Commit a632fb547e23fe129a579fabf60a992fd7d98d02
2018-06-24T15:22:10
[truetype] Increase precision while applying VF deltas. It turned out that we incorrectly round CVT and glyph point deltas before accumulation, leading to severe positioning errors if there are many delta values to sum up. Problem reported by Akiem Helmling <akiem@underware.nl> and analyzed by Behdad. * src/truetype/ttgxvar.c (ft_var_readpackeddelta): Return deltas in 16.16 format. (tt_face_var_cvt): Collect deltas in `cvt_deltas', which is a 16.16 format array, and add the accumulated values to the CVT at the end of the function. (TT_Vary_Apply_Glyph_Deltas): Store data in `points_org' and `points_out' in 16.16 format. Collect deltas in `point_deltas_x' and `point_deltas_y', which are 16.16 format arrays, and add the accumulated values to the glyph coordinates at the end of the function.