render_freestyle_svg.py

   1 # ##### BEGIN GPL LICENSE BLOCK #####
   2 #
   3 #  This program is free software; you can redistribute it and/or
   4 #  modify it under the terms of the GNU General Public License
   5 #  as published by the Free Software Foundation; either version 2
   6 #  of the License, or (at your option) any later version.
   7 #
   8 #  This program is distributed in the hope that it will be useful,
   9 #  but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 #  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 #  GNU General Public License for more details.
  12 #
  13 #  You should have received a copy of the GNU General Public License
  14 #  along with this program; if not, write to the Free Software Foundation,
  15 #  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16 #
  17 # ##### END GPL LICENSE BLOCK #####
  18
  19 # <pep8 compliant>
  20
  21 bl_info = {
  22     "name": "Freestyle SVG Exporter",
  23     "author": "Folkert de Vries",
  24     "version": (1, 0),
  25     "blender": (2, 80, 0),
  26     "location": "Properties > Render > Freestyle SVG Export",
  27     "description": "Exports Freestyle's stylized edges in SVG format",
  28     "warning": "",
  29     "doc_url": "{BLENDER_MANUAL_URL}/addons/render/render_freestyle_svg.html",
  30     "support": 'OFFICIAL',
  31     "category": "Render",
  32 }
  33
  34 import bpy
  35 import parameter_editor
  36 import itertools
  37 import os
  38
  39 import xml.etree.cElementTree as et
  40
  41 from bpy.app.handlers import persistent
  42 from collections import OrderedDict
  43 from functools import partial
  44 from mathutils import Vector
  45
  46 from freestyle.types import (
  47         StrokeShader,
  48         Interface0DIterator,
  49         Operators,
  50         Nature,
  51         StrokeVertex,
  52         )
  53 from freestyle.utils import (
  54     getCurrentScene,
  55     BoundingBox,
  56     is_poly_clockwise,
  57     StrokeCollector,
  58     material_from_fedge,
  59     get_object_name,
  60     )
  61 from freestyle.functions import (
  62     GetShapeF1D,
  63     CurveMaterialF0D,
  64     )
  65 from freestyle.predicates import (
  66         AndBP1D,
  67         AndUP1D,
  68         ContourUP1D,
  69         ExternalContourUP1D,
  70         MaterialBP1D,
  71         NotBP1D,
  72         NotUP1D,
  73         OrBP1D,
  74         OrUP1D,
  75         pyNatureUP1D,
  76         pyZBP1D,
  77         pyZDiscontinuityBP1D,
  78         QuantitativeInvisibilityUP1D,
  79         SameShapeIdBP1D,
  80         TrueBP1D,
  81         TrueUP1D,
  82         )
  83 from freestyle.chainingiterators import ChainPredicateIterator
  84 from parameter_editor import get_dashed_pattern
  85
  86 from bpy.props import (
  87         BoolProperty,
  88         EnumProperty,
  89         PointerProperty,
  90         )
  91
  92
  93 # use utf-8 here to keep ElementTree happy, end result is utf-16
  94 svg_primitive = """<?xml version="1.0" encoding="ascii" standalone="no"?>
  95 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  96   "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
  97 <svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="{:d}" height="{:d}">
  98 </svg>"""
  99
 100
 101 # xml namespaces
 102 namespaces = {
 103     "inkscape": "http://www.inkscape.org/namespaces/inkscape",
 104     "svg": "http://www.w3.org/2000/svg",
 105     "sodipodi": "http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd",
 106     "": "http://www.w3.org/2000/svg",
 107     }
 108
 109
 110 # wrap XMLElem.find, so the namespaces don't need to be given as an argument
 111 def find_xml_elem(obj, search, namespaces, *, all=False):
 112     if all:
 113         return obj.findall(search, namespaces=namespaces)
 114     return obj.find(search, namespaces=namespaces)
 115
 116 find_svg_elem = partial(find_xml_elem, namespaces=namespaces)
 117
 118
 119 def render_height(scene):
 120     return int(scene.render.resolution_y * scene.render.resolution_percentage / 100)
 121
 122
 123 def render_width(scene):
 124     return int(scene.render.resolution_x * scene.render.resolution_percentage / 100)
 125
 126
 127 def format_rgb(color):
 128     return 'rgb({}, {}, {})'.format(*(int(v * 255) for v in color))
 129
 130
 131 # stores the state of the render, used to differ between animation and single frame renders.
 132 class RenderState:
 133
 134     # Note that this flag is set to False only after the first frame
 135     # has been written to file.
