minetest.register_node( "technic:marble", {
	description = "Marble",
	tiles = { "technic_marble.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
}) 

minetest.register_node( "technic:marble_bricks", {
	description = "Marble Bricks",
	tiles = { "technic_marble_bricks.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
}) 

minetest.register_craft({
	output = 'technic:marble_bricks 4',
	recipe = {
		{'technic:marble','technic:marble'},
		{'technic:marble','technic:marble'}
	}
})

minetest.register_node( "technic:granite", {
	description = "Granite",
	tiles = { "technic_granite.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
}) 

minetest.register_node( "technic:obsidian", {
	description = "Obsidian",
	tiles = { "technic_obsidian.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
}) 

stairsplus.register_stair_and_slab_and_panel_and_micro("marble", "technic:marble",
		{cracky=3},
		{"technic_marble.png"},
		"Marble Stairs",
		"Marble Slab",
		"Marble Panel",
		"Marble Microblock",
		"marble")
stairsplus.register_stair_and_slab_and_panel_and_micro("marble_bricks", "technic:marble_bricks",
		{cracky=3},
		{"technic_marble_bricks.png"},
		"Marble Bricks Stairs",
		"Marble Bricks Slab",
		"Marble Bricks Panel",
		"Marble Bricks Microblock",
		"marble_bricks")
stairsplus.register_stair_and_slab_and_panel_and_micro("granite", "technic:granite",
		{cracky=3},
		{"technic_granite.png"},
		"Granite Stairs",
		"Granite Slab",
		"Granite Panel",
		"Granite Microblock",
		"granite")
stairsplus.register_stair_and_slab_and_panel_and_micro("obsidian", "technic:obsidian",
		{cracky=3},
		{"technic_obsidian.png"},
		"Obsidian Stairs",
		"Obsidian Slab",
		"Obsidian Panel",
		"Obsidian Microblock",
		"obsidian")

minetest.register_node( "technic:mineral_diamond", {
	description = "Diamond Ore",
	tiles = { "default_stone.png^technic_mineral_diamond.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
	drop = 'craft "technic:diamond" 1',
}) 

minetest.register_craftitem( "technic:diamond", {
	description = "Diamond",
	inventory_image = "technic_diamond.png",
	on_place_on_ground = minetest.craftitem_place_item,
})

minetest.register_node( "technic:mineral_uranium", {
	description = "Uranium Ore",
	tiles = { "default_stone.png^technic_mineral_uranium.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
	drop = 'craft "technic:uranium" 1',
}) 

minetest.register_craftitem( "technic:uranium", {
	description = "Uranium",
	inventory_image = "technic_uranium.png",
	on_place_on_ground = minetest.craftitem_place_item,
})

minetest.register_node( "technic:mineral_chromium", {
	description = "Chromium Ore",
	tiles = { "default_stone.png^technic_mineral_chromium.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
	drop = 'craft "technic:chromium_lump" 1',
}) 

minetest.register_craftitem( "technic:chromium_lump", {
	description = "Chromium Lump",
	inventory_image = "technic_chromium_lump.png",
	on_place_on_ground = minetest.craftitem_place_item,
})

minetest.register_craftitem( "technic:chromium_ingot", {
	description = "Chromium Ingot",
	inventory_image = "technic_chromium_ingot.png",
	on_place_on_ground = minetest.craftitem_place_item,
})

minetest.register_craft({
				type = 'cooking',
				output = "technic:chromium_ingot",
				recipe = "technic:chromium_lump"
			})


minetest.register_node( "technic:mineral_zinc", {
	description = "Zinc Ore",
	tile_images = { "default_stone.png^technic_mineral_zinc.png" },
	is_ground_content = true,
	groups = {cracky=3},
	sounds = default.node_sound_stone_defaults(),
	drop = 'craft "technic:zinc_lump" 1',
})

minetest.register_craftitem( "technic:zinc_lump", {
	description = "Zinc Lump",
	inventory_image = "technic_zinc_lump.png",
})

minetest.register_craftitem( "technic:zinc_ingot", {
	description = "Zinc Ingot",
	inventory_image = "technic_zinc_ingot.png",
})

minetest.register_craftitem( "technic:stainless_steel_ingot", {
	description = "Stainless Steel Ingot",
	inventory_image = "technic_stainless_steel_ingot.png",
})

minetest.register_craftitem( "technic:brass_ingot", {
	description = "Brass Ingot",
	inventory_image = "technic_brass_ingot.png",
})

minetest.register_craft({
				type = 'cooking',
				output = "technic:zinc_ingot",
				recipe = "technic:zinc_lump"
			})


local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, ore_per_chunk, height_min, height_max)
	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)
	local num_chunks = math.floor(chunks_per_volume * volume)
	local chunk_size = 3
	if ore_per_chunk <= 4 then
		chunk_size = 2
	end
	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
	--print("generate_ore num_chunks: "..dump(num_chunks))
	for i=1,num_chunks do
	if (y_max-chunk_size+1 <= y_min) then return end
		local y0 = pr:next(y_min, y_max-chunk_size+1)
		if y0 >= height_min and y0 <= height_max then
			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
			local p0 = {x=x0, y=y0, z=z0}
			for x1=0,chunk_size-1 do
			for y1=0,chunk_size-1 do
			for z1=0,chunk_size-1 do
				if pr:next(1,inverse_chance) == 1 then
					local x2 = x0+x1
					local y2 = y0+y1
					local z2 = z0+z1
					local p2 = {x=x2, y=y2, z=z2}
					if minetest.env:get_node(p2).name == wherein then
						minetest.env:set_node(p2, {name=name})
					end
				end
			end
			end
			end
		end
	end
	--print("generate_ore done")
end

