Creating png image from SVG command

createImageFromSVG.kts

import java.io.File
import java.awt.Color
import java.awt.Graphics2D
import java.awt.BasicStroke
import java.awt.image.BufferedImage
import java.awt.geom.AffineTransform
import java.awt.geom.GeneralPath as Path
import javax.imageio.ImageIO
import java.util.ArrayList

class SVGParser { 
    private val isUpperCase: (s:String)->Boolean = { it==it.toUpperCase() }

    private fun createTokenList(svgCmds: String):ArrayList<Token> {
        val tokenList = ArrayList<Token>()
        val regex = Regex("[MmLlHhVvZz]")
        svgCmds.forEach { 
            if( regex.matches( it.toString() ) ){
                val token = Token(it)
                tokenList.add(token)
            }
            else {
                val lastToken = tokenList[tokenList.size-1]
                lastToken.params += it.toString()
            }
        }
        return tokenList
    }

    fun parse(svgCmds: String): Path {
        val path = Path()

        var currentX = 0f
        var currentY = 0f

        val proc:(token: Token, drawCmd:( x:Float, y:Float)->Unit )->Unit = { token, drawCmd ->
            // x,y 値を得る
            val x = token.getX(currentX)
            val y = token.getY(currentY)

            // 描写実行
            drawCmd(x, y)

            // currentX,Y 値の更新
            currentX = x
            currentY = y
        }

        createTokenList( svgCmds ).forEach { token->
            val svgCmd = token.type 
            when(svgCmd) {
                'M', 'm' -> proc(token, {x,y->path.moveTo(x, y)} )
                'L', 'H', 'V', 'l', 'h', 'v' -> proc(token, {x,y->path.lineTo(x, y)} )
                'Z', 'z' -> path.closePath()
            }
        }

        return path
    }

    class Token(type: Char) {
        val type = type
        var params = ""
    
        companion object { val BR = System.getProperty("line.separator") }
        
        // 改行を削除 
        private fun fix(s: String): String = s.split( delimiters = BR ).map({it.trim()}).joinToString( separator = "" )

        private fun toFloat( params: String, index: Int ): Float {
            val fixedParams = fix(params)
            val array = fixedParams.split( regex=Regex("[, ]") )
            return if( index<array.size ){ array[index].toFloat() } else { 0f }
        }
    
        fun getX(currentX: Float):Float {
            var retVal:Float = 0f
            val v0 = toFloat(params,0)
            when(type) {
                'H' -> retVal = v0 // X座標だけがかわるタイプ
                'h' -> retVal = v0 + currentX // X座標だけがかわるタイプ

                'V','v' -> retVal = currentX // Y座標だけがかわるタイプ( Xはカレントを維持 )

                'M','L' -> retVal = v0
                'm','l' -> retVal = v0 + currentX
            }
            return retVal
        }

        fun getY(currentY: Float):Float {
            var retVal:Float = 0f
            val v0 = toFloat(params,0)
            val v1 = toFloat(params,1)

            when(type) {
                'H','h' -> retVal = currentY // X座標だけがかわるタイプ ( Yはカレントを維持 )

                'V' -> retVal = v0 // Y座標だけがかわるタイプ
                'v' -> retVal = v0 + currentY // Y座標だけがかわるタイプ

                'M','L' -> retVal = v1
                'm','l' -> retVal = v1 + currentY
            }
            return retVal
        }
    }
}


//
// SVGの大きさは 24x24 を基準とする.
//

val svgCmds = if( args.size>0 ){ args[0] } else { "M16 6 l2.29 2.29 l-4.88 4.88 l-4 -4 L2 16.59 L3.41 18 l6 -6 l4 4 l6.3 -6.29 L22 12 V6 z" }
val outputPngFile = if( args.size>1 ){ File(args[1]) } else { File("r.png") }
val width  = if(args.size>2){ args[2].toInt() } else { 96 }
val height = if(args.size>3){ args[3].toInt() } else { 96 }


val path = SVGParser().parse(svgCmds)

val img = BufferedImage( width, height, BufferedImage.TYPE_4BYTE_ABGR )
val g = img.graphics as Graphics2D
g.color = Color.WHITE
g.fillRect(0,0,width,height )

val scaleX = width.toDouble()/24.toDouble()
val scaleY = height.toDouble()/24.toDouble()
val transform = AffineTransform.getScaleInstance( scaleX, scaleY )
val path2 = path.createTransformedShape( transform )

g.color = Color.BLACK
g.fill(path2)

g.dispose()
ImageIO.write(img,"PNG", outputPngFile)