2012-03-22 02:19:27 +04:00
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"""
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weasyprint.images
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-----------------
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2011-12-08 19:31:03 +04:00
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2012-03-22 02:19:27 +04:00
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Fetch and decode images in various formats.
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2011-12-08 19:31:03 +04:00
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"""
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|
2017-03-25 02:33:36 +03:00
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import math
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2012-02-17 21:49:58 +04:00
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from io import BytesIO
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2020-10-25 16:54:08 +03:00
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from itertools import cycle
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2016-02-26 15:58:47 +03:00
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from xml.etree import ElementTree
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2011-12-08 19:31:03 +04:00
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2013-02-25 19:26:39 +04:00
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import cairosvg.parser
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import cairosvg.surface
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2020-06-07 01:32:47 +03:00
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import pydyf
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2020-06-03 18:58:53 +03:00
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from PIL import Image
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2016-01-15 15:15:02 +03:00
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2019-06-02 19:06:25 +03:00
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from .layout.percentages import percentage
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2017-03-25 02:33:36 +03:00
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from .logger import LOGGER
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from .urls import URLFetchingError, fetch
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2013-02-25 19:26:39 +04:00
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2013-04-03 18:00:31 +04:00
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2013-06-21 00:32:28 +04:00
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class ImageLoadingError(ValueError):
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"""An error occured when loading an image.
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The image data is probably corrupted or in an invalid format.
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"""
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@classmethod
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def from_exception(cls, exception):
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name = type(exception).__name__
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value = str(exception)
|
2020-05-30 16:48:24 +03:00
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return cls(f'{name}: {value}' if value else name)
|
2013-06-21 00:32:28 +04:00
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2020-01-02 14:06:58 +03:00
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class RasterImage:
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2020-07-31 15:46:36 +03:00
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def __init__(self, pillow_image, optimize_image):
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2020-06-03 18:58:53 +03:00
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self.pillow_image = pillow_image
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2020-07-31 15:46:36 +03:00
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self.optimize_image = optimize_image
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2020-06-03 18:58:53 +03:00
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self._intrinsic_width = pillow_image.width
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self._intrinsic_height = pillow_image.height
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2013-04-03 20:15:32 +04:00
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self.intrinsic_ratio = (
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2013-07-26 19:26:30 +04:00
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self._intrinsic_width / self._intrinsic_height
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if self._intrinsic_height != 0 else float('inf'))
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2016-02-26 15:58:47 +03:00
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def get_intrinsic_size(self, image_resolution, _font_size):
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2013-07-26 19:26:30 +04:00
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# Raster images are affected by the 'image-resolution' property.
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return (self._intrinsic_width / image_resolution,
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self._intrinsic_height / image_resolution)
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2013-04-03 15:34:14 +04:00
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2013-04-03 18:00:31 +04:00
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def draw(self, context, concrete_width, concrete_height, image_rendering):
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2019-06-01 02:32:13 +03:00
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has_size = (
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concrete_width > 0
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and concrete_height > 0
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and self._intrinsic_width > 0
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and self._intrinsic_height > 0
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)
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if not has_size:
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return
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|
2020-07-31 15:46:36 +03:00
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image_name = context.add_image(
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self.pillow_image, image_rendering, self.optimize_image)
|
2019-06-01 02:32:13 +03:00
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# Use the real intrinsic size here,
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# not affected by 'image-resolution'.
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2020-06-03 18:58:53 +03:00
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context.push_state()
|
2020-06-03 20:47:34 +03:00
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context.transform(
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concrete_width, 0, 0, -concrete_height, 0, concrete_height)
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2020-06-03 18:58:53 +03:00
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context.draw_x_object(image_name)
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context.pop_state()
|
2011-12-08 19:31:03 +04:00
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2013-02-25 19:26:39 +04:00
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class ScaledSVGSurface(cairosvg.surface.SVGSurface):
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"""
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Have the cairo Surface object have intrinsic dimension
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in pixels instead of points.
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"""
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@property
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def device_units_per_user_units(self):
|
2019-12-23 17:34:49 +03:00
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scale = super().device_units_per_user_units
|
2013-02-25 19:26:39 +04:00
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return scale / 0.75
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|
2020-01-02 14:06:58 +03:00
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class FakeSurface:
|
2016-02-26 15:58:47 +03:00
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"""Fake CairoSVG surface used to get SVG attributes."""
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context_height = 0
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context_width = 0
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font_size = 12
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dpi = 96
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|
2020-01-02 14:06:58 +03:00
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class SVGImage:
|
2017-06-07 12:37:53 +03:00
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def __init__(self, svg_data, base_url, url_fetcher):
|
2012-02-21 15:59:06 +04:00
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|
# Don’t pass data URIs to CairoSVG.
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# They are useless for relative URIs anyway.
|
2013-04-03 15:34:14 +04:00
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self._base_url = (
|
2013-04-04 21:48:23 +04:00
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base_url if not base_url.lower().startswith('data:') else None)
|
2013-04-03 15:34:14 +04:00
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self._svg_data = svg_data
|
2017-06-07 12:37:53 +03:00
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|
self._url_fetcher = url_fetcher
|
2013-04-03 15:34:14 +04:00
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|
2013-06-21 00:32:28 +04:00
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try:
|
2016-02-26 15:58:47 +03:00
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|
self._tree = ElementTree.fromstring(self._svg_data)
|
2013-06-21 00:32:28 +04:00
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|
except Exception as e:
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|
raise ImageLoadingError.from_exception(e)
|
2016-02-26 15:58:47 +03:00
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|
2017-06-23 13:23:22 +03:00
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|
def _cairosvg_url_fetcher(self, src, mimetype):
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|
data = self._url_fetcher(src)
|
2017-11-11 16:21:16 +03:00
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|
if 'string' in data:
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|
return data['string']
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|
return data['file_obj'].read()
|
2017-06-23 13:23:22 +03:00
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|
2016-02-26 15:58:47 +03:00
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def get_intrinsic_size(self, _image_resolution, font_size):
