kopia lustrzana https://github.com/inkstitch/inkstitch
292 wiersze
10 KiB
Python
292 wiersze
10 KiB
Python
# Authors: see git history
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#
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# Copyright (c) 2010 Authors
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# Licensed under the GNU GPL version 3.0 or later. See the file LICENSE for details.
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import json
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import os
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from copy import deepcopy
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from inkex import styles
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from lxml import etree
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from ..elements import nodes_to_elements
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from ..exceptions import InkstitchException
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from ..i18n import _, get_languages
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from ..stitches.auto_satin import auto_satin
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from ..svg import PIXELS_PER_MM
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from ..svg.tags import INKSCAPE_LABEL, SVG_GROUP_TAG, SVG_PATH_TAG
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from ..utils import Point
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from .font_variant import FontVariant
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class FontError(InkstitchException):
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pass
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def font_metadata(name, default=None, multiplier=None):
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def getter(self):
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value = self.metadata.get(name, default)
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if multiplier is not None:
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value *= multiplier
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return value
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return property(getter)
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def localized_font_metadata(name, default=None):
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def getter(self):
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# If the font contains a localized version of the attribute, use it.
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for language in get_languages():
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attr = "%s_%s" % (name, language)
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if attr in self.metadata:
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return self.metadata.get(attr)
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if name in self.metadata:
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# This may be a font packaged with Ink/Stitch, in which case the
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# text will have been sent to CrowdIn for community translation.
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# Try to fetch the translated version.
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original_metadata = self.metadata.get(name)
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localized_metadata = ""
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if original_metadata != "":
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localized_metadata = _(original_metadata)
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return localized_metadata
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else:
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return default
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return property(getter)
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class Font(object):
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"""Represents a font with multiple variants.
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Each font may have multiple FontVariants for left-to-right, right-to-left,
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etc. Each variant has a set of Glyphs, one per character.
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Properties:
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path -- the path to the directory containing this font
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metadata -- A dict of information about the font.
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name -- Shortcut property for metadata["name"]
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license -- contents of the font's LICENSE file, or None if no LICENSE file exists.
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variants -- A dict of FontVariants, with keys in FontVariant.VARIANT_TYPES.
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"""
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def __init__(self, font_path):
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self.path = font_path
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self.metadata = {}
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self.license = None
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self.variants = {}
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self._load_metadata()
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self._load_license()
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def _load_metadata(self):
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try:
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with open(os.path.join(self.path, "font.json"), encoding="utf-8") as metadata_file:
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self.metadata = json.load(metadata_file)
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except IOError:
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pass
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def _load_license(self):
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try:
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with open(os.path.join(self.path, "LICENSE"), encoding="utf-8") as license_file:
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self.license = license_file.read()
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except IOError:
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pass
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def _load_variants(self):
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if not self.variants:
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for variant in FontVariant.VARIANT_TYPES:
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try:
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self.variants[variant] = FontVariant(self.path, variant, self.default_glyph)
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except IOError:
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# we'll deal with missing variants when we apply lettering
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pass
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name = localized_font_metadata('name', '')
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description = localized_font_metadata('description', '')
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default_glyph = font_metadata('defalt_glyph', "<EFBFBD>")
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leading = font_metadata('leading', 5, multiplier=PIXELS_PER_MM)
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kerning_pairs = font_metadata('kerning_pairs', {})
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auto_satin = font_metadata('auto_satin', True)
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min_scale = font_metadata('min_scale', 1.0)
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max_scale = font_metadata('max_scale', 1.0)
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# use values from SVG Font, exemple:
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# <font horiz-adv-x="45" ... <glyph .... horiz-adv-x="49" glyph-name="A" /> ... <hkern ... k="3"g1="A" g2="B" /> .... />
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# Example font.json : "horiz_adv_x": {"A":49},
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horiz_adv_x = font_metadata('horiz_adv_x', {})
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# Example font.json : "horiz_adv_x_default" : 45,
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horiz_adv_x_default = font_metadata('horiz_adv_x_default')
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# Define by <glyph glyph-name="space" unicode=" " horiz-adv-x="22" />, Example font.json : "horiz_adv_x_space":22,
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word_spacing = font_metadata('horiz_adv_x_space', 0)
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reversible = font_metadata('reversible', True)
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@property
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def id(self):
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return os.path.basename(self.path)
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@property
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def default_variant(self):
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# Set default variant to any existing variant if default font file is missing
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default_variant = font_metadata('default_variant', FontVariant.LEFT_TO_RIGHT)
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font_variants = self.has_variants()
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if default_variant not in font_variants and len(font_variants) > 0:
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default_variant = font_variants[0]
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return default_variant
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@property
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def preview_image(self):
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preview_image_path = os.path.join(self.path, "preview.png")
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if os.path.isfile(preview_image_path):
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return preview_image_path
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return None
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def has_variants(self):
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# returns available variants
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font_variants = []
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for variant in FontVariant.VARIANT_TYPES:
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if os.path.isfile(os.path.join(self.path, "%s.svg" % variant)):
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font_variants.append(variant)
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if not font_variants:
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raise FontError(_("The font '%s' has no variants.") % self.name)
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return font_variants
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def render_text(self, text, destination_group, variant=None, back_and_forth=True, trim=False):
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"""Render text into an SVG group element."""
