adding GR backend

Author: v0dro

ext/grruby/grruby.c

@@ -1031,8 +1031,9 @@ static VALUE version(VALUE self){
 
 void Init_grruby()
 {
-  VALUE mGRruby  = rb_define_module("GR");
-  VALUE mGR3ruby = rb_define_module("GR3");
+  VALUE mRubyplot = rb_define_module("Rubyplot");
+  VALUE mGRruby  = rb_define_module_under("GR", mRubyplot);
+  VALUE mGR3ruby = rb_define_module_under("GR3", mRubyplot);
 
   rb_define_singleton_method(mGRruby,"opengks",opengks,0);
   rb_define_singleton_method(mGRruby,"closegks",closegks,0);

lib/rubyplot.rb

@@ -13,14 +13,18 @@
 require 'rubyplot/spi'
 
 module Rubyplot
-  @@backend = Rubyplot::Backend::MagickWrapper.new
   class << self
     def backend
-      @@backend
+      @backend
     end
 
-    def set_backend_magick
-      @@backed = Rubyplot::Backend::MagickWrapper.new
+    def set_backend b
+      case b
+      when :magick
+        @backend = Rubyplot::Backend::MagickWrapper.new
+      when :gr
+        @backend = Rubyplot::Backend::GRWrapper.new
+      end
     end
   end
 end # module Rubyplot

lib/rubyplot/artist/polygon.rb

@@ -2,7 +2,6 @@ module Rubyplot
   module Artist
     class Polygon < Base
       def initialize(owner, coords:, fill_opacity: 0.0, color: :default, stroke: 'transparent')
-        @backend = owner.backend
         @coords = coords
         @fill_opacity = fill_opacity
         @color = color

lib/rubyplot/backend.rb

@@ -1 +1,2 @@
 require_relative 'backend/magick_wrapper'
+require_relative 'backend/gr_wrapper'

lib/rubyplot/backend/gr_wrapper.rb

@@ -0,0 +1,7 @@
+module Rubyplot
+  module Backend
+    class GRWrapper
+      
+    end # class GRWrapper
+  end # module Backend
+end # module Rubyplot