n == "snow:snow" or "snow:needles_decorated" then
+		if n == "air" or n == "ignore" then
 			env:add_node(pos,node)
 		end
 	end
-	local leaves = "snow:needles"
-	if xmas then leaves = "snow:needles_decorated" end
 	--Clear ground.
 	for x=-1,1 do
 	for z=-1,1 do
@@ -21,48 +44,24 @@ function snow.make_pine(pos,snow,xmas)
 		end
 	end
 	end
-	--Make tree.
-	for i=0, 4 do
-		local env = minetest.env
-		if i==1 or i==2 then
-			for x=-1,1 do
-			for z=-1,1 do
-				local x = pos.x + x
-				local z = pos.z + z
-				try_node({x=x,y=pos.y+i,z=z},{name=leaves})
-				if snow and x ~= 0 and z ~= 0 and perlin1:get2d({x=x,y=z}) > 0.53 then
-					try_node({x=x,y=pos.y+i+1,z=z},{name="snow:snow"})
-				end
-			end
-			end
-		end
-		if i==3 or i==4 then
-			local x = pos.x
-			local y = pos.y+i
-			local z = pos.z
-			try_node({x=x+1,y=y,z=z},{name=leaves})
-			try_node({x=x-1,y=y,z=z},{name=leaves})
-			try_node({x=x,y=y,z=z+1},{name=leaves})
-			try_node({x=x,y=y,z=z-1},{name=leaves})
-			if snow then
-				if perlin1:get2d({x=x+1,y=z}) > 0.53 then
-					try_node({x=x+1,y=y+1,z=z},{name="snow:snow"})
-				end
-				if perlin1:get2d({x=x+1,y=z}) > 0.53 then
-					try_node({x=x-1,y=y+1,z=z},{name="snow:snow"})
-				end
-				if perlin1:get2d({x=x,y=z+1}) > 0.53 then
-					try_node({x=x,y=y+1,z=z+1},{name="snow:snow"})
-				end
-				if perlin1:get2d({x=x,y=z-1}) > 0.53 then
-					try_node({x=x,y=y+1,z=z-1},{name="snow:snow"})
-				end
-			end
-		end
-		try_node({x=pos.x,y=pos.y+i,z=pos.z},{name="default:tree"})
+	if xmas then
+		env:remove_node(pos)
+		minetest.env:spawn_tree(pos, xmas_tree)
+	else
+		minetest.env:spawn_tree(pos, pine_tree)
+	end
+	if snow then
+		local x,z = pos.x,pos.z
+		try_node({x=x+1,y=pos.y+3,z=z+1},{name="snow:snow"})
+		try_node({x=x-1,y=pos.y+3,z=z-1},{name="snow:snow"})
+		try_node({x=x-1,y=pos.y+3,z=z+1},{name="snow:snow"})
+		try_node({x=x+1,y=pos.y+3,z=z-1},{name="snow:snow"})
+		
+		try_node({x=x+1,y=pos.y+5,z=z},{name="snow:snow"})
+		try_node({x=x-1,y=pos.y+5,z=z},{name="snow:snow"})
+		try_node({x=x,y=pos.y+5,z=z+1},{name="snow:snow"})
+		try_node({x=x,y=pos.y+5,z=z-1},{name="snow:snow"})
 	end
-	try_node({x=pos.x,y=pos.y+5,z=pos.z},{name=leaves})
-	try_node({x=pos.x,y=pos.y+6,z=pos.z},{name=leaves})
 	if xmas then
 		try_node({x=pos.x,y=pos.y+7,z=pos.z},{name="snow:star"})
 	elseif snow and perlin1:get2d({x=pos.x,y=pos.z}) > 0.53 then