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526 lines
20 KiB
Python
526 lines
20 KiB
Python
"""Parse and draw definitions: gradients, patterns, masks, uses…"""
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from itertools import cycle
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from math import ceil, hypot
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from ..matrix import Matrix
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from .bounding_box import is_valid_bounding_box
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from .utils import alpha_value, color, parse_url, size, transform
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def use(svg, node, font_size):
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"""Draw use tags."""
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from . import NOT_INHERITED_ATTRIBUTES, SVG
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x, y = svg.point(node.get('x'), node.get('y'), font_size)
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for attribute in ('x', 'y', 'viewBox', 'mask'):
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if attribute in node.attrib:
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del node.attrib[attribute]
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parsed_url = parse_url(node.get_href(svg.url))
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svg_url = parse_url(svg.url)
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if svg_url.scheme == 'data':
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svg_url = parse_url('')
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same_origin = (
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parsed_url[:3] == ('', '', '') or
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parsed_url[:3] == svg_url[:3])
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if parsed_url.fragment and same_origin:
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if parsed_url.fragment in svg.use_cache:
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tree = svg.use_cache[parsed_url.fragment].copy()
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else:
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try:
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tree = svg.tree.get_child(parsed_url.fragment).copy()
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except Exception:
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return
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else:
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svg.use_cache[parsed_url.fragment] = tree
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else:
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url = parsed_url.geturl()
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try:
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bytestring_svg = svg.url_fetcher(url)
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use_svg = SVG(bytestring_svg, url)
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except Exception:
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return
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else:
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use_svg.get_intrinsic_size(font_size)
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tree = use_svg.tree
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if tree.tag in ('svg', 'symbol'):
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# Explicitely specified
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# https://www.w3.org/TR/SVG11/struct.html#UseElement
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tree._etree_node.tag = 'svg'
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if 'width' in node.attrib and 'height' in node.attrib:
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tree.attrib['width'] = node.attrib['width']
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tree.attrib['height'] = node.attrib['height']
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# Cascade
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for key, value in node.attrib.items():
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if key not in NOT_INHERITED_ATTRIBUTES:
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if key not in tree.attrib:
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tree.attrib[key] = value
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node.override_iter(iter((tree,)))
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svg.stream.transform(e=x, f=y)
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def draw_gradient_or_pattern(svg, node, name, font_size, opacity, stroke):
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"""Draw given gradient or pattern."""
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if name in svg.gradients:
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return draw_gradient(
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svg, node, svg.gradients[name], font_size, opacity, stroke)
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elif name in svg.patterns:
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return draw_pattern(
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svg, node, svg.patterns[name], font_size, opacity, stroke)
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def draw_gradient(svg, node, gradient, font_size, opacity, stroke):
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"""Draw given gradient node."""
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# TODO: merge with Gradient.draw
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positions = []
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colors = []
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for child in gradient:
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positions.append(max(
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positions[-1] if positions else 0,
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size(child.get('offset'), font_size, 1)))
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stop_opacity = alpha_value(child.get('stop-opacity', 1)) * opacity
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stop_color = color(child.get('stop-color', 'black'))
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if stop_opacity < 1:
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stop_color = tuple(
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stop_color[:3] + (stop_color[3] * stop_opacity,))
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colors.append(stop_color)
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if not colors:
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return False
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elif len(colors) == 1:
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red, green, blue, alpha = colors[0]
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svg.stream.set_color_rgb(red, green, blue)
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if alpha != 1:
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svg.stream.set_alpha(alpha, stroke=stroke)
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return True
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bounding_box = svg.calculate_bounding_box(node, font_size, stroke)
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if not is_valid_bounding_box(bounding_box):
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return False
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if gradient.get('gradientUnits') == 'userSpaceOnUse':
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width, height = svg.inner_width, svg.inner_height
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matrix = Matrix()
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else:
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width, height = 1, 1
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e, f, a, d = bounding_box
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matrix = Matrix(a=a, d=d, e=e, f=f)
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spread = gradient.get('spreadMethod', 'pad')
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if spread in ('repeat', 'reflect'):
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if positions[0] > 0:
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positions.insert(0, 0)
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colors.insert(0, colors[0])
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if positions[-1] < 1:
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positions.append(1)
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colors.append(colors[-1])
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else:
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# Add explicit colors at boundaries if needed, because PDF doesn’t
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# extend color stops that are not displayed
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if positions[0] == positions[1]:
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if gradient.tag == 'radialGradient':
