Font implementation for GDX (issue #4), various format changes on the spritesheets

terrarumsansbitmap/gdx/GameFontBase.kt

@@ -0,0 +1,648 @@
+package net.torvald.terrarumsansbitmap.gdx
+
+import com.badlogic.gdx.Gdx
+import com.badlogic.gdx.graphics.Pixmap
+import com.badlogic.gdx.graphics.Texture
+import com.badlogic.gdx.graphics.g2d.*
+import java.io.BufferedOutputStream
+import java.io.File
+import java.io.FileOutputStream
+import java.util.zip.GZIPInputStream
+
+/**
+ * LibGDX port of Terrarum Sans Bitmap implementation
+ *
+ * Filename and Extension for the spritesheet is hard-coded, which are:
+ *
+ *  - ascii_variable.tga
+ *  - hangul_johab.tga
+ *  - LatinExtA_variable.tga
+ *  - LatinExtB_variable.tga
+ *  - kana.tga
+ *  - cjkpunct.tga
+ *  - wenquanyi.tga.gz
+ *  - cyrillic_variable.tga
+ *  - fullwidth_forms.tga
+ *  - unipunct_variable.tga
+ *  - greek_variable.tga
+ *  - thai_variable.tga
+ *  - puae000-e0ff.tga
+ *
+ *
+ * Glyphs are drawn lazily (calculated on-the-fly, rather than load up all), which is inevitable as we just can't load
+ * up 40k+ characters on the machine, which will certainly make loading time painfully long.
+ *
+ * Created by minjaesong on 2017-06-15.
+ */
+class GameFontBase(fontDir: String, val noShadow: Boolean = false) : BitmapFont() {
+
+    private fun getHanChosung(hanIndex: Int) = hanIndex / (JUNG_COUNT * JONG_COUNT)
+    private fun getHanJungseong(hanIndex: Int) = hanIndex / JONG_COUNT % JUNG_COUNT
+    private fun getHanJongseong(hanIndex: Int) = hanIndex % JONG_COUNT
+
+    private val jungseongWide = arrayOf(8, 12, 13, 17, 18, 21)
+    private val jungseongComplex = arrayOf(9, 10, 11, 14, 15, 16, 22)
+
+    private fun isJungseongWide(hanIndex: Int) = jungseongWide.contains(getHanJungseong(hanIndex))
+    private fun isJungseongComplex(hanIndex: Int) = jungseongComplex.contains(getHanJungseong(hanIndex))
+
+    private fun getHanInitialRow(hanIndex: Int): Int {
+        val ret: Int
+
+        if (isJungseongWide(hanIndex))
+            ret = 2
+        else if (isJungseongComplex(hanIndex))
+            ret = 4
+        else
+            ret = 0
+
+        return if (getHanJongseong(hanIndex) == 0) ret else ret + 1
+    }
+
+    private fun getHanMedialRow(hanIndex: Int) = if (getHanJongseong(hanIndex) == 0) 6 else 7
+
+    private fun getHanFinalRow(hanIndex: Int): Int {
+        val jungseongIndex = getHanJungseong(hanIndex)
+
+        return if (jungseongWide.contains(jungseongIndex))
+            8
+        else
+            9
+    }
+
+    private fun isHangul(c: Char) = c.toInt() in 0xAC00..0xD7A3
+    private fun isAscii(c: Char) = c.toInt() in 0..0xFF
+    //private fun isRunic(c: Char) = runicList.contains(c)
+    private fun isExtA(c: Char) = c.toInt() in 0x100..0x17F
+    private fun isExtB(c: Char) = c.toInt() in 0x180..0x24F
+    private fun isKana(c: Char) = c.toInt() in 0x3040..0x30FF
+    private fun isCJKPunct(c: Char) = c.toInt() in 0x3000..0x303F
