Terrarum-sans-bitmap/README.md

Terrarum Sans Bitmap

This font is a bitmap font used in my game project, Terrarum (hence the name). It Supports ExtA, Romanian (subset of ExtB), Cyrillic, Greek, Chinese, Japanese and Korean.

The code for the fonts are meant to be used with Slick2d (extends Font class). If you are not using the framework, please refer to next section to implement the font metrics correctly on your system.

The issue page is open. If you have some issues to submit, or have a question, please leave it on the page.

Font metrics

The font expects both variable widths and fixed width to be supported. Any images with _variable means it expects variable widths. Anything else expects fixed width. romana_narrow has width of 6 (no, not 5), romana_wide has width of 9, cjkpunct has width of 10, kana has width of 12, hangul_johab has width of 11, wenquanyi has width of 16.

Parsing glyph widths for variable font sheets

Width is encoded in binary number, on pixels. If you open the image, every glyph has vertical dots on their right side (to be exact, every (16k - 1)th pixel on x axis). Topmost dot represents 1. For example, ASCII glyph 'C' has width of 9, 'W' has width of 11, " (double quote) has width of 6.

Implementing Korean writing system

There are 10 sets of Hangul glyph pieces. Top 6 concerns initials, middle 2 concerns medials, and bottom 2 concerns finals. On the rightmost side, there's eight assembled glyphs to help you with (assuming you have basic knowledge on the writing system). Top 6 tells you how to use 6 initials, and bottom 2 tells you how to use 2 finals.

This is a Kotlin-like pseudocode for assembling the glyph:

jungseongWide = arrayOf(8, 12, 13, 17, 18, 21)
jungseongComplex = arrayOf(9, 10, 11, 14, 15, 16, 22)

function 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
}

function isJungseongWide(hanIndex: Int) = jungseongWide.contains(getHanJungseong(hanIndex))
function isJungseongComplex(hanIndex: Int) = jungseongComplex.contains(getHanJungseong(hanIndex))

function 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
}

function getHanMedialRow(hanIndex: Int) = if (getHanJongseong(hanIndex) == 0) 6 else 7

function getHanFinalRow(hanIndex: Int): Int {
    val jungseongIndex = getHanJungseong(hanIndex)

    return if (jungseongWide.contains(jungseongIndex))
        8
    else
        9
}

function isHangul(c: Char) = c.toInt() >= 0xAC00 && c.toInt() < 0xD7A4

...

for (each Char on the string) {
    if (isHangul(Char)) {
        val hIndex = Char.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)

        // get sub image from sprite sheet
        val choseongImage =  hangulSheet.getSubImage(indexCho, choRow)
        val jungseongImage = hangulSheet.getSubImage(indexJung, jungRow)
        val jongseongImage = hangulSheet.getSubImage(indexJong, jongRow)
        
        // actual drawing part
        draw choseongImage to somewhere you want
        draw jungseongImage on top of choseongImage
        draw jongseongImage on top of choseongImage
    }
    ...
}

Acknowledgement

Thanks to kind people of /r/Typography for amazing feedbacks.