MATH Table: Add API to check availability of math data.

src/Makefile.sources

@@ -75,6 +75,7 @@ HB_OT_sources = \
 	hb-ot-layout-gsubgpos-private.hh \
 	hb-ot-layout-gsub-table.hh \
 	hb-ot-layout-jstf-table.hh \
+	hb-ot-layout-math-table.hh \
 	hb-ot-layout-private.hh \
 	hb-ot-map.cc \
 	hb-ot-map-private.hh \

src/hb-ot-layout-math-table.hh

@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2016  Igalia S.L.
+ *
+ *  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.
+ *
+ * Igalia Author(s): Frédéric Wang
+ */
+
+#ifndef HB_OT_LAYOUT_MATH_TABLE_HH
+#define HB_OT_LAYOUT_MATH_TABLE_HH
+
+#include "hb-open-type-private.hh"
+#include "hb-ot-layout-common-private.hh"
+
+namespace OT {
+
+/*
+ * MATH -- The MATH Table
+ */
+
+struct MATH
+{
+  static const hb_tag_t tableTag        = HB_OT_TAG_MATH;
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (version.sanitize (c) &&
+                  likely (version.major == 1));
+  }
+
+protected:
+  FixedVersion<>version;                 /* Version of the MATH table
+                                            initially set to 0x00010000u */
+public:
+  DEFINE_SIZE_STATIC (4);
+};
+
+} /* mathspace OT */
+
+
+#endif /* HB_OT_LAYOUT_MATH_TABLE_HH */

src/hb-ot-layout-private.hh

@@ -124,6 +124,7 @@ namespace OT {
   struct GDEF;
   struct GSUB;
   struct GPOS;
+  struct MATH;
 }
 
 struct hb_ot_layout_lookup_accelerator_t
@@ -152,10 +153,12 @@ struct hb_ot_layout_t
   hb_blob_t *gdef_blob;
   hb_blob_t *gsub_blob;
   hb_blob_t *gpos_blob;
+  hb_blob_t *math_blob;
 
   const struct OT::GDEF *gdef;
   const struct OT::GSUB *gsub;
   const struct OT::GPOS *gpos;
+  const struct OT::MATH *math;
 
   unsigned int gsub_lookup_count;
   unsigned int gpos_lookup_count;

src/hb-ot-layout.cc

@@ -35,6 +35,7 @@
 #include "hb-ot-layout-gsub-table.hh"
 #include "hb-ot-layout-gpos-table.hh"
 #include "hb-ot-layout-jstf-table.hh"
+#include "hb-ot-layout-math-table.hh"
 
 #include "hb-ot-map-private.hh"
 
@@ -60,6 +61,10 @@ _hb_ot_layout_create (hb_face_t *face)
   layout->gpos_blob = OT::Sanitizer<OT::GPOS>::sanitize (face->reference_table (HB_OT_TAG_GPOS));
   layout->gpos = OT::Sanitizer<OT::GPOS>::lock_instance (layout->gpos_blob);
 
+  // The MATH table is rarer so we only try and load it in _get_math
+  layout->math_blob = NULL;
+  layout->math = NULL;
+
   {
     /*
      * The ugly business of blacklisting individual fonts' tables happen here!
@@ -178,6 +183,8 @@ _hb_ot_layout_destroy (hb_ot_layout_t *layout)
   hb_blob_destroy (layout->gsub_blob);
   hb_blob_destroy (layout->gpos_blob);
 
+  if (layout->math_blob) hb_blob_destroy (layout->math_blob);
+
   free (layout);
 }
 
@@ -199,6 +206,21 @@ _get_gpos (hb_face_t *face)
   if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::GPOS);
   return *hb_ot_layout_from_face (face)->gpos;
 }
+static inline const OT::MATH&
+_get_math (hb_face_t *face)
+{
+  if (unlikely (!hb_ot_shaper_face_data_ensure (face))) return OT::Null(OT::MATH);
+
+  hb_ot_layout_t * layout = hb_ot_layout_from_face (face);
+
+  // If the MATH table is not loaded yet, do it now.
+  if (!layout->math_blob) {
+    layout->math_blob = OT::Sanitizer<OT::MATH>::sanitize (face->reference_table (HB_OT_TAG_MATH));
+    layout->math = OT::Sanitizer<OT::MATH>::lock_instance (layout->math_blob);
+  }
+
+  return *layout->math;
+}
 