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# Avoid negative radius for radial gradients
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positions.insert(0, 0)
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else:
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positions.insert(0, positions[0] - 1)
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colors.insert(0, colors[0])
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if positions[-2] == positions[-1]:
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positions.append(positions[-1] + 1)
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colors.append(colors[-1])
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if 'gradientTransform' in gradient.attrib:
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transform_matrix = transform(
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gradient.get('gradientTransform'), font_size,
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svg.normalized_diagonal)
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matrix = transform_matrix @ matrix
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if gradient.tag == 'linearGradient':
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shading_type = 2
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x1, y1 = (
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size(gradient.get('x1', 0), font_size, width),
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size(gradient.get('y1', 0), font_size, height))
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x2, y2 = (
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size(gradient.get('x2', '100%'), font_size, width),
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size(gradient.get('y2', 0), font_size, height))
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positions, colors, coords = spread_linear_gradient(
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spread, positions, colors, x1, y1, x2, y2, bounding_box, matrix)
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else:
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assert gradient.tag == 'radialGradient'
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shading_type = 3
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cx, cy = (
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size(gradient.get('cx', '50%'), font_size, width),
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size(gradient.get('cy', '50%'), font_size, height))
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r = size(gradient.get('r', '50%'), font_size, hypot(width, height))
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fx, fy = (
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size(gradient.get('fx', cx), font_size, width),
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size(gradient.get('fy', cy), font_size, height))
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fr = size(gradient.get('fr', 0), font_size, hypot(width, height))
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positions, colors, coords = spread_radial_gradient(
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spread, positions, colors, fx, fy, fr, cx, cy, r, width, height,
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matrix)
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alphas = [color[3] for color in colors]
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alpha_couples = [
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(alphas[i], alphas[i + 1])
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for i in range(len(alphas) - 1)]
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color_couples = [
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[colors[i][:3], colors[i + 1][:3], 1]
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for i in range(len(colors) - 1)]
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# Premultiply colors
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for i, alpha in enumerate(alphas):
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if alpha == 0:
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if i > 0:
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color_couples[i - 1][1] = color_couples[i - 1][0]
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if i < len(colors) - 1:
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color_couples[i][0] = color_couples[i][1]
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for i, (a0, a1) in enumerate(alpha_couples):
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if 0 not in (a0, a1) and (a0, a1) != (1, 1):
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color_couples[i][2] = a0 / a1
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bx1, by1 = 0, 0
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if 'gradientTransform' in gradient.attrib:
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bx1, by1 = transform_matrix.invert.transform_point(bx1, by1)
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bx2, by2 = transform_matrix.invert.transform_point(width, height)
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width, height = bx2 - bx1, by2 - by1
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# Ensure that width and height are positive to please some PDF readers
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if bx1 > bx2:
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width = -width
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bx1, bx2 = bx2, bx1
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if by1 > by2:
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height = -height
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by1, by2 = by2, by1
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pattern = svg.stream.add_pattern(
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bx1, by1, width, height, width, height, matrix @ svg.stream.ctm)
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group = pattern.add_group(bx1, by1, width, height)
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domain = (positions[0], positions[-1])
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extend = spread not in ('repeat', 'reflect')
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encode = (len(colors) - 1) * (0, 1)
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bounds = positions[1:-1]
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sub_functions = (
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group.create_interpolation_function(domain, c0, c1, n)
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for c0, c1, n in color_couples)
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function = group.create_stitching_function(
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domain, encode, bounds, sub_functions)
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shading = group.add_shading(
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shading_type, 'RGB', domain, coords, extend, function)
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if any(alpha != 1 for alpha in alphas):
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alpha_stream = group.set_alpha_state(bx1, by1, width, height)
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domain = (positions[0], positions[-1])
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extend = spread not in ('repeat', 'reflect')
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encode = (len(colors) - 1) * (0, 1)
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bounds = positions[1:-1]
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sub_functions = (
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group.create_interpolation_function((0, 1), [c0], [c1], 1)
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for c0, c1 in alpha_couples)
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function = group.create_stitching_function(
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domain, encode, bounds, sub_functions)
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alpha_shading = alpha_stream.add_shading(
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shading_type, 'Gray', domain, coords, extend, function)
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alpha_stream.stream = [f'/{alpha_shading.id} sh']
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group.paint_shading(shading.id)
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pattern.set_alpha(1)
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pattern.draw_x_object(group.id)
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svg.stream.set_color_space('Pattern', stroke=stroke)
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svg.stream.set_color_special(pattern.id, stroke=stroke)
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return True
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def spread_linear_gradient(spread, positions, colors, x1, y1, x2, y2,
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bounding_box, matrix):
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"""Repeat linear gradient."""
