From 21f671bc453ba42b03402774a7e07fa0d3733099 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Thu, 13 Oct 2022 11:25:29 -0600
Subject: [PATCH] [glyf] Add stub VarCompositeGlyph

---
 src/OT/glyf/Glyph.hh             |   1 +
 src/OT/glyf/VarCompositeGlyph.hh | 157 +++++++++++++++++++++++++++++++
 2 files changed, 158 insertions(+)
 create mode 100644 src/OT/glyf/VarCompositeGlyph.hh

diff --git a/src/OT/glyf/Glyph.hh b/src/OT/glyf/Glyph.hh
index b8e547e32..d98ea5184 100644
--- a/src/OT/glyf/Glyph.hh
+++ b/src/OT/glyf/Glyph.hh
@@ -7,6 +7,7 @@
 #include "GlyphHeader.hh"
 #include "SimpleGlyph.hh"
 #include "CompositeGlyph.hh"
+#include "VarCompositeGlyph.hh"
 
 
 namespace OT {
diff --git a/src/OT/glyf/VarCompositeGlyph.hh b/src/OT/glyf/VarCompositeGlyph.hh
new file mode 100644
index 000000000..4599c81e0
--- /dev/null
+++ b/src/OT/glyf/VarCompositeGlyph.hh
@@ -0,0 +1,157 @@
+#ifndef OT_GLYF_VARCOMPOSITEGLYPH_HH
+#define OT_GLYF_VARCOMPOSITEGLYPH_HH
+
+
+#include "../../hb-open-type.hh"
+
+
+namespace OT {
+namespace glyf_impl {
+
+
+struct VarCompositeGlyphRecord
+{
+  protected:
+  enum var_composite_glyph_flag_t
+  {
+    ARG_1_AND_2_ARE_WORDS	= 0x0001,
+    ARGS_ARE_XY_VALUES		= 0x0002,
+    ROUND_XY_TO_GRID		= 0x0004,
+    WE_HAVE_A_SCALE		= 0x0008,
+    MORE_COMPONENTS		= 0x0020,
+    WE_HAVE_AN_X_AND_Y_SCALE	= 0x0040,
+    WE_HAVE_A_TWO_BY_TWO	= 0x0080,
+    WE_HAVE_INSTRUCTIONS	= 0x0100,
+    USE_MY_METRICS		= 0x0200,
+    OVERLAP_COMPOUND		= 0x0400,
+    SCALED_COMPONENT_OFFSET	= 0x0800,
+    UNSCALED_COMPONENT_OFFSET	= 0x1000,
+#ifndef HB_NO_BEYOND_64K
+    GID_IS_24BIT		= 0x2000
+#endif
+  };
+
+  public:
+  unsigned int get_size () const
+  {
+    unsigned int size = min_size;
+    /* glyphIndex is 24bit instead of 16bit */
+#ifndef HB_NO_BEYOND_64K
+    if (flags & GID_IS_24BIT) size += HBGlyphID24::static_size - HBGlyphID16::static_size;
+#endif
+    /* arg1 and 2 are int16 */
+    if (flags & ARG_1_AND_2_ARE_WORDS) size += 4;
+    /* arg1 and 2 are int8 */
+    else size += 2;
+
+    /* One x 16 bit (scale) */
+    if (flags & WE_HAVE_A_SCALE) size += 2;
+    /* Two x 16 bit (xscale, yscale) */
+    else if (flags & WE_HAVE_AN_X_AND_Y_SCALE) size += 4;
+    /* Four x 16 bit (xscale, scale01, scale10, yscale) */
+    else if (flags & WE_HAVE_A_TWO_BY_TWO) size += 8;
+
+    return size;
+  }
+
+  void transform_points (contour_point_vector_t &points) const
+  {
+    float matrix[4];
+    contour_point_t trans;
+    if (get_transformation (matrix, trans))
+    {
+      points.transform (matrix);
+      points.translate (trans);
+    }
+  }
+
+  bool get_transformation (float (&matrix)[4], contour_point_t &trans) const
+  {
+    matrix[0] = matrix[3] = 1.f;
+    matrix[1] = matrix[2] = 0.f;
+
+    const auto *p = &StructAfter<const HBINT8> (flags);
+#ifndef HB_NO_BEYOND_64K
+    if (flags & GID_IS_24BIT)
+      p += HBGlyphID24::static_size;
+    else
+#endif
+      p += HBGlyphID16::static_size;
+    int tx, ty;
+    if (flags & ARG_1_AND_2_ARE_WORDS)
+    {
+      tx = *(const HBINT16 *) p;
+      p += HBINT16::static_size;
+      ty = *(const HBINT16 *) p;
+      p += HBINT16::static_size;
+    }
+    else
+    {
+      tx = *p++;
+      ty = *p++;
+    }
+    trans.init ((float) tx, (float) ty);
+
+    {
+      const F2DOT14 *points = (const F2DOT14 *) p;
+      if (flags & WE_HAVE_A_SCALE)
+      {
+	matrix[0] = matrix[3] = points[0].to_float ();
+	return true;
+      }
+      else if (flags & WE_HAVE_AN_X_AND_Y_SCALE)
+      {
+	matrix[0] = points[0].to_float ();
+	matrix[3] = points[1].to_float ();
+	return true;
+      }
+      else if (flags & WE_HAVE_A_TWO_BY_TWO)
+      {
+	matrix[0] = points[0].to_float ();
+	matrix[1] = points[1].to_float ();
+	matrix[2] = points[2].to_float ();
+	matrix[3] = points[3].to_float ();
+	return true;
+      }
+    }
+    return tx || ty;
+  }
+
+  public:
+  hb_codepoint_t get_gid () const
+  {
+#ifndef HB_NO_BEYOND_64K
+    if (flags & GID_IS_24BIT)
+      return StructAfter<const HBGlyphID24> (flags);
+    else
+#endif
+      return StructAfter<const HBGlyphID16> (flags);
+  }
+
+  protected:
+  HBUINT16	flags;
+  HBUINT24	pad;
+  public:
+  DEFINE_SIZE_MIN (4);
+};
+
+using var_composite_iter_t = composite_iter_tmpl<VarCompositeGlyphRecord>;
+
+struct VarCompositeGlyph
+{
+  const GlyphHeader &header;
+  hb_bytes_t bytes;
+  VarCompositeGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
+    header (header_), bytes (bytes_) {}
+
+  var_composite_iter_t iter () const
+  { return var_composite_iter_t (bytes, &StructAfter<VarCompositeGlyphRecord, GlyphHeader> (header)); }
+
+};
+
+
+} /* namespace glyf_impl */
+} /* namespace OT */
+
+
+#endif /* OT_GLYF_VARCOMPOSITEGLYPH_HH */