+    private fun isUniHan(c: Char) = c.toInt() in 0x3400..0x9FFF
+    private fun isCyrilic(c: Char) = c.toInt() in 0x400..0x4FF // 4FF: futureproof; currently only up to 45F is supported
+    private fun isFullwidthUni(c: Char) = c.toInt() in 0xFF00..0xFF1F
+    private fun isUniPunct(c: Char) = c.toInt() in 0x2000..0x206F
+    private fun isGreek(c: Char) = c.toInt() in 0x370..0x3CE
+    private fun isThai(c: Char) = c.toInt() in 0xE00..0xE7F
+    private fun isThaiDiacritics(c: Char) = c.toInt() in 0xE34..0xE3A
+                                            || c.toInt() in 0xE47..0xE4E
+                                            || c.toInt() == 0xE31
+    private fun isCustomSym(c: Char) = c.toInt() in 0xE000..0xE0FF
+
+
+
+    private fun extAindexX(c: Char) = (c.toInt() - 0x100) % 16
+    private fun extAindexY(c: Char) = (c.toInt() - 0x100) / 16
+
+    private fun extBindexX(c: Char) = (c.toInt() - 0x180) % 16
+    private fun extBindexY(c: Char) = (c.toInt() - 0x180) / 16
+
+    //private fun runicIndexX(c: Char) = runicList.indexOf(c) % 16
+    //private fun runicIndexY(c: Char) = runicList.indexOf(c) / 16
+
+    private fun kanaIndexX(c: Char) = (c.toInt() - 0x3040) % 16
+    private fun kanaIndexY(c: Char) = (c.toInt() - 0x3040) / 16
+
+    private fun cjkPunctIndexX(c: Char) = (c.toInt() - 0x3000) % 16
+    private fun cjkPunctIndexY(c: Char) = (c.toInt() - 0x3000) / 16
+
+    private fun cyrilicIndexX(c: Char) = (c.toInt() - 0x400) % 16
+    private fun cyrilicIndexY(c: Char) = (c.toInt() - 0x400) / 16
+
+    private fun fullwidthUniIndexX(c: Char) = (c.toInt() - 0xFF00) % 16
+    private fun fullwidthUniIndexY(c: Char) = (c.toInt() - 0xFF00) / 16
+
+    private fun uniPunctIndexX(c: Char) = (c.toInt() - 0x2000) % 16
+    private fun uniPunctIndexY(c: Char) = (c.toInt() - 0x2000) / 16
+
+    private fun unihanIndexX(c: Char) = (c.toInt() - 0x3400) % 256
+    private fun unihanIndexY(c: Char) = (c.toInt() - 0x3400) / 256
+
+    private fun greekIndexX(c: Char) = (c.toInt() - 0x370) % 16
+    private fun greekIndexY(c: Char) = (c.toInt() - 0x370) / 16
+
+    private fun thaiIndexX(c: Char) = (c.toInt() - 0xE00) % 16
+    private fun thaiIndexY(c: Char) = (c.toInt() - 0xE00) / 16
+
+    private fun symbolIndexX(c: Char) = (c.toInt() - 0xE000) % 16
+    private fun symbolIndexY(c: Char) = (c.toInt() - 0xE000) / 16
+
+    private val unihanWidthSheets = arrayOf(
+            SHEET_UNIHAN,
+            SHEET_FW_UNI
+    )
+    private val variableWidthSheets = arrayOf(
+            SHEET_ASCII_VARW,
+            SHEET_EXTA_VARW,
+            SHEET_EXTB_VARW,
+            SHEET_CYRILIC_VARW,
+            SHEET_UNI_PUNCT,
+            SHEET_GREEK_VARW,
+            SHEET_THAI_VARW
+    )
+
+    private val fontParentDir = if (fontDir.endsWith('/') || fontDir.endsWith('\\')) fontDir else "$fontDir/"
+    private val fileList = arrayOf( // MUST BE MATCHING WITH SHEET INDICES!!