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# TODO: merge with LinearGradient.layout
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from ..images import gradient_average_color, normalize_stop_positions
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first, last, positions = normalize_stop_positions(positions)
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if spread in ('repeat', 'reflect'):
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# Render as a solid color if the first and last positions are equal
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# See https://drafts.csswg.org/css-images-3/#repeating-gradients
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if first == last:
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average_color = gradient_average_color(colors, positions)
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return 1, 'solid', None, [], [average_color]
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# Define defined gradient length and steps between positions
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stop_length = last - first
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position_steps = [
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positions[i + 1] - positions[i]
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for i in range(len(positions) - 1)]
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# Create cycles used to add colors
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if spread == 'repeat':
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next_steps = cycle((0, *position_steps))
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next_colors = cycle(colors)
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previous_steps = cycle((0, *position_steps[::-1]))
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previous_colors = cycle(colors[::-1])
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else:
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assert spread == 'reflect'
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next_steps = cycle((0, *position_steps[::-1], 0, *position_steps))
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next_colors = cycle(colors[::-1] + colors)
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previous_steps = cycle((0, *position_steps, 0, *position_steps[::-1]))
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previous_colors = cycle(colors + colors[::-1])
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# Normalize bounding box
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bx1, by1, bw, bh = bounding_box
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bx1, bx2 = (bx1, bx1 + bw) if bw > 0 else (bx1 + bw, bx1)
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by1, by2 = (by1, by1 + bh) if bh > 0 else (by1 + bh, by1)
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# Transform gradient vector coordinates
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tx1, ty1 = matrix.transform_point(x1, y1)
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tx2, ty2 = matrix.transform_point(x2, y2)
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# Find the extremities of the repeating vector, by projecting the
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# bounding box corners on the gradient vector
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xb, yb = tx1, ty1
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xv, yv = tx2 - tx1, ty2 - ty1
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xa1, xa2 = (bx1, bx2) if tx1 < tx2 else (bx2, bx1)
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ya1, ya2 = (by1, by2) if ty1 < ty2 else (by2, by1)
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min_vector = ((xa1 - xb) * xv + (ya1 - yb) * yv) / hypot(xv, yv) ** 2
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max_vector = ((xa2 - xb) * xv + (ya2 - yb) * yv) / hypot(xv, yv) ** 2
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# Add colors after last step
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while last < max_vector:
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step = next(next_steps)
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colors.append(next(next_colors))
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positions.append(positions[-1] + step)
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last += step * stop_length
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# Add colors before first step
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while first > min_vector:
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step = next(previous_steps)
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colors.insert(0, next(previous_colors))
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positions.insert(0, positions[0] - step)
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first -= step * stop_length
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x1, x2 = x1 + (x2 - x1) * first, x1 + (x2 - x1) * last
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y1, y2 = y1 + (y2 - y1) * first, y1 + (y2 - y1) * last
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coords = (x1, y1, x2, y2)
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return positions, colors, coords
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def spread_radial_gradient(spread, positions, colors, fx, fy, fr, cx, cy, r,
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width, height, matrix):
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"""Repeat radial gradient."""