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|
# Vector images may be affected by the font size.
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fake_surface = FakeSurface()
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fake_surface.font_size = font_size
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|
# Percentages don't provide an intrinsic size, we transform percentages
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|
# into 0 using a (0, 0) context size:
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# http://www.w3.org/TR/SVG/coords.html#IntrinsicSizing
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self._width = cairosvg.surface.size(
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fake_surface, self._tree.get('width'))
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|
self._height = cairosvg.surface.size(
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|
|
fake_surface, self._tree.get('height'))
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|
_, _, viewbox = cairosvg.surface.node_format(fake_surface, self._tree)
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|
self._intrinsic_width = self._width or None
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|
self._intrinsic_height = self._height or None
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|
self.intrinsic_ratio = None
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|
|
if viewbox:
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|
|
|
if self._width and self._height:
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|
self.intrinsic_ratio = self._width / self._height
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|
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|
else:
|
2016-02-26 17:28:43 +03:00
|
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|
|
if viewbox[2] and viewbox[3]:
|
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|
self.intrinsic_ratio = viewbox[2] / viewbox[3]
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|
|
|
if self._width:
|
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|
self._intrinsic_height = (
|
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|
|
|
self._width / self.intrinsic_ratio)
|
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|
|
|
elif self._height:
|
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|
|
|
self._intrinsic_width = (
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|
|
|
self._height * self.intrinsic_ratio)
|
2016-02-26 15:58:47 +03:00
|
|
|
|
elif self._width and self._height:
|
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|
|
|
self.intrinsic_ratio = self._width / self._height
|
2013-07-26 19:26:30 +04:00
|
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|
|
return self._intrinsic_width, self._intrinsic_height
|
2013-04-03 15:34:14 +04:00
|
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|
|
|
2013-04-04 21:48:23 +04:00
|
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|
|
def draw(self, context, concrete_width, concrete_height, _image_rendering):
|
2016-02-26 17:29:05 +03:00
|
|
|
|
try:
|
|
|
|
|
svg = ScaledSVGSurface(
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|
|
|
|
cairosvg.parser.Tree(
|
2017-06-07 12:37:53 +03:00
|
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|
|
bytestring=self._svg_data, url=self._base_url,
|
2017-06-23 13:23:22 +03:00
|
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|
url_fetcher=self._cairosvg_url_fetcher),
|
2019-05-20 13:28:35 +03:00
|
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|
|
output=None, dpi=96, output_width=concrete_width,
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|
output_height=concrete_height)
|
2016-02-26 17:29:05 +03:00
|
|
|
|
if svg.width and svg.height:
|
|
|
|
|
context.scale(
|
|
|
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|
concrete_width / svg.width, concrete_height / svg.height)
|
|
|
|
|
context.set_source_surface(svg.cairo)
|
|
|
|
|
context.paint()
|
2020-05-30 16:48:24 +03:00
|
|
|
|
except Exception as exception:
|
2017-07-25 14:59:56 +03:00
|
|
|
|
LOGGER.error(
|
2020-05-30 16:48:24 +03:00
|
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|
|
'Failed to draw an SVG image at %r: %s',
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self._base_url, exception)
|
2012-01-12 22:26:27 +04:00
|
|
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|
|
|
|
|
2020-06-22 17:05:14 +03:00
|
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|
|
def get_image_from_uri(cache, url_fetcher, optimize_images, url,
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|
|
forced_mime_type=None):
|
2013-02-26 18:04:52 +04:00
|
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|
|
"""Get a cairo Pattern from an image URI."""
|
2013-06-20 15:58:24 +04:00
|
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|
missing = object()
|
2013-06-21 00:32:28 +04:00
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image = cache.get(url, missing)
|
2013-06-20 15:58:24 +04:00
|
|
|
|
if image is not missing:
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|
|
return image
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|
|
|
2011-12-08 19:31:03 +04:00
|
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|
try:
|
2013-06-21 00:32:28 +04:00
|
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|
|
with fetch(url_fetcher, url) as result:
|
2016-08-26 15:34:28 +03:00
|
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|
|
if 'string' in result:
|
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|
|
string = result['string']
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|
|
|
else:
|
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|
|
string = result['file_obj'].read()
|
2013-06-20 15:58:24 +04:00
|
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|
mime_type = forced_mime_type or result['mime_type']
|
2013-04-03 15:34:14 +04:00
|
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|
|
if mime_type == 'image/svg+xml':
|
2016-08-26 15:34:28 +03:00
|
|
|
|
# No fallback for XML-based mimetypes as defined by MIME
|
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|
|
|
# Sniffing Standard, see https://mimesniff.spec.whatwg.org/
|
2017-06-07 12:37:53 +03:00
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|
image = SVGImage(string, url, url_fetcher)
|
2012-07-29 00:11:28 +04:00
|
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|
else:
|
2016-08-26 15:34:28 +03:00
|
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|
|
# Try to rely on given mimetype
|
2013-06-21 00:32:28 +04:00
|
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try:
|
2020-06-03 18:58:53 +03:00
|
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|
pillow_image = Image.open(BytesIO(string))
|
|
|
|
|
except Exception as exception:
|
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|
|
|
raise ImageLoadingError.from_exception(exception)
|
|
|
|
|
else:
|
2020-07-31 15:46:36 +03:00
|
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|
|
image = RasterImage(pillow_image, optimize_images)
|
2020-06-03 18:58:53 +03:00
|
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|
2020-05-30 16:48:24 +03:00
|
|
|
|
except (URLFetchingError, ImageLoadingError) as exception:
|
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|
|
|
LOGGER.error('Failed to load image at %r: %s', url, exception)
|
2012-09-26 18:59:40 +04:00
|
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|
|
image = None
|
2013-06-21 00:32:28 +04:00
|
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|
|
cache[url] = image
|
2012-09-26 18:59:40 +04:00
|
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|
return image
|
2013-04-04 21:48:23 +04:00
|
|
|
|
|
|
|
|
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|
2020-10-24 18:42:13 +03:00
|
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|
|
def process_color_stops(vector_length, positions):
|
|
|
|
|
"""Give color stops positions on the gradient vector.
|
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|
|
|
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|
|
|
|
``vector_length`` is the distance between the starting point and ending
|
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|
|
point of the vector gradient.
|
2013-04-04 21:48:23 +04:00
|
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|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
``positions`` is a list of ``None``, or ``Dimension`` in px or %. 0 is the
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|
starting point, 1 the ending point.