+            "ascii_variable.tga",
+            "hangul_johab.tga",
+            "LatinExtA_variable.tga",
+            "LatinExtB_variable.tga",
+            "kana.tga",
+            "cjkpunct.tga",
+            "wenquanyi.tga.gz",
+            "cyrilic_variable.tga",
+            "fullwidth_forms.tga",
+            "unipunct_variable.tga",
+            "greek_variable.tga",
+            "thai_variable.tga",
+            "puae000-e0ff.tga"
+    )
+    private val cyrilic_bg = "cyrilic_bulgarian_variable.tga"
+    private val cyrilic_sr = "cyrilic_serbian_variable.tga"
+    private val codeRange = arrayOf( // MUST BE MATCHING WITH SHEET INDICES!!
+            0..0xFF,
+            0xAC00..0xD7A3,
+            0x100..0x17F,
+            0x180..0x24F,
+            0x3040..0x30FF,
+            0x3000..0x303F,
+            0x3400..0x9FFF,
+            0x400..0x4FF,
+            0xFF00..0xFF1F,
+            0x2000..0x206F,
+            0x370..0x3CE,
+            0xE00..0xE7F,
+            0xE000..0xE0FF
+    )
+    private val glyphWidths: HashMap<Int, Int> = HashMap()
+    private val sheets: Array<TextureRegionPack>
+
+
+    init {
+        val sheetsPack = ArrayList<TextureRegionPack>()
+
+        // first we create pixmap to read pixels, then make texture using pixmap
+        fileList.forEachIndexed { index, it ->
+            val isVariable1 = it.endsWith("_variable.tga")
+            val isVariable2 = variableWidthSheets.contains(index)
+            val isVariable = isVariable1 && isVariable2
+
+            // idiocity check
+            if (isVariable1 && !isVariable2)
+                throw Error("[TerrarumSansBitmap] font is named as variable on the name but not enlisted as")
+            else if (!isVariable1 && isVariable2)
+                throw Error("[TerrarumSansBitmap] font is enlisted as variable on the name but not named as")
+
+
+            val pixmap: Pixmap
+
+
+            // unpack gz if applicable
+            if (it.endsWith(".gz")) {
+                val gzi = GZIPInputStream(Gdx.files.internal(fontParentDir + it).read(8192))
+                val wholeFile = gzi.readBytes()
+                gzi.close()
+                val fos = BufferedOutputStream(FileOutputStream("tmp_wenquanyi.tga"))
+                fos.write(wholeFile)
+                fos.flush()
+                fos.close()
+
+                pixmap = Pixmap(Gdx.files.internal("tmp_wenquanyi.tga"))
+
+                File("tmp_wenquanyi.tga").delete()
+            }
+            else {
+                pixmap = Pixmap(Gdx.files.internal(fontParentDir + it))
+            }
+
+
+            if (isVariable) {
+                println("[TerrarumSansBitmap] loading texture $it [VARIABLE]")
+                buildWidthTable(pixmap, codeRange[index], 16)
+            }
+            else {
+                println("[TerrarumSansBitmap] loading texture $it")
+            }
+
+            val texture = Texture(pixmap)
+            val texRegPack = if (isVariable) {
+                TextureRegionPack(texture, W_VAR_INIT, H, HGAP_VAR, 0)
+            }
+            else if (index == SHEET_UNIHAN) {
+                TextureRegionPack(texture, W_UNIHAN, H_UNIHAN) // the only exception that is height is 16
+            }
+            // below they all have height of 20 'H'
+            else if (index == SHEET_FW_UNI) {
+                TextureRegionPack(texture, W_UNIHAN, H)
+            }
+            else if (index == SHEET_CJK_PUNCT) {
+                TextureRegionPack(texture, W_ASIAN_PUNCT, H)
+            }
+            else if (index == SHEET_KANA) {
+                TextureRegionPack(texture, W_KANA, H)
+            }
