Merge pull request #867 from googlefonts/vmtx

[subset] Add vmtx subsetting.

src/hb-subset.cc

@@ -252,6 +252,12 @@ _subset_table (hb_subset_plan_t *plan,
     case HB_OT_TAG_hmtx:
       result = _subset<const OT::hmtx> (plan);
       break;
+    case HB_OT_TAG_vhea:
+      DEBUG_MSG(SUBSET, nullptr, "skip vhea handled by vmtx");
+      return true;
+    case HB_OT_TAG_vmtx:
+      result = _subset<const OT::vmtx> (plan);
+      break;
     case HB_OT_TAG_maxp:
       result = _subset<const OT::maxp> (plan);
       break;

test/api/Makefile.am

@@ -36,6 +36,7 @@ TEST_PROGS = \
 	test-subset-hdmx \
 	test-subset-hmtx \
 	test-subset-os2 \
+	test-subset-vmtx \
 	test-unicode \
 	test-version \
 	$(NULL)
@@ -46,6 +47,7 @@ test_subset_glyf_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_hdmx_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_hmtx_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_os2_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
+test_subset_vmtx_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 
 test_unicode_CPPFLAGS = \
 	$(AM_CPPFLAGS) \

test/api/test-subset-vmtx.c

@@ -0,0 +1,99 @@
+/*
+ * Copyright © 2018  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Garret Rieger
+ */
+
+#include <stdbool.h>
+
+#include "hb-test.h"
+#include "hb-subset-test.h"
+
+/* Unit tests for hmtx subsetting */
+
+static void check_num_vmetrics(hb_face_t *face, uint16_t expected_num_vmetrics)
+{
+  hb_blob_t *vhea_blob = hb_face_reference_table (face, HB_TAG ('v','h','e','a'));
+  hb_blob_t *vmtx_blob = hb_face_reference_table (face, HB_TAG ('v','m','t','x'));
+
+  unsigned int vhea_len;
+  uint8_t *raw_vhea = (uint8_t *) hb_blob_get_data(vhea_blob, &vhea_len);
+  uint16_t num_vmetrics = (raw_vhea[vhea_len - 2] << 8) + raw_vhea[vhea_len - 1];
+  g_assert_cmpuint(expected_num_vmetrics, ==, num_vmetrics);
+
+  hb_blob_destroy (vhea_blob);
+  hb_blob_destroy (vmtx_blob);
+}
+
+static void
+test_subset_vmtx_simple_subset (void)
+{
+  hb_face_t *face_full = hb_subset_test_open_font ("fonts/Mplus1p-Regular.660E,6975,73E0,5EA6,8F38,6E05.ttf");
+  hb_face_t *face_subset = hb_subset_test_open_font ("fonts/Mplus1p-Regular.660E.ttf");
+
+  hb_set_t *codepoints = hb_set_create ();
+  hb_set_add (codepoints, 0x660E);
+
+  hb_face_t *face_full_subset = hb_subset_test_create_subset (face_full, hb_subset_test_create_input (codepoints));
+  hb_set_destroy (codepoints);
+
+  check_num_vmetrics(face_full_subset, 1); /* nothing has same width */
+  hb_subset_test_check (face_subset, face_full_subset, HB_TAG ('v','m','t','x'));
+
+  hb_face_destroy (face_full_subset);
+  hb_face_destroy (face_full);
+  hb_face_destroy (face_subset);
+}
+
+static void
+test_subset_vmtx_noop (void)
+{
+  hb_face_t *face_full = hb_subset_test_open_font ("fonts/Mplus1p-Regular.660E,6975,73E0,5EA6,8F38,6E05.ttf");
+
+  hb_set_t *codepoints = hb_set_create();
+  hb_set_add (codepoints, 0x660E);
+  hb_set_add (codepoints, 0x6975);
+  hb_set_add (codepoints, 0x73E0);
+  hb_set_add (codepoints, 0x5EA6);
+  hb_set_add (codepoints, 0x8F38);
+  hb_set_add (codepoints, 0x6E05);
+  hb_face_t *face_full_subset = hb_subset_test_create_subset (face_full, hb_subset_test_create_input (codepoints));
+  hb_set_destroy (codepoints);
+
+  check_num_vmetrics(face_full_subset, 1); /* all have the same width */
+  hb_subset_test_check (face_full, face_full_subset, HB_TAG ('v','m','t','x'));
+
+  hb_face_destroy (face_full_subset);
+  hb_face_destroy (face_full);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_subset_vmtx_simple_subset);
+  hb_test_add (test_subset_vmtx_noop);
+
+  return hb_test_run();
+}