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|
|
|
|
|
|
|
|
|
See http://dev.w3.org/csswg/css-images-3/#color-stop-syntax.
|
2013-04-04 21:48:23 +04:00
|
|
|
|
|
|
|
|
|
Return processed color stops, as a list of floats in px.
|
|
|
|
|
|
|
|
|
|
"""
|
2020-10-24 18:42:13 +03:00
|
|
|
|
# Resolve percentages
|
|
|
|
|
positions = [percentage(position, vector_length) for position in positions]
|
|
|
|
|
|
2013-04-04 21:48:23 +04:00
|
|
|
|
# First and last default to 100%
|
|
|
|
|
if positions[0] is None:
|
|
|
|
|
positions[0] = 0
|
|
|
|
|
if positions[-1] is None:
|
2020-10-24 18:42:13 +03:00
|
|
|
|
positions[-1] = vector_length
|
2013-04-04 21:48:23 +04:00
|
|
|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
# Make sure positions are increasing
|
2013-04-04 21:48:23 +04:00
|
|
|
|
previous_pos = positions[0]
|
|
|
|
|
for i, position in enumerate(positions):
|
|
|
|
|
if position is not None:
|
|
|
|
|
if position < previous_pos:
|
|
|
|
|
positions[i] = previous_pos
|
|
|
|
|
else:
|
|
|
|
|
previous_pos = position
|
|
|
|
|
|
|
|
|
|
# Assign missing values
|
|
|
|
|
previous_i = -1
|
|
|
|
|
for i, position in enumerate(positions):
|
|
|
|
|
if position is not None:
|
|
|
|
|
base = positions[previous_i]
|
|
|
|
|
increment = (position - base) / (i - previous_i)
|
2018-01-14 03:48:17 +03:00
|
|
|
|
for j in range(previous_i + 1, i):
|
2013-04-04 21:48:23 +04:00
|
|
|
|
positions[j] = base + j * increment
|
|
|
|
|
previous_i = i
|
2020-10-24 18:42:13 +03:00
|
|
|
|
|
2013-04-12 17:29:21 +04:00
|
|
|
|
return positions
|
|
|
|
|
|
|
|
|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
def normalize_stop_positions(positions):
|
|
|
|
|
"""Normalize stop positions between 0 and 1.
|
|
|
|
|
|
|
|
|
|
Return ``(first, last, positions)``.
|
|
|
|
|
|
|
|
|
|
first: original position of the first position.
|
|
|
|
|
last: original position of the last position.
|
|
|
|
|
positions: list of positions between 0 and 1.
|
|
|
|
|
|
|
|
|
|
"""
|
|
|
|
|
first, last = positions[0], positions[-1]
|
2013-04-08 19:28:46 +04:00
|
|
|
|
total_length = last - first
|
2020-10-24 18:42:13 +03:00
|
|
|
|
if total_length == 0:
|
|
|
|
|
positions = [0] * len(positions)
|
2013-04-17 18:57:17 +04:00
|
|
|
|
else:
|
2020-10-24 18:42:13 +03:00
|
|
|
|
positions = [(pos - first) / total_length for pos in positions]
|
2013-04-17 18:57:17 +04:00
|
|
|
|
return first, last, positions
|
2013-04-04 21:48:23 +04:00
|
|
|
|
|
|
|
|
|
|
2013-04-08 19:28:46 +04:00
|
|
|
|
def gradient_average_color(colors, positions):
|
|
|
|
|
"""
|
2020-10-24 18:42:13 +03:00
|
|
|
|
http://dev.w3.org/csswg/css-images-3/#gradient-average-color
|
2013-04-08 19:28:46 +04:00
|
|
|
|
"""
|
|
|
|
|
nb_stops = len(positions)
|
2013-04-12 17:29:21 +04:00
|
|
|
|
assert nb_stops > 1
|
2013-04-08 19:28:46 +04:00
|
|
|
|
assert nb_stops == len(colors)
|
|
|
|
|
total_length = positions[-1] - positions[0]
|
|
|
|
|
if total_length == 0:
|
2013-04-17 15:10:36 +04:00
|
|
|
|
positions = list(range(nb_stops))
|
2013-04-08 19:28:46 +04:00
|
|
|
|
total_length = nb_stops - 1
|
|
|
|
|
premul_r = [r * a for r, g, b, a in colors]
|
|
|
|
|
premul_g = [g * a for r, g, b, a in colors]
|
|
|
|
|
premul_b = [b * a for r, g, b, a in colors]
|
|
|
|
|
alpha = [a for r, g, b, a in colors]
|
|
|
|
|
result_r = result_g = result_b = result_a = 0
|
|
|
|
|
total_weight = 2 * total_length
|
|
|
|
|
for i, position in enumerate(positions[1:], 1):
|
|
|
|
|
weight = (position - positions[i - 1]) / total_weight
|
|
|
|
|
for j in (i - 1, i):
|
|
|
|
|
result_r += premul_r[j] * weight
|
|
|
|
|
result_g += premul_g[j] * weight
|
|
|
|
|
result_b += premul_b[j] * weight
|
|
|
|
|
result_a += alpha[j] * weight
|
|
|
|
|
# Un-premultiply:
|
|
|
|
|
return (result_r / result_a, result_g / result_a,
|
2013-04-17 18:57:17 +04:00
|
|
|
|
result_b / result_a, result_a) if result_a != 0 else (0, 0, 0, 0)
|
2013-04-08 19:28:46 +04:00
|
|
|
|
|
|
|
|
|
|
2020-01-02 14:06:58 +03:00
|
|
|
|
class Gradient:
|
2013-04-11 12:39:23 +04:00
|
|
|
|
def __init__(self, color_stops, repeating):
|
2013-04-12 17:29:21 +04:00
|
|
|
|
assert color_stops
|
2013-04-11 12:39:23 +04:00
|
|
|
|
#: List of (r, g, b, a), list of Dimension
|
2020-10-24 18:42:13 +03:00
|
|
|
|
self.colors = tuple(color for color, position in color_stops)
|
|
|
|
|
self.stop_positions = tuple(position for _, position in color_stops)
|
2013-04-11 12:39:23 +04:00
|
|
|
|
#: bool
|
|
|
|
|
self.repeating = repeating
|
|
|
|
|
|
2016-02-26 15:58:47 +03:00
|
|
|
|
def get_intrinsic_size(self, _image_resolution, _font_size):