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# TODO: merge with RadialGradient._repeat
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from ..images import gradient_average_color, normalize_stop_positions
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first, last, positions = normalize_stop_positions(positions)
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fr, r = fr + (r - fr) * first, fr + (r - fr) * last
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if spread in ('repeat', 'reflect'):
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# Keep original lists and values, they’re useful
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original_colors = colors.copy()
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original_positions = positions.copy()
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# Get the maximum distance between the center and the corners, to find
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# how many times we have to repeat the colors outside
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tw, th = matrix.invert.transform_point(width, height)
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max_distance = hypot(
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max(abs(fx), abs(tw - fx)), max(abs(fy), abs(th - fy)))
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gradient_length = r - fr
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repeat_after = ceil((max_distance - r) / gradient_length)
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if repeat_after > 0:
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# Repeat colors and extrapolate positions
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repeat = 1 + repeat_after
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if spread == 'repeat':
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colors *= repeat
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else:
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assert spread == 'reflect'
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colors = []
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for i in range(repeat):
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colors += original_colors[::-1 if i % 2 else 1]
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positions = [
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i + position for i in range(repeat) for position in positions]
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r += gradient_length * repeat_after
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if fr == 0:
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# Inner circle has 0 radius, no need to repeat inside, return
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coords = (fx, fy, fr, cx, cy, r)
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return positions, colors, coords
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# Find how many times we have to repeat the colors inside
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repeat_before = fr / gradient_length
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# Set the inner circle size to 0
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fr = 0
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# Find how many times the whole gradient can be repeated
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full_repeat = int(repeat_before)
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if full_repeat:
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# Repeat colors and extrapolate positions
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if spread == 'repeat':
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colors += original_colors * full_repeat
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else:
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assert spread == 'reflect'
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for i in range(full_repeat):
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colors += original_colors[
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::-1 if (i + repeat_after) % 2 else 1]
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positions = [
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i - full_repeat + position for i in range(full_repeat)
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for position in original_positions] + positions
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# Find the ratio of gradient that must be added to reach the center
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partial_repeat = repeat_before - full_repeat
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if partial_repeat == 0:
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# No partial repeat, return
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coords = (fx, fy, fr, cx, cy, r)
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return positions, colors, coords
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# Iterate through positions in reverse order, from the outer
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# circle to the original inner circle, to find positions from
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# the inner circle (including full repeats) to the center
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assert (original_positions[0], original_positions[-1]) == (0, 1)
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assert 0 < partial_repeat < 1
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reverse = original_positions[::-1]
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ratio = 1 - partial_repeat
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if spread == 'reflect':
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original_colors = original_colors[::-1]
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for i, position in enumerate(reverse, start=1):
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if position == ratio:
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# The center is a color of the gradient, truncate original
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# colors and positions and prepend them
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colors = original_colors[-i:] + colors
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new_positions = [
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position - full_repeat - 1
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for position in original_positions[-i:]]
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positions = new_positions + positions
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break
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if position < ratio:
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# The center is between two colors of the gradient,
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# define the center color as the average of these two
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# gradient colors
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color = original_colors[-i]
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next_color = original_colors[-(i - 1)]
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next_position = original_positions[-(i - 1)]
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average_colors = [color, color, next_color, next_color]
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average_positions = [position, ratio, ratio, next_position]
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zero_color = gradient_average_color(
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average_colors, average_positions)
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colors = [zero_color] + original_colors[-(i - 1):] + colors
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new_positions = [
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position - 1 - full_repeat for position
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in original_positions[-(i - 1):]]
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positions = [ratio - 1 - full_repeat, *new_positions, *positions]
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break
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coords = (fx, fy, fr, cx, cy, r)
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return positions, colors, coords
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def draw_pattern(svg, node, pattern, font_size, opacity, stroke):
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"""Draw given gradient node."""
