Re-implement nyancat generation in Lua (they don't occur in the exact same spots...

diff --git a/mods/default/mapgen.lua b/mods/default/mapgen.lua
index 2937636a0bc90c0ddbabcfe7631d6a8f0033dd39..7bea2717e9caaaa38d6b7142dfb0209e390df209 100644 (file)
--- a/mods/default/mapgen.lua
+++ b/mods/default/mapgen.lua
@@ -80,6 +80,54 @@ function default.make_cactus(pos, size)
        end
 end
 
+-- facedir: 0/1/2/3 (head node facedir value)
+-- length: length of rainbow tail
+function default.make_nyancat(pos, facedir, length)
+       local tailvec = {x=0, y=0, z=0}
+       if facedir == 0 then
+               tailvec.z = 1
+       elseif facedir == 1 then
+               tailvec.x = 1
+       elseif facedir == 2 then
+               tailvec.z = -1
+       elseif facedir == 3 then
+               tailvec.x = -1
+       else
+               print("default.make_nyancat(): Invalid facedir: "+dump(facedir))
+               facedir = 0
+               tailvec.z = 1
+       end
+       local p = {x=pos.x, y=pos.y, z=pos.z}
+       minetest.env:set_node(p, {name="default:nyancat", param2=facedir})
+       for i=1,length do
+               p.x = p.x + tailvec.x
+               p.z = p.z + tailvec.z
+               minetest.env:set_node(p, {name="default:nyancat_rainbow"})
+       end
+end
+
+function generate_nyancats(seed, minp, maxp)
+       local height_min = -31000
+       local height_max = -32
+       if maxp.y < height_min or minp.y > height_max then
+               return
+       end
+       local y_min = math.max(minp.y, height_min)
+       local y_max = math.min(maxp.y, height_max)
+       local volume = (maxp.x-minp.x+1)*(y_max-y_min+1)*(maxp.z-minp.z+1)
+       local pr = PseudoRandom(seed + 9324342)
+       local max_num_nyancats = math.floor(volume / (16*16*16))
+       for i=1,max_num_nyancats do
+               if pr.next(0, 1000) == 0 then
+                       local x0 = pr:next(minp.x, maxp.x)
+                       local y0 = pr:next(minp.y, maxp.y)
+                       local z0 = pr:next(minp.z, maxp.z)
+                       local p0 = {x=x0, y=y0, z=z0}
+                       default.make_nyancat(p0, pr:next(0,3), pr:next(3,15))
+               end
+       end
+end
+
 minetest.register_on_generated(function(minp, maxp, seed)
        -- Generate regular ores
        generate_ore("default:stone_with_coal", "default:stone", minp, maxp, seed+0, 1/8/8/8,    3, 8, -31000,  64)
@@ -220,5 +268,8 @@ minetest.register_on_generated(function(minp, maxp, seed)
                end
                end
        end
+
+       -- Generate nyan cats
+       generate_nyancats(seed, minp, maxp)
 end)