| """ |
| Low-level text helper utilities. |
| """ |
|
|
| import dataclasses |
|
|
| from . import _api |
| from .ft2font import KERNING_DEFAULT, LOAD_NO_HINTING |
|
|
|
|
| LayoutItem = dataclasses.make_dataclass( |
| "LayoutItem", ["ft_object", "char", "glyph_idx", "x", "prev_kern"]) |
|
|
|
|
| def warn_on_missing_glyph(codepoint): |
| _api.warn_external( |
| "Glyph {} ({}) missing from current font.".format( |
| codepoint, |
| chr(codepoint).encode("ascii", "namereplace").decode("ascii"))) |
| block = ("Hebrew" if 0x0590 <= codepoint <= 0x05ff else |
| "Arabic" if 0x0600 <= codepoint <= 0x06ff else |
| "Devanagari" if 0x0900 <= codepoint <= 0x097f else |
| "Bengali" if 0x0980 <= codepoint <= 0x09ff else |
| "Gurmukhi" if 0x0a00 <= codepoint <= 0x0a7f else |
| "Gujarati" if 0x0a80 <= codepoint <= 0x0aff else |
| "Oriya" if 0x0b00 <= codepoint <= 0x0b7f else |
| "Tamil" if 0x0b80 <= codepoint <= 0x0bff else |
| "Telugu" if 0x0c00 <= codepoint <= 0x0c7f else |
| "Kannada" if 0x0c80 <= codepoint <= 0x0cff else |
| "Malayalam" if 0x0d00 <= codepoint <= 0x0d7f else |
| "Sinhala" if 0x0d80 <= codepoint <= 0x0dff else |
| None) |
| if block: |
| _api.warn_external( |
| f"Matplotlib currently does not support {block} natively.") |
|
|
|
|
| def layout(string, font, *, kern_mode=KERNING_DEFAULT): |
| """ |
| Render *string* with *font*. For each character in *string*, yield a |
| (glyph-index, x-position) pair. When such a pair is yielded, the font's |
| glyph is set to the corresponding character. |
| |
| Parameters |
| ---------- |
| string : str |
| The string to be rendered. |
| font : FT2Font |
| The font. |
| kern_mode : int |
| A FreeType kerning mode. |
| |
| Yields |
| ------ |
| glyph_index : int |
| x_position : float |
| """ |
| x = 0 |
| prev_glyph_idx = None |
| char_to_font = font._get_fontmap(string) |
| base_font = font |
| for char in string: |
| |
| font = char_to_font.get(char, base_font) |
| glyph_idx = font.get_char_index(ord(char)) |
| kern = ( |
| base_font.get_kerning(prev_glyph_idx, glyph_idx, kern_mode) / 64 |
| if prev_glyph_idx is not None else 0. |
| ) |
| x += kern |
| glyph = font.load_glyph(glyph_idx, flags=LOAD_NO_HINTING) |
| yield LayoutItem(font, char, glyph_idx, x, kern) |
| x += glyph.linearHoriAdvance / 65536 |
| prev_glyph_idx = glyph_idx |
|
|