|
|
|
|
|
# Gradients are not affected by image resolution, parent or font size.
|
2013-07-26 19:26:30 +04:00
|
|
|
|
return None, None
|
|
|
|
|
|
|
|
|
|
intrinsic_ratio = None
|
|
|
|
|
|
2013-04-08 19:28:46 +04:00
|
|
|
|
def draw(self, context, concrete_width, concrete_height, _image_rendering):
|
2020-11-30 21:12:41 +03:00
|
|
|
|
# TODO: handle color spaces
|
2020-10-24 18:42:13 +03:00
|
|
|
|
scale_y, type_, points, positions, colors = self.layout(
|
|
|
|
|
concrete_width, concrete_height)
|
2020-06-07 01:32:47 +03:00
|
|
|
|
|
2020-06-08 00:40:01 +03:00
|
|
|
|
if type_ == 'solid':
|
|
|
|
|
context.rectangle(0, 0, concrete_width, concrete_height)
|
2020-11-30 21:12:41 +03:00
|
|
|
|
red, green, blue, alpha = colors[0]
|
|
|
|
|
context.set_color_rgb(red, green, blue)
|
|
|
|
|
if alpha != 1:
|
|
|
|
|
context.set_alpha(alpha, stroke=None)
|
2020-06-08 00:40:01 +03:00
|
|
|
|
context.fill()
|
|
|
|
|
return
|
|
|
|
|
|
2020-06-07 01:32:47 +03:00
|
|
|
|
shading = context.add_shading()
|
|
|
|
|
shading['ShadingType'] = 2 if type_ == 'linear' else 3
|
|
|
|
|
shading['ColorSpace'] = '/DeviceRGB'
|
2020-10-25 15:41:23 +03:00
|
|
|
|
shading['Domain'] = pydyf.Array([positions[0], positions[-1]])
|
2020-10-24 18:42:13 +03:00
|
|
|
|
shading['Coords'] = pydyf.Array(points)
|
|
|
|
|
shading['Function'] = pydyf.Dictionary({
|
|
|
|
|
'FunctionType': 3,
|
2020-10-25 15:41:23 +03:00
|
|
|
|
'Domain': pydyf.Array([positions[0], positions[-1]]),
|
2020-10-24 18:42:13 +03:00
|
|
|
|
'Encode': pydyf.Array((len(colors) - 1) * [0, 1]),
|
|
|
|
|
'Bounds': pydyf.Array(positions[1:-1]),
|
|
|
|
|
'Functions': pydyf.Array([
|
|
|
|
|
pydyf.Dictionary({
|
|
|
|
|
'FunctionType': 2,
|
|
|
|
|
'Domain': pydyf.Array([0, 1]),
|
|
|
|
|
'C0': pydyf.Array(colors[i][:3]),
|
|
|
|
|
'C1': pydyf.Array(colors[i + 1][:3]),
|
|
|
|
|
'N': 1,
|
|
|
|
|
}) for i in range(len(colors) - 1)
|
|
|
|
|
]),
|
|
|
|
|
})
|
2020-10-25 15:41:23 +03:00
|
|
|
|
if not self.repeating:
|
|
|
|
|
shading['Extend'] = pydyf.Array([b'true', b'true'])
|
2020-10-24 21:46:38 +03:00
|
|
|
|
context.transform(1, 0, 0, scale_y, 0, 0)
|
2020-11-30 21:12:41 +03:00
|
|
|
|
|
|
|
|
|
alphas = [color[3] for color in colors]
|
|
|
|
|
if any(alpha != 1 for alpha in alphas):
|
|
|
|
|
alpha_stream = context.add_transparency_group(
|
|
|
|
|
[0, 0, concrete_width, concrete_height])
|
|
|
|
|
alpha_state = pydyf.Dictionary({
|
|
|
|
|
'Type': '/ExtGState',
|
|
|
|
|
'SMask': pydyf.Dictionary({
|
|
|
|
|
'Type': '/Mask',
|
|
|
|
|
'S': '/Luminosity',
|
|
|
|
|
'G': alpha_stream,
|
|
|
|
|
}),
|
|
|
|
|
'ca': 1,
|
|
|
|
|
'AIS': 'false',
|
|
|
|
|
})
|
|
|
|
|
alpha_state_id = f'as{len(context._alpha_states)}'
|
|
|
|
|
context._alpha_states[alpha_state_id] = alpha_state
|
|
|
|
|
context.set_state(alpha_state_id)
|
|
|
|
|
|
|
|
|
|
alpha_shading = alpha_stream.add_shading()
|
|
|
|
|
alpha_shading['ShadingType'] = 2 if type_ == 'linear' else 3
|
|
|
|
|
alpha_shading['ColorSpace'] = '/DeviceGray'
|
|
|
|
|
alpha_shading['Domain'] = pydyf.Array(
|
|
|
|
|
[positions[0], positions[-1]])
|
|
|
|
|
alpha_shading['Coords'] = pydyf.Array(points)
|
|
|
|
|
alpha_shading['Function'] = pydyf.Dictionary({
|
|
|
|
|
'FunctionType': 3,
|
|
|
|
|
'Domain': pydyf.Array([positions[0], positions[-1]]),
|
|
|
|
|
'Encode': pydyf.Array((len(colors) - 1) * [0, 1]),
|
|
|
|
|
'Bounds': pydyf.Array(positions[1:-1]),
|
|
|
|
|
'Functions': pydyf.Array([
|
|
|
|
|
pydyf.Dictionary({
|
|
|
|
|
'FunctionType': 2,
|
|
|
|
|
'Domain': pydyf.Array([0, 1]),
|
|
|
|
|
'C0': pydyf.Array([alphas[i]]),
|
|
|
|
|
'C1': pydyf.Array([alphas[i + 1]]),
|
|
|
|
|
'N': 1,
|
|
|
|
|
}) for i in range(len(alphas) - 1)
|
|
|
|
|
]),
|
|
|
|
|
})
|
|
|
|
|
if not self.repeating:
|
|
|
|
|
alpha_shading['Extend'] = pydyf.Array([b'true', b'true'])
|
|
|
|
|
alpha_stream.transform(1, 0, 0, scale_y, 0, 0)
|
|
|
|
|
alpha_stream.stream = [f'/{alpha_shading.id} sh']
|
|
|
|
|
|
2020-06-07 01:32:47 +03:00
|
|
|
|
context.shading(shading.id)
|
|
|
|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
def layout(self, width, height):
|
2020-06-07 12:04:12 +03:00
|
|
|
|
"""Get layout information about the gradient.