minetest.register_on_generated(function(minp, maxp, seed)
generate_ore("technic:mineral_diamond", "default:stone", minp, maxp, seed+21,   1/11/11/11,    4, -31000,  -450)
generate_ore("technic:mineral_uranium", "default:stone", minp, maxp, seed+22,   1/10/10/10,    3, -300,  -80)
generate_ore("technic:mineral_chromium", "default:stone", minp, maxp, seed+23,   1/10/10/10,    2, -31000,  -100)
generate_ore("technic:mineral_zinc", "default:stone", minp, maxp, seed+24,   1/9/9/9,    4, -31000,  2)
generate_ore("technic:marble", "default:stone", minp, maxp, seed+25,	1/128, 20, -100, -32)
generate_ore("technic:granite", "default:stone", minp, maxp, seed+25,	1/128, 15, -190, -90)
generate_stratus("technic:obsidian",
                {"default:stone"},
                {"default:lava_source"},{"default:air"},
                  minp, maxp, seed+4, 10, 25, 7, -450, -31000, -450)
end)

function generate_stratus(name, wherein, ceilin, ceil, minp, maxp, seed, stratus_chance, radius, radius_y, deep, height_min, height_max)
  if maxp.y < height_min or minp.y > height_max then
    return
  end
  -- it will be only generate a stratus for every 100 m of area
  local stratus_per_volume=1
  local area=45
  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)/area)*((y_max-y_min+1)/area)*((maxp.z-minp.z+1)/area)
  local pr = PseudoRandom(seed)
  local blocks = math.floor(stratus_per_volume*volume)
  print(" <<"..dump(name)..">>");
  if blocks == 0 then
    blocks = 1
  end
  print(" blocks: "..dump(blocks).." in vol: "..dump(volume).." ("..dump(maxp.x-minp.x+1)..","..dump(y_max-y_min+1)..","..dump(maxp.z-minp.z+1)..")")
  for i=1,blocks do
    local x = pr:next(1,stratus_chance)
    if x == 1 then
      -- TODO deep
      local y0=y_max-radius_y+1
      if y0 < y_min then
        y0=y_min
      else
        y0=pr:next(y_min, y0)
      end
      local x0 = maxp.x-radius+1
      if x0 < minp.x then
        x0 = minp.x
      else
        x0 = pr:next(minp.x, x0)
      end
      local z0 = maxp.z-radius+1
      if z0 < minp.z then
        x0 = minp.z
      else
        z0 = pr:next(minp.z, z0)
      end
      local p0 = {x=x0, y=y0, z=z0}
      local n = minetest.env:get_node(p0).name
      local i = 0
      --print(" upper node "..n)
      x = 0
      for k, v in ipairs(ceilin) do
        if n == v then
          x = 1
          break
        end
      end
      if x == 1 then
        -- search for the node to replace
        --print(" Searching nodes to replace from "..dump(y0-1).." to "..dump(y_min))
        for y1=y0-1,y_min,-1 do
          p0.y=y1
          n = minetest.env:get_node(p0).name
          x = 0
          for k, v in ipairs(wherein) do
            if n == v then
              x = 1
              break
            end
          end
          if x == 1 then
            y0=y1-deep
            if y0 < y_min then
              y0 = y_min
            end
            break
          end
        end
        local rx=pr:next(radius/2,radius)+1
        local rz=pr:next(radius/2,radius)+1
        local ry=pr:next(radius_y/2,radius_y)+1
        --print(" area of generation ("..dump(rx)..","..dump(rz)..","..dump(ry)..")")
        for x1=0,rx do
          rz = rz + 3 - pr:next(1,6)
          if rz < 1 then
            rz = 1
          end
          for z1=pr:next(1,3),rz do
            local ry0=ry+ pr:next(1,3)
            for y1=pr:next(1,3),ry0 do
              local x2 = x0+x1
              local y2 = y0+y1
              local z2 = z0+z1
              local p2 = {x=x2, y=y2, z=z2}
              n = minetest.env:get_node(p2).name
              x = 0
              for k, v in ipairs(wherein) do
                if n == v then
                  x = 1
                  break
                end
              end
              if x == 1 then
                if ceil == nil then
                  minetest.env:set_node(p2, {name=name})
                  i = i +1
                else
                  local p3 = {p2.x,p2.y+1,p2}
                  if minetest.env:get_node(p3).name == ceil then
                     minetest.env:set_node(p2, {name=name})
                     i = i +1
                  end
                end
              end
            end
          end
        end
        print(" generated "..dump(i).." blocks in ("..dump(x0)..","..dump(y0)..","..dump(z0)..")")
      end

    end
  end
  --print("generate_ore done")
end