Allowing for save_png to rotate either direction

lib/squib/api/save.rb

@@ -25,14 +25,14 @@ def save(opts = {})
     # @option opts [Enumerable] range (:all) the range of cards over which this will be rendered. See {file:README.md#Specifying_Ranges Specifying Ranges}
     # @option opts [String] dir (_output) the directory for the output to be sent to. Will be created if it doesn't exist.
     # @option opts [String] prefix (card_) the prefix of the file name to be printed.
-    # @option opts [Boolean] rotate (false) if true, the saved cards will be rotated 90 degrees clockwise. Intended to rendering landscape instead of portrait.
+    # @option opts [Boolean, :clockwise, :counterclockwise] rotate (false) if true, the saved cards will be rotated 90 degrees clockwise. Or, rotate by the number of radians. Intended to rendering landscape instead of portrait.
     # @return [nil] Returns nothing
     # @api public
     def save_png(opts = {})
       opts = needs(opts,[:range, :creatable_dir, :prefix, :rotate])
       @progress_bar.start("Saving PNGs to #{opts[:dir]}/#{opts[:prefix]}*", @cards.size) do |bar|
         opts[:range].each do |i| 
-          @cards[i].save_png(i, opts[:dir], opts[:prefix], opts[:rotate])
+          @cards[i].save_png(i, opts[:dir], opts[:prefix], opts[:rotate], opts[:angle])
           bar.increment
         end
       end

lib/squib/graphics/save_images.rb

@@ -3,9 +3,9 @@ class Card
 
     # :nodoc:
     # @api private 
-    def save_png(i, dir, prefix, rotate)
-      if rotate
-        surface = rotated_image
+    def save_png(i, dir, prefix, do_rotate, angle)
+      if [true, :clockwise, :counterclockwise].include?(do_rotate)
+        surface = rotated_image(angle)
       else
         surface = @cairo_surface
       end
@@ -14,10 +14,10 @@ def save_png(i, dir, prefix, rotate)
 
     # :nodoc:
     # @api private
-    def rotated_image
+    def rotated_image(angle)
       rotated_cc = Cairo::Context.new(Cairo::ImageSurface.new(@height, @width) )
       rotated_cc.translate(@height * 0.5, @width * 0.5)
-      rotated_cc.rotate(0.5 * Math::PI)
+      rotated_cc.rotate(angle)
       rotated_cc.translate(@width * -0.5, @height * -0.5)
       rotated_cc.set_source(@cairo_surface)
       rotated_cc.paint

lib/squib/input_helpers.rb

@@ -26,6 +26,7 @@ def needs(opts, params)
       opts = radiusify(opts) if params.include? :rect_radius
       opts = svgidify(opts) if params.include? :svgid
       opts = formatify(opts) if params.include? :formats
+      opts = rotateify(opts) if params.include? :rotate
       opts
     end
     module_function :needs
@@ -175,5 +176,19 @@ def svgidify(opts)
     end
     module_function :svgidify
 
+    # :nodoc:
+    # @api private
+    def rotateify(opts)
+      case opts[:rotate]
+      when true, :clockwise
+        opts[:angle] = 0.5 * Math::PI
+      when :counterclockwise
+        opts[:angle] = 1.5 * Math::PI
+      end
+      Squib.logger.debug {"After rotateify: #{opts}"}
+      opts
+    end
+    module_function :svgidify
+
   end
 end