Update badge rendering to reflect actual render

* Switch to showing the PNG version by default, as this reflects what
  will actually be rendered and sent to the printer
* Include the greyscale filter
* Include the twemoji font we'll use for rendering the badges

pinaxcon/templates/registrasion/badge.svg

@@ -12,6 +12,9 @@
 -->
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
 <svg width="100%" height="100%" viewBox="0 0 1749 1241" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-miterlimit:10;">
+  <filter id="grayscale">
+    <feColorMatrix type="saturate" values="0"/>
+  </filter>
     <g transform="matrix(1.15527,0,0,1.15527,-22.9233,770.581)">
         <g transform="matrix(1,0,0,1,358.181,164.105)">
             <path d="M0,24.414L0,18.184L3.151,15.141C6.52,11.845 8.44,10.323 8.44,8.44C8.44,7.136 7.824,6.991 5.615,6.991C3.296,6.991 0.435,7.534 0.435,7.534L0.072,1.34C0.072,1.34 3.84,0 7.933,0C13.366,0 16.735,2.463 16.735,7.244C16.735,11.41 15.54,13.438 11.591,16.191L9.164,17.894L16.59,17.894L16.59,24.414L0,24.414Z" style="fill:rgb(78,135,160);fill-rule:nonzero;"/>
@@ -1020,16 +1023,16 @@
     </g>
     <g transform="matrix(0.876643,0,0,0.876643,62.2881,185.276)">
         <g transform="matrix(0.607846,0,0,0.607922,138.923,372.07)">
-            <text x="0px" y="0px" style="font-family:'Roboto-Regular', 'Roboto';font-size:144.577px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.name }}</text>
+            <text x="0px" y="0px" filter="url(#grayscale)" style="font-family:'Roboto-Regular', 'Roboto', 'Twitter Color Emoji';font-size:144.577px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.name }}</text>
         </g>
         <g transform="matrix(0.607846,0,0,0.607922,138.923,449.05)">
-            <text x="0px" y="0px" style="font-family:'Roboto-Regular', 'Roboto';font-size:96.385px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.company }}</text>
+            <text x="0px" y="0px" filter="url(#grayscale)" style="font-family:'Roboto-Regular', 'Roboto', 'Twitter Color Emoji';font-size:96.385px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.company }}</text>
         </g>
         <g transform="matrix(0.607846,0,0,0.607922,140.5,504.582)">
-            <text x="0px" y="0px" style="font-family:'Roboto-Regular', 'Roboto';font-size:60.24px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.free_text_1 }}</text>
+            <text x="0px" y="0px" filter="url(#grayscale)" style="font-family:'Roboto-Regular', 'Roboto', 'Twitter Color Emoji';font-size:60.24px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.free_text_1 }}</text>
         </g>
         <g transform="matrix(0.607846,0,0,0.607922,140.5,550.359)">
-            <text x="0px" y="0px" style="font-family:'Roboto-Regular', 'Roboto';font-size:60.24px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.free_text_2 }}</text>
+            <text x="0px" y="0px" filter="url(#grayscale)" style="font-family:'Roboto-Regular', 'Roboto', 'Twitter Color Emoji';font-size:60.24px;">{{ user.attendee.attendeeprofilebase.attendeeprofile.free_text_2 }}</text>
         </g>
         <g transform="matrix(0.999321,0,0,0.999446,0,-507.874)">
             <g id="text23417" transform="matrix(1,0,0,1,353.552,780.612)">

vendor/registrasion/registrasion/views.py

@@ -2,6 +2,7 @@ import datetime
 import zipfile
 import os
 import logging
+import subprocess
 
 from django.contrib import messages
 
@@ -38,7 +39,6 @@ from django.template import Context, Template, loader
 
 from lxml import etree
 from copy import deepcopy
-from cairosvg import svg2pdf, svg2png
 
 from registrasion.forms import BadgeForm, ticket_selection
 from registrasion.contrib.badger import (
@@ -57,7 +57,6 @@ _GuidedRegistrationSection = namedtuple(
     )
 )
 
-
 @util.all_arguments_optional
 class GuidedRegistrationSection(_GuidedRegistrationSection):
     ''' Represents a section of a guided registration page.
@@ -1115,26 +1114,44 @@ def _get_badge_template_name():
     return os.path.join(settings.PROJECT_ROOT, 'pinaxcon', 'templates',
                         settings.BADGER_DEFAULT_SVG)
 @login_required
-def user_badge(request, format="svg"):
+def user_badge(request, format="png"):
     '''Shows the logged-in user their badge'''
 
     return render_badge(request.user, format)
 
 @user_passes_test(_staff_only)
-def badge(request, user_id, format="svg"):
+def badge(request, user_id, format="png"):
-    ''' Renders a single user's badge (SVG). '''
+    ''' Renders a single user's badge (PNG). '''
 
     user_id = int(user_id)
     user = User.objects.get(pk=user_id)
 
     return render_badge(user, format)
 
-def render_badge(user, format="svg"):
+def _convert_img(img, outformat="png",dpi=200,width=None):
+    if hasattr(img, "encode"): #a string, or a SafeText
+        img=img.encode()
+    width = width or dpi*5.83 #5.83 inches in A6 portrait
+    conversion_cmdline = [
+        "convert",
+        "-density",str(dpi),
+        "-resize",str(width),
+        ]
+    if outformat=="png":
+        conversion_cmdline.extend(["-background","white",
+                                   "-flatten"])
+    conversion_cmdline.extend(["-", "{}:-".format(outformat)])
+    out = subprocess.run(conversion_cmdline,
+                         input=img,
+                         stdout=subprocess.PIPE).stdout
+    return out
+
+def render_badge(user, format="png"):
     rendered = render_badge_svg(user)
     if format == "png":
-        rendered = svg2png(bytestring=rendered, dpi=72, scale=3)
+        rendered = _convert_img(rendered, outformat="png")
     elif format == "pdf":
-        rendered = svg2pdf(bytestring=rendered, dpi=72, scale=3)
+        rendered = _convert_img(rendered, outformat="pdf")
 
     response = HttpResponse(rendered)