[kerx] Implement Format4 action_type=2 coordinate-based attachment

Untested.

diff --git a/src/hb-aat-layout-kerx-table.hh b/src/hb-aat-layout-kerx-table.hh
index 019efd5..a54e297 100644 (file)
--- a/src/hb-aat-layout-kerx-table.hh
+++ b/src/hb-aat-layout-kerx-table.hh
@@ -343,6 +343,7 @@ struct KerxSubTableFormat4
 
       if (mark_set && entry->data.ankrActionIndex != 0xFFFF)
       {
+       hb_glyph_position_t &o = buffer->cur_pos();
        switch (action_type)
        {
          case 0: /* Control Point Actions.*/
@@ -373,12 +374,9 @@ struct KerxSubTableFormat4
                                                                currAnchorPoint,
                                                                c->face->get_num_glyphs (),
                                                                c->ankr_end);
-           hb_glyph_position_t &o = buffer->cur_pos();
+
            o.x_offset = c->font->em_scale_x (markAnchor.xCoordinate) - c->font->em_scale_x (currAnchor.xCoordinate);
            o.y_offset = c->font->em_scale_y (markAnchor.yCoordinate) - c->font->em_scale_y (currAnchor.yCoordinate);
-           o.attach_type() = ATTACH_TYPE_MARK;
-           o.attach_chain() = (int) mark - (int) buffer->idx;
-           buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
          }
          break;
 
@@ -387,14 +385,19 @@ struct KerxSubTableFormat4
            const FWORD *data = (const FWORD *) &ankrData[entry->data.ankrActionIndex];
            if (!c->sanitizer.check_array (data, 4))
              return false;
-           HB_UNUSED int markX = *data++;
-           HB_UNUSED int markY = *data++;
-           HB_UNUSED int currX = *data++;
-           HB_UNUSED int currY = *data++;
-           /* TODO */
+           int markX = *data++;
+           int markY = *data++;
+           int currX = *data++;
+           int currY = *data++;
+
+           o.x_offset = c->font->em_scale_x (markX) - c->font->em_scale_x (currX);
+           o.y_offset = c->font->em_scale_y (markY) - c->font->em_scale_y (currY);
          }
          break;
        }
+       o.attach_type() = ATTACH_TYPE_MARK;
+       o.attach_chain() = (int) mark - (int) buffer->idx;
+       buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT;
       }
 
       if (flags & Mark)