+            else if (index == SHEET_HANGUL) {
+                TextureRegionPack(texture, W_HANGUL, H)
+            }
+            else if (index == SHEET_CUSTOM_SYM) {
+                TextureRegionPack(texture, SIZE_CUSTOM_SYM, SIZE_CUSTOM_SYM) // TODO variable
+            }
+            else throw IllegalArgumentException("[TerrarumSansBitmap] Unknown sheet index: $index")
+
+
+            sheetsPack.add(texRegPack)
+
+            pixmap.dispose() // you are terminated
+        }
+
+        sheets = sheetsPack.toTypedArray()
+    }
+
+
+    fun reload(locale: String) {
+        if (locale.startsWith("ru")) {
+            val pixmap = Pixmap(Gdx.files.internal(fontParentDir + fileList[SHEET_CYRILIC_VARW]))
+            val texture = Texture(pixmap)
+            sheets[SHEET_CYRILIC_VARW].dispose()
+            sheets[SHEET_CYRILIC_VARW] = TextureRegionPack(texture, W_VAR_INIT, H, HGAP_VAR, 0)
+            pixmap.dispose()
+        }
+        else if (locale.startsWith("bg")) {
+            val pixmap = Pixmap(Gdx.files.internal(fontParentDir + cyrilic_bg))
+            val texture = Texture(pixmap)
+            sheets[SHEET_CYRILIC_VARW].dispose()
+            sheets[SHEET_CYRILIC_VARW] = TextureRegionPack(texture, W_VAR_INIT, H, HGAP_VAR, 0)
+            pixmap.dispose()
+        }
+        else if (locale.startsWith("sr")) {
+            val pixmap = Pixmap(Gdx.files.internal(fontParentDir + cyrilic_sr))
+            val texture = Texture(pixmap)
+            sheets[SHEET_CYRILIC_VARW].dispose()
+            sheets[SHEET_CYRILIC_VARW] = TextureRegionPack(texture, W_VAR_INIT, H, HGAP_VAR, 0)
+            pixmap.dispose()
+        }
+    }
+
+
+    override fun getLineHeight(): Float = H.toFloat()
+
+    override fun getXHeight() = lineHeight
+    override fun getCapHeight() = lineHeight
+    override fun getAscent() = 0f
+    override fun getDescent() = 0f
+
+    override fun isFlipped() = false
+
+    override fun setFixedWidthGlyphs(glyphs: CharSequence) {
+        throw UnsupportedOperationException("Nope, no monospace, and figures are already fixed width, bruv.")
+    }
+
+
+    init {
+        setUseIntegerPositions(true)
+        setOwnsTexture(true)
+    }
+
+    private val offsetUnihan = (H - H_UNIHAN) / 2
+    private val offsetCustomSym = (H - SIZE_CUSTOM_SYM) / 2
+
+    private var textBuffer: CharSequence = ""
+    private var textBWidth = intArrayOf() // absolute posX of glyphs from print-origin
+
+    override fun draw(batch: Batch, str: CharSequence, x: Float, y: Float): GlyphLayout? {
+        if (textBuffer != str) {
+            textBuffer = str
+            val widths = getWidthOfCharSeq(str)
+
+            textBWidth = Array(str.length, { charIndex ->
+                if (charIndex == 0)
+                    0
+                else {
+                    var acc = 0
+                    (0..charIndex - 1).forEach { acc += widths[it] }
+                    /*return*/acc
+                }
+            }).toIntArray()
+        }
+
+
+        //print("[TerrarumSansBitmap] widthTable for $textBuffer: ")
+        //textBWidth.forEach { print("$it ") }; println()
+
+
+        val mainCol = this.color.cpy()
+        val shadowCol = this.color.cpy().mul(0.5f)
+
+
+        textBuffer.forEachIndexed { index, c ->
+            val sheetID = getSheetType(c)
+            val sheetXY = getSheetwisePosition(c)
+
+            //println("[TerrarumSansBitmap] sprite:  $sheetID:${sheetXY[0]}x${sheetXY[1]}")
+
+            if (sheetID != SHEET_HANGUL) {
+
+                if (!noShadow) {
+                    batch.color = shadowCol
+                    batch.draw(
+                            sheets[sheetID].get(sheetXY[0], sheetXY[1]),
