Merge pull request #823 from googlefonts/hdmx

[subset] Add hdmx subsetting.

src/Makefile.sources

@@ -20,6 +20,7 @@ HB_BASE_sources = \
 	hb-ot-cbdt-table.hh \
 	hb-ot-cmap-table.hh \
 	hb-ot-glyf-table.hh \
+	hb-ot-hdmx-table.hh \
 	hb-ot-head-table.hh \
 	hb-ot-hhea-table.hh \
 	hb-ot-hmtx-table.hh \

src/hb-ot-hdmx-table.hh

@@ -0,0 +1,198 @@
+/*
+ * 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
+ */
+
+#ifndef HB_OT_HDMX_TABLE_HH
+#define HB_OT_HDMX_TABLE_HH
+
+#include "hb-open-type-private.hh"
+
+namespace OT {
+
+
+/*
+ * hdmx - Horizontal Device Metric
+ */
+
+#define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')
+
+struct DeviceRecord
+{
+  struct SubsetView
+  {
+    const DeviceRecord *source_device_record;
+    hb_subset_plan_t *subset_plan;
+
+    inline void init(const DeviceRecord *source_device_record,
+		     hb_subset_plan_t   *subset_plan)
+    {
+      this->source_device_record = source_device_record;
+      this->subset_plan = subset_plan;
+    }
+
+    inline unsigned int len () const
+    {
+      return this->subset_plan->gids_to_retain_sorted.len;
+    }
+
+    inline const HBUINT8& operator [] (unsigned int i) const
+    {
+      if (unlikely (i >= len())) return Null(HBUINT8);
+      hb_codepoint_t gid = this->subset_plan->gids_to_retain_sorted [i];
+      return this->source_device_record->widths[gid];
+    }
+  };
+
+  static inline unsigned int get_size (unsigned int count)
+  {
+    unsigned int raw_size = min_size + count * HBUINT8::static_size;
+    if (raw_size % 4)
+      /* Align to 32 bits */
+      return raw_size + (4 - (raw_size % 4));
+    return raw_size;
+  }
+
+  inline bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
+  {
+    TRACE_SERIALIZE (this);
+
+    if (unlikely (!c->allocate_size<DeviceRecord> (get_size (subset_view.len()))))
+      return_trace (false);
+
+    this->pixel_size.set (subset_view.source_device_record->pixel_size);
+    this->max_width.set (subset_view.source_device_record->max_width);
+
+    for (unsigned int i = 0; i < subset_view.len(); i++)
+      widths[i].set (subset_view[i]);
+
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c, unsigned int size_device_record) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this) &&
+			  c->check_range (this, size_device_record)));
+  }
+
+  HBUINT8 pixel_size;   /* Pixel size for following widths (as ppem). */
+  HBUINT8 max_width;    /* Maximum width. */
+  HBUINT8 widths[VAR];  /* Array of widths (numGlyphs is from the 'maxp' table). */
+  public:
+  DEFINE_SIZE_ARRAY (2, widths);
+};
+
+
+struct hdmx
+{
+  static const hb_tag_t tableTag = HB_OT_TAG_hdmx;
+
+  inline unsigned int get_size (void) const
+  {
+    return min_size + num_records * size_device_record;
+  }
+
+  inline const DeviceRecord& operator [] (unsigned int i) const
+  {
+    if (unlikely (i >= num_records)) return Null(DeviceRecord);
+    return StructAtOffset<DeviceRecord> (this, min_size + i * size_device_record);
+  }
+
+  inline bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan)
+  {
+    TRACE_SERIALIZE (this);
+
+    if (unlikely (!c->extend_min ((*this))))  return_trace (false);
+
+    this->version.set (source_hdmx->version);
+    this->num_records.set (source_hdmx->num_records);
+    this->size_device_record.set (DeviceRecord::get_size (plan->gids_to_retain_sorted.len));
+
+    for (unsigned int i = 0; i < source_hdmx->num_records; i++)
+    {
+      DeviceRecord::SubsetView subset_view;
+      subset_view.init (&(*source_hdmx)[i], plan);
+
+      c->start_embed<DeviceRecord> ()->serialize (c, subset_view);
+    }
+
+    return_trace (true);
+  }
+
+  static inline size_t get_subsetted_size (hb_subset_plan_t *plan)
+  {
+    return min_size + DeviceRecord::get_size (plan->gids_to_retain_sorted.len);
+  }
+
+  inline bool subset (hb_subset_plan_t *plan) const
+  {
+    size_t dest_size = get_subsetted_size (plan);
+    hdmx *dest = (hdmx *) malloc (dest_size);
+    if (unlikely (!dest))
+    {
+      DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size);
+      return false;
+    }
+
+    hb_serialize_context_t c (dest, dest_size);
+    hdmx *hdmx_prime = c.start_serialize<hdmx> ();
+    if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan)) {
+      free (dest);
+      return false;
+    }
+    c.end_serialize ();
+
+    hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest,
+						 dest_size,
+						 HB_MEMORY_MODE_READONLY,
+						 dest,
+						 free);
+    bool result = hb_subset_plan_add_table (plan, HB_OT_TAG_hdmx, hdmx_prime_blob);
+    hb_blob_destroy (hdmx_prime_blob);
+
+    return result;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && version == 0 &&
+		  !_hb_unsigned_int_mul_overflows (num_records, size_device_record) &&
+		  c->check_range (this, get_size()));
+  }
+
+  protected:
+  HBUINT16	version;		/* Table version number (0) */
+  HBUINT16	num_records;		/* Number of device records. */
+  HBUINT32	size_device_record;	/* Size of a device record, 32-bit aligned. */
+  HBUINT8	data[VAR];		/* Array of device records. */
+  public:
+  DEFINE_SIZE_ARRAY (8, data);
+};
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_HDMX_TABLE_HH */