|
|
|
|
|
|
|
|
|
|
width, height: Gradient box. Top-left is at coordinates (0, 0).
|
2020-10-24 18:42:13 +03:00
|
|
|
|
|
|
|
|
|
Returns (scale_y, type_, points, positions, colors).
|
|
|
|
|
|
|
|
|
|
scale_y: vertical scale of the gradient. float, used for ellipses
|
|
|
|
|
radial gradients. 1 otherwise.
|
|
|
|
|
type_: gradient type.
|
|
|
|
|
points: coordinates of useful points, depending on type_:
|
|
|
|
|
'solid': None.
|
|
|
|
|
'linear': (x0, y0, x1, y1)
|
2013-04-11 12:39:23 +04:00
|
|
|
|
coordinates of the starting and ending points.
|
2020-10-24 18:42:13 +03:00
|
|
|
|
'radial': (cx0, cy0, radius0, cx1, cy1, radius1)
|
2013-04-11 12:39:23 +04:00
|
|
|
|
coordinates of the starting end ending circles
|
2020-10-24 18:42:13 +03:00
|
|
|
|
positions: positions of the color stops. list of floats in between 0
|
|
|
|
|
and 1 (0 at the starting point, 1 at the ending point).
|
|
|
|
|
colors: list of (r, g, b, a).
|
2013-04-08 19:28:46 +04:00
|
|
|
|
|
|
|
|
|
"""
|
|
|
|
|
raise NotImplementedError
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
class LinearGradient(Gradient):
|
2013-04-04 21:48:23 +04:00
|
|
|
|
def __init__(self, color_stops, direction, repeating):
|
2013-04-11 18:06:28 +04:00
|
|
|
|
Gradient.__init__(self, color_stops, repeating)
|
2020-10-24 18:42:13 +03:00
|
|
|
|
# ('corner', keyword) or ('angle', radians)
|
2013-04-04 21:48:23 +04:00
|
|
|
|
self.direction_type, self.direction = direction
|
|
|
|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
def layout(self, width, height):
|
|
|
|
|
# Only one color, render the gradient as a solid color
|
2013-04-12 17:29:21 +04:00
|
|
|
|
if len(self.colors) == 1:
|
2020-06-08 00:40:01 +03:00
|
|
|
|
return 1, 'solid', None, [], [self.colors[0]]
|
2020-10-24 18:42:13 +03:00
|
|
|
|
|
|
|
|
|
# Define the (dx, dy) unit vector giving the direction of the gradient.
|
2013-04-11 12:39:23 +04:00
|
|
|
|
# Positive dx: right, positive dy: down.
|
2013-04-04 21:48:23 +04:00
|
|
|
|
if self.direction_type == 'corner':
|
2020-10-24 18:42:13 +03:00
|
|
|
|
y, x = self.direction.split('_')
|
2020-10-24 22:35:17 +03:00
|
|
|
|
factor_x = -1 if x == 'left' else 1
|
|
|
|
|
factor_y = -1 if y == 'top' else 1
|
2013-04-08 19:28:46 +04:00
|
|
|
|
diagonal = math.hypot(width, height)
