* Add support for gradient patterns.

git-svn-id: svn+ssh://svn.dotswitch.net/var/svn/dotswitch/projects/library/plugins/purl@2117 c432a1ab-ec09-0410-8e5f-fb625be92370

lib/purl.rb

@@ -15,6 +15,7 @@ def initialize(options = {})
       load_feature Features::Resize
       load_feature Features::ResizeMacro
       load_feature Features::Cairo
+      load_feature Features::CairoGradient
       yield self
     end
   end

lib/purl/features/cairo.rb

@@ -9,6 +9,7 @@ def operators
           Op.new(:xtc, 1),
           Op.new(:rgb, 4),
           Op.new(:rgba, 5),
+          Op.new(:pattern, 2),
           Op.new(:linewidth, 2),
           Op.new(:stroke, 1),
           Op.new(:fill, 1),
@@ -41,6 +42,11 @@ def rgba(ctx, r, g, b, a)
         Result.new(ctx)
       end
 
+      def pattern(ctx, pattern)
+        ctx.set_source pattern
+        Result.new(ctx)
+      end
+
       def linewidth(ctx, w)
         ctx.set_line_width w
         Result.new(ctx)

lib/purl/features/cairo_gradient.rb

@@ -0,0 +1,41 @@
+module Purl
+  module Features::CairoGradient
+    class << self
+      def operators
+        [
+          Op.new(:'grad.linear', 4, :grad_linear),
+          Op.new(:'grad.radial', 6, :grad_radial),
+          Op.new(:'grad.concentric', 4, :grad_concentric),
+          Op.new(:rgbo, 5, :rgb_stop),
+          Op.new(:rgbao, 6, :rgba_stop),
+        ]
+      end
+
+      def grad_linear(x1, y1, x2, y2)
+        Result.new(::Cairo::LinearPattern.new(x1, y1, x2, y2))
+      end
+
+      def grad_radial(x1, y1, r1, x2, y2, r2)
+        Result.new(::Cairo::RadialPattern.new(x1, y1, r1, x2, y2, r2))
+      end
+
+      def grad_concentric(x, y, r1, r2)
+        Result.new(::Cairo::RadialPattern.new(x, y, r1, x, y, r2))
+      end
+
+      def rgb_stop(grad, r, g, b, offset)
+        raise UnexpectedArgument unless ::Cairo::GradientPattern === grad
+        grad.add_color_stop_rgb offset, r, g, b
+
+        Result.new(grad)
+      end
+
+      def rgba_stop(grad, r, g, b, a, offset)
+        raise UnexpectedArgument unless ::Cairo::GradientPattern === grad
+        grad.add_color_stop_rgba offset, r, g, b, a
+
+        Result.new(grad)
+      end
+    end
+  end
+end