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self._load_variants()
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if variant is None:
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variant = self.default_variant
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if back_and_forth and self.reversible:
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glyph_sets = [self.get_variant(variant), self.get_variant(FontVariant.reversed_variant(variant))]
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else:
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glyph_sets = [self.get_variant(variant)] * 2
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position = Point(0, 0)
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for i, line in enumerate(text.splitlines()):
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glyph_set = glyph_sets[i % 2]
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line = line.strip()
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letter_group = self._render_line(line, position, glyph_set)
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if back_and_forth and self.reversible and i % 2 == 1:
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letter_group[:] = reversed(letter_group)
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destination_group.append(letter_group)
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position.x = 0
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position.y += self.leading
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if self.auto_satin and len(destination_group) > 0:
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self._apply_auto_satin(destination_group, trim)
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# make sure font stroke styles have always a similar look
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for element in destination_group.iterdescendants(SVG_PATH_TAG):
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dash_array = ""
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stroke_width = ""
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style = styles.Style(element.get('style'))
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if style.get('fill') == 'none':
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stroke_width = ";stroke-width:1px"
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if style.get('stroke-width'):
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style.pop('stroke-width')
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if style.get('stroke-dasharray') and style.get('stroke-dasharray') != 'none':
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stroke_width = ";stroke-width:0.5px"
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dash_array = ";stroke-dasharray:3, 1"
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element.set('style', '%s%s%s' % (style.to_str(), stroke_width, dash_array))
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return destination_group
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def get_variant(self, variant):
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return self.variants.get(variant, self.variants[self.default_variant])
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def _render_line(self, line, position, glyph_set):
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"""Render a line of text.
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An SVG XML node tree will be returned, with an svg:g at its root. If
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the font metadata requests it, Auto-Satin will be applied.
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Parameters:
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line -- the line of text to render.
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position -- Current position. Will be updated to point to the spot
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immediately after the last character.
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glyph_set -- a FontVariant instance.
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Returns:
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An svg:g element containing the rendered text.
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"""
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group = etree.Element(SVG_GROUP_TAG, {
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INKSCAPE_LABEL: line
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})
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last_character = None
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for character in line:
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if character == " ":
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position.x += self.word_spacing
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last_character = None
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else:
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glyph = glyph_set[character] or glyph_set[self.default_glyph]
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if glyph is not None:
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node = self._render_glyph(glyph, position, character, last_character)
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group.append(node)
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last_character = character
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return group
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def _render_glyph(self, glyph, position, character, last_character):
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"""Render a single glyph.
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An SVG XML node tree will be returned, with an svg:g at its root.
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Parameters:
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glyph -- a Glyph instance
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position -- Current position. Will be updated based on the width
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of this character and the letter spacing.
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character -- the current Unicode character.
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last_character -- the previous character in the line, or None if
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we're at the start of the line or a word.
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"""
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# Concerning min_x: I add it before moving the letter because it is to
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# take into account the margin in the drawing of the letter. With respect
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# to point 0 the letter can start at 5 or -5. The letters have a defined
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# place in the drawing that's important.
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# Then to calculate the position of x for the next letter I have to remove
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# the min_x margin because the horizontal adv is calculated from point 0 of the drawing.
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node = deepcopy(glyph.node)
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if last_character is not None:
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position.x += glyph.min_x - self.kerning_pairs.get(last_character + character, 0)
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transform = "translate(%s, %s)" % position.as_tuple()
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node.set('transform', transform)
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horiz_adv_x_default = self.horiz_adv_x_default
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if horiz_adv_x_default is None:
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horiz_adv_x_default = glyph.width + glyph.min_x
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position.x += self.horiz_adv_x.get(character, horiz_adv_x_default) - glyph.min_x
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return node
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def _apply_auto_satin(self, group, trim):
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"""Apply Auto-Satin to an SVG XML node tree with an svg:g at its root.
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The group's contents will be replaced with the results of the auto-
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satin operation. Any nested svg:g elements will be removed.
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"""
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elements = nodes_to_elements(group.iterdescendants(SVG_PATH_TAG))
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auto_satin(elements, preserve_order=True, trim=trim)
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