Correct font region for atlas texture

    private fun correctFontRegions(atlasImageFileNameNoExtension: String) {
        val sb = StringBuilder()
        val x = "x=".intern()
        val y = "y=".intern()
        val nl = "\n".intern()
        val space = ' '
        val fontsList = files?.filter { it.extension == "fnt" } ?: return
        fontsList.forEach files@{ f ->
            val lines = lazy { f.readLines() }.value
            if (lines.any { it.contains(f.nameWithoutExtension) }) {
                val newLines = StringBuilder()
                val fontRegion = atlas.findRegion(f.nameWithoutExtension)
                val regionX = fontRegion.regionX
                val regionY = fontRegion.regionY
                lines.forEach fileLines@{ line ->
                    if (line.contains(x)) {
                        sb.clear()
                        val strX = line.indexOf(x) + x.length
                        var strXEnd = strX
                        while (line[strXEnd] != space) strXEnd++
                        strXEnd--
                        val fontCharX = line.slice(strX..strXEnd).toInt()
                        val newX = fontCharX + regionX
                        sb.append(line.replaceRange(strX, strXEnd + 1, newX.toString()))

                        val strY = sb.indexOf(y) + y.length
                        var strYEnd = strY
                        while (sb[strYEnd] != space) strYEnd++
                        strYEnd--
                        val fontCharY = sb.slice(strY..strYEnd).toString().toInt()
                        val newY = fontCharY + regionY
                        sb.replaceRange(strY, strYEnd + 1, newY.toString()).also { newLines.append(it.toString() + nl) }
                    } else {
                        if (line.contains(f.nameWithoutExtension)) {
                            line.replace(f.nameWithoutExtension, atlasImageFileNameNoExtension).also { newLines.append(it + nl) }
                        } else {
                            newLines.append(line + nl)
                        }
                    }
                }
                f.writeText(newLines.toString())
                Gdx.app.log(f.name, "has been fixed")
            } else {
                Gdx.app.log(f.name, "has already been corrected earlier.")
            }
        }
    }