Fix font compositing (close #32)

package.json

@@ -24,6 +24,7 @@
     "color": "0.11.3",
     "cors": "2.7.1",
     "express": "4.14.0",
+    "glyph-pbf-composite": "0.0.2",
     "handlebars": "4.0.5",
     "mapbox-gl-native": "3.2.1",
     "mbtiles": "0.9.0",

src/serve_font.js

@@ -1,12 +1,9 @@
 'use strict';
 
-var async = require('async'),
-    path = require('path'),
-    fs = require('fs');
-
 var clone = require('clone'),
     express = require('express');
 
+var utils = require('./utils');
 
 module.exports = function(options, allowedFonts) {
   var app = express().disable('x-powered-by');
@@ -15,41 +12,14 @@ module.exports = function(options, allowedFonts) {
 
   var fontPath = options.paths.fonts;
 
-  var getFontPbf = function(name, range, callback) {
-    // if some of the files failed to load (does not exist or not allowed),
-    // return empty buffer so the other fonts can still work
-    if (allowedFonts[name]) {
-      var filename = path.join(fontPath, name, range + '.pbf');
-      return fs.readFile(filename, function(err, data) {
-        if (err) {
-          console.log('Font load error:', filename);
-          return callback(null, new Buffer([]));
-        } else {
-          return callback(null, data);
-        }
-      });
-    } else {
-      return callback(null, new Buffer([]));
-    }
-  };
-
   app.get('/:fontstack/:range([\\d]+-[\\d]+).pbf',
       function(req, res, next) {
     var fontstack = decodeURI(req.params.fontstack);
     var range = req.params.range;
 
-    var fonts = fontstack.split(',');
-
-    var queue = [];
-    fonts.forEach(function(font) {
-      queue.push(function(callback) {
-        getFontPbf(font, range, callback);
-      });
-    });
-
-    return async.parallel(queue, function(err, results) {
-      var concated = Buffer.concat(results);
-      if (err || concated.length == 0) {
+    return utils.getFontsPbf(allowedFonts, fontPath, fontstack, range,
+        function(err, concated) {
+      if (err || concated.length === 0) {
         return res.status(400).send('');
       } else {
         res.header('Content-type', 'application/x-protobuf');

src/serve_rendered.js

@@ -56,12 +56,20 @@ module.exports = function(options, repo, params, id) {
         request: function(req, callback) {
           var protocol = req.url.split(':')[0];
           //console.log('Handling request:', req);
-          if (protocol == 'sprites' || protocol == 'fonts') {
+          if (protocol == 'sprites') {
             var dir = options.paths[protocol];
             var file = unescape(req.url).substring(protocol.length + 3);
             fs.readFile(path.join(dir, file), function(err, data) {
               callback(err, { data: data });
             });
+          } else if (protocol == 'fonts') {
+            var parts = req.url.split('/');
+            var fontstack = unescape(parts[2]);
+            var range = parts[3].split('.')[0];
+            utils.getFontsPbf(null, options.paths[protocol], fontstack, range,
+                function(err, concated) {
+              callback(err, {data: concated});
+            });
           } else if (protocol == 'mbtiles') {
             var parts = req.url.split('/');
             var source = map.sources[parts[2]];

src/utils.js

@@ -1,5 +1,11 @@
 'use strict';
 
+var async = require('async'),
+    path = require('path'),
+    fs = require('fs');
+
+var glyphCompose = require('glyph-pbf-composite');
+
 module.exports.getTileUrls = function(req, domains, path, format) {
 
   if (domains) {
@@ -37,3 +43,36 @@ module.exports.fixTileJSONCenter = function(tileJSON) {
     ];
   }
 };
+
+module.exports.getFontsPbf = function(allowedFonts, fontPath, names, range, callback) {
+  var getFontPbf = function(name, range, callback) {
+    if (!allowedFonts || allowedFonts[name]) {
+      var filename = path.join(fontPath, name, range + '.pbf');
+      return fs.readFile(filename, function(err, data) {
+        if (err) {
+          return callback(new Error('Font load error: ' + name));
+        } else {
+          return callback(null, data);
+        }
+      });
+    } else {
+      return callback(new Error('Font not allowed: ' + name));
+    }
+  };
+
+  var fonts = names.split(',');
+  var queue = [];
+  fonts.forEach(function(font) {
+    queue.push(function(callback) {
+      getFontPbf(font, range, callback);
+    });
+  });
+
+  return async.parallel(queue, function(err, results) {
+    if (err) {
+      callback(err, new Buffer([]));
+    } else {
+      callback(err, glyphCompose.combine(results));
+    }
+  });
+};

test/style.js

@@ -42,7 +42,7 @@ describe('Fonts', function() {
   testIs('/fonts/Open Sans Regular/65280-65533.pbf', /application\/x-protobuf/);
   testIs('/fonts/Open Sans Bold,Open Sans Regular/0-255.pbf',
          /application\/x-protobuf/);
-  testIs('/fonts/Nonsense,Open Sans Bold/0-255.pbf', /application\/x-protobuf/);
+  testIs('/fonts/Nonsense,Open Sans Bold/0-255.pbf', /./, 400);
 
   testIs('/fonts/Nonsense/0-255.pbf', /./, 400);
   testIs('/fonts/Nonsense1,Nonsense2/0-255.pbf', /./, 400);