From 9670c27161c4ad86468faece4f964676eafec78e Mon Sep 17 00:00:00 2001
From: ShadowNinja <shadowninja@minetest.net>
Date: Fri, 13 Jun 2014 14:03:14 -0400
Subject: [PATCH] Clean up treegen code

---
 mods/default/functions.lua |  50 ------
 mods/default/trees.lua     | 315 ++++++++++++++++++++-----------------
 2 files changed, 174 insertions(+), 191 deletions(-)

diff --git a/mods/default/functions.lua b/mods/default/functions.lua
index 80e8c80d..fe553c51 100644
--- a/mods/default/functions.lua
+++ b/mods/default/functions.lua
@@ -127,56 +127,6 @@ end
 minetest.register_on_punchnode(on_punchnode)
 
 
---
--- Grow trees
---
-
-minetest.register_abm({
-	nodenames = {"default:sapling"},
-	interval = 10,
-	chance = 50,
-	action = function(pos, node)
-		local nu =  minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name
-		local is_soil = minetest.get_item_group(nu, "soil")
-		if is_soil == 0 then
-			return
-		end
-		
-		minetest.log("action", "A sapling grows into a tree at "..minetest.pos_to_string(pos))
-		local vm = minetest.get_voxel_manip()
-		local minp, maxp = vm:read_from_map({x=pos.x-16, y=pos.y, z=pos.z-16}, {x=pos.x+16, y=pos.y+16, z=pos.z+16})
-		local a = VoxelArea:new{MinEdge=minp, MaxEdge=maxp}
-		local data = vm:get_data()
-		default.grow_tree(data, a, pos, math.random(1, 4) == 1, math.random(1,100000))
-		vm:set_data(data)
-		vm:write_to_map(data)
-		vm:update_map()
-	end
-})
-
-minetest.register_abm({
-	nodenames = {"default:junglesapling"},
-	interval = 10,
-	chance = 50,
-	action = function(pos, node)
-		local nu =  minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name
-		local is_soil = minetest.get_item_group(nu, "soil")
-		if is_soil == 0 then
-			return
-		end
-		
-		minetest.log("action", "A jungle sapling grows into a tree at "..minetest.pos_to_string(pos))
-		local vm = minetest.get_voxel_manip()
-		local minp, maxp = vm:read_from_map({x=pos.x-16, y=pos.y-1, z=pos.z-16}, {x=pos.x+16, y=pos.y+16, z=pos.z+16})
-		local a = VoxelArea:new{MinEdge=minp, MaxEdge=maxp}
-		local data = vm:get_data()
-		default.grow_jungletree(data, a, pos, math.random(1,100000))
-		vm:set_data(data)
-		vm:write_to_map(data)
-		vm:update_map()
-	end
-})
-
 --
 -- Lavacooling
 --
diff --git a/mods/default/trees.lua b/mods/default/trees.lua
index e68c0554..5752fe0d 100644
--- a/mods/default/trees.lua
+++ b/mods/default/trees.lua
@@ -1,150 +1,183 @@
+--
+-- Grow trees
+--
+
+local random = math.random
+
+local function can_grow(pos)
+	local node_under = minetest.get_node_or_nil({x = pos.x, y = pos.y - 1, z = pos.z})
+	if not node_under then
+		return false
+	end
+	local name_under = node_under.name
+	local is_soil = minetest.get_item_group(name_under, "soil")
+	if is_soil == 0 then
+		return false
+	end
+	return true
+end
+
+minetest.register_abm({
+	nodenames = {"default:sapling"},
+	interval = 10,
+	chance = 50,
+	action = function(pos, node)
+		if not can_grow(pos) then
+			return
+		end
+
+		minetest.log("action", "A sapling grows into a tree at "..minetest.pos_to_string(pos))
+		default.grow_tree(pos, random(1, 4) == 1)
+	end
+})
+
+minetest.register_abm({
+	nodenames = {"default:junglesapling"},
+	interval = 10,
+	chance = 50,
+	action = function(pos, node)
+		if not can_grow(pos) then
+			return
+		end
+
+		minetest.log("action", "A jungle sapling grows into a tree at "..
+				minetest.pos_to_string(pos))
+		default.grow_jungletree(pos)
+	end
+})
+
+
 local c_air = minetest.get_content_id("air")
-local c_ignore = minetest.get_content_id("ignore")
-local c_tree = minetest.get_content_id("default:tree")
-local c_leaves = minetest.get_content_id("default:leaves")
 local c_apple = minetest.get_content_id("default:apple")
 
