[STAT] Add table parsing (#1384)

5 files changed, 290 insertions, 8 deletions

diff --git a/src/Makefile.sources b/src/Makefile.sources
index f83d6dcc..3dcd771f 100644
--- a/src/Makefile.sources
+++ b/src/Makefile.sources
@@ -158,6 +158,7 @@ HB_OT_sources = \
 	hb-ot-shape-fallback.hh \
 	hb-ot-shape-fallback.cc \
 	hb-ot-shape.hh \
+	hb-ot-stat-table.hh \
 	hb-ot-var.cc \
 	hb-ot-var-avar-table.hh \
 	hb-ot-var-fvar-table.hh \
diff --git a/src/hb-ot-face.hh b/src/hb-ot-face.hh
index 13c3a96d..3ca875e7 100644
--- a/src/hb-ot-face.hh
+++ b/src/hb-ot-face.hh
@@ -49,6 +49,8 @@
     HB_OT_ACCELERATOR(OT, glyf) \
     HB_OT_TABLE(OT, VORG) \
     HB_OT_ACCELERATOR(OT, name) \
+    HB_OT_TABLE(OT, OS2) \
+    HB_OT_TABLE(OT, STAT) \
     /* OpenType shaping. */ \
     HB_OT_ACCELERATOR(OT, GDEF) \
     HB_OT_ACCELERATOR(OT, GSUB) \
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index cf8cbd35..b19b25a3 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -33,10 +33,12 @@
 #include "hb-ot-face.hh"
 
 #include "hb-ot-cmap-table.hh"
+#include "hb-ot-glyf-table.hh"
 #include "hb-ot-hmtx-table.hh"
 #include "hb-ot-kern-table.hh"
+#include "hb-ot-os2-table.hh"
 #include "hb-ot-post-table.hh"
-#include "hb-ot-glyf-table.hh"
+#include "hb-ot-stat-table.hh" // Just so we compile it; unused otherwise.
 #include "hb-ot-vorg-table.hh"
 #include "hb-ot-color-cbdt-table.hh"
 #include "hb-ot-color-sbix-table.hh"
diff --git a/src/hb-ot-hmtx-table.hh b/src/hb-ot-hmtx-table.hh
index 80994c15..e2f55579 100644
--- a/src/hb-ot-hmtx-table.hh
+++ b/src/hb-ot-hmtx-table.hh
@@ -194,17 +194,14 @@ struct hmtxvmtx
       bool got_font_extents = false;
       if (T::os2Tag)
       {
-	hb_blob_t *os2_blob = hb_sanitize_context_t().reference_table<OS2> (face);
-	const OS2 *os2_table = os2_blob->as<OS2> ();
 #define USE_TYPO_METRICS (1u<<7)
-	if (0 != (os2_table->fsSelection & USE_TYPO_METRICS))
+	if (0 != (face->table.OS2->fsSelection & USE_TYPO_METRICS))
 	{
-	  ascender = abs (os2_table->sTypoAscender);
-	  descender = -abs (os2_table->sTypoDescender);
-	  line_gap = os2_table->sTypoLineGap;
+	  ascender = abs (face->table.OS2->sTypoAscender);
+	  descender = -abs (face->table.OS2->sTypoDescender);
+	  line_gap = face->table.OS2->sTypoLineGap;
 	  got_font_extents = (ascender | descender) != 0;
 	}
-	hb_blob_destroy (os2_blob);
       }
 