 136     is_preview = True
 137
 138
 139 @persistent
 140 def render_init(scene):
 141     RenderState.is_preview = True
 142
 143
 144 @persistent
 145 def render_write(scene):
 146     RenderState.is_preview = False
 147
 148
 149 def is_preview_render(scene):
 150     return RenderState.is_preview or scene.svg_export.mode == 'FRAME'
 151
 152
 153 def create_path(scene):
 154     """Creates the output path for the svg file"""
 155     path = os.path.dirname(scene.render.frame_path())
 156     file_dir_path = os.path.dirname(bpy.data.filepath)
 157
 158     # try to use the given path if it is absolute
 159     if os.path.isabs(path):
 160         dirname = path
 161
 162     # otherwise, use current file's location as a start for the relative path
 163     elif bpy.data.is_saved and file_dir_path:
 164         dirname = os.path.normpath(os.path.join(file_dir_path, path))
 165
 166     # otherwise, use the folder from which blender was called as the start
 167     else:
 168         dirname = os.path.abspath(bpy.path.abspath(path))
 169
 170
 171     basename = bpy.path.basename(scene.render.filepath)
 172     if scene.svg_export.mode == 'FRAME':
 173         frame = "{:04d}".format(scene.frame_current)
 174     else:
 175         frame = "{:04d}-{:04d}".format(scene.frame_start, scene.frame_end)
 176
 177     return os.path.join(dirname, basename + frame + ".svg")
 178
 179
 180 class SVGExporterLinesetPanel(bpy.types.Panel):
 181     """Creates a Panel in the Render Layers context of the properties editor"""
 182     bl_idname = "RENDER_PT_SVGExporterLinesetPanel"
 183     bl_space_type = 'PROPERTIES'
 184     bl_label = "Freestyle Line Style SVG Export"
 185     bl_region_type = 'WINDOW'
 186     bl_context = "view_layer"
 187
 188     def draw(self, context):
 189         layout = self.layout
 190
 191         scene = context.scene
 192         svg = scene.svg_export
 193         freestyle = context.window.view_layer.freestyle_settings
 194
 195         try:
 196             linestyle = freestyle.linesets.active.linestyle
 197
 198         except AttributeError:
 199             # Linestyles can be removed, so 0 linestyles is possible.
 200             # there is nothing to draw in those cases.
 201             # see https://developer.blender.org/T49855
 202             return
 203
 204         else:
 205             layout.active = (svg.use_svg_export and freestyle.mode != 'SCRIPT')
 206             row = layout.row()
 207             column = row.column()
 208             column.prop(linestyle, 'use_export_strokes')
 209
 210             column = row.column()
 211             column.active = svg.object_fill
 212             column.prop(linestyle, 'use_export_fills')
 213
 214             row = layout.row()
 215             row.prop(linestyle, "stroke_color_mode", expand=True)
 216
 217
 218 class SVGExport(bpy.types.PropertyGroup):
 219     """Implements the properties for the SVG exporter"""
 220     bl_idname = "RENDER_PT_svg_export"
 221
 222     use_svg_export: BoolProperty(
 223             name="SVG Export",
 224             description="Export Freestyle edges to an .svg format",
 225             )
 226     split_at_invisible: BoolProperty(
 227             name="Split at Invisible",
 228             description="Split the stroke at an invisible vertex",
 229             )
 230     object_fill: BoolProperty(
 231             name="Fill Contours",
 232             description="Fill the contour with the object's material color",
 233             )
 234     mode: EnumProperty(
 235             name="Mode",
 236             items=(
 237                 ('FRAME', "Frame", "Export a single frame", 0),
 238                 ('ANIMATION', "Animation", "Export an animation", 1),
 239                 ),
 240             default='FRAME',
 241             )
 242     line_join_type: EnumProperty(
 243             name="Line Join",
 244             items=(
 245                 ('MITER', "Miter", "Corners are sharp", 0),
 246                 ('ROUND', "Round", "Corners are smoothed", 1),
 247                 ('BEVEL', "Bevel", "Corners are beveled", 2),
 248                 ),
 249             default='ROUND',
 250             )
 251
 252
 253 class SVGExporterPanel(bpy.types.Panel):
 254     """Creates a Panel in the render context of the properties editor"""
 255     bl_idname = "RENDER_PT_SVGExporterPanel"
 256     bl_space_type = 'PROPERTIES'
 257     bl_label = "Freestyle SVG Export"
 258     bl_region_type = 'WINDOW'
 259     bl_context = "render"
 260
 261     def draw_header(self, context):
 262         self.layout.prop(context.scene.svg_export, "use_svg_export", text="")
 263
 264     def draw(self, context):
 265         layout = self.layout
 266
 267         scene = context.scene
 268         svg = scene.svg_export
 269         freestyle = context.window.view_layer.freestyle_settings
 270
 271         layout.active = (svg.use_svg_export and freestyle.mode != 'SCRIPT')
 272
 273         row = layout.row()
 274         row.prop(svg, "mode", expand=True)
 275
 276         row = layout.row()
 277         row.prop(svg, "split_at_invisible")
 278         row.prop(svg, "object_fill")
 279
 280         row = layout.row()
 281         row.prop(svg, "line_join_type", expand=True)
 282
 283
 284 @persistent
 285 def svg_export_header(scene):
 286     if not (scene.render.use_freestyle and scene.svg_export.use_svg_export):
 287         return
 288
 289     # write the header only for the first frame when animation is being rendered
 290     if not is_preview_render(scene) and scene.frame_current != scene.frame_start:
 291         return
 292
 293     # this may fail still. The error is printed to the console.
