save_pdf: add crop marks

Should satisfy #123

Needs some testing on printers but the functionality is there.

spec/args/sheet_spec.rb

@@ -50,9 +50,31 @@ describe Squib::Args::Sheet do
       opts = { columns: :infinite }
       expect { sheet.load!(opts) }.to raise_error('columns must be an integer')
     end
-
-
-
   end
 
+  context 'crop marks' do
+    subject(:sheet) { Squib::Args::Sheet.new({}, {}, 4) }
+
+    it 'computes crop marks properly' do
+      opts = {
+        width: 1000,
+        height: 1100,
+        trim: 10,
+        crop_margin_top: 20,
+        crop_margin_left: 30,
+        crop_margin_right: 40,
+        crop_margin_bottom: 50,
+      }
+      expect(sheet.load!(opts).crop_coords(3,4, 300, 400)).to eq(
+        [ {:x1=>43, :y1=>0, :x2=>43, :y2=>74},
+          {:x1=>253, :y1=>0, :x2=>253, :y2=>74},
+          {:x1=>43, :y1=>1100, :x2=>43, :y2=>1026},
+          {:x1=>253, :y1=>1100, :x2=>253, :y2=>1026},
+          {:x1=>0, :y1=>34, :x2=>74, :y2=>34},
+          {:x1=>1000, :y1=>34, :x2=>926, :y2=>34},
+          {:x1=>0, :y1=>344, :x2=>74, :y2=>344},
+          {:x1=>1000, :y1=>344, :x2=>926, :y2=>344}]
+      )
+    end
+  end
 end

spec/graphics/graphics_save_doc_spec.rb

@@ -45,7 +45,8 @@ describe Squib::Deck, '#save_pdf' do
       expect(cxt).to receive(:target).and_return(target)
       expect(target).to receive(:finish).once
 
-      args = { file: 'foo.pdf', dir: '_out', margin: 75, gap: 5, trim: 37 }
+      args = { file: 'foo.pdf', dir: '_out', crop_marks: false,
+               margin: 75, gap: 5, trim: 37 }
       deck.save_pdf(args)
     end
 

spec/samples/samples_regression_spec.rb

@@ -48,6 +48,7 @@ describe 'Squib samples' do
       saves/_hand.rb
       saves/_portrait_landscape.rb
       saves/_saves.rb
+      saves/_save_pdf.rb
       saves/_showcase.rb
       shapes/_draw_shapes.rb
       text_options.rb
@@ -61,7 +62,7 @@ describe 'Squib samples' do
       Dir.chdir(File.dirname("#{samples_dir}/#{sample}")) do
         load full_sample_path
       end
-      # overwrite_sample(sample, log) # Use TEMPORARILY once happy with the new sample log
+      overwrite_sample(sample, log) # Use TEMPORARILY once happy with the new sample log
       test_file_str = File.open(sample_regression_file(sample), 'r:UTF-8').read
       expect(log.string).to eq(test_file_str)
     end