+                            x + textBWidth[index] + 1,
+                            y +
+                            if (sheetID == SHEET_UNIHAN) // evil exceptions
+                                offsetUnihan
+                            else if (sheetID == SHEET_CUSTOM_SYM)
+                                offsetCustomSym
+                            else 0
+                    )
+                    batch.draw(
+                            sheets[sheetID].get(sheetXY[0], sheetXY[1]),
+                            x + textBWidth[index],
+                            y - 1 +
+                            if (sheetID == SHEET_UNIHAN) // evil exceptions
+                                offsetUnihan
+                            else if (sheetID == SHEET_CUSTOM_SYM)
+                                offsetCustomSym
+                            else 0
+                    )
+                    batch.draw(
+                            sheets[sheetID].get(sheetXY[0], sheetXY[1]),
+                            x + textBWidth[index] + 1,
+                            y - 1 +
+                            if (sheetID == SHEET_UNIHAN) // evil exceptions
+                                offsetUnihan
+                            else if (sheetID == SHEET_CUSTOM_SYM)
+                                offsetCustomSym
+                            else 0
+                    )
+                }
+
+
+                batch.color = mainCol
+                batch.draw(
+                        sheets[sheetID].get(sheetXY[0], sheetXY[1]),
+                        x + textBWidth[index],
+                        y +
+                        if (sheetID == SHEET_UNIHAN) // evil exceptions
+                            offsetUnihan
+                        else if (sheetID == SHEET_CUSTOM_SYM)
+                            offsetCustomSym
+                        else 0
+                )
+            }
+            else { // JOHAB (assemble) HANGUL
+                val hangulSheet = sheets[SHEET_HANGUL]
+                val hIndex = c.toInt() - 0xAC00
+
+                val indexCho = getHanChosung(hIndex)
+                val indexJung = getHanJungseong(hIndex)
+                val indexJong = getHanJongseong(hIndex)
+
+                val choRow = getHanInitialRow(hIndex)
+                val jungRow = getHanMedialRow(hIndex)
+                val jongRow = getHanFinalRow(hIndex)
+
+
+                if (!noShadow) {
+                    batch.color = shadowCol
+
+                    batch.draw(hangulSheet.get(indexCho, choRow), x + textBWidth[index] + 1, y)
+                    batch.draw(hangulSheet.get(indexJung, jungRow), x + textBWidth[index], y - 1)
+                    batch.draw(hangulSheet.get(indexJong, jongRow), x + textBWidth[index] + 1, y - 1)
+                }
+
+
+                batch.color = mainCol
+                batch.draw(hangulSheet.get(indexCho, choRow), x + textBWidth[index], y)
+                batch.draw(hangulSheet.get(indexJung, jungRow), x + textBWidth[index], y)
+                batch.draw(hangulSheet.get(indexJong, jongRow), x + textBWidth[index], y)
+            }
+        }
+
+        this.color = mainCol
+
+        return null
+    }
+
+
+    override fun dispose() {
+        super.dispose()
+
+        sheets.forEach { it.dispose() }
+    }
+
+    private fun getWidthOfCharSeq(s: CharSequence): IntArray {
+        val len = IntArray(s.length)
+        for (i in 0..s.lastIndex) {
+            val chr = s[i]
+            val ctype = getSheetType(s[i])
+
+            if (variableWidthSheets.contains(ctype)) {
+                len[i] = try {
+                    glyphWidths[chr.toInt()]!!
