Add crop marks to PDF output

bin/svggvs

@@ -46,6 +46,8 @@ module SVGGVS
       end
     end
 
+    CARDS_PER_PAGE = 9
+
     desc "pdf", "Create PDF of card images"
     def pdf
       pngs
@@ -58,19 +60,23 @@ module SVGGVS
         tmp_target
       end
 
-      png_slices = trimmed_pngs.each_slice(9)
+      png_slices = trimmed_pngs.each_slice(CARDS_PER_PAGE)
 
-      page_count = trimmed_pngs.length / 9
+      page_count = trimmed_pngs.length / CARDS_PER_PAGE
 
       placeholder = tmp_target_for("placeholder.png")
       system %{convert -size #{context.session.pdf_card_size} xc:white #{placeholder}}
 
+      pdf_obj = SVGGVS::PDF.new(card_size: context.session.pdf_card_size)
+
       pages = Parallel.map(png_slices.each_with_index) do |files, page_index|
+        tmp_pdf_png_target = tmp_path.join("page%05d.pdf" % page_index)
         tmp_pdf_target = tmp_path.join("page%05d.pdf" % page_index)
 
         files += Array.new(9 - files.length, placeholder)
 
-        system %{montage -density #{context.session.pdf_dpi} -geometry +0+0 #{files.join(' ')} #{tmp_pdf_target}}
+        system %{montage -density #{context.session.pdf_dpi} -geometry +0+0 #{files.join(' ')} #{tmp_pdf_png_target}}
+        system %{convert -density #{context.session.pdf_dpi} #{tmp_pdf_png_target} -bordercolor white -border #{SVGGVS::PDF.border_size} #{pdf_obj.generate_crop_mark_draws.join(' ')} #{tmp_pdf_target}}.tap { |o| p o }
 
         tmp_pdf_target
       end

lib/svggvs.rb

@@ -3,6 +3,7 @@ require_relative './svggvs/target'
 require_relative './svggvs/context'
 require_relative './svggvs/session'
 require_relative './svggvs/data_source'
+require_relative './svggvs/pdf'
 
 module SVGGVS
 end

lib/svggvs/pdf.rb

@@ -0,0 +1,57 @@
+module SVGGVS
+  CROP_MARK_SIZE = 20.freeze
+
+  class PDF
+    def initialize(options)
+      @options = options
+    end
+
+    def self.border_size
+      ([ CROP_MARK_SIZE ] * 2).join('x')
+    end
+
+    def page_size_with_crop_marks
+      [ card_width * 3, card_height * 3 ].collect { |size| size + CROP_MARK_SIZE * 2 }.join('x')
+    end
+
+    def generate_crop_mark_directives
+      (0..3).collect { |index|
+        pos_x = CROP_MARK_SIZE + index * card_width
+        pos_y = CROP_MARK_SIZE + index * card_height
+
+        [ [ 0 ], [ CROP_MARK_SIZE + page_height ] ].collect { |size|
+          [ pos_x ] + size + [ pos_x, size.first + CROP_MARK_SIZE ]
+        } +
+        [ [ 0 ], [ CROP_MARK_SIZE + page_width ] ].collect { |size|
+          size + [ pos_y ] + [ size.first + CROP_MARK_SIZE, pos_y ]
+        }
+      }.flatten(1).collect { |sx, sy, ex, ey| "#{sx},#{sy} #{ex},#{ey}" }
+    end
+
+    def generate_crop_mark_draws
+      generate_crop_mark_directives.collect { |coords| %{-stroke black -strokewidth 3 -draw "line #{coords}"} }
+    end
+
+    private
+    def card_width
+      card_size.first
+    end
+
+    def card_height
+      card_size.last
+    end
+
+    def page_height
+      card_height * 3
+    end
+
+    def page_width
+      card_width * 3
+    end
+
+    def card_size
+      @card_size ||= @options[:card_size].split('x').collect(&:to_i)
+    end
+  end
+end
+

spec/spec_helper.rb

@@ -0,0 +1,2 @@
+$: << File.expand_path('../lib', __FILE__)
+

spec/svggvs/pdf_spec.rb

@@ -0,0 +1,46 @@
+require_relative '../spec_helper'
+require 'svggvs/pdf'
+require 'digest/md5'
+
+describe SVGGVS::PDF do
+  subject { SVGGVS::PDF.new(options) }
+
+  let(:options) {
+    { card_size: '100x100' }
+  }
+
+  describe '#page_size_with_crop_marks' do
+    it "should have the right size" do
+      subject.page_size_with_crop_marks.should be == "340x340"
+    end
+  end
+
+  describe '#generate_crop_mark_directives' do
+    let(:result) {
+      [
+        "20,0 20,20",
+        "20,320 20,340",
+        "120,0 120,20",
+        "120,320 120,340",
+        "220,0 220,20",
+        "220,320 220,340",
+        "320,0 320,20",
+        "320,20 340,20",
+        "320,120 340,120",
+        "320,220 340,220",
+        "320,320 320,340",
+        "320,320 340,320",
+        "0,20 20,20",
+        "0,120 20,120",
+        "0,220 20,220",
+        "0,320 20,320",
+      ]
+    }
+
+    it 'should create correct definitions' do
+      subject.generate_crop_mark_directives.each { |coords|
+        result.should include(coords)
+      }
+    end
+  end
+end

svggvs.gemspec

@@ -22,4 +22,6 @@ Gem::Specification.new do |gem|
   gem.add_dependency 'parallel'
   gem.add_dependency 'roo'
   gem.add_dependency 'activesupport'
+
+  gem.add_development_dependency 'rspec'
 end