Merge pull request #303 from gagern/metrics

Improve font metrics creation

Makefile

@@ -79,8 +79,11 @@ test:
 	./node_modules/.bin/jasmine-node test/katex-spec.js
 	./node_modules/.bin/jasmine-node contrib/auto-render/auto-render-spec.js
 
+PERL=perl
+PYTHON=$(shell python2 --version >/dev/null 2>&1 && echo python2 || echo python)
+
 metrics:
-	cd metrics && ./mapping.pl | ./extract_tfms.py | ./extract_ttfs.py | ./replace_line.py
+	cd metrics && $(PERL) ./mapping.pl | $(PYTHON) ./extract_tfms.py | $(PYTHON) ./extract_ttfs.py | $(PYTHON) ./format_json.py > ../src/fontMetricsData.json
 
 clean:
 	rm -rf build/*

metrics/README.md

@@ -7,15 +7,15 @@ There are several requirements for generating the metrics used by KaTeX.
   this by running `tex --version`, and seeing if it has a line that looks like
   > kpathsea version 6.2.0
 
-- You need the JSON module for perl. You can install this either from CPAN or with
-  your package manager.
+- You need the JSON module for perl. You can install this either from CPAN
+  (possibly using the `cpan` command line tool) or with your package manager.
 
-- You need the python fontforge module. This is probably either installed with
-  fontforge or can be installed from your package manager.
+- You need the python module fonttools. You can install this either from PyPi
+  (using `easy_install` or `pip`) or with your package manager.
 
 Once you have these things, run
 
     make metrics
 
-which should generate new metrics and place them into `fontMetrics.js`. You're
-done!
+which should generate new metrics and place them into `fontMetricsData.json`.
+You're done!

metrics/extract_ttfs.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 
-import fontforge
+from fontTools.ttLib import TTFont
 import sys
 import json
 
@@ -60,36 +60,50 @@ def main():
     start_json = json.load(sys.stdin)
 
     for font, chars in metrics_to_extract.iteritems():
-        fontInfo = fontforge.open("../static/fonts/KaTeX_" + font + ".ttf")
+        fontInfo = TTFont("../static/fonts/KaTeX_" + font + ".ttf")
+        glyf = fontInfo["glyf"]
+        unitsPerEm = float(fontInfo["head"].unitsPerEm)
 
-        for glyph in fontInfo.glyphs():
-            try:
-                char = unichr(glyph.unicode)
-            except ValueError:
+        # We keep ALL Unicode cmaps, not just fontInfo["cmap"].getcmap(3, 1).
+        # This is playing it extra safe, since it reports inconsistencies.
+        # Platform 0 is Unicode, platform 3 is Windows. For platform 3,
+        # encoding 1 is UCS-2 and encoding 10 is UCS-4.
+        cmap = [t.cmap for t in fontInfo["cmap"].tables
+                if (t.platformID == 0)
+                or (t.platformID == 3 and t.platEncID in (1, 10))]
+
+        for char, base_char in chars.iteritems():
+            code = ord(char)
+            names = set(t.get(code) for t in cmap)
+            if not names:
+                sys.stderr.write(
+                    "Codepoint {} of font {} maps to no name\n"
+                    .format(code, font))
                 continue
+            if len(names) != 1:
+                sys.stderr.write(
+                    "Codepoint {} of font {} maps to multiple names: {}\n"
+                    .format(code, font, ", ".join(sorted(names))))
+                continue
+            name = names.pop()
 
-            if char in chars:
-                _, depth, _, height = glyph.boundingBox()
+            height = depth = italic = skew = 0
+            glyph = glyf[name]
+            if glyph.numberOfContours:
+                height = glyph.yMax
+                depth = -glyph.yMin
+            if base_char:
+                base_char_str = str(ord(base_char))
+                base_metrics = start_json[font][base_char_str]
+                italic = base_metrics["italic"]
+                skew = base_metrics["skew"]
 
-                depth = -depth
-
-                base_char = chars[char]
-                if base_char:
-                    base_char_str = str(ord(base_char))
-                    base_metrics = start_json[font][base_char_str]
-
-                    italic = base_metrics["italic"]
-                    skew = base_metrics["skew"]
-                else:
-                    italic = 0
-                    skew = 0
-
-                start_json[font][ord(char)] = {
-                    "height": height / fontInfo.em,
-                    "depth": depth / fontInfo.em,
-                    "italic": italic,
-                    "skew": skew,
-                }
+            start_json[font][str(code)] = {
+                "height": height / unitsPerEm,
+                "depth": depth / unitsPerEm,
+                "italic": italic,
+                "skew": skew,
+            }
 
     sys.stdout.write(
         json.dumps(start_json, separators=(',', ':'), sort_keys=True))

