whitelines.rb

require 'cairo'

# Device
devices = {
  github: {
    width: 1920,
    height: 256,
    pixels_per_mm: 12,
  },
  manta: {
    abbrev: 'a5',
    width: 1920,
    height: 2560,
    pixels_per_mm: 12,
  },
  nomad: {
    abbrev: 'a6',
    width: 1404,
    height: 1872,
    pixels_per_mm: 12,
  }
}

# settings
colors = {
  plain: {
    background: 1,
    dot_color: 0.5,
    dot_radius: 2,
    line_color: 0.2,
    line_width: 1,
  },
  white: {
    background: 0.80,
    dot_color: 1,
    dot_radius: 3,
    line_color: 1,
    line_width: 4,
  },
  "white dark": {
    background: 0.78,
    dot_color: 1,
    dot_radius: 3,
    line_color: 1,
    line_width: 4,
  }
}

devices.each do |device_name, specs|
  width = specs[:width]
  height = specs[:height]
  pixels_per_mm = specs[:pixels_per_mm]

  ['dot grid', 'lines', 'grid'].each do |style|
    colors.each do |theme, colors|
      background = colors[:background]
      dot_color = colors[:dot_color]
      dot_radius = colors[:dot_radius]
      line_color = colors[:line_color]
      line_width = colors[:line_width]

      (2..10).to_a.each do |grid_size_mm|
        square_size = pixels_per_mm * grid_size_mm
        background_color = [background, background, background]
        dot_color_color = [dot_color, dot_color, dot_color]
        line_color_color = [line_color, line_color, line_color]

        rows = height % square_size != 0 ? height / square_size : height / square_size - 1
        columns = width % square_size != 0 ? width / square_size : width / square_size - 1

        offset_x = (width - (square_size * columns)) / 2
        offset_y = (height - (square_size * rows)) / 2

        # Create a PNG surface
        surface = Cairo::ImageSurface.new(:argb32, width, height)
        context = Cairo::Context.new(surface)

        # Fill the background
        context.set_source_rgb(*background_color)
        context.paint

        if (style == 'dot grid')
          context.set_source_rgb(*dot_color_color)

          (rows + 1).times do |row|
            (columns + 1).times do |col|
              x = offset_x + col * square_size
              y = offset_y + row * square_size
              context.arc(x, y, dot_radius, 0, 2 * Math::PI) # Draw a circle (dot)
              context.fill # Fill the dot
            end
          end
        else
          # Draw the grid
          context.set_source_rgb(*line_color_color)
          context.set_line_width(line_width)

          # Draw vertical grid lines
          if (style == 'grid')
            (columns + 1).times do |col|
              x = offset_x + col * square_size
              context.move_to(x, 0)            # Start at the top edge
              context.line_to(x, height)       # Go to the bottom edge
            end
          end

          # Draw horizontal grid lines
          (rows + 1).times do |row|
            y = offset_y + row * square_size
            context.move_to(0, y)            # Start at the left edge
            context.line_to(width, y)        # Go to the right edge
          end

          # Stroke the grid lines
          context.stroke
        end

        # Save to a PNG file
        output_file = "#{grid_size_mm}mm #{style} #{theme}.png"
        surface.write_to_png("#{device_name}/#{output_file}")
        surface.write_to_png("all_devices/#{specs[:abbrev]}_#{output_file}") unless specs[:abbrev].nil?
        puts "PNG file saved as #{output_file}"
      end
    end
  end
end