|
2013-04-12 17:29:21 +04:00
|
|
|
|
# Note the direction swap: dx based on height, dy based on width
|
|
|
|
|
# The gradient line is perpendicular to a diagonal.
|
2013-04-11 12:39:23 +04:00
|
|
|
|
dx = factor_x * height / diagonal
|
|
|
|
|
dy = factor_y * width / diagonal
|
2013-04-04 21:48:23 +04:00
|
|
|
|
else:
|
2020-10-24 18:42:13 +03:00
|
|
|
|
assert self.direction_type == 'angle'
|
2013-04-08 19:28:46 +04:00
|
|
|
|
angle = self.direction # 0 upwards, then clockwise
|
2013-04-11 12:39:23 +04:00
|
|
|
|
dx = math.sin(angle)
|
|
|
|
|
dy = -math.cos(angle)
|
2020-10-24 18:42:13 +03:00
|
|
|
|
|
2020-10-25 17:52:58 +03:00
|
|
|
|
# Round dx and dy to avoid floating points errors caused by
|
|
|
|
|
# trigonometry and angle units conversions
|
|
|
|
|
dx, dy = round(dx, 9), round(dy, 9)
|
|
|
|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
# Normalize colors positions
|
|
|
|
|
colors = list(self.colors)
|
|
|
|
|
vector_length = abs(width * dx) + abs(height * dy)
|
|
|
|
|
positions = process_color_stops(vector_length, self.stop_positions)
|
|
|
|
|
if not self.repeating:
|
|
|
|
|
# Add explicit colors at boundaries if needed, because PDF doesn’t
|
|
|
|
|
# extend color stops that are not displayed
|
|
|
|
|
if positions[0] == positions[1]:
|
|
|
|
|
positions.insert(0, positions[0] - 1)
|
|
|
|
|
colors.insert(0, colors[0])
|
|
|
|
|
if positions[-2] == positions[-1]:
|
|
|
|
|
positions.append(positions[-1] + 1)
|
|
|
|
|
colors.append(colors[-1])
|
|
|
|
|
first, last, positions = normalize_stop_positions(positions)
|
|
|
|
|
|
2020-10-25 16:54:08 +03:00
|
|
|
|
if self.repeating:
|
|
|
|
|
# Render as a solid color if the first and last positions are equal
|
|
|
|
|
# See https://drafts.csswg.org/css-images-3/#repeating-gradients
|
|
|
|
|
if first == last:
|
|
|
|
|
color = gradient_average_color(colors, positions)
|
|
|
|
|
return 1, 'solid', None, [], [color]
|
|
|
|
|
|
|
|
|
|
# Define defined gradient length and steps between positions
|
|
|
|
|
stop_length = last - first
|
|
|
|
|
assert stop_length > 0
|
|
|
|
|
position_steps = [
|
|
|
|
|
positions[i + 1] - positions[i]
|
|
|
|
|
for i in range(len(positions) - 1)]
|
|
|
|
|
|
2020-10-25 22:18:13 +03:00
|
|
|
|
# Create cycles used to add colors
|
2020-10-25 17:52:58 +03:00
|
|
|
|
next_steps = cycle([0] + position_steps)
|
2020-10-25 16:54:08 +03:00
|
|
|
|
next_colors = cycle(colors)
|
2020-10-25 22:18:13 +03:00
|
|
|
|
previous_steps = cycle([0] + position_steps[::-1])
|
|
|
|
|
previous_colors = cycle(colors[::-1])
|
|
|
|
|
|
|
|
|
|
# Add colors after last step
|
2020-10-25 16:54:08 +03:00
|
|
|
|
while last < vector_length:
|
|
|
|
|
step = next(next_steps)
|
|
|
|
|
colors.append(next(next_colors))
|
|
|
|
|
positions.append(positions[-1] + step)
|
|
|
|
|
last += step * stop_length
|
|
|
|
|
|
|
|
|
|
# Add colors before last step
|
|
|
|
|
while first > 0:
|
2020-10-25 17:52:58 +03:00
|
|
|
|
step = next(previous_steps)
|
2020-10-25 16:54:08 +03:00
|
|
|
|
colors.insert(0, next(previous_colors))
|
|
|
|
|
positions.insert(0, positions[0] - step)
|
|
|
|
|
first -= step * stop_length
|
2020-10-24 18:42:13 +03:00
|
|
|
|
|
|
|
|
|
# Define the coordinates of the starting and ending points
|
|
|
|
|
start_x = (width - dx * vector_length) / 2
|
|
|
|
|
start_y = (height - dy * vector_length) / 2
|
|
|
|
|
points = (
|
|
|
|
|
start_x + dx * first, start_y + dy * first,
|
|
|
|
|
start_x + dx * last, start_y + dy * last)
|
|
|
|
|
|
|
|
|
|
return 1, 'linear', points, positions, colors
|
2013-04-08 19:28:46 +04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
class RadialGradient(Gradient):
|
2013-04-11 18:06:28 +04:00
|
|
|
|
def __init__(self, color_stops, shape, size, center, repeating):
|
|
|
|
|
Gradient.__init__(self, color_stops, repeating)
|
2013-04-11 12:39:23 +04:00
|
|
|
|
# Center of the ending shape. (origin_x, pos_x, origin_y, pos_y)
|
2013-04-11 18:06:28 +04:00
|
|
|
|
self.center = center
|
2020-10-25 09:32:41 +03:00
|
|
|
|
# Type of ending shape: 'circle' or 'ellipse'
|
2013-04-11 12:39:23 +04:00
|
|
|
|
self.shape = shape
|
|
|
|
|
# size_type: 'keyword'
|
|
|
|
|
# size: 'closest-corner', 'farthest-corner',
|
|
|
|
|
# 'closest-side', or 'farthest-side'
|
|
|
|
|
# size_type: 'explicit'
|
|
|
|
|
# size: (radius_x, radius_y)
|
|
|
|
|
self.size_type, self.size = size
|
|
|
|
|
|
2020-10-24 18:42:13 +03:00
|
|
|
|
def layout(self, width, height):
|
2020-10-24 21:46:38 +03:00
|
|
|
|
# Only one color, render the gradient as a solid color
|
2013-04-12 17:29:21 +04:00
|
|
|
|
if len(self.colors) == 1:
|
2020-06-08 00:40:01 +03:00
|
|
|
|
return 1, 'solid', None, [], [self.colors[0]]
|
2020-10-24 21:46:38 +03:00
|
|
|
|
|
|
|
|
|
# Define the center of the gradient
|
2013-04-11 18:06:28 +04:00
|
|
|
|
origin_x, center_x, origin_y, center_y = self.center
|
2019-06-02 19:06:25 +03:00
|
|
|
|
center_x = percentage(center_x, width)
|
|
