cartographer/map_formspec.lua

local scale = 0.25;

local variant_odds = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 4 };
local function get_variant(random)
    return variant_odds[random:next(1, 12)];
end

local map_formspec_prefix = [[
    formspec_version[3]
    size[%f,%f]
    real_coordinates[true]
    style_type[image_button;border=false]
]];

local tile = "image[%f,%f;%f,%f;%s]";
local marker = "animated_image[%f,%f;%f,%f;%s:%d,%d]";

local function generate_map(data, x, y, w, h, player_x, player_y, spawn_x, spawn_y, death_x, death_y, detail, is_visible, user)
    local str = "";
    local random = PcgRandom(x + y + w + h); -- TODO: Better seed
    for i = x,x + w,1 do
        local fx = (i - x) * (scale - 0.01);
        local column = data.generated[i];
        for j = y + h,y,-1 do
            local fy = (y + h - j) * (scale - 0.01);
            if column == nil or column[j] == nil or (is_visible and not is_visible(user, i, j)) then
                str = str..tile:format(fx, fy, scale, scale, "cartographer_unknown_biome." .. tostring(get_variant(random)) .. ".png")
            else
                local name = minetest.get_biome_name(column[j].biome);
                local height = column[j].height;
                local biome = cartographer.get_biome_texture(name, math.floor(height + 0.5), detail);

                if biome == nil then
                    -- minetest.chat_send_all(name);
                    str = str..tile:format(fx, fy, scale, scale, "cartographer_unknown_biome." .. tostring(get_variant(random)) .. ".png")
                else
                    if height > 0 then
                        str = str..tile:format(fx, fy, scale, scale, "cartographer_cliff.png")
                    end

                    str = str..tile:format(fx, fy, scale, scale, biome .. "." .. tostring(get_variant(random)) .. ".png")
                end

                if i == player_x and j == player_y then
                    str = str..marker:format(fx, fy, scale, scale, "cartographer_player_icon.png", 2, 500)
                -- elseif i == death_x and j == death_y then
                --     str = str..marker:format(fx, fy - (height * 0.025), scale, scale, "dicon.png")
                -- elseif i == spawn_x and j == spawn_y then
                --     str = str..marker:format(fx, fy - (height * 0.025), scale, scale, "cartographer_home_icon.png")
                end
            end
        end
    end

    return str;
end

function cartographer.get_map_formspec(data, x, y, w, h, spawn_x, spawn_y, death_x, death_y, detail)
    return map_formspec_prefix:format(w * scale, h * scale)..generate_map(data, x - (w * 0.5), y - (h * 0.5), w, h, x, y, spawn_x, spawn_y, death_x, death_y, detail);
end

function cartographer.get_map_formspec_map(data, map, x, y, spawn_x, spawn_y, death_x, death_y)
    return map_formspec_prefix:format(map.w * scale, map.h * scale)..generate_map(data, map.x, map.z, map.w, map.h, x, y, spawn_x, spawn_y, death_x, death_y, map.detail, cartographer.is_filled, map);
end