       hb_blob_t *_hea_blob = hb_sanitize_context_t().reference_table<H> (face);
diff --git a/src/hb-ot-stat-table.hh b/src/hb-ot-stat-table.hh
new file mode 100644
index 00000000..02c376e5
--- /dev/null
+++ b/src/hb-ot-stat-table.hh
@@ -0,0 +1,280 @@
+/*
+ * Copyright © 2018  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_STAT_TABLE_HH
+#define HB_OT_STAT_TABLE_HH
+
+#include "hb-open-type.hh"
+#include "hb-ot-layout-common.hh"
+
+/*
+ * STAT -- Style Attributes
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/stat
+ */
+#define HB_OT_TAG_STAT HB_TAG('S','T','A','T')
+
+
+namespace OT {
+
+enum
+{
+  OLDER_SIBLING_FONT_ATTRIBUTE = 0x0001,	/* If set, this axis value table
+						 * provides axis value information
+						 * that is applicable to other fonts
+						 * within the same font family. This
+						 * is used if the other fonts were
+						 * released earlier and did not include
+						 * information about values for some axis.
+						 * If newer versions of the other
+						 * fonts include the information
+						 * themselves and are present,
+						 * then this record is ignored. */
+  ELIDABLE_AXIS_VALUE_NAME = 0x0002		/* If set, it indicates that the axis
+						 * value represents the “normal” value
+						 * for the axis and may be omitted when
+						 * composing name strings. */
+  // Reserved = 0xFFFC				/* Reserved for future use — set to zero. */
+};
+
+struct StatAxisRecord
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+
+  protected:
+  Tag		axisTag;	/* A tag identifying the axis of design variation. */
+  NameID	axisNameID;	/* The name ID for entries in the 'name' table that
+				 * provide a display string for this axis. */
+  HBUINT16	axisOrdering;	/* A value that applications can use to determine
+				 * primary sorting of face names, or for ordering
+				 * of descriptors when composing family or face names. */
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+struct AxisValueFormat1
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier — set to 1. */
+  HBUINT16	axisIndex;	/* Zero-base index into the axis record array
+				 * identifying the axis of design variation
+				 * to which the axis value record applies.
+				 * Must be less than designAxisCount. */
+  HBUINT16	flags;		/* Flags — see below for details. */
+  NameID	valueNameID;	/* The name ID for entries in the 'name' table
+				 * that provide a display string for this
+				 * attribute value. */
+  Fixed		value;		/* A numeric value for this attribute value. */
+  public:
+  DEFINE_SIZE_STATIC (12);
+};
+
+struct AxisValueFormat2
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier — set to 2. */
+  HBUINT16	axisIndex;	/* Zero-base index into the axis record array
+				 * identifying the axis of design variation
+				 * to which the axis value record applies.
+				 * Must be less than designAxisCount. */
+  HBUINT16	flags;		/* Flags — see below for details. */
+  NameID	valueNameID;	/* The name ID for entries in the 'name' table
+				 * that provide a display string for this
+				 * attribute value. */
+  Fixed		nominalValue;	/* A numeric value for this attribute value. */
+  Fixed		rangeMinValue;	/* The minimum value for a range associated
+				 * with the specified name ID. */
+  Fixed		rangeMaxValue;	/* The maximum value for a range associated
+				 * with the specified name ID. */
+  public:
+  DEFINE_SIZE_STATIC (20);
+};
+
+struct AxisValueFormat3
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier — set to 3. */
+  HBUINT16	axisIndex;	/* Zero-base index into the axis record array
+				 * identifying the axis of design variation
+				 * to which the axis value record applies.
+				 * Must be less than designAxisCount. */
+  HBUINT16	flags;		/* Flags — see below for details. */
+  NameID	valueNameID;	/* The name ID for entries in the 'name' table
+				 * that provide a display string for this
+				 * attribute value. */
+  Fixed		value;		/* A numeric value for this attribute value. */
+  Fixed		linkedValue;	/* The numeric value for a style-linked mapping
+				 * from this value. */
+  public:
+  DEFINE_SIZE_STATIC (16);
+};
+
+struct AxisValueRecord
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+
+  protected:
+  HBUINT16	axisIndex;	/* Zero-base index into the axis record array
+				 * identifying the axis to which this value
+				 * applies. Must be less than designAxisCount. */
+  Fixed		value;		/* A numeric value for this attribute value. */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct AxisValueFormat4
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this)));
+  }
+
+  protected:
+  HBUINT16	format;		/* Format identifier — set to 4. */
+  HBUINT16	axisCount;	/* The total number of axes contributing to
+				 * this axis-values combination. */
+  HBUINT16	flags;		/* Flags — see below for details. */
+  NameID	valueNameID;	/* The name ID for entries in the 'name' table
+				 * that provide a display string for this
+				 * attribute value. */
+  UnsizedArrayOf<AxisValueRecord>
+		axisValues;	/* Array of AxisValue records that provide the
+				 * combination of axis values, one for each
+				 * contributing axis. */
+  public:
+  DEFINE_SIZE_ARRAY (8, axisValues);
+};
+
+struct AxisValue
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (c->check_struct (this)))
+      return_trace (false);
+
+    switch (u.format)
+    {
+    case 1:  return_trace (likely (u.format1.sanitize (c)));
+    case 2:  return_trace (likely (u.format2.sanitize (c)));
+    case 3:  return_trace (likely (u.format3.sanitize (c)));
+    case 4:  return_trace (likely (u.format4.sanitize (c)));
+    default: return_trace (true);
+    }
+  }
+
+  protected:
+  union
+  {
+  HBUINT16		format;
+  AxisValueFormat1	format1;
+  AxisValueFormat2	format2;
+  AxisValueFormat3	format3;
+  AxisValueFormat4	format4;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+struct STAT
+{
+  static const hb_tag_t tableTag = HB_OT_TAG_STAT;
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (likely (c->check_struct (this) &&
+			  majorVersion == 1 &&
+			  minorVersion > 0 &&
+			  designAxesOffset.sanitize (c, this, designAxisCount) &&
+			  offsetToAxisValueOffsets.sanitize (c, this, axisValueCount, &(this+offsetToAxisValueOffsets))));
+  }
+
+  protected:
+  HBUINT16	majorVersion;	/* Major version number of the style attributes
+				 * table — set to 1. */
+  HBUINT16	minorVersion;	/* Minor version number of the style attributes
+				 * table — set to 2. */
+  HBUINT16	designAxisSize;	/* The size in bytes of each axis record. */
+  HBUINT16	designAxisCount;/* The number of design axis records. In a
+				 * font with an 'fvar' table, this value must be
+				 * greater than or equal to the axisCount value
+				 * in the 'fvar' table. In all fonts, must
+				 * be greater than zero if axisValueCount
+				 * is greater than zero. */
+  LOffsetTo<UnsizedArrayOf<StatAxisRecord>, false>
+		designAxesOffset;
+				/* Offset in bytes from the beginning of
+				 * the STAT table to the start of the design
+				 * axes array. If designAxisCount is zero,
+				 * set to zero; if designAxisCount is greater
+				 * than zero, must be greater than zero. */
+  HBUINT16	axisValueCount;	/* The number of axis value tables. */
+  LOffsetTo<UnsizedArrayOf<OffsetTo<AxisValue> >, false>
+		offsetToAxisValueOffsets;
+				/* Offset in bytes from the beginning of
+				 * the STAT table to the start of the design
+				 * axes value offsets array. If axisValueCount
+				 * is zero, set to zero; if axisValueCount is
+				 * greater than zero, must be greater than zero. */
+  NameID	elidedFallbackNameID;
+				/* Name ID used as fallback when projection of
+				 * names into a particular font model produces
+				 * a subfamily name containing only elidable
+				 * elements. */
+  public:
+  DEFINE_SIZE_STATIC (20);
+};
+
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_STAT_TABLE_HH */