Embed wrapping fix

Draw call locations now calculated after all string replacements. Does this fix the center and right align embed? Quick testing could not find any errors, but more thorough testing needed.

lib/squib/graphics/text.rb

@@ -105,6 +105,7 @@ module Squib
       layout.markup   = str
       clean_str       = layout.text
       draw_calls = []
+      searches = []
       while (key = next_embed(embed.rules.keys, clean_str)) != nil
         rule          = embed.rules[key]
         spacing       = rule[:width] * Pango::SCALE
@@ -112,17 +113,20 @@ module Squib
         str.sub!(key, "<span size=\"0\">a<span letter_spacing=\"#{spacing.to_i}\">a</span>a</span>")
         layout.markup = str
         clean_str     = layout.text
-        rect          = layout.index_to_pos(index)
+        searches << { index: index, rule: rule }
+      end
+      searches.each do |search|
+        rect          = layout.index_to_pos(search[:index])
         iter          = layout.iter
-        while iter.next_char! && iter.index < index; end
+        while iter.next_char! && iter.index < search[:index]; end
         case layout.alignment
           when Pango::Layout::Alignment::CENTER,
                Pango::Layout::Alignment::RIGHT
             Squib.logger.warn "Center- or right-aligned text do not always embed properly. This is a known issue with a workaround. See https://github.com/andymeneely/squib/issues/46"
         end
-        x             = Pango.pixels(rect.x) + rule[:dx]
-        y             = Pango.pixels(rect.y) + rule[:dy]
-        draw_calls << {x: x, y: y, draw: rule[:draw]} # defer drawing until we've valigned
+        x             = Pango.pixels(rect.x) + search[:rule][:dx]
+        y             = Pango.pixels(rect.y) + search[:rule][:dy]
+        draw_calls << {x: x, y: y, draw: search[:rule][:draw]} # defer drawing until we've valigned
       end
       return draw_calls
     end