Round to four decimal places anywhere real numbers are used

example/lines.rb

@@ -3,8 +3,8 @@
 pdf = PDF::Core::Renderer.new(PDF::Core::DocumentState.new({}))
 
 pdf.start_new_page
-pdf.add_content("%.3f %.3f m" % [100, 500])
-pdf.add_content("%.3f %.3f l" % [300, 550])
+pdf.add_content("#{PDF::Core.real_params([100,500])} m")
+pdf.add_content("#{PDF::Core.real_params([300,550])} l")
 pdf.add_content("S")
 
 pdf.render_file("x.pdf")

lib/pdf/core/graphics_state.rb

@@ -63,11 +63,17 @@ def initialize(previous_state = nil)
       end
 
       def dash_setting
+        return "[] 0 d" unless @dash[:dash]
+
         if @dash[:dash].kind_of?(Array)
-          "[#{@dash[:dash].join(' ')}] #{@dash[:phase]} d"
+          array = @dash[:dash]
         else
-          "[#{@dash[:dash]} #{@dash[:space]}] #{@dash[:phase]} d"
+          array = [@dash[:dash], @dash[:space]]
         end
+
+
+        "[#{PDF::Core.real_params(array)}] "+
+        "#{PDF::Core.real(@dash[:phase])} d"
       end
 
       private

lib/pdf/core/pdf_object.rb

@@ -12,6 +12,14 @@ module PDF
   module Core
     module_function
 
+    def real(num)
+      num.to_f.round(4)
+    end
+
+    def real_params(array)
+      array.map { |e| real(e) }.join(" ")
+    end
+
     def utf8_to_utf16(str)
       "\xFE\xFF".force_encoding(::Encoding::UTF_16BE) + str.encode(::Encoding::UTF_16BE)
     end
@@ -43,12 +51,10 @@ def PdfObject(obj, in_content_stream = false)
       when TrueClass  then "true"
       when FalseClass then "false"
       when Numeric
-        if (str = String(obj)) =~ /e/i
-          # scientific notation is not supported in PDF
-          sprintf("%.16f", obj).gsub(/\.?0+\z/, "")
-        else
-          str
-        end
+        obj = real(obj) unless obj.kind_of?(Integer)
+
+        String(obj) # NOTE: this can fail on huge floating point numbers,
+                    # but it seems unlikely to ever happen in practice.
       when Array
         "[" << obj.map { |e| PdfObject(e, in_content_stream) }.join(' ') << "]"
       when PDF::Core::LiteralString

lib/pdf/core/renderer.rb

@@ -47,8 +47,9 @@ def deref(obj)
       #
       #  # Raw line drawing example:
       #  x1,y1,x2,y2 = 100,500,300,550
-      #  pdf.add_content("%.3f %.3f m" % [ x1, y1 ])  # move
-      #  pdf.add_content("%.3f %.3f l" % [ x2, y2 ])  # draw path
+      #
+      #  pdf.add_content("#{PDF::Core.real_params([x1, y1])} m")   # move
+      #  pdf.add_content("#{PDF::Core.real_params([ x2, y2 ])} l") # draw path
       #  pdf.add_content("S") # stroke
       #
       def add_content(str)

lib/pdf/core/text.rb

@@ -204,9 +204,9 @@ def character_spacing(amount=nil)
           yield
         else
           @character_spacing = amount
-          add_content "\n%.3f Tc" % amount
+          add_content "\n#{PDF::Core.real(amount)} Tc"
           yield
-          add_content "\n%.3f Tc" % original_character_spacing
+          add_content "\n#{PDF::Core.real(original_character_spacing)} Tc"
           @character_spacing = original_character_spacing
         end
       end
@@ -222,9 +222,10 @@ def word_spacing(amount=nil)
           yield
         else
           @word_spacing = amount
-          add_content "\n%.3f Tw" % amount
+          add_content "\n#{PDF::Core.real(amount)} Tw"
           yield
-          add_content "\n%.3f Tw" % original_word_spacing
+          add_content "\n#{PDF::Core.real(original_word_spacing)} Tw"
+
           @word_spacing = original_word_spacing
         end
       end
@@ -237,7 +238,7 @@ def add_text_content(text, x, y, options)
         if options[:rotate]
           rad = options[:rotate].to_f * Math::PI / 180
           arr = [ Math.cos(rad), Math.sin(rad), -Math.sin(rad), Math.cos(rad), x, y ]
-          add_content "%.3f %.3f %.3f %.3f %.3f %.3f Tm" % arr
+          add_content "#{PDF::Core.real_params(array)} Tm"
         else
           add_content "#{x} #{y} Td"
         end

spec/decimal_rounding_spec.rb

@@ -0,0 +1,12 @@
+# encoding: binary
+require_relative "spec_helper"
+
+describe "Decimal rounding" do
+  it "should round floating point numbers to four decimal places" do
+    PDF::Core.real(1.23456789).should == 1.2346
+  end
+
+  it "should be able to create a PDF parameter list of rounded decimals" do
+    PDF::Core.real_params([1,2.34567,Math::PI]).should == "1.0 2.3457 3.1416"
+  end
+end

spec/pdf_object_spec.rb

@@ -14,10 +14,10 @@
   end
 
   it "should convert a Ruby number to PDF number" do
-    PDF::Core::PdfObject(1).should == "1"
-    PDF::Core::PdfObject(1.214112421).should == "1.214112421"
-    # scientific notation is not valid in PDF
-    PDF::Core::PdfObject(0.000005).should == "0.000005"
+    PDF::Core::PdfObject(42).should == "42"
+
+    # numbers are rounded to four decimal places
+    PDF::Core::PdfObject(1.214112421).should == "1.2141"
   end
 
   it "should convert a Ruby time object to a PDF timestamp" do