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from . import Pattern
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pattern._etree_node.tag = 'svg'
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bounding_box = svg.calculate_bounding_box(node, font_size, stroke)
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if not is_valid_bounding_box(bounding_box):
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return False
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x, y = bounding_box[0], bounding_box[1]
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matrix = Matrix(e=x, f=y)
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if pattern.get('patternUnits') == 'userSpaceOnUse':
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pattern_width = size(pattern.get('width', 0), font_size, 1)
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pattern_height = size(pattern.get('height', 0), font_size, 1)
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else:
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width, height = bounding_box[2], bounding_box[3]
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pattern_width = (
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size(pattern.attrib.pop('width', '1'), font_size, 1) * width)
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pattern_height = (
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size(pattern.attrib.pop('height', '1'), font_size, 1) * height)
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if 'viewBox' not in pattern:
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pattern.attrib['width'] = pattern_width
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pattern.attrib['height'] = pattern_height
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if pattern.get('patternContentUnits') == 'objectBoundingBox':
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pattern.attrib['transform'] = f'scale({width}, {height})'
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# Fail if pattern has an invalid size
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if pattern_width == 0 or pattern_height == 0:
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return False
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if 'patternTransform' in pattern.attrib:
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transform_matrix = transform(
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pattern.get('patternTransform'), font_size, svg.inner_diagonal)
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matrix = transform_matrix @ matrix
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matrix = matrix @ svg.stream.ctm
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stream_pattern = svg.stream.add_pattern(
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0, 0, pattern_width, pattern_height, pattern_width, pattern_height,
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matrix)
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stream_pattern.set_alpha(opacity)
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|
||
group = stream_pattern.add_group(0, 0, pattern_width, pattern_height)
|
||
Pattern(pattern, svg).draw(
|
||
group, pattern_width, pattern_height, svg.base_url,
|
||
svg.url_fetcher, svg.context)
|
||
stream_pattern.draw_x_object(group.id)
|
||
svg.stream.set_color_space('Pattern', stroke=stroke)
|
||
svg.stream.set_color_special(stream_pattern.id, stroke=stroke)
|
||
return True
|
||
|
||
|
||
def apply_filters(svg, node, filter_node, font_size):
|
||
"""Apply filters defined in given filter node."""
|
||
for child in filter_node:
|
||
if child.tag == 'feOffset':
|
||
if filter_node.get('primitiveUnits') == 'objectBoundingBox':
|
||
bounding_box = svg.calculate_bounding_box(node, font_size)
|
||
if is_valid_bounding_box(bounding_box):
|
||
_, _, width, height = bounding_box
|
||
dx = size(child.get('dx', 0), font_size, 1) * width
|
||
dy = size(child.get('dy', 0), font_size, 1) * height
|
||
else:
|
||
dx = dy = 0
|
||
else:
|
||
dx, dy = svg.point(
|
||
child.get('dx', 0), child.get('dy', 0), font_size)
|
||
svg.stream.transform(e=dx, f=dy)
|
||
elif child.tag == 'feBlend':
|
||
mode = child.get('mode', 'normal')
|
||
mode = mode.replace('-', ' ').title().replace(' ', '')
|
||
svg.stream.set_blend_mode(mode)
|
||
|
||
|
||
def paint_mask(svg, node, mask, font_size):
|
||
"""Apply given mask node."""
|
||
mask._etree_node.tag = 'g'
|
||
|
||
if mask.get('maskUnits') == 'userSpaceOnUse':
|
||
width_ref, height_ref = svg.inner_width, svg.inner_height
|
||
else:
|
||
width_ref, height_ref = svg.point(
|
||
node.get('width'), node.get('height'), font_size)
|
||
|
||
mask.attrib['x'] = size(mask.get('x', '-10%'), font_size, width_ref)
|
||
mask.attrib['y'] = size(mask.get('y', '-10%'), font_size, height_ref)
|
||
mask.attrib['height'] = size(
|
||
mask.get('height', '120%'), font_size, height_ref)
|
||
mask.attrib['width'] = size(
|
||
mask.get('width', '120%'), font_size, width_ref)
|
||
|
||
if mask.get('maskUnits') == 'userSpaceOnUse':
|
||
x, y = mask.get('x'), mask.get('y')
|
||
width, height = mask.get('width'), mask.get('height')
|
||
mask.attrib['viewBox'] = f'{x} {y} {width} {height}'
|
||
else:
|
||
x, y = 0, 0
|
||
width, height = width_ref, height_ref
|
||
|
||
svg_stream = svg.stream
|
||
svg.stream = svg.stream.set_alpha_state(x, y, width, height)
|
||
svg.draw_node(mask, font_size)
|
||
svg.stream = svg_stream
|
||
|
||
|
||
def clip_path(svg, node, font_size):
|
||
"""Store a clip path definition."""
|
||
if 'id' in node.attrib:
|
||
svg.paths[node.attrib['id']] = node
|