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Python

"""
Text layouting utilities.
"""
from .ft2font import KERNING_DEFAULT, LOAD_NO_HINTING
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
last_glyph_idx = None
for char in string:
glyph_idx = font.get_char_index(ord(char))
kern = (font.get_kerning(last_glyph_idx, glyph_idx, kern_mode)
if last_glyph_idx is not None else 0) / 64
x += kern
glyph = font.load_glyph(glyph_idx, flags=LOAD_NO_HINTING)
yield glyph_idx, x
x += glyph.linearHoriAdvance / 65536
last_glyph_idx = glyph_idx