local ns = firefly
local modname = minetest.get_current_modname()

ns.fonts = {}

function ns.rasterize(str, font, max_width)
    if not font then font = "firefly_normal" end
    local atlas = ns.fonts[font] or minetest.parse_json(ns.read_file(minetest.get_modpath(modname).."/fonts/"..font..".json"))
    if not ns.fonts[font] then
        ns.fonts[font] = atlas
    end
    
    local newline = string.byte("\n", 1)
    
    local out = {}
    local width = 0
    local height = 0
    local x = 0
    local y = 0
    for i = 0, #str do
        local char = str:byte(i)
        if not char then goto continue end
        if char == newline then
            goto continue
        end
        local glyph = atlas[string.char(char)]
        
        local num = #out
        out[num +1] = ":"
        out[num +2] = x
        out[num +3] = ","
        out[num +4] = y
        out[num +5] = "="
        out[num +6] = font
        out[num +7] = "/firefly_char_"
        out[num +8] = char
        out[num +9] = ".png"
        
        x = x +glyph.width +glyph.advance
        if x > width then
            width = x
        end
        ::continue::
    end
    return "[combine:"..width.."x"..height..table.concat(out)
end