+                }
+                catch (e: kotlin.KotlinNullPointerException) {
+                    println("[TerrarumSansBitmap] no width data for glyph number ${Integer.toHexString(chr.toInt()).toUpperCase()}")
+                    //System.exit(1)
+                    W_LATIN_WIDE // failsafe
+                }
+            }
+            else if (ctype == SHEET_CJK_PUNCT)
+                len[i] = W_ASIAN_PUNCT
+            else if (ctype == SHEET_HANGUL)
+                len[i] = W_HANGUL
+            else if (ctype == SHEET_KANA)
+                len[i] = W_KANA
+            else if (unihanWidthSheets.contains(ctype))
+                len[i] = W_UNIHAN
+            else if (isThaiDiacritics(s[i]))
+                len[i] = 0 // set width of the glyph as -W_LATIN_WIDE
+            else if (ctype == SHEET_CUSTOM_SYM)
+                len[i] = SIZE_CUSTOM_SYM
+            else
+                len[i] = W_LATIN_WIDE
+
+            if (scale > 1) len[i] *= scale
+
+            if (i < s.lastIndex) len[i] += interchar
+        }
+        return len
+    }
+
+    private fun getSheetType(c: Char): Int {
+        if (isHangul(c))
+            return SHEET_HANGUL
+        else if (isKana(c))
+            return SHEET_KANA
+        else if (isUniHan(c))
+            return SHEET_UNIHAN
+        else if (isAscii(c))
+            return SHEET_ASCII_VARW
+        else if (isExtA(c))
+            return SHEET_EXTA_VARW
+        else if (isExtB(c))
+            return SHEET_EXTB_VARW
+        else if (isCyrilic(c))
+            return SHEET_CYRILIC_VARW
+        else if (isUniPunct(c))
+            return SHEET_UNI_PUNCT
+        else if (isCJKPunct(c))
+            return SHEET_CJK_PUNCT
+        else if (isFullwidthUni(c))
+            return SHEET_FW_UNI
+        else if (isGreek(c))
+            return SHEET_GREEK_VARW
+        else if (isThai(c))
+            return SHEET_THAI_VARW
+        else if (isCustomSym(c))
+            return SHEET_CUSTOM_SYM
+        else
+            return SHEET_UNKNOWN
+        // fixed width
+        // fallback
+    }
+
+    private fun getSheetwisePosition(ch: Char): IntArray {
+        val sheetX: Int; val sheetY: Int
+        when (getSheetType(ch)) {
+            SHEET_UNIHAN -> {
+                sheetX = unihanIndexX(ch)
+                sheetY = unihanIndexY(ch)
+            }
+            SHEET_EXTA_VARW -> {
+                sheetX = extAindexX(ch)
+                sheetY = extAindexY(ch)
+            }
+            SHEET_EXTB_VARW -> {
+                sheetX = extBindexX(ch)
+                sheetY = extBindexY(ch)
+            }
+            SHEET_KANA -> {
+                sheetX = kanaIndexX(ch)
+                sheetY = kanaIndexY(ch)
+            }
+            SHEET_CJK_PUNCT -> {
+                sheetX = cjkPunctIndexX(ch)
+                sheetY = cjkPunctIndexY(ch)
+            }
+            SHEET_CYRILIC_VARW -> {
+                sheetX = cyrilicIndexX(ch)
+                sheetY = cyrilicIndexY(ch)
+            }
+            SHEET_FW_UNI -> {
+                sheetX = fullwidthUniIndexX(ch)
+                sheetY = fullwidthUniIndexY(ch)
+            }
+            SHEET_UNI_PUNCT -> {
+                sheetX = uniPunctIndexX(ch)
+                sheetY = uniPunctIndexY(ch)
+            }
+            SHEET_GREEK_VARW -> {
+                sheetX = greekIndexX(ch)
+                sheetY = greekIndexY(ch)
