Class: JekyllImgFlow::Providers::Imagemagick

Inherits:
BaseProvider show all
Defined in:
lib/jekyll-imgflow/providers/imagemagick.rb

Overview

ImageMagick provider implementation using the standardized tag interface

Constant Summary

Constants inherited from BaseProvider

BaseProvider::KNOWN_OPERATIONS, BaseProvider::SMARTCROP_POSITIONS

Instance Attribute Summary

Attributes inherited from BaseProvider

#config

Instance Method Summary collapse

Methods inherited from BaseProvider

#add_watermark, #alpha_opacity=, #check_http_service, #convert_format, #crop, #encode_file_url, #format, #initialize, #opacity, #operations, #optimize, provider_name, #quality, #quality=, #reset_operations, #resize, #supports_operation?, supports_operation?, unsupported_operations, #watermark

Constructor Details

This class inherits a constructor from JekyllImgFlow::Providers::BaseProvider

Instance Method Details

#available? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jekyll-imgflow/providers/imagemagick.rb', line 15

def available?
  # Check if magick or convert CLI is available
  _, _, status1 = Open3.capture3("which", "magick")
  _, _, status2 = Open3.capture3("which", "convert")
  status1.success? || status2.success?
end

#build_combined_imagemagick_command(input_path, output_path) ⇒ Object 



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# File 'lib/jekyll-imgflow/providers/imagemagick.rb', line 37

def build_combined_imagemagick_command(input_path, output_path)
  # Start with base command.
  # For SVGs, set -density before the input so ImageMagick rasterizes
  # at a reasonable resolution instead of the full viewBox (which can
  # be 10000x8500 = 85M pixels, making each conversion take 10+ seconds).
  # With the rsvg delegate installed, -density controls the render DPI.
  # Without rsvg, ImageMagick uses its slow internal MSVG parser.
  command_parts = if svg?(input_path)
                    ["magick", "-density", svg_density.to_s, input_path.shellescape]
                  else
                    ["magick", input_path.shellescape]
                  end

  # Add all operations
  @operations.each do |operation|
    case operation[:type]
    when :resize
      # Tags now provide complete calculated values
      command_parts << "-resize" << if operation[:height]
                                      "#{operation[:width]}x#{operation[:height]}!"
                                    else
                                      operation[:width].to_s
                                    end

    when :crop
      opts = operation[:options]
      params = operation[:params] || {}

      # Check for keep parameter (ImageMagick doesn't support smartcrop, but we handle it gracefully)
      keep = opts[:keep] || params[:keep] || params[:position]

      if operation[:ratio] && keep && SMARTCROP_POSITIONS.include?(keep.to_s)
        # ImageMagick doesn't support smartcrop, but we handle the keep parameter
        # Use center gravity as a reasonable fallback for smartcrop requests
        crop_width = opts[:calculated_width]
        crop_height = opts[:calculated_height]
        crop_x = opts[:calculated_x]
        crop_y = opts[:calculated_y]

        # Use gravity center for smartcrop-like behavior
        crop_spec = "#{crop_width}x#{crop_height}+#{crop_x}+#{crop_y}"
        command_parts << "-gravity" << "center"
      else
        # Use basic cropping
        if operation[:ratio]
          crop_x = opts[:calculated_x]
          crop_y = opts[:calculated_y]
          crop_width = opts[:calculated_width]
          crop_height = opts[:calculated_height]
        else
          crop_x = opts[:x]
          crop_y = opts[:y]
          crop_width = opts[:width]
          crop_height = opts[:height]
        end
        crop_spec = "#{crop_width}x#{crop_height}+#{crop_x}+#{crop_y}"
      end
      command_parts << "-crop" << crop_spec

    when :quality
      magick_quality = translate_quality_to_imagemagick(operation[:quality])
      command_parts << "-quality" << magick_quality.to_s

    when :format
      # Assume validated input from tags
      # Format is handled by output filename extension
      # Quality is set separately if needed
      unless @operations.any? { |op| op[:type] == :quality }
        default_quality = @config&.quality || raise("No quality configured")
        command_parts << "-quality" << default_quality.to_s
      end

    when :watermark
      watermark_path = operation[:watermark_path]
      position = operation[:options][:position]

      # Translate compass directions to ImageMagick gravity format
      gravity = translate_position(position)

      # Add watermark as composite operation
      command_parts << watermark_path.shellescape
      command_parts << "-gravity" << gravity
      command_parts << "-composite"

    when :alpha_opacity
      opacity = operation[:opacity]
      alpha_value = (opacity * 100).round
      command_parts << "-alpha" << "set"
      command_parts << "-channel" << "A"
      command_parts << "-evaluate" << "multiply" << "#{alpha_value}%"
    end
  end

  # Add output filename
  command_parts << output_path.shellescape

  command_parts.join(" ")
end

#execute(input_path, output_path) ⇒ Object 



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# File 'lib/jekyll-imgflow/providers/imagemagick.rb', line 22

def execute(input_path, output_path)
  return if @operations.empty?

  # Warn once per build about SVG performance with ImageMagick
  warn_svg_performance if svg?(input_path) && !self.class.instance_variable_get(:@svg_warning_shown)

  # Build single ImageMagick command with all operations combined
  command = build_combined_imagemagick_command(input_path, output_path)
  execute_command(command)

  output_path
ensure
  reset_operations
end

#translate_position(position) ⇒ Object 



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# File 'lib/jekyll-imgflow/providers/imagemagick.rb', line 136

def translate_position(position)
  case position
  when "northwest" then "NorthWest"
  when "northeast" then "NorthEast"
  when "southwest" then "SouthWest"
  when "southeast" then "SouthEast"
  when "center" then "Center"
  else position
  end
end