Merge branch 'patterns-alt' of git://github.com/cheba/prawn

lib/prawn/graphics.rb

@@ -12,7 +12,7 @@
 require "prawn/graphics/join_style"
 require "prawn/graphics/transparency"
 require "prawn/graphics/transformation"
-require "prawn/graphics/gradient"
+require "prawn/graphics/patterns"
 
 module Prawn
 
@@ -30,7 +30,7 @@ module Graphics
     include JoinStyle
     include Transparency
     include Transformation
-    include Gradient
+    include Patterns
 
     #######################################################################
     # Low level drawing operations must map the point to absolute coords! #

lib/prawn/graphics/color.rb

@@ -95,7 +95,14 @@ def color_type(color)
         when String
           :RGB
         when Array
-          :CMYK
+          case color.length
+          when 3
+            :RGB
+          when 4
+            :CMYK
+          else
+            raise ArgumentError, "Unknown type of color: #{color.inspect}"
+          end
         end
       end
 

lib/prawn/graphics/patterns.rb

@@ -0,0 +1,137 @@
+# encoding: utf-8
+
+# patterns.rb : Implements axial & radial gradients
+#
+# Originally implemented by Wojciech Piekutowski. November, 2009
+# Copyright September 2012, Alexander Mankuta. All Rights Reserved.
+#
+# This is free software. Please see the LICENSE and COPYING files for details.
+#
+module Prawn
+  module Graphics
+    module Patterns
+
+      # Sets the fill gradient from color1 to color2.
+      # old arguments: point, width, height, color1, color2, options = {}
+      # new arguments: from, to, color1, color1
+      #            or  from, r1, to, r2, color1, color2
+      def fill_gradient(*args)
+        if args[1].is_a?(Array) || args[2].is_a?(Array)
+          set_gradient(:fill, *args)
+        else
+          warn "[DEPRECATION] 'fill_gradient(point, width, height,...)' is deprecated in favor of 'fill_gradient(from, to,...)'. " +
+               "Old arguments will be removed in release 1.1"
+          set_gradient :fill, args[0], [args[0].first, args[0].last - args[2]], args[3], args[4]
+        end
+      end
+
+      # Sets the stroke gradient from color1 to color2.
+      # old arguments: point, width, height, color1, color2, options = {}
+      # new arguments: from, to, color1, color2
+      #            or  from, r1, to, r2, color1, color2
+      def stroke_gradient(*args)
+        if args[1].is_a?(Array) || args[2].is_a?(Array)
+          set_gradient(:stroke, *args)
+        else
+          warn "[DEPRECATION] 'stroke_gradient(point, width, height,...)' is deprecated in favor of 'stroke_gradient(from, to,...)'. " +
+               "Old arguments will be removed in release 1.1"
+          set_gradient :stroke, args[0], [args[0].first, args[0].last - args[2]], args[3], args[4]
+        end
+      end
+
+      private
+
+      def set_gradient(type, *grad)
+        patterns = page.resources[:Pattern] ||= {}
+
+        registry_key = gradient_registry_key grad
+
+        if patterns["SP#{registry_key}"]
+          shading = patterns["SP#{registry_key}"]
+        else
+          unless shading = gradient_registry[registry_key]
+            shading = gradient(*grad)
+            gradient_registry[registry_key] = shading
+          end
+
+          patterns["SP#{registry_key}"] = shading
+        end
+
+        operator = case type
+        when :fill
+          'scn'
+        when :stroke
+          'SCN'
+        else
+          raise ArgumentError, "unknown type '#{type}'"
+        end
+
+        set_color_space type, :Pattern
+        add_content "/SP#{registry_key} #{operator}"
+      end
+
+      def gradient_registry_key(gradient)
+        if gradient[1].is_a?(Array) # axial
+          [
+            map_to_absolute(gradient[0]),
+            map_to_absolute(gradient[1]),
+            gradient[2], gradient[3]
+          ]
+        else # radial
+          [
+            map_to_absolute(gradient[0]),
+            gradient[1],
+            map_to_absolute(gradient[2]),
+            gradient[3],
+            gradient[4], gradient[5]
+          ]
+        end.hash
+      end
+
+      def gradient_registry
+        @gradient_registry ||= {}
+      end
+
+      def gradient(*args)
+        if args.length != 4 && args.length != 6
+          raise ArgumentError, "Unknown type of gradient: #{args.inspect}"
+        end
+
+        color1 = normalize_color(args[-2]).dup.freeze
+        color2 = normalize_color(args[-1]).dup.freeze
+
+        if color_type(color1) != color_type(color2)
+          raise ArgumentError, "Both colors must be of the same color space: #{color1.inspect} and #{color2.inspect}"
+        end
+
+        process_color color1
+        process_color color2
+
+        shader = ref!({
+          :FunctionType => 2,
+          :Domain => [0.0, 1.0],
+          :C0 => color1,
+          :C1 => color2,
+          :N => 1.0,
+        })
+
+        shading = ref!({
+          :ShadingType => args.length == 4 ? 2 : 3, # axial : radial shading
+          :ColorSpace => color_space(color1),
+          :Coords => args.length == 4 ?
+                        [0, 0, args[1].first - args[0].first, args[1].last - args[0].last] :
+                        [0, 0, args[1], args[2].first - args[0].first, args[2].last - args[0].last, args[3]],
+          :Function => shader,
+          :Extend => [true, true],
+        })
+
+        shading_pattern = ref!({
+          :PatternType => 2, # shading pattern
+          :Shading => shading,
+          :Matrix => [1, 0,
+                      0, 1] + map_to_absolute(args[0]),
+        })
+      end
+    end
+  end
+end

