showcase: use correct width&height vars

Fixes #179

docs/dsl/showcase.rst

@@ -63,3 +63,14 @@ file
 
 Examples
 --------
+
+This sample `lives here <https://github.com/andymeneely/squib/tree/master/samples/saves>`_.
+
+.. literalinclude:: ../../samples/saves/_showcase.rb
+  :language: ruby
+  :linenos:
+
+.. raw:: html
+
+  <img src="../saves/showcase_expected.png" class="figure">
+  <img src="../saves/showcase2_expected.png" class="figure">

lib/squib/card.rb

@@ -52,7 +52,11 @@ module Squib
     end
 
     def finish!
+      begin
         @cairo_surface.finish
+      rescue Cairo::SurfaceFinishedError
+        # do nothin - if it's already finished that's fine
+      end
     end
 
     ########################

lib/squib/graphics/showcase.rb

@@ -33,7 +33,7 @@ module Squib
     # :nodoc:
     # @api private
     def trim_rounded(src, trim, radius)
-      trim_cc = Cairo::Context.new(Cairo::ImageSurface.new(src.width - 2.0 * trim, src.height - 2.0 * trim))
+      trim_cc = Cairo::Context.new(Cairo::ImageSurface.new(@width - 2.0 * trim, @height - 2.0 * trim))
       trim_cc.rounded_rectangle(0, 0, trim_cc.target.width, trim_cc.target.height, radius, radius)
       trim_cc.set_source(src, -1 * trim, -1 * trim)
       trim_cc.clip

lib/squib/version.rb

@@ -6,5 +6,5 @@ module Squib
   # Most of the time this is in the alpha of the next release.
   # e.g. v0.0.5a is on its way to becoming v0.0.5
   #
-  VERSION = '0.12.0a'
+  VERSION = '0.12.0b'
 end

samples/backend/_backend.rb

@@ -16,18 +16,11 @@ Squib::Deck.new(cards: 2, config: '_backend-config.yml') do
   # We can still rasterize whenever we want
   save_png prefix: 'backend_'
 
+  showcase file: 'showcase.png', fill_color: 'white'
+
   # And our PDFs will be vectorized .
   save_pdf file: 'backend_vectorized.pdf', gap: 5
 
   # This one is a known issue. Masking an SVG onto an SVG backend is still buggy.
   # svg        file: 'glass-heart.svg', x: 100, y: 200, width: 100, height: 100, mask: :sangria
-
-  # This one is, unfortunately, not possible with svg back ends
-  #   Cairo lacks a perspective transform (currently), so we have to
-  #   use a striping method, which assumes raster. Fortunately, Cairo
-  #   has perspective transforms on its roadmap,
-  #   so perhaps this can be done someday with all vectors.
-  #
-  # showcase file: 'showcase.png', fill_color: 'white'
-
 end