[meta] New API, hb_ot_metadata_reference_entry for fetching meta entries

docs/harfbuzz-sections.txt

@@ -607,6 +607,12 @@ hb_ot_math_get_min_connector_overlap
 hb_ot_math_get_glyph_assembly
 </SECTION>
 
+<SECTION>
+<FILE>hb-ot-metadata</FILE>
+hb_ot_metadata_reference_entry
+hb_ot_metadata_t
+</SECTION>
+
 <SECTION>
 <FILE>hb-ot-metrics</FILE>
 hb_ot_metrics_t

src/Makefile.sources

@@ -89,6 +89,7 @@ HB_BASE_sources = \
 	hb-ot-math.cc \
 	hb-ot-maxp-table.hh \
 	hb-ot-meta-table.hh \
+	hb-ot-metadata.cc \
 	hb-ot-metrics.cc \
 	hb-ot-metrics.hh \
 	hb-ot-name-language-static.hh \
@@ -194,6 +195,7 @@ HB_BASE_headers = \
 	hb-ot-font.h \
 	hb-ot-layout.h \
 	hb-ot-math.h \
+	hb-ot-metadata.h \
 	hb-ot-metrics.h \
 	hb-ot-name.h \
 	hb-ot-shape.h \

src/harfbuzz.cc

@@ -16,6 +16,7 @@
 #include "hb-ot-layout.cc"
 #include "hb-ot-map.cc"
 #include "hb-ot-math.cc"
+#include "hb-ot-metadata.cc"
 #include "hb-ot-metrics.cc"
 #include "hb-ot-name.cc"
 #include "hb-ot-shape-complex-arabic.cc"

src/hb-config.hh

@@ -66,6 +66,7 @@
 #define HB_NO_LAYOUT_COLLECT_GLYPHS
 #define HB_NO_LAYOUT_UNUSED
 #define HB_NO_MATH
+#define HB_NO_META
 #define HB_NO_METRICS
 #define HB_NO_MMAP
 #define HB_NO_NAME

src/hb-ot-face-table-list.hh

@@ -62,7 +62,9 @@ HB_OT_ACCELERATOR (OT, name)
 #ifndef HB_NO_STAT
 HB_OT_TABLE (OT, STAT)
 #endif
-//HB_OT_TABLE (OT, meta)
+#ifndef HB_NO_META
+HB_OT_ACCELERATOR (OT, meta)
+#endif
 
 /* Vertical layout. */
 HB_OT_TABLE (OT, vhea)

src/hb-ot-face.cc

@@ -32,6 +32,7 @@
 #include "hb-ot-cff2-table.hh"
 #include "hb-ot-hmtx-table.hh"
 #include "hb-ot-kern-table.hh"
+#include "hb-ot-meta-table.hh"
 #include "hb-ot-name-table.hh"
 #include "hb-ot-post-table.hh"
 #include "hb-ot-color-cbdt-table.hh"

src/hb-ot-layout.cc

@@ -48,7 +48,6 @@
 #include "hb-ot-layout-gpos-table.hh"
 #include "hb-ot-layout-base-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-ot-layout-jstf-table.hh" // Just so we compile it; unused otherwise.
-#include "hb-ot-meta-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-ot-name-table.hh"
 #include "hb-ot-os2-table.hh"
 

src/hb-ot-meta-table.hh

@@ -40,6 +40,11 @@ namespace OT {
 
 struct DataMap
 {
+  int cmp (hb_tag_t a) const { return tag.cmp (a); }
+
+  hb_blob_t *reference_entry (hb_blob_t *meta_blob) const
+  { return hb_blob_create_sub_blob (meta_blob, dataZ, dataLength); }
+
   bool sanitize (hb_sanitize_context_t *c, const void *base) const
   {
     TRACE_SANITIZE (this);
@@ -62,6 +67,19 @@ struct meta
 {
   static constexpr hb_tag_t tableTag = HB_OT_TAG_meta;
 
+  struct accelerator_t
+  {
+    void init (hb_face_t *face)
+    { table = hb_sanitize_context_t ().reference_table<meta> (face); }
+    void fini () { table.destroy (); }
+
+    hb_blob_t *reference_entry (hb_tag_t tag) const
+    { return table->dataMaps.lsearch (tag, Null (DataMap)).reference_entry (table.get_blob ()); }
+
+    private:
+    hb_blob_ptr_t<meta> table;
+  };
+
   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
@@ -83,6 +101,8 @@ struct meta
   DEFINE_SIZE_ARRAY (16, dataMaps);
 };
 