|
|
|
center_y = percentage(center_y, height)
|
2013-04-11 12:39:23 +04:00
|
|
|
|
if origin_x == 'right':
|
2013-04-11 18:06:28 +04:00
|
|
|
|
center_x = width - center_x
|
2013-04-11 12:39:23 +04:00
|
|
|
|
if origin_y == 'bottom':
|
2013-04-11 18:06:28 +04:00
|
|
|
|
center_y = height - center_y
|
2013-04-11 12:39:23 +04:00
|
|
|
|
|
2020-10-24 21:46:38 +03:00
|
|
|
|
# Resolve sizes and vertical scale
|
2020-10-24 21:49:42 +03:00
|
|
|
|
size_x, size_y = self._handle_degenerate(
|
|
|
|
|
*self._resolve_size(width, height, center_x, center_y))
|
2013-04-11 12:39:23 +04:00
|
|
|
|
scale_y = size_y / size_x
|
|
|
|
|
|
2020-10-24 21:46:38 +03:00
|
|
|
|
# Normalize colors positions
|
|
|
|
|
colors = list(self.colors)
|
2013-04-12 17:29:21 +04:00
|
|
|
|
positions = process_color_stops(size_x, self.stop_positions)
|
2020-10-24 21:46:38 +03:00
|
|
|
|
if not self.repeating:
|
|
|
|
|
# Add explicit colors at boundaries if needed, because PDF doesn’t
|
|
|
|
|
# extend color stops that are not displayed
|
|
|
|
|
if positions[0] > 0 and positions[0] == positions[1]:
|
|
|
|
|
positions.insert(0, 0)
|
|
|
|
|
colors.insert(0, colors[0])
|
|
|
|
|
if positions[-2] == positions[-1]:
|
|
|
|
|
positions.append(positions[-1] + 1)
|
|
|
|
|
colors.append(colors[-1])
|
2020-10-24 22:35:17 +03:00
|
|
|
|
if positions[0] < 0:
|
|
|
|
|
# PDF doesn’t like negative radiuses, shift into the positive realm
|
|
|
|
|
if self.repeating:
|
|
|
|
|
# Add vector lengths to first position until positive
|
|
|
|
|
vector_length = positions[-1] - positions[0]
|
|
|
|
|
offset = vector_length * (1 + (-positions[0] // vector_length))
|
|
|
|
|
positions = [position + offset for position in positions]
|
|
|
|
|
else:
|
|
|
|
|
# Only keep colors with position >= 0, interpolate if needed
|
|
|
|
|
if positions[-1] <= 0:
|
|
|
|
|
# All stops are negative, fill with the last color
|
|
|
|
|
return 1, 'solid', None, [], [self.colors[-1]]
|
|
|
|
|
for i, position in enumerate(positions):
|
|
|
|
|
if position == 0:
|
|
|
|
|
# Keep colors and positions from this rank
|
|
|
|
|
colors, positions = colors[i:], positions[i:]
|
|
|
|
|
break
|
|
|
|
|
if position > 0:
|
|
|
|
|
# Interpolate with previous rank to get color at 0
|
|
|
|
|
color = colors[i]
|
|
|
|
|
previous_color = colors[i - 1]
|
|
|
|
|
previous_position = positions[i - 1]
|
2020-10-25 15:41:23 +03:00
|
|
|
|
assert previous_position < 0
|
2020-10-24 22:35:17 +03:00
|
|
|
|
intermediate_color = gradient_average_color(
|
|
|
|
|
[previous_color, previous_color, color, color],
|
|
|
|
|
[previous_position, 0, 0, position])
|
|
|
|
|
colors = [intermediate_color] + colors[i:]
|
|
|
|
|
positions = [0] + positions[i:]
|
|
|
|
|
break
|
2020-10-24 21:46:38 +03:00
|
|
|
|
first, last, positions = normalize_stop_positions(positions)
|
|
|
|
|
|
|
|
|
|
# Render as a solid color if the first and last positions are the same
|
|
|
|
|
# See https://drafts.csswg.org/css-images-3/#repeating-gradients
|
|
|
|
|
if first == last and self.repeating:
|
2013-04-11 12:39:23 +04:00
|
|
|
|
color = gradient_average_color(colors, positions)
|
2020-06-08 00:40:01 +03:00
|
|
|
|
return 1, 'solid', None, [], [color]
|
2013-04-11 12:39:23 +04:00
|
|
|
|
|
2020-10-24 21:46:38 +03:00
|
|
|
|
# Define the coordinates of the gradient circles
|
|
|
|
|
points = (
|
|
|
|
|
center_x, center_y / scale_y, first,
|
|
|
|
|
center_x, center_y / scale_y, last)
|
2013-04-17 18:57:17 +04:00
|
|
|
|
|
2020-10-25 15:41:23 +03:00
|
|
|
|
if self.repeating:
|
|
|
|
|
points, positions, colors = self._repeat(
|
|
|
|
|
width, height, scale_y, points, positions, colors)
|
|
|
|
|
|
2020-10-24 21:46:38 +03:00
|
|
|
|
return scale_y, 'radial', points, positions, colors
|
2013-04-11 12:39:23 +04:00
|
|
|
|
|
2020-10-25 15:41:23 +03:00
|
|
|
|
def _repeat(self, width, height, scale_y, points, positions, colors):
|
|
|
|
|
# Keep original lists and values, they’re useful
|
|
|
|
|
original_colors = colors.copy()
|
|
|
|
|
original_positions = positions.copy()
|
|
|
|
|
gradient_length = points[5] - points[2]
|
|
|
|
|
|
|
|
|
|
# Get the maximum distance between the center and the corners, to find
|
|
|
|
|
# how many times we have to repeat the colors outside
|
|
|
|
|
max_distance = max(
|
|
|
|
|
math.hypot(width - points[0], height / scale_y - points[1]),
|
|
|
|
|
math.hypot(width - points[0], -points[1] * scale_y),
|
|
|
|
|
math.hypot(-points[0], height / scale_y - points[1]),
|
|
|
|
|
math.hypot(-points[0], -points[1] * scale_y))
|
|
|
|
|
repeat_after = math.ceil((max_distance - points[5]) / gradient_length)
|
|
|
|
|
if repeat_after > 0:
|
|
|
|
|
# Repeat colors and extrapolate positions
|
|
|
|
|
repeat = 1 + repeat_after
|
|
|
|
|
colors *= repeat
|
|
|
|
|
positions = [
|
|
|
|
|
i + position for i in range(repeat) for position in positions]
|
|
|
|
|
points = points[:5] + (points[5] + gradient_length * repeat_after,)
|
|
|
|
|
|
|
|