src/hb-subset.cc

@@ -35,6 +35,7 @@
 #include "hb-open-file-private.hh"
 #include "hb-ot-cmap-table.hh"
 #include "hb-ot-glyf-table.hh"
+#include "hb-ot-hdmx-table.hh"
 #include "hb-ot-head-table.hh"
 #include "hb-ot-hhea-table.hh"
 #include "hb-ot-hmtx-table.hh"
@@ -83,12 +84,15 @@ static bool
 _subset (hb_subset_plan_t *plan)
 {
   OT::Sanitizer<TableType> sanitizer;
+
   hb_blob_t *source_blob = sanitizer.sanitize (plan->source->reference_table (TableType::tableTag));
   const TableType *table = OT::Sanitizer<TableType>::lock_instance (source_blob);
-    hb_bool_t result = table->subset(plan);
+
+  hb_bool_t result = false;
+  if (table != &OT::Null(TableType))
+    result = table->subset(plan);
 
   hb_blob_destroy (source_blob);
-
   hb_tag_t tag = TableType::tableTag;
   DEBUG_MSG(SUBSET, nullptr, "OT::%c%c%c%c::subset %s", HB_UNTAG(tag), result ? "success" : "FAILED!");
   return result;
@@ -229,6 +233,9 @@ _subset_table (hb_subset_plan_t *plan,
     case HB_OT_TAG_glyf:
       result = _subset<const OT::glyf> (plan);
       break;
+    case HB_OT_TAG_hdmx:
+      result = _subset<const OT::hdmx> (plan);
+      break;
     case HB_OT_TAG_head:
       // SKIP head, it's handled by glyf
       result = true;

test/api/Makefile.am

@@ -33,6 +33,7 @@ TEST_PROGS = \
 	test-shape \
 	test-subset-cmap \
 	test-subset-glyf \
+	test-subset-hdmx \
 	test-subset-hmtx \
 	test-subset-os2 \
 	test-unicode \
@@ -42,6 +43,7 @@ TEST_PROGS = \
 test_subset_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_cmap_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 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/api/test-subset-hdmx.c

@@ -0,0 +1,81 @@
+/*
+ * 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 hdmx subsetting */
+
+
+static void
+test_subset_hdmx_simple_subset (void)
+{
+  hb_face_t *face_abc = hb_subset_test_open_font ("fonts/Roboto-Regular.abc.ttf");
+  hb_face_t *face_ac = hb_subset_test_open_font ("fonts/Roboto-Regular.ac.ttf");
+
+  hb_set_t *codepoints = hb_set_create ();
+  hb_set_add (codepoints, 'a');
+  hb_set_add (codepoints, 'c');
+  hb_face_t *face_abc_subset = hb_subset_test_create_subset (face_abc, codepoints);
+  hb_set_destroy (codepoints);
+
+  hb_subset_test_check (face_ac, face_abc_subset, HB_TAG ('h','d','m','x'));
+
+  hb_face_destroy (face_abc_subset);
+  hb_face_destroy (face_abc);
+  hb_face_destroy (face_ac);
+}
+
+static void
+test_subset_hdmx_noop (void)
+{
+  hb_face_t *face_abc = hb_subset_test_open_font("fonts/Roboto-Regular.abc.ttf");
+
+  hb_set_t *codepoints = hb_set_create();
+  hb_set_add (codepoints, 'a');
+  hb_set_add (codepoints, 'b');
+  hb_set_add (codepoints, 'c');
+  hb_face_t *face_abc_subset = hb_subset_test_create_subset (face_abc, codepoints);
+  hb_set_destroy (codepoints);
+
+  hb_subset_test_check (face_abc, face_abc_subset, HB_TAG ('h','d','m','x'));
+
+  hb_face_destroy (face_abc_subset);
+  hb_face_destroy (face_abc);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_subset_hdmx_simple_subset);
+  hb_test_add (test_subset_hdmx_noop);
+
+  return hb_test_run();
+}