 294     with open(create_path(scene), "w") as f:
 295         f.write(svg_primitive.format(render_width(scene), render_height(scene)))
 296
 297
 298 @persistent
 299 def svg_export_animation(scene):
 300     """makes an animation of the exported SVG file """
 301     render = scene.render
 302     svg = scene.svg_export
 303
 304     if render.use_freestyle and svg.use_svg_export and not is_preview_render(scene):
 305         write_animation(create_path(scene), scene.frame_start, render.fps)
 306
 307
 308 def write_animation(filepath, frame_begin, fps):
 309     """Adds animate tags to the specified file."""
 310     tree = et.parse(filepath)
 311     root = tree.getroot()
 312
 313     linesets = find_svg_elem(tree, ".//svg:g[@inkscape:groupmode='lineset']", all=True)
 314     for i, lineset in enumerate(linesets):
 315         name = lineset.get('id')
 316         frames = find_svg_elem(lineset, ".//svg:g[@inkscape:groupmode='frame']", all=True)
 317         n_of_frames = len(frames)
 318         keyTimes = ";".join(str(round(x / n_of_frames, 3)) for x in range(n_of_frames)) + ";1"
 319
 320         style = {
 321             'attributeName': 'display',
 322             'values': "none;" * (n_of_frames - 1) + "inline;none",
 323             'repeatCount': 'indefinite',
 324             'keyTimes': keyTimes,
 325             'dur': "{:.3f}s".format(n_of_frames / fps),
 326             }
 327
 328         for j, frame in enumerate(frames):
 329             id = 'anim_{}_{:06n}'.format(name, j + frame_begin)
 330             # create animate tag
 331             frame_anim = et.XML('<animate id="{}" begin="{:.3f}s" />'.format(id, (j - n_of_frames) / fps))
 332             # add per-lineset style attributes
 333             frame_anim.attrib.update(style)
 334             # add to the current frame
 335             frame.append(frame_anim)
 336
 337     # write SVG to file
 338     indent_xml(root)
 339     tree.write(filepath, encoding='ascii', xml_declaration=True)
 340
 341
 342 # - StrokeShaders - #
 343 class SVGPathShader(StrokeShader):
 344     """Stroke Shader for writing stroke data to a .svg file."""
