[VORG] Add VORG table

Cherry-picked from cff-subset branch.

src/Makefile.sources

@@ -153,6 +153,7 @@ HB_OT_sources = \
 	hb-ot-var-fvar-table.hh \
 	hb-ot-var-hvar-table.hh \
 	hb-ot-var-mvar-table.hh \
+	hb-ot-vorg-table.hh \
 	$(NULL)
 
 HB_OT_RAGEL_GENERATED_sources = \

src/hb-ot-face.cc

@@ -31,6 +31,7 @@
 #include "hb-ot-hmtx-table.hh"
 #include "hb-ot-kern-table.hh"
 #include "hb-ot-post-table.hh"
+#include "hb-ot-vorg-table.hh"
 #include "hb-ot-color-cbdt-table.hh"
 #include "hb-ot-layout-gdef-table.hh"
 #include "hb-ot-layout-gsub-table.hh"

src/hb-ot-face.hh

@@ -68,6 +68,7 @@
     HB_OT_ACCELERATOR(OT, post) \
     HB_OT_ACCELERATOR(OT, kern) \
     HB_OT_ACCELERATOR(OT, glyf) \
+    HB_OT_TABLE(OT, VORG) \
     /* OpenType color fonts. */ \
     HB_OT_TABLE(OT, COLR) \
     HB_OT_TABLE(OT, CPAL) \

src/hb-ot-vorg-table.hh

@@ -0,0 +1,168 @@
+/*
+ * Copyright © 2018 Adobe Systems Incorporated.
+ *
+ *  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.
+ *
+ * Adobe Author(s): Michiharu Ariza
+ */
+
+#ifndef HB_OT_VORG_TABLE_HH
+#define HB_OT_VORG_TABLE_HH
+
+#include "hb-open-type.hh"
+
+/*
+ * VORG -- Vertical Origin Table
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/vorg
+ */
+#define HB_OT_TAG_VORG HB_TAG('V','O','R','G')
+
+namespace OT {
+
+struct VertOriginMetric
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  public:
+  GlyphID	glyph;
+  FWORD		vertOriginY;
+
+  public:
+  DEFINE_SIZE_STATIC (4);
+};
+
+struct VORG
+{
+  static const hb_tag_t tableTag = HB_OT_TAG_VORG;
+
+  inline bool _subset (const hb_subset_plan_t *plan,
+                       const VORG *vorg_table,
+                       const hb_vector_t<VertOriginMetric> &subset_metrics,
+                       unsigned int dest_sz,
+                       void *dest) const
+  {
+    hb_serialize_context_t c (dest, dest_sz);
+
+    VORG *subset_table = c.start_serialize<VORG> ();
+    if (unlikely (!c.extend_min (*subset_table)))
+      return false;
+
+    subset_table->version.major.set (1);
+    subset_table->version.minor.set (0);
+
+    subset_table->defaultVertOriginY.set (vorg_table->defaultVertOriginY);
+    subset_table->vertYOrigins.len.set (subset_metrics.len);
+
+    bool success = true;
+    if (subset_metrics.len > 0)
+    {
+      unsigned int  size = VertOriginMetric::static_size * subset_metrics.len;
+      VertOriginMetric  *metrics = c.allocate_size<VertOriginMetric> (size);
+      if (likely (metrics != nullptr))
+        memcpy (metrics, &subset_metrics[0], size);
+      else
+        success = false;
+    }
+    c.end_serialize ();
+
+    return success;
+  }
+
+  inline bool subset (hb_subset_plan_t *plan) const
+  {
+    hb_blob_t *vorg_blob = hb_sanitize_context_t().reference_table<VORG> (plan->source);
+    const VORG *vorg_table = vorg_blob->as<VORG> ();
+
+    /* count the number of glyphs to be included in the subset table */
+    hb_vector_t<VertOriginMetric> subset_metrics;
+    subset_metrics.init ();
+    unsigned int glyph = 0;
+    unsigned int i = 0;
+    while ((glyph < plan->glyphs.len) && (i < vertYOrigins.len))
+    {
+      if (plan->glyphs[glyph] > vertYOrigins[i].glyph)
+        i++;
+      else if (plan->glyphs[glyph] < vertYOrigins[i].glyph)
+        glyph++;
+      else
+      {
+        VertOriginMetric *metrics = subset_metrics.push ();
+        metrics->glyph.set (glyph);
+        metrics->vertOriginY.set (vertYOrigins[i].vertOriginY);
+        glyph++;
+        i++;
+      }
+    }
+
+    /* alloc the new table */
+    unsigned int dest_sz = VORG::min_size + VertOriginMetric::static_size * subset_metrics.len;
+    void *dest = (void *) malloc (dest_sz);
+    if (unlikely (!dest))
+    {
+      subset_metrics.fini ();
+      hb_blob_destroy (vorg_blob);
+      return false;
+    }
+
+    /* serialize the new table */
+    if (!_subset (plan, vorg_table, subset_metrics, dest_sz, dest))
+    {
+      subset_metrics.fini ();
+      free (dest);
+      hb_blob_destroy (vorg_blob);
+      return false;
+    }
+
+    hb_blob_t *result = hb_blob_create ((const char *)dest,
+                                        dest_sz,
+                                        HB_MEMORY_MODE_READONLY,
+                                        dest,
+                                        free);
+    bool success = plan->add_table (HB_OT_TAG_VORG, result);
+    hb_blob_destroy (result);
+    subset_metrics.fini ();
+    hb_blob_destroy (vorg_blob);
+    return success;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+                  version.major == 1 &&
+                  vertYOrigins.sanitize (c));
+  }
+
+  protected:
+  FixedVersion<>	version;		/* Version of VORG table. Set to 0x00010000u. */
+  FWORD			defaultVertOriginY;	/* The default vertical origin */
+  ArrayOf<VertOriginMetric>vertYOrigins;	/* The array of vertical origins */
+
+  public:
+  DEFINE_SIZE_ARRAY(8, vertYOrigins);
+};
+} /* namespace OT */
+
+#endif /* HB_OT_VORG_TABLE_HH */