-function default.grow_tree(data, a, pos, is_apple_tree, seed)
-        --[[
-                NOTE: Tree-placing code is currently duplicated in the engine
-                and in games that have saplings; both are deprecated but not
-                replaced yet
-        ]]--
-        local pr = PseudoRandom(seed)
-        local th = pr:next(4, 5)
-        local x, y, z = pos.x, pos.y, pos.z
-        for yy = y, y+th-1 do
-                local vi = a:index(x, yy, z)
-                if a:contains(x, yy, z) and (data[vi] == c_air or yy == y) then
-                        data[vi] = c_tree
-                end
-        end
-        y = y+th-1 -- (x, y, z) is now last piece of trunk
-        local leaves_a = VoxelArea:new{MinEdge={x=-2, y=-1, z=-2}, MaxEdge={x=2, y=2, z=2}}
-        local leaves_buffer = {}
-        
-        -- Force leaves near the trunk
-        local d = 1
-        for xi = -d, d do
-        for yi = -d, d do
-        for zi = -d, d do
-                leaves_buffer[leaves_a:index(xi, yi, zi)] = true
-        end
-        end
-        end
-        
-        -- Add leaves randomly
-        for iii = 1, 8 do
-                local d = 1
-                local xx = pr:next(leaves_a.MinEdge.x, leaves_a.MaxEdge.x - d)
-                local yy = pr:next(leaves_a.MinEdge.y, leaves_a.MaxEdge.y - d)
-                local zz = pr:next(leaves_a.MinEdge.z, leaves_a.MaxEdge.z - d)
-                
-                for xi = 0, d do
-                for yi = 0, d do
-                for zi = 0, d do
-                        leaves_buffer[leaves_a:index(xx+xi, yy+yi, zz+zi)] = true
-                end
-                end
-                end
-        end
-        
-        -- Add the leaves
-        for xi = leaves_a.MinEdge.x, leaves_a.MaxEdge.x do
-        for yi = leaves_a.MinEdge.y, leaves_a.MaxEdge.y do
-        for zi = leaves_a.MinEdge.z, leaves_a.MaxEdge.z do
-                if a:contains(x+xi, y+yi, z+zi) then
-                        local vi = a:index(x+xi, y+yi, z+zi)
-                        if data[vi] == c_air or data[vi] == c_ignore then
-                                if leaves_buffer[leaves_a:index(xi, yi, zi)] then
-                                        if is_apple_tree and pr:next(1, 100) <=  10 then
-                                                data[vi] = c_apple
-                                        else
-                                                data[vi] = c_leaves
-                                        end
-                                end
-                        end
-                end
-        end
-        end
-        end
+local function add_trunk_and_leaves(data, a, pos, tree_cid, leaves_cid,
+		height, size, iters, is_apple_tree)
+	local x, y, z = pos.x, pos.y, pos.z
+
+	-- Trunk
+	for y_dist = 0, height - 1 do
+		local vi = a:index(x, y + y_dist, z)
+		if y_dist == 0 or data[vi] == c_air or data[vi] == leaves_cid then
+			data[vi] = tree_cid
+		end
+	end
+
+	-- Force leaves near the trunk
+	for z_dist = -1, 1 do
+	for y_dist = -size, 1 do
+		local vi = a:index(x - 1, y + height + y_dist, z + z_dist)
+		for x_dist = -1, 1 do
+			if data[vi] == c_air then
+				if is_apple_tree and random(1, 8) == 1 then
+					data[vi] = c_apple
+				else
+					data[vi] = leaves_cid
+				end
+			end
+			vi = vi + 1
+		end
+	end
+	end
+
+	-- Randomly add leaves in 2x2x2 clusters.
+	for i = 1, iters do
+		local clust_x = x + random(-size, size - 1)
+		local clust_y = y + height + random(-size, 0)
+		local clust_z = z + random(-size, size - 1)
+
+		for xi = 0, 1 do
+		for yi = 0, 1 do
+		for zi = 0, 1 do
+			local vi = a:index(clust_x + xi, clust_y + yi, clust_z + zi)
+			if data[vi] == c_air then
+				if is_apple_tree and random(1, 8) == 1 then
+					data[vi] = c_apple
+				else
+					data[vi] = leaves_cid
+				end
+			end
+		end
+		end
+		end
+	end
+end
+
+
+local c_tree = minetest.get_content_id("default:tree")
+local c_leaves = minetest.get_content_id("default:leaves")
+
+function default.grow_tree(pos, is_apple_tree, bad)
+	--[[
+		NOTE: Tree-placing code is currently duplicated in the engine
+		and in games that have saplings; both are deprecated but not
+		replaced yet
+	--]]
+	if bad then
+		error("Deprecated use of default.grow_tree")
+	end
+
+	local x, y, z = pos.x, pos.y, pos.z
+	local height = random(4, 5)
+
+	local vm = minetest.get_voxel_manip()
+	local minp, maxp = vm:read_from_map(
+			{x = pos.x - 2, y = pos.y, z = pos.z - 2},
+			{x = pos.x + 2, y = pos.y + height + 1, z = pos.z + 2}
+	)
+	local a = VoxelArea:new({MinEdge = minp, MaxEdge = maxp})
+	local data = vm:get_data()
+
+	add_trunk_and_leaves(data, a, pos, c_tree, c_leaves, height, 2, 8, is_apple_tree)
+
+	vm:set_data(data)
+	vm:write_to_map()
+	vm:update_map()
 end
 
 local c_jungletree = minetest.get_content_id("default:jungletree")
 local c_jungleleaves = minetest.get_content_id("default:jungleleaves")
 