+struct meta_accelerator_t : meta::accelerator_t {};
+
 } /* namespace OT */
 
 

src/hb-ot-metadata.cc

@@ -0,0 +1,57 @@
+/*
+ * Copyright © 2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#include "hb.hh"
+
+#ifndef HB_NO_META
+
+#include "hb-ot-meta-table.hh"
+
+/**
+ * SECTION:hb-ot-metadata
+ * @title: hb-ot-metadata
+ * @short_description: OpenType Metadata
+ * @include: hb-ot.h
+ *
+ * Functions for fetching metadata from fonts.
+ **/
+
+/**
+ * hb_ot_meta_reference_entry:
+ * @face: a #hb_face_t object.
+ * @meta_tag: tag of metadata you like to have.
+ *
+ * It fetches metadata entry of a given tag from a font.
+ *
+ * Returns: (transfer full): A blob containing the blob.
+ *
+ * Since: REPLACEME
+ **/
+hb_blob_t *
+hb_ot_metadata_reference_entry (hb_face_t *face, hb_ot_metadata_t meta_tag)
+{
+  return face->table.meta->reference_entry (meta_tag);
+}
+
+#endif

src/hb-ot-metadata.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright © 2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#ifndef HB_OT_H_IN
+#error "Include <hb-ot.h> instead."
+#endif
+
+#ifndef HB_OT_METADATA_H
+#define HB_OT_METADATA_H
+
+#include "hb.h"
+
+HB_BEGIN_DECLS
+
+/**
+ * hb_ot_metadata_t:
+ *
+ * From https://docs.microsoft.com/en-us/typography/opentype/spec/meta
+ *
+ * Since: REPLACEME
+ **/
+typedef enum {
+/*
+   HB_OT_METADATA_APPL			= HB_TAG ('a','p','p','l'),
+   HB_OT_METADATA_BILD			= HB_TAG ('b','i','l','d'),
+*/
+  HB_OT_METADATA_DESIGN_LANGUAGES	= HB_TAG ('d','l','n','g'),
+  HB_OT_METADATA_SUPPORTED_LANGUAGES	= HB_TAG ('s','l','n','g')
+} hb_ot_metadata_t;
+
+HB_EXTERN hb_blob_t *
+hb_ot_metadata_reference_entry (hb_face_t *face, hb_ot_metadata_t tag);
+
+HB_END_DECLS
+
+#endif /* HB_OT_METADATA_H */

src/hb-ot.h

@@ -35,6 +35,7 @@
 #include "hb-ot-font.h"
 #include "hb-ot-layout.h"
 #include "hb-ot-math.h"
+#include "hb-ot-metadata.h"
 #include "hb-ot-metrics.h"
 #include "hb-ot-name.h"
 #include "hb-ot-shape.h"

test/api/Makefile.am

@@ -84,6 +84,7 @@ TEST_PROGS += \
 	test-ot-color \
 	test-ot-ligature-carets \
 	test-ot-name \
+	test-ot-metadata \
 	test-ot-metrics \
 	test-ot-tag \
 	test-ot-extents-cff \

test/api/test-ot-metadata.c

@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2019  Ebrahim Byagowi
+ *
+ *  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.
+ */
+
+#include "hb-test.h"
+
+#include <hb-ot.h>
+
+/* Unit tests for hb-ot-metadata.h */
+
+static void
+test_ot_metadata_reference_entry (void)
+{
+  hb_face_t *face = hb_test_open_font_file ("fonts/meta.ttf");
+  hb_blob_t *dlng = hb_ot_metadata_reference_entry (face, HB_OT_METADATA_DESIGN_LANGUAGES);
+  g_assert_cmpint (hb_blob_get_length (dlng), ==, 8);
+  g_assert_cmpmem (hb_blob_get_data (dlng, NULL), 8, "ar,de,fa", 8);
+  hb_blob_destroy (dlng);
+  hb_blob_t *fslf = hb_ot_metadata_reference_entry (face, (hb_ot_metadata_t) HB_TAG ('f','s','l','f'));
+  g_assert_cmpint (hb_blob_get_length (fslf), ==, 12);
+  hb_blob_destroy (fslf);
+  hb_blob_t *nacl = hb_ot_metadata_reference_entry (face, (hb_ot_metadata_t) HB_TAG ('n','a','c','l'));
+  g_assert_cmpint (hb_blob_get_length (nacl), ==, 0);
+  hb_blob_destroy (nacl);
+  hb_blob_t *slng = hb_ot_metadata_reference_entry (face, HB_OT_METADATA_SUPPORTED_LANGUAGES);
+  g_assert_cmpint (hb_blob_get_length (slng), ==, 11);
+  g_assert_cmpmem (hb_blob_get_data (slng, NULL), 11, "ar,de,en,fa", 11);
+  hb_blob_destroy (slng);
+  hb_face_destroy (face);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+  hb_test_add (test_ot_metadata_reference_entry);
+  return hb_test_run ();
+}