manual/graphics/color.rb

@@ -21,10 +21,4 @@
 
   # Both together
   fill_and_stroke_circle [400, 100], 50
-
-  # Gradient
-  fill_gradient [10, 330], 400, 50, 'F0FF00', '0000FF'
-  bounding_box [10, 300], :width => 450, :height => 150 do
-    text "Gradient!", :size => 60
-  end
 end

manual/graphics/gradients.rb

@@ -0,0 +1,37 @@
+# encoding: utf-8
+#
+# Note that because of the way PDF renders radial gradients in order to get
+# solid fill your start circle must be fully inside your end circle.
+# Otherwise you will get triangle fill like illustrated in the example below.
+
+require File.expand_path(File.join(File.dirname(__FILE__),
+                                   %w[.. example_helper]))
+
+filename = File.basename(__FILE__).gsub('.rb', '.pdf')
+Prawn::Example.generate(filename) do
+  stroke_axis
+  self.line_width = 10
+
+  fill_gradient [50, 300], [150, 200], 'ff0000', '0000ff'
+  fill_rectangle [50, 300], 100, 100
+
+  stroke_gradient [200, 200], [300, 300], '00ffff', 'ffff00'
+  stroke_rectangle [200, 300], 100, 100
+
+  fill_gradient [350, 300], [450, 200], 'ff0000', '0000ff'
+  stroke_gradient [350, 200], [450, 300], '00ffff', 'ffff00'
+  fill_and_stroke_rectangle [350, 300], 100, 100
+
+  fill_gradient [100, 100], 0, [100, 100], 70.71, 'ff0000', '0000ff'
+  fill_rectangle [50, 150], 100, 100
+
+  stroke_gradient [250, 100], 45, [250, 100], 70.71, '00ffff', 'ffff00'
+  stroke_rectangle [200, 150], 100, 100
+
+  stroke_gradient [400, 100], 45, [400, 100], 70.71, '00ffff', 'ffff00'
+  fill_gradient [400, 100], 0, [400, 100], 70.71, 'ff0000', '0000ff'
+  fill_and_stroke_rectangle [350, 150], 100, 100
+
+  fill_gradient [500, 300], 15, [500, 50], 0, 'ff0000', '0000ff'
+  fill_rectangle [485, 300], 30, 250
+end

manual/graphics/graphics.rb

@@ -28,6 +28,7 @@
       s.example "stroke_join"
       s.example "stroke_dash"
       s.example "color"
+      s.example "gradients"
       s.example "transparency"
       s.example "soft_masks"
       s.example "fill_rules"