|
|
if points[2] == 0:
|
|
|
|
|
# Inner circle has 0 radius, no need to repeat inside, return
|
|
|
|
|
return points, positions, colors
|
|
|
|
|
|
|
|
|
|
# Find how many times we have to repeat the colors inside
|
|
|
|
|
repeat_before = points[2] / gradient_length
|
|
|
|
|
|
|
|
|
|
# Set the inner circle size to 0
|
|
|
|
|
points = points[:2] + (0,) + points[3:]
|
|
|
|
|
|
|
|
|
|
# Find how many times the whole gradient can be repeated
|
|
|
|
|
full_repeat = int(repeat_before)
|
|
|
|
|
if full_repeat:
|
|
|
|
|
# Repeat colors and extrapolate positions
|
|
|
|
|
colors += original_colors * full_repeat
|
|
|
|
|
positions = [
|
|
|
|
|
i - full_repeat + position for i in range(full_repeat)
|
|
|
|
|
for position in original_positions] + positions
|
|
|
|
|
|
|
|
|
|
# Find the ratio of gradient that must be added to reach the center
|
|
|
|
|
partial_repeat = repeat_before - full_repeat
|
|
|
|
|
if partial_repeat == 0:
|
|
|
|
|
# No partial repeat, return
|
|
|
|
|
return points, positions, colors
|
|
|
|
|
|
|
|
|
|
# Iterate through positions in reverse order, from the outer
|
|
|
|
|
# circle to the original inner circle, to find positions from
|
|
|
|
|
# the inner circle (including full repeats) to the center
|
|
|
|
|
assert (original_positions[0], original_positions[-1]) == (0, 1)
|
|
|
|
|
assert 0 < partial_repeat < 1
|
|
|
|
|
reverse = original_positions[::-1]
|
|
|
|
|
ratio = 1 - partial_repeat
|
|
|
|
|
for i, position in enumerate(reverse, start=1):
|
|
|
|
|
if position == ratio:
|
|
|
|
|
# The center is a color of the gradient, truncate original
|
|
|
|
|
# colors and positions and prepend them
|
|
|
|
|
colors = original_colors[-i:] + colors
|
|
|
|
|
new_positions = [
|
|
|
|
|
position - full_repeat - 1
|
|
|
|
|
for position in original_positions[-i:]]
|
|
|
|
|
positions = new_positions + positions
|
|
|
|
|
return points, positions, colors
|
|
|
|
|
if position < ratio:
|
|
|
|
|
# The center is between two colors of the gradient,
|
|
|
|
|
# define the center color as the average of these two
|
|
|
|
|
# gradient colors
|
|
|
|
|
color = original_colors[-i]
|
|
|
|
|
next_color = original_colors[-(i - 1)]
|
|
|
|
|
next_position = original_positions[-(i - 1)]
|
|
|
|
|
average_colors = [color, color, next_color, next_color]
|
|
|
|
|
average_positions = [position, ratio, ratio, next_position]
|
|
|
|
|
zero_color = gradient_average_color(
|
|
|
|
|
average_colors, average_positions)
|
|
|
|
|
colors = [zero_color] + original_colors[-(i - 1):] + colors
|
|
|
|
|
new_positions = [
|
|
|
|
|
position - 1 - full_repeat for position
|
|
|
|
|
in original_positions[-(i - 1):]]
|
|
|
|
|
positions = (
|
|
|
|
|
[ratio - 1 - full_repeat] + new_positions + positions)
|
|
|
|
|
return points, positions, colors
|
|
|
|
|
|
2013-04-11 18:06:28 +04:00
|
|
|
|
def _resolve_size(self, width, height, center_x, center_y):
|
2020-10-25 09:32:41 +03:00
|
|
|
|
"""Resolve circle size of the radial gradient."""
|
2013-04-11 12:39:23 +04:00
|
|
|
|
if self.size_type == 'explicit':
|
2013-04-16 18:18:47 +04:00
|
|
|
|
size_x, size_y = self.size
|
2019-06-02 19:06:25 +03:00
|
|
|
|
size_x = percentage(size_x, width)
|
|
|
|
|
size_y = percentage(size_y, height)
|
2019-06-01 02:32:13 +03:00
|
|
|
|
return size_x, size_y
|
2013-04-11 18:06:28 +04:00
|
|
|
|
left = abs(center_x)
|
|
|
|
|
right = abs(width - center_x)
|
|
|
|
|
top = abs(center_y)
|
|
|
|
|
bottom = abs(height - center_y)
|
2013-04-16 18:18:47 +04:00
|
|
|
|
pick = min if self.size.startswith('closest') else max
|
|
|
|
|
if self.size.endswith('side'):
|
2013-04-11 12:39:23 +04:00
|
|
|
|
if self.shape == 'circle':
|
2013-04-16 18:18:47 +04:00
|
|
|
|
size_xy = pick(left, right, top, bottom)
|
2013-04-11 12:39:23 +04:00
|
|
|
|
return size_xy, size_xy
|
|
|
|
|
# else: ellipse
|
2013-04-16 18:18:47 +04:00
|
|
|
|
return pick(left, right), pick(top, bottom)
|
|
|
|
|
# else: corner
|
|
|
|
|
if self.shape == 'circle':
|
|
|
|
|
size_xy = pick(math.hypot(left, top), math.hypot(left, bottom),
|
|
|
|
|
math.hypot(right, top), math.hypot(right, bottom))
|
|
|
|
|
return size_xy, size_xy
|
|
|
|
|
# else: ellipse
|
|
|
|
|
corner_x, corner_y = pick(
|
|
|
|
|
(left, top), (left, bottom), (right, top), (right, bottom),
|
|
|
|
|
key=lambda a: math.hypot(*a))
|
|
|
|
|
return corner_x * math.sqrt(2), corner_y * math.sqrt(2)
|
2020-10-24 21:46:38 +03:00
|
|
|
|
|
|
|
|
|
def _handle_degenerate(self, size_x, size_y):
|
2020-10-25 09:32:41 +03:00
|
|
|
|
"""Handle degenerate radial gradients.
|
|
|
|
|
|
|
|
|
|
See https://drafts.csswg.org/css-images-3/#degenerate-radials
|
|
|
|
|
|
|
|
|
|
"""
|
2020-10-24 21:46:38 +03:00
|
|
|
|
if size_x == size_y == 0:
|
|
|
|
|
size_x = size_y = 1e-7
|
|
|
|
|
elif size_x == 0:
|
|
|
|
|
size_x = 1e-7
|
|
|
|
|
size_y = 1e7
|
|
|
|
|
elif size_y == 0:
|
|
|
|
|
size_x = 1e7
|
|
|
|
|
size_y = 1e-7
|
|
|
|
|
return size_x, size_y
|