 345     def __init__(self, name, style, filepath, res_y, split_at_invisible, stroke_color_mode, frame_current):
 346         StrokeShader.__init__(self)
 347         # attribute 'name' of 'StrokeShader' objects is not writable, so _name is used
 348         self._name = name
 349         self.filepath = filepath
 350         self.h = res_y
 351         self.frame_current = frame_current
 352         self.elements = []
 353         self.split_at_invisible = split_at_invisible
 354         self.stroke_color_mode = stroke_color_mode # BASE | FIRST | LAST
 355         self.style = style
 356
 357
 358     @classmethod
 359     def from_lineset(cls, lineset, filepath, res_y, split_at_invisible, use_stroke_color, frame_current, *, name=""):
 360         """Builds a SVGPathShader using data from the given lineset"""
 361         name = name or lineset.name
 362         linestyle = lineset.linestyle
 363         # extract style attributes from the linestyle and scene
 364         svg = getCurrentScene().svg_export
 365         style = {
 366             'fill': 'none',
 367             'stroke-width': linestyle.thickness,
 368             'stroke-linecap': linestyle.caps.lower(),
 369             'stroke-opacity': linestyle.alpha,
 370             'stroke': format_rgb(linestyle.color),
 371             'stroke-linejoin': svg.line_join_type.lower(),
 372             }
 373         # get dashed line pattern (if specified)
 374         if linestyle.use_dashed_line:
 375             style['stroke-dasharray'] = ",".join(str(elem) for elem in get_dashed_pattern(linestyle))
 376         # return instance
 377         return cls(name, style, filepath, res_y, split_at_invisible, use_stroke_color, frame_current)
 378
 379
 380     @staticmethod
 381     def pathgen(stroke, style, height, split_at_invisible, stroke_color_mode, f=lambda v: not v.attribute.visible):
 382         """Generator that creates SVG paths (as strings) from the current stroke """
 383         if len(stroke) <= 1:
 384             return ""
 385
 386         if stroke_color_mode != 'BASE':
 387             # try to use the color of the first or last vertex
 388             try:
 389                 index = 0 if stroke_color_mode == 'FIRST' else -1
 390                 color = format_rgb(stroke[index].attribute.color)
 391                 style["stroke"] = color
 392             except (ValueError, IndexError):
 393                 # default is linestyle base color
 394                 pass
 395
 396         # put style attributes into a single svg path definition
 397         path = '\n<path ' + "".join('{}="{}" '.format(k, v) for k, v in style.items()) + 'd=" M '
 398
 399         it = iter(stroke)
 400         # start first path
 401         yield path
 402         for v in it:
 403             x, y = v.point
 404             yield '{:.3f}, {:.3f} '.format(x, height - y)
 405             if split_at_invisible and v.attribute.visible is False:
 406                 # end current and start new path;
 407                 yield '" />' + path
 408                 # fast-forward till the next visible vertex
 409                 it = itertools.dropwhile(f, it)
 410                 # yield next visible vertex
 411                 svert = next(it, None)
 412                 if svert is None:
 413                     break
 414                 x, y = svert.point
 415                 yield '{:.3f}, {:.3f} '.format(x, height - y)
 416         # close current path
 417         yield '" />'
 418
 419     def shade(self, stroke):
 420         stroke_to_paths = "".join(self.pathgen(stroke, self.style, self.h, self.split_at_invisible, self.stroke_color_mode)).split("\n")
 421         # convert to actual XML. Empty strokes are empty strings; they are ignored.
 422         self.elements.extend(et.XML(elem) for elem in stroke_to_paths if elem) # if len(elem.strip()) > len(self.path))
 423
 424     def write(self):
 425         """Write SVG data tree to file """
 426         tree = et.parse(self.filepath)
 427         root = tree.getroot()
 428         name = self._name
 429         scene = bpy.context.scene
 430
 431         # create <g> for lineset as a whole (don't overwrite)
 432         # when rendering an animation, frames will be nested in here, otherwise a group of strokes and optionally fills.
 433         lineset_group = find_svg_elem(tree, ".//svg:g[@id='{}']".format(name))
 434         if lineset_group is None:
 435             lineset_group = et.XML('<g/>')
 436             lineset_group.attrib = {
 437                 'id': name,
 438                 'xmlns:inkscape': namespaces["inkscape"],
 439                 'inkscape:groupmode': 'lineset',
 440                 'inkscape:label': name,
 441                 }
 442             root.append(lineset_group)
 443
 444         # create <g> for the current frame
 445         id = "frame_{:04n}".format(self.frame_current)
 446
 447         stroke_group = et.XML("<g/>")
 448         stroke_group.attrib = {
 449             'xmlns:inkscape': namespaces["inkscape"],
 450             'inkscape:groupmode': 'layer',
 451             'id': 'strokes',
 452             'inkscape:label': 'strokes'
 453             }
 454         # nest the structure
 455         stroke_group.extend(self.elements)
 456         if scene.svg_export.mode == 'ANIMATION':
 457             frame_group = et.XML("<g/>")
