RedMew/map_gen/presets/maltease_crossings.lua

-- Map by Jayefuu, plague006 and grilledham
-- Map in the shape of a maltese cross, with narrow water bridges around the spawn to force "interesting" transfer of materials

local b = require 'map_gen.shared.builders'
local math = require "utils.math"
local degrees = math.rad

local function value(base, mult, pow)
    return function(x, y)
        local d_sq = x * x + y * y
        return base + mult * d_sq ^ (pow / 2) -- d ^ pow
    end
end

local function no_trees(world, tile)
    if not tile then
        return
    end
    for _, e in ipairs(
        world.surface.find_entities_filtered(
            {type = 'tree', area = {{world.x, world.y}, {world.x + 1, world.y + 1}}}
        )
    ) do
        e.destroy()
    end
    return tile
end

local function no_resources(world, tile)
    for _, e in ipairs(
        world.surface.find_entities_filtered(
            {type = 'resource', area = {{world.x, world.y}, {world.x + 1, world.y + 1}}}
        )
    ) do
        e.destroy()
    end
    return tile
end

local starting_area = 59

local gradient = 0.05
local tiles_half = (starting_area) * 0.5

local function maltese_cross(x,y)
	--Create maltese shape

	local abs_x = math.abs(x)
	local abs_y = math.abs(y)

	return not (abs_x > (tiles_half+(abs_y*gradient)) and abs_y > (tiles_half+(abs_x*gradient)))
end

-- create water crossings and pattern
local water_line =
        b.any {
        b.rectangle(10,8)
    }
water_line = b.change_tile(water_line, true, 'water')

local waters = b.single_y_pattern(water_line, 9)
local bounds = b.rectangle(10, starting_area+1)
waters = b.choose(bounds, waters, b.empty_shape)
waters = b.translate(waters,34,0)

local water_pattern = b.any{
	    waters,
	    b.rotate(waters,degrees(90)),
	    b.rotate(waters,degrees(180)),
	    b.rotate(waters,degrees(270))
    }

-- create the starting area as a grass square
local starting_square =  b.rectangle(60, 60)
starting_square = b.change_tile(starting_square, true, 'grass-1')

local starting_patch = b.circle(20)
local starting_coal = b.resource(starting_patch, 'coal', value(1800, 0.8, 1.5))
local starting_iron = b.resource(starting_patch, 'iron-ore', value(3000, 0.8, 1.5))
local starting_copper = b.resource(starting_patch, 'copper-ore',  value(2200, 0.75, 1.5))
local starting_stone = b.resource(starting_patch, 'stone',  value(1100, 0.75, 1.5))
local null = b.no_entity
local starting_resources = b.segment_pattern({null,starting_coal,null,starting_copper,null,starting_stone,null,starting_iron})
starting_resources = b.rotate(starting_resources, degrees(45/2))
-- starting_circle = b.circle(14)

-- ore generation
local patch = b.circle(20)
local small_patch = b.circle(8)
local patches = b.single_pattern(patch, 220, 220)

local stone = b.resource(patch, 'stone', value(100, 0.75, 1.1))
local oil = b.resource(b.throttle_world_xy(small_patch,1,4,1,4), 'crude-oil', value(33000, 50, 1.05))
local coal = b.resource(patch, 'coal',  value(100, 0.75, 1.1))
local uranium = b.resource(small_patch, 'uranium-ore', value(200, 0.75, 1.1))

local pattern1 =
{
    {stone, oil,stone},
    {stone, oil, oil},
    {stone, stone, stone}
}
local stone_arm = b.grid_pattern(pattern1, 3, 3,  220,220)

local pattern2 =
{
    {coal, coal, coal},
    {coal, coal, coal},
    {coal, coal, uranium}
}
local coal_arm = b.grid_pattern(pattern2, 3, 3,  220, 220)
local iron = b.resource(patches, 'iron-ore', value(500, 0.8, 1.075))
local copper = b.resource(patches, 'copper-ore',  value(400, 0.75, 1.1))

local resources = b.segment_pattern({null,coal_arm,null,copper,null,stone_arm,null,iron})
resources = b.rotate(resources, degrees(45/2))

-- worm islands
local worm_island = b.rectangle(20,300)
local worm_island_end = b.circle(10)
worm_island = b.any{
	worm_island_end,
	b.translate(worm_island,0,-150),
	b.translate(worm_island_end,0,-300)
}
worm_island = b.change_tile(worm_island, true, 'grass-1')

--[[
local worm_names = {
    'small-worm-turret',
    'medium-worm-turret',
    'big-worm-turret'
}
]]--

local max_worm_chance = 64 / 128
local worm_chance_factor = 1 --/ (192 * 512)
local function worms(_, _, world)
    local wx, wy = world.x, world.y
    local d = math.sqrt(wx * wx + wy * wy)
    local worm_chance = d - 20
    if worm_chance > 0 then
        worm_chance = worm_chance * worm_chance_factor
        worm_chance = math.min(worm_chance, max_worm_chance)
        if math.random() < worm_chance then
            return {name = 'big-worm-turret'}

        end
    end
end

worm_island = b.apply_entity(worm_island, worms)
worm_island = b.apply_effect(worm_island, no_trees)

local worm_islands = b.any{
	b.rotate(b.translate(worm_island,0,-110),degrees(45)),
	b.rotate(b.translate(worm_island,0,-110),degrees(45+90)),
	b.rotate(b.translate(worm_island,0,-110),degrees(45+180)),
	b.rotate(b.translate(worm_island,0,-110),degrees(45+270))
}

-- create the start area using the water and grass square
local start_area =
    b.any {
    water_pattern,
    starting_square
}

-- finalising some bits
start_area = b.apply_entity(start_area, starting_resources)     -- adds a different density ore patch to start
maltese_cross = b.change_tile(maltese_cross, true, 'grass-1')
maltese_cross = b.apply_entity(maltese_cross, resources)        -- adds our custom ore gen
local sea = b.change_tile(b.full_shape, true, 'water')          -- turn the void to water
sea = b.fish(sea, 0.00125)                                      -- feesh!
local map = b.any{worm_islands, start_area, maltese_cross, sea} -- combine everything
map = b.apply_effect(map, no_resources)                         -- removes vanilla ores

return map