Just a snippet to parse vector drawable's pathData for VectorImage in Compose

parse_vector_pathData.rb

# ruby parse_vector_pathData.rb "<pathData>"
#
# @example ruby parse_vector_pathData.rb "M2...Z"
# 
# <pathData> is a pathData attribute of path node.

pathData = ARGV[0]

kotlinPathNodeChunks = []

cursor_idx = 0

while cursor_idx != nil && cursor_idx < pathData.length do
    current_cursor_idx = cursor_idx
    
    # Node Kind
    c = pathData[current_cursor_idx]
    
    # Node Data
    data_length = pathData[current_cursor_idx + 1..].index(/[A-Za-z]/) || pathData[current_cursor_idx + 1..].length
    data = pathData[current_cursor_idx + 1, data_length]
    
    # Move to the next Node Kind
    cursor_idx = current_cursor_idx + data_length + 1

    STDERR.puts "current_cursor_idx: #{current_cursor_idx}, cursor_idx: #{cursor_idx}"
    STDERR.puts "c: #{c}, next_c: #{pathData[cursor_idx]}"
    STDERR.puts data

    args = data.split(/[ ,]/)

    case c
    when "M"
        kotlinPathNodeChunks << "PathNode.MoveTo(x = #{args[0]}f, y = #{args[1]}f)"
    when "L"
        kotlinPathNodeChunks << "PathNode.LineTo(x = #{args[0]}f, y = #{args[1]}f)"
    when "C"
        kotlinPathNodeChunks << <<-EOF
        PathNode.CurveTo(
            x1 = #{args[0]}f,
            y1 = #{args[1]}f,
            x2 = #{args[2]}f,
            y2 = #{args[3]}f,
            x3 = #{args[4]}f,
            y3 = #{args[5]}f
        )
        EOF
    when "H"
        kotlinPathNodeChunks << "PathNode.HorizontalTo(x = #{args[0]}f)"
    when "h"
        kotlinPathNodeChunks << "PathNode.RelativeHorizontalTo(dx = #{args[0]}f)"
    when "V"
        kotlinPathNodeChunks << "PathNode.VerticalTo(y = #{args[0]}f)"
    when "v"
        kotlinPathNodeChunks << "PathNode.RelativeVerticalTo(dy = #{args[0]}f)"
    when "S"
        kotlinPathNodeChunks << <<-EOF
        PathNode.ReflectiveCurveTo(
            x1 = #{args[0]}f,
            y1 = #{args[1]}f,
            x2 = #{args[2]}f,
            y2 = #{args[3]}f
        )
        EOF
    when "s"
        kotlinPathNodeChunks << <<-EOF
        PathNode.RelativeReflectiveCurveTo(
            dx1 = #{args[0]}f,
            dy1 = #{args[1]}f,
            dx2 = #{args[2]}f,
            dy2 = #{args[3]}f
        )
        EOF
    when "A"
        kotlinPathNodeChunks << <<-EOF
        PathNode.ArcTo(
            horizontalEllipseRadius = #{args[0]}f,
            verticalEllipseRadius = #{args[1]}f,
            theta = #{args[2]}f,
            isMoreThanHalf = #{args[3] == "1" ? "true" : "false"},
            isPositiveArc = #{args[4] == "1" ? "true" : "false"},
            arcStartX = #{args[5]}f,
            arcStartY = #{args[6]}f
        )
        EOF
    when "Z"
    when "z"
        kotlinPathNodeChunks << "PathNode.Close"
    else
        raise "unknown command: #{c}" # more nodes are not supported yet...
    end
end

puts kotlinPathNodeChunks.join(",\n")