Coverage for /usr/lib/python3/dist-packages/matplotlib/_text_helpers.py: 96%

1""" 

2Low-level text helper utilities. 

3""" 

4 

5import dataclasses 

6 

7from . import _api 

8from .ft2font import KERNING_DEFAULT, LOAD_NO_HINTING 

9 

10 

11LayoutItem = dataclasses.make_dataclass( 

12 "LayoutItem", ["ft_object", "char", "glyph_idx", "x", "prev_kern"]) 

13 

14 

15def warn_on_missing_glyph(codepoint): 

16 _api.warn_external( 

17 "Glyph {} ({}) missing from current font.".format( 

18 codepoint, 

19 chr(codepoint).encode("ascii", "namereplace").decode("ascii"))) 

20 block = ("Hebrew" if 0x0590 <= codepoint <= 0x05ff else 

21 "Arabic" if 0x0600 <= codepoint <= 0x06ff else 

22 "Devanagari" if 0x0900 <= codepoint <= 0x097f else 

23 "Bengali" if 0x0980 <= codepoint <= 0x09ff else 

24 "Gurmukhi" if 0x0a00 <= codepoint <= 0x0a7f else 

25 "Gujarati" if 0x0a80 <= codepoint <= 0x0aff else 

26 "Oriya" if 0x0b00 <= codepoint <= 0x0b7f else 

27 "Tamil" if 0x0b80 <= codepoint <= 0x0bff else 

28 "Telugu" if 0x0c00 <= codepoint <= 0x0c7f else 

29 "Kannada" if 0x0c80 <= codepoint <= 0x0cff else 

30 "Malayalam" if 0x0d00 <= codepoint <= 0x0d7f else 

31 "Sinhala" if 0x0d80 <= codepoint <= 0x0dff else 

32 None) 

33 if block: 

34 _api.warn_external( 

35 f"Matplotlib currently does not support {block} natively.") 

36 

37 

38def layout(string, font, *, kern_mode=KERNING_DEFAULT): 

39 """ 

40 Render *string* with *font*. For each character in *string*, yield a 

41 (glyph-index, x-position) pair. When such a pair is yielded, the font's 

42 glyph is set to the corresponding character. 

43 

44 Parameters 

45 ---------- 

46 string : str 

47 The string to be rendered. 

48 font : FT2Font 

49 The font. 

50 kern_mode : int 

51 A FreeType kerning mode. 

52 

53 Yields 

54 ------ 

55 glyph_index : int 

56 x_position : float 

57 """ 

58 x = 0 

59 prev_glyph_idx = None 

60 char_to_font = font._get_fontmap(string) 

61 base_font = font 

62 for char in string: 

63 # This has done the fallback logic 

64 font = char_to_font.get(char, base_font) 

65 glyph_idx = font.get_char_index(ord(char)) 

66 kern = ( 

67 base_font.get_kerning(prev_glyph_idx, glyph_idx, kern_mode) / 64 

68 if prev_glyph_idx is not None else 0. 

69 ) 

70 x += kern 

71 glyph = font.load_glyph(glyph_idx, flags=LOAD_NO_HINTING) 

72 yield LayoutItem(font, char, glyph_idx, x, kern) 

73 x += glyph.linearHoriAdvance / 65536 

74 prev_glyph_idx = glyph_idx