Terrarum/src/net/torvald/terrarum/imagefont/BigAlphNum.kt

package net.torvald.terrarum.imagefont

import com.badlogic.gdx.graphics.Color
import com.badlogic.gdx.graphics.g2d.Batch
import com.badlogic.gdx.graphics.g2d.BitmapFont
import com.badlogic.gdx.graphics.g2d.GlyphLayout
import net.torvald.terrarum.roundToFloat
import net.torvald.terrarumsansbitmap.gdx.TextureRegionPack

/**
 * Created by minjaesong on 2023-09-03.
 */
object BigAlphNum : BitmapFont() {

    internal const val W = 12
    internal const val H = 16

    internal val fontSheet = TextureRegionPack("./assets/graphics/fonts/code.tga", W, H)


    private const val interchar = 1

    init {
        setOwnsTexture(true)
        setUseIntegerPositions(true)
    }

    fun getWidth(str: String): Int {
        var l = 0
        for (char in str) {
            if (!isColourCodeHigh(char) && !isColourCodeLow(char)) {
                l += 1
            }
        }
        return (W + interchar) * l
    }

    lateinit var colMain: Color
    lateinit var colShadow: Color

    override fun draw(batch: Batch, text: CharSequence, x: Float, y: Float): GlyphLayout? {
        val originalColour = batch.color.cpy()
        colMain = batch.color.cpy()
        colShadow = colMain.cpy().mul(0.5f, 0.5f, 0.5f, 1f)

        val x = x.roundToFloat()
        val y = y.roundToFloat()

        var charsPrinted = 0
        text.forEachIndexed { index, c ->
            if (isColourCodeHigh(c)) {
                val cchigh = c
                val cclow = text[index + 1]
                val colour = getColour(cchigh, cclow)

                colMain = colour
                colShadow = colMain.cpy().mul(0.5f, 0.5f, 0.5f, 1f)
            }
            else if (c in 0.toChar()..255.toChar()) {
                val ccode = c.code - 48

                if (ccode in 0..47) {
                    batch.color = colShadow
                    batch.draw(fontSheet.get(ccode % 16, ccode / 16), x + charsPrinted * (W + interchar) + 1, y)
                    batch.draw(fontSheet.get(ccode % 16, ccode / 16), x + charsPrinted * (W + interchar), y + 1)
                    batch.draw(fontSheet.get(ccode % 16, ccode / 16), x + charsPrinted * (W + interchar) + 1, y + 1)


                    batch.color = colMain
                    batch.draw(fontSheet.get(ccode % 16, ccode / 16), x + charsPrinted * (W + interchar), y)
                }

                charsPrinted += 1
            }
        }


        batch.color = originalColour

        return null
    }

    override fun getLineHeight() = H.toFloat()
    override fun getCapHeight() = getLineHeight()
    override fun getXHeight() = getLineHeight()



    private fun isColourCodeHigh(c: Char) = c.code in 0b110110_1111000000..0b110110_1111111111
    private fun isColourCodeLow(c: Char) = c.code in 0b110111_0000000000..0b110111_1111111111

    private fun getColour(charHigh: Char, charLow: Char): Color { // input: 0x10ARGB, out: RGBA8888
        val codePoint = Character.toCodePoint(charHigh, charLow)

        if (colourBuffer.containsKey(codePoint))
            return colourBuffer[codePoint]!!

        val a = codePoint.and(0xF000).ushr(12)
        val r = codePoint.and(0x0F00).ushr(8)
        val g = codePoint.and(0x00F0).ushr(4)
        val b = codePoint.and(0x000F)

        val col = Color(r.shl(28) or r.shl(24) or g.shl(20) or g.shl(16) or b.shl(12) or b.shl(8) or a.shl(4) or a)


        colourBuffer[codePoint] = col
        return col
    }

    private val colourBuffer = HashMap<Int, Color>()
}