metrics/format_json.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+
+import sys
+import json
+
+data = json.load(sys.stdin)
+sep = "{\n"
+for font in sorted(data):
+  sys.stdout.write(sep + json.dumps(font))
+  sep = ": {\n  "
+  for glyph in sorted(data[font], key=int):
+      sys.stdout.write(sep + json.dumps(glyph) + ": ")
+      sys.stdout.write(json.dumps(data[font][glyph], sort_keys=True))
+      sep = ",\n  "
+  sep = "\n},\n"
+sys.stdout.write("\n}}\n");

metrics/mapping.pl

@@ -135,8 +135,6 @@ $map{cmmi10} = {
     0x2E => 0x25B9,         # \triangleright
     0x2F => 0x25C3,         # \triangleleft
 
-    0x3A => 0x2E,           # .
-    0x3B => 0x2C,           # ,
     0x3C => 0x3C,           # <
     0x3D => 0x2215,         # /
     0x3E => 0x3E,           # >
@@ -148,16 +146,19 @@ $map{cmmi10} = {
     0x5F => 0x2322,         # \frown
     0x60 => 0x2113,         # \ell
 
-    0x7B => 0x131,          # \imath
-    0x7C => 0x237,          # \jmath
     0x7D => 0x2118,         # \wp
     0x7E => [0x20D7,-653,0],# \vec
+  ],
+
+  "Main-Italic" => [
+    0x7B => 0x131,          # \imath
+    0x7C => 0x237,          # \jmath
   ]
 };
 
 $map{cmsy10} = {
   "Main-Regular" => [
-    [0,1] => 0x2212,        # -
+    0 => 0x2212,            # -
     1 => 0x22C5,            # \cdot
     2 => 0xD7,              # \times
     3 => 0x2217,            # \ast
@@ -425,8 +426,6 @@ $map{cmti10} = {
     [7,8] => 0x3A5,         # \Upsilon, \Phi
     [9,0xA] => 0x3A8,       # \Psi, \Omega
 
-    0x10 => 0x131,          # \imath (roman)
-    0x11 => 0x237,          # \jmath (roman)
     0x12 => [0x300,-511,0], # \grave (combining)
     0x13 => [0x301,-511,0], # \acute (combining)
     0x14 => [0x30C,-511,0], # \check (combining)
@@ -557,8 +556,6 @@ $map{cmmib10} = {
     0x2E => 0x25B9,         # \triangleright
     0x2F => 0x25C3,         # \triangleleft
 
-    0x3A => 0x2E,           # .
-    0x3B => 0x2C,           # ,
     0x3C => 0x3C,           # <
     0x3D => 0x2215,         # /
     0x3E => 0x3E,           # >
@@ -571,8 +568,6 @@ $map{cmmib10} = {
     0x60 => 0x2113,         # \ell
     0x68 => 0x210F,         # \hbar (bar added below)
 
-    0x7B => 0x131,          # \imath
-    0x7C => 0x237,          # \jmath
     0x7D => 0x2118,         # \wp
     0x7E => [0x20D7,-729,0],# \vec
   ],
@@ -580,7 +575,7 @@ $map{cmmib10} = {
 
 $map{cmbsy10} = {
   "Main-Bold" => [
-    [0,1] => 0x2212,        # -
+    0 => 0x2212,            # -
     1 => 0x22C5,            # \cdot
     2 => 0xD7,              # \times
     3 => 0x2217,            # \ast
@@ -973,6 +968,12 @@ sub add_to_output {
         "yshift" => $yshift
     };
 
+    if (defined($output{$mjfont}{$to})) {
+        print STDERR "Duplicate mapping $to for $mjfont: " .
+            $output{$mjfont}{$to}{font} . ":" .
+            $output{$mjfont}{$to}{char} . " vs. $cmfont:$from\n";
+        die "Duplicate mapping!"; # disable this line to see all of them
+    }
     $output{$mjfont}{$to} = $data;
 }
 

metrics/replace_line.py

@@ -1,17 +0,0 @@
-#!/usr/bin/env python2
-
-import sys
-
-with open("../src/fontMetrics.js", "r") as metrics:
-    old_lines = file.readlines(metrics)
-
-replace = sys.stdin.read()
-
-with open("../src/fontMetrics.js", "w") as output:
-    for line in old_lines:
-        if line.startswith("var metricMap"):
-            output.write("var metricMap = ")
-            output.write(replace)
-            output.write(";\n")
-        else:
-            output.write(line)

package.json

@@ -14,7 +14,7 @@
   ],
   "license": "MIT",
   "devDependencies": {
-    "browserify": "~2.29.1",
+    "browserify": "^10.2.4",
     "clean-css": "~2.2.15",
     "express": "~3.3.3",
     "jasmine-node": "2.0.0-beta4",