-function default.grow_jungletree(data, a, pos, seed)
-        --[[
-                NOTE: Tree-placing code is currently duplicated in the engine
-                and in games that have saplings; both are deprecated but not
-                replaced yet
-        ]]--
-        local pr = PseudoRandom(seed)
-        local x, y, z = pos.x, pos.y, pos.z
-        for xi = -1, 1 do
-        for zi = -1, 1 do
-                if pr:next(1, 3) >= 2 then
-                        local vi1 = a:index(x+xi, y, z+zi)
-                        local vi2 = a:index(x+xi, y-1, z+zi)
-                        if a:contains(x+xi, y-1, z+zi) and data[vi2] == c_air then
-                                data[vi2] = c_jungletree
-                        elseif a:contains(x+xi, y, z+zi) and data[vi1] == c_air then
-                                data[vi1] = c_jungletree
-                        end
-                end
-        end
-        end
-        
-        local th = pr:next(8, 12)
-        for yy = y, y+th-1 do
-                local vi = a:index(x, yy, z)
-                if a:contains(x, yy, z) and (data[vi] == c_air or yy == y) then
-                        data[vi] = c_jungletree
-                end
-        end
-        y = y+th-1 -- (x, y, z) is now last piece of trunk
-        local leaves_a = VoxelArea:new{MinEdge={x=-3, y=-2, z=-3}, MaxEdge={x=3, y=2, z=3}}
-        local leaves_buffer = {}
-        
-        -- Force leaves near the trunk
-        local d = 1
-        for xi = -d, d do
-        for yi = -d, d do
-        for zi = -d, d do
-                leaves_buffer[leaves_a:index(xi, yi, zi)] = true
-        end
-        end
-        end
-        
-        -- Add leaves randomly
-        for iii = 1, 30 do
-                local d = 1
-                local xx = pr:next(leaves_a.MinEdge.x, leaves_a.MaxEdge.x - d)
-                local yy = pr:next(leaves_a.MinEdge.y, leaves_a.MaxEdge.y - d)
-                local zz = pr:next(leaves_a.MinEdge.z, leaves_a.MaxEdge.z - d)
-                
-                for xi = 0, d do
-                for yi = 0, d do
-                for zi = 0, d do
-                        leaves_buffer[leaves_a:index(xx+xi, yy+yi, zz+zi)] = true
-                end
-                end
-                end
-        end
-        
-        -- Add the leaves
-        for xi = leaves_a.MinEdge.x, leaves_a.MaxEdge.x do
-        for yi = leaves_a.MinEdge.y, leaves_a.MaxEdge.y do
-        for zi = leaves_a.MinEdge.z, leaves_a.MaxEdge.z do
-                if a:contains(x+xi, y+yi, z+zi) then
-                        local vi = a:index(x+xi, y+yi, z+zi)
-                        if data[vi] == c_air or data[vi] == c_ignore then
-                                if leaves_buffer[leaves_a:index(xi, yi, zi)] then
-                                        data[vi] = c_jungleleaves
-                                end
-                        end
-                end
-        end
-        end
-        end
+function default.grow_jungletree(pos, bad)
+	--[[
+		NOTE: Tree-placing code is currently duplicated in the engine
+		and in games that have saplings; both are deprecated but not
+		replaced yet
+	--]]
+	if bad then
+		error("Deprecated use of default.grow_jungletree")
+	end
+
+	local x, y, z = pos.x, pos.y, pos.z
+	local height = random(8, 12)
+
+	local vm = minetest.get_voxel_manip()
+	local minp, maxp = vm:read_from_map(
+			{x = pos.x - 3, y = pos.y - 1,  z = pos.z - 3},
+			{x = pos.x + 3, y = pos.y + height + 1, z = pos.z + 3})
+	local a = VoxelArea:new({MinEdge = minp, MaxEdge = maxp})
+	local data = vm:get_data()
+
+	add_trunk_and_leaves(data, a, pos, c_jungletree, c_jungleleaves, height, 3, 30, false)
+
+	-- Roots
+	for z_dist = -1, 1 do
+		local vi_1 = a:index(x - 1, y - 1, z + z_dist)
+		local vi_2 = a:index(x - 1, y,     z + z_dist)
+		for x_dist = -1, 1 do
+			if random(1, 3) >= 2 then
+				if data[vi_1] == c_air then
+					data[vi_1] = c_jungletree
+				elseif data[vi_2] == c_air then
+					data[vi_2] = c_jungletree
+				end
+			end
+			vi_1 = vi_1 + 1
+			vi_2 = vi_2 + 1
+		end
+	end
+
+	vm:set_data(data)
+	vm:write_to_map()
+	vm:update_map()
 end
+