 
 /*
@@ -1190,3 +1212,26 @@ hb_ot_layout_substitute_lookup (OT::hb_apply_context_t *c,
 {
   apply_string<GSUBProxy> (c, lookup, accel);
 }
+
+/*
+ * OT::MATH
+ */
+
+/**
+ * hb_ot_layout_has_math_data:
+ *
+ * @face: #hb_face_t to test
+ *
+ * This function allows to verify the presence of an OpenType MATH table on the
+ * face. If so, such a table will be loaded into memory and sanitized. You can
+ * then safely call other functions for math layout and shaping.
+ *
+ * Return value: #TRUE if face has a MATH table and #FALSE otherwise
+ *
+ * Since: ????
+ **/
+hb_bool_t
+hb_ot_layout_has_math_data (hb_face_t *face)
+{
+  return &_get_math (face) != &OT::Null(OT::MATH);
+}

src/hb-ot-layout.h

@@ -42,6 +42,7 @@ HB_BEGIN_DECLS
 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
 #define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
+#define HB_OT_TAG_MATH HB_TAG('M','A','T','H')
 
 
 /*
@@ -297,6 +298,12 @@ hb_ot_layout_get_size_params (hb_face_t    *face,
 			      unsigned int *range_end          /* OUT.  May be NULL */);
 
 
+/*
+ * MATH
+ */
+
+HB_EXTERN hb_bool_t
+hb_ot_layout_has_math_data (hb_face_t *face);
 HB_END_DECLS
 
 #endif /* HB_OT_LAYOUT_H */

test/api/Makefile.am

@@ -43,10 +43,22 @@ endif
 
 
 if HAVE_OT
+
 TEST_PROGS += \
 	test-ot-tag \
 	$(NULL)
-endif
+
+if HAVE_FREETYPE
+TEST_PROGS += \
+	test-ot-layout-math \
+	$(NULL)
+test_ot_layout_math_LDADD = $(LDADD)
+test_ot_layout_math_CPPFLAGS = $(AM_CPPFLAGS)
+test_ot_layout_math_CPPFLAGS += $(FREETYPE_CFLAGS)
+test_ot_layout_math_LDADD += $(FREETYPE_LIBS)
+endif # HAVE_FREETYPE
+
+endif # HAVE_OT
 
 # Tests for header compilation
 TEST_PROGS += \

test/api/test-ot-layout-math.c

@@ -0,0 +1,98 @@
+/*
+ * Copyright © 2016  Igalia S.L.
+ *
+ *  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.
+ *
+ * Igalia Author(s): Frédéric Wang
+ */
+
+
+#include "hb-test.h"
+
+#include "hb-ft.h"
+#include "hb-ot.h"
+
+/* Unit tests for hb-ot-layout.h - OpenType MATH table  */
+
+static FT_Library ft_library;
+static FT_Face ft_face;
+static hb_font_t *hb_font;
+static hb_face_t *hb_face;
+
+static void
+initFreeType()
+{
+  FT_Error ft_error;
+  if ((ft_error = FT_Init_FreeType (&ft_library)))
+    abort();
+}
+
+static void
+cleanupFreeType()
+{
+  FT_Done_FreeType (ft_library);
+}
+
+static void
+openFont(const char* fontFile)
+{
+  FT_Error ft_error;
+  if ((ft_error = FT_New_Face (ft_library, fontFile, 0, &ft_face)))
+    abort();
+  unsigned int fontSize = 1000;
+  if ((ft_error = FT_Set_Char_Size (ft_face, fontSize, fontSize, 0, 0)))
+    abort();
+  hb_font = hb_ft_font_create (ft_face, NULL);
+  hb_face = hb_ft_face_create_cached(ft_face);
+}
+
+static void
+closeFont()
+{
+  hb_font_destroy (hb_font);
+  FT_Done_Face (ft_face);
+}
+
+static void
+test_has_math_data (void)
+{
+  initFreeType();
+
+  openFont("fonts/MathTestFontNone.otf");
+  g_assert(!hb_ot_layout_has_math_data (hb_face)); // MATH table not available
+  closeFont();
+
+  openFont("fonts/MathTestFontEmpty.otf");
+  g_assert(hb_ot_layout_has_math_data (hb_face)); // MATH table available
+  closeFont();
+
+  cleanupFreeType();
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_has_math_data);
+
+  return hb_test_run();
+}