[ft/draw] Implement hb-draw for hb-ft

src/hb-ft.cc

@@ -33,12 +33,14 @@
 
 #include "hb-ft.h"
 
+#include "hb-draw.hh"
 #include "hb-font.hh"
 #include "hb-machinery.hh"
 #include "hb-cache.hh"
 
 #include FT_ADVANCES_H
 #include FT_MULTIPLE_MASTERS_H
+#include FT_OUTLINE_H
 #include FT_TRUETYPE_TABLES_H
 
 
@@ -565,6 +567,82 @@ hb_ft_get_font_h_extents (hb_font_t *font HB_UNUSED,
   return true;
 }
 
+#ifndef HB_NO_DRAW
+
+static int
+_hb_ft_move_to (const FT_Vector *to,
+		hb_draw_session_t *drawing)
+{
+  drawing->move_to (to->x, to->y);
+  return FT_Err_Ok;
+}
+
+static int
+_hb_ft_line_to (const FT_Vector *to,
+		hb_draw_session_t *drawing)
+{
+  drawing->line_to (to->x, to->y);
+  return FT_Err_Ok;
+}
+
+static int
+_hb_ft_conic_to (const FT_Vector *control,
+		 const FT_Vector *to,
+		 hb_draw_session_t *drawing)
+{
+  drawing->quadratic_to (control->x, control->y,
+			 to->x, to->y);
+  return FT_Err_Ok;
+}
+
+static int
+_hb_ft_cubic_to (const FT_Vector *control1,
+		 const FT_Vector *control2,
+		 const FT_Vector *to,
+		 hb_draw_session_t *drawing)
+{
+  drawing->cubic_to (control1->x, control1->y,
+		     control2->x, control2->y,
+		     to->x, to->y);
+  return FT_Err_Ok;
+}
+
+static void
+hb_ft_get_glyph_shape (hb_font_t *font HB_UNUSED,
+		       void *font_data,
+		       hb_codepoint_t glyph,
+		       hb_draw_funcs_t *draw_funcs, void *draw_data,
+		       void *user_data HB_UNUSED)
+{
+  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
+  hb_lock_t lock (ft_font->lock);
+  FT_Face ft_face = ft_font->ft_face;
+
+  if (unlikely (FT_Load_Glyph (ft_face, glyph,
+			       FT_LOAD_NO_BITMAP | ft_font->load_flags)))
+    return;
+
+  if (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE)
+    return;
+
+  const FT_Outline_Funcs outline_funcs = {
+    (FT_Outline_MoveToFunc) _hb_ft_move_to,
+    (FT_Outline_LineToFunc) _hb_ft_line_to,
+    (FT_Outline_ConicToFunc) _hb_ft_conic_to,
+    (FT_Outline_CubicToFunc) _hb_ft_cubic_to,
+    0, /* shift */
+    0, /* delta */
+  };
+
+  hb_draw_session_t draw_session (draw_funcs, draw_data);
+
+  FT_Outline_Decompose (&ft_face->glyph->outline,
+			&outline_funcs,
+			&draw_session);
+}
+#endif
+
+
 static inline void free_static_ft_funcs ();
 
 static struct hb_ft_font_funcs_lazy_loader_t : hb_font_funcs_lazy_loader_t<hb_ft_font_funcs_lazy_loader_t>
@@ -596,6 +674,10 @@ static struct hb_ft_font_funcs_lazy_loader_t : hb_font_funcs_lazy_loader_t<hb_ft
     hb_font_funcs_set_glyph_name_func (funcs, hb_ft_get_glyph_name, nullptr, nullptr);
     hb_font_funcs_set_glyph_from_name_func (funcs, hb_ft_get_glyph_from_name, nullptr, nullptr);
 
+#ifndef HB_NO_DRAW
+    hb_font_funcs_set_glyph_shape_func (funcs, hb_ft_get_glyph_shape, nullptr, nullptr);
+#endif
+
     hb_font_funcs_make_immutable (funcs);
 
     hb_atexit (free_static_ft_funcs);