Added a grid shape

Close #68

lib/squib/api/shapes.rb

@@ -91,6 +91,31 @@ module Squib
       range.each { |i| @cards[i].ellipse(box[i], draw[i]) }
     end
 
+    # Draw an unlimited grid
+    #
+    # @example
+    #   grid x: 0, y: 0, width: 15, height: 15
+    #
+    # Options support Arrays, see {file:README.md#Arrays_and_Singleton_Expansion Arrays and Singleon Expansion}
+    #
+    # @option opts range [Enumerable, :all] (:all) the range of cards over which this will be rendered. See {file:README.md#Specifying_Ranges Specifying Ranges}
+    # @option opts x [Integer] (0) the x-coordinate to place. Supports Unit Conversion, see {file:README.md#Units Units}.
+    # @option opts y [Integer] (0) the y-coordinate to place. Supports Unit Conversion, see {file:README.md#Units Units}.
+    # @option opts width [Integer] the width of the rectangle. Supports Unit Conversion, see {file:README.md#Units Units}.
+    # @option opts height [Integer] the height of the rectangle. Supports Unit Conversion, see {file:README.md#Units Units}.
+    # @option opts stroke_color [String] (:black) the color with which to stroke the outside of the rectangle. {file:README.md#Specifying_Colors___Gradients Specifying Colors & Gradients}
+    # @option opts stroke_width [Decimal] (2.0) the width of the outside stroke. Supports Unit Conversion, see {file:README.md#Units Units}.
+    # @option opts dash [String] ('') define a dash pattern for the stroke. Provide a string with space-separated numbers that define the pattern of on-and-off alternating strokes, measured in pixels by defautl. Supports Unit Conversion, see {file:README.md#Units Units} (e.g. `'0.02in 0.02in'`).
+    # @option opts layout [String, Symbol] (nil) entry in the layout to use as defaults for this command. See {file:README.md#Custom_Layouts Custom Layouts}
+    # @return [nil] intended to be void
+    # @api public
+    def grid(opts = {})
+      range = Args::CardRange.new(opts[:range], deck_size: size)
+      draw  = Args::Draw.new(custom_colors).load!(opts, expand_by: size, layout: layout, dpi: dpi)
+      box   = Args::Box.new(self).load!(opts, expand_by: size, layout: layout, dpi: dpi)
+      range.each { |i| @cards[i].grid(box[i], draw[i]) }
+    end
+
     # Draw a triangle using the given coordinates
     #
     # @example

lib/squib/graphics/shapes.rb

@@ -47,6 +47,16 @@ module Squib
       end
     end
 
+    # :nodoc:
+    # @api private
+    def grid(box, draw)
+      x, y, w, h = box.x, box.y, box.width, box.height
+      use_cairo do |cc|
+        (x..@width + w).step(w)  { |ix| line_xy( ix, y - @height, ix, @height + y, draw) }
+        (y..@height + h).step(h) { |iy| line_xy( x - @width, iy, @width + x, iy, draw) }
+      end
+    end
+
     # :nodoc:
     # @api private
     def triangle(tri, draw)
@@ -59,10 +69,16 @@ module Squib
     # :nodoc:
     # @api private
     def line(coord, draw)
+      line_xy(coord.x1, coord.y1, coord.x2, coord.y2, draw)
+    end
+
+    # :nodoc:
+    # @api private
+    def line_xy(x1, y1, x2, y2, draw)
       use_cairo do |cc|
-        cc.move_to(coord.x1, coord.y1)
-        cc.line_to(coord.x2, coord.y2)
-        cc.fill_n_stroke(draw)
+        cc.move_to(x1, y1)
+        cc.line_to(x2, y2)
+        cc.fancy_stroke(draw)
       end
     end