+            }
+            SHEET_THAI_VARW -> {
+                sheetX = thaiIndexX(ch)
+                sheetY = thaiIndexY(ch)
+            }
+            SHEET_CUSTOM_SYM -> {
+                sheetX = symbolIndexX(ch)
+                sheetY = symbolIndexY(ch)
+            }
+            else -> {
+                sheetX = ch.toInt() % 16
+                sheetY = ch.toInt() / 16
+            }
+        }
+
+        return intArrayOf(sheetX, sheetY)
+    }
+
+    fun buildWidthTable(pixmap: Pixmap, codeRange: IntRange, cols: Int = 16) {
+        val binaryCodeOffset = W_VAR_INIT
+
+        val cellW = W_VAR_INIT + 1
+        val cellH = H
+
+        for (code in codeRange) {
+
+            val cellX = ((code - codeRange.start) % cols) * cellW
+            val cellY = ((code - codeRange.start) / cols) * cellH
+
+            val codeStartX = cellX + binaryCodeOffset
+            val codeStartY = cellY
+
+            var glyphWidth = 0
+            for (downCtr in 0..3) {
+                // if ALPHA is not zero, assume it's 1
+                if (pixmap.getPixel(codeStartX, codeStartY + downCtr).and(0xFF) != 0) {
+                    glyphWidth = glyphWidth or (1 shl downCtr)
+                }
+            }
+
+            glyphWidths[code] = glyphWidth
+        }
+    }
+
+
+    companion object {
+
+        internal val JUNG_COUNT = 21
+        internal val JONG_COUNT = 28
+
+        internal val W_ASIAN_PUNCT = 10
+        internal val W_HANGUL = 12
+        internal val W_KANA = 12
+        internal val W_UNIHAN = 16
+        internal val W_LATIN_WIDE = 9 // width of regular letters
+        internal val W_VAR_INIT = 15
+
+        internal val HGAP_VAR = 1
+
+        internal val H = 20
+        internal val H_UNIHAN = 16
+
+        internal val SIZE_CUSTOM_SYM = 18
+
+        internal val SHEET_ASCII_VARW =     0
+        internal val SHEET_HANGUL =         1
+        internal val SHEET_EXTA_VARW =      2
+        internal val SHEET_EXTB_VARW =      3
+        internal val SHEET_KANA =           4
+        internal val SHEET_CJK_PUNCT =      5
+        internal val SHEET_UNIHAN =         6
+        internal val SHEET_CYRILIC_VARW =   7
+        internal val SHEET_FW_UNI =         8
+        internal val SHEET_UNI_PUNCT =      9
+        internal val SHEET_GREEK_VARW =     10
+        internal val SHEET_THAI_VARW =      11
+        internal val SHEET_CUSTOM_SYM =     12
+
+        internal val SHEET_UNKNOWN = 254
+
+        /**
+         * Runic letters list used for game. The set is
+         * Younger Futhark + Medieval rune 'e' + Punct + Runic Almanac
+
+         * BEWARE OF SIMILAR-LOOKING RUNES, especially:
+
+         * * Algiz ᛉ instead of Maðr ᛘ
+
+         * * Short-Twig Hagall ᚽ instead of Runic Letter E ᛂ
+
+         * * Runic Letter OE ᚯ instead of Óss ᚬ
+
+         * Examples:
+         * ᛭ᛋᛁᚴᚱᛁᚦᛦ᛭
+         * ᛭ᛂᛚᛋᛅ᛭ᛏᚱᚢᛏᚾᛁᚾᚴᚢᚾᛅ᛬ᛅᚱᚾᛅᛏᛅᛚᛋ
+         */
+        //internal val runicList = arrayOf('ᚠ', 'ᚢ', 'ᚦ', 'ᚬ', 'ᚱ', 'ᚴ', 'ᚼ', 'ᚾ', 'ᛁ', 'ᛅ', 'ᛋ', 'ᛏ', 'ᛒ', 'ᛘ', 'ᛚ', 'ᛦ', 'ᛂ', '᛬', '᛫', '᛭', 'ᛮ', 'ᛯ', 'ᛰ')
+        // TODO expand to full Unicode runes
+
+        var interchar = 0
+        var scale = 1
+            set(value) {
+                if (value > 0) field = value
+                else throw IllegalArgumentException("Font scale cannot be zero or negative (input: $value)")
+            }
+    }
+
+}