 458             frame_group.attrib = {'id': id, 'inkscape:groupmode': 'frame', 'inkscape:label': id}
 459             frame_group.append(stroke_group)
 460             lineset_group.append(frame_group)
 461         else:
 462             lineset_group.append(stroke_group)
 463
 464         # write SVG to file
 465         print("SVG Export: writing to", self.filepath)
 466         indent_xml(root)
 467         tree.write(self.filepath, encoding='ascii', xml_declaration=True)
 468
 469
 470 class SVGFillBuilder:
 471     def __init__(self, filepath, height, name):
 472         self.filepath = filepath
 473         self._name = name
 474         self.stroke_to_fill = partial(self.stroke_to_svg, height=height)
 475
 476     @staticmethod
 477     def pathgen(vertices, path, height):
 478         yield path
 479         for point in vertices:
 480             x, y = point
 481             yield '{:.3f}, {:.3f} '.format(x, height - y)
 482         yield ' z" />'  # closes the path; connects the current to the first point
 483
 484
 485     @staticmethod
 486     def get_merged_strokes(strokes):
 487         def extend_stroke(stroke, vertices):
 488             for vert in map(StrokeVertex, vertices):
 489                 stroke.insert_vertex(vert, stroke.stroke_vertices_end())
 490             return stroke
 491
 492         base_strokes = tuple(stroke for stroke in strokes if not is_poly_clockwise(stroke))
 493         merged_strokes = OrderedDict((s, list()) for s in base_strokes)
 494
 495         for stroke in filter(is_poly_clockwise, strokes):
 496             for base in base_strokes:
 497                 # don't merge when diffuse colors don't match
 498                 if diffuse_from_stroke(stroke) != diffuse_from_stroke(stroke):
 499                     continue
 500                 # only merge when the 'hole' is inside the base
 501                 elif stroke_inside_stroke(stroke, base):
 502                     merged_strokes[base].append(stroke)
 503                     break
 504                 # if it isn't a hole, it is likely that there are two strokes belonging
 505                 # to the same object separated by another object. let's try to join them
 506                 elif (get_object_name(base) == get_object_name(stroke) and
 507                       diffuse_from_stroke(stroke) == diffuse_from_stroke(stroke)):
 508                     base = extend_stroke(base, (sv for sv in stroke))
 509                     break
 510             else:
 511                 # if all else fails, treat this stroke as a base stroke
 512                 merged_strokes.update({stroke:  []})
 513         return merged_strokes
 514
 515
 516     def stroke_to_svg(self, stroke, height, parameters=None):
 517         if parameters is None:
 518             *color, alpha = diffuse_from_stroke(stroke)
 519             color = tuple(int(255 * c) for c in color)
 520             parameters = {
 521                 'fill_rule': 'evenodd',
 522                 'stroke': 'none',
 523                 'fill-opacity': alpha,
 524                 'fill': 'rgb' + repr(color),
 525             }
 526         param_str = " ".join('{}="{}"'.format(k, v) for k, v in parameters.items())
 527         path = '<path {} d=" M '.format(param_str)
 528         vertices = (svert.point for svert in stroke)
 529         s = "".join(self.pathgen(vertices, path, height))
 530         result = et.XML(s)
 531         return result
 532
 533     def create_fill_elements(self, strokes):
 534         """Creates ElementTree objects by merging stroke objects together and turning them into SVG paths."""
 535         merged_strokes = self.get_merged_strokes(strokes)
 536         for k, v in merged_strokes.items():
 537             base = self.stroke_to_fill(k)
 538             fills = (self.stroke_to_fill(stroke).get("d") for stroke in v)
 539             merged_points = " ".join(fills)
 540             base.attrib['d'] += merged_points
 541             yield base
 542
 543     def write(self, strokes):
 544         """Write SVG data tree to file """
 545
 546         tree = et.parse(self.filepath)
 547         root = tree.getroot()
 548         scene = bpy.context.scene
 549         name = self._name
 550
 551         lineset_group = find_svg_elem(tree, ".//svg:g[@id='{}']".format(self._name))
 552         if lineset_group is None:
 553             lineset_group = et.XML('<g/>')
 554             lineset_group.attrib = {
 555                 'id': name,
 556                 'xmlns:inkscape': namespaces["inkscape"],
 557                 'inkscape:groupmode': 'lineset',
 558                 'inkscape:label': name,
 559                 }
 560             root.append(lineset_group)
 561             print('added new lineset group ', name)
 562
 563
 564         # <g> for the fills of the current frame
 565         fill_group = et.XML('<g/>')
 566         fill_group.attrib = {
 567             'xmlns:inkscape': namespaces["inkscape"],
 568             'inkscape:groupmode': 'layer',
 569             'inkscape:label': 'fills',
 570             'id': 'fills'
 571            }
 572
 573         fill_elements = self.create_fill_elements(strokes)
 574         fill_group.extend(reversed(tuple(fill_elements)))
 575         if scene.svg_export.mode == 'ANIMATION':
 576             # add the fills to the <g> of the current frame
 577             frame_group = find_svg_elem(lineset_group, ".//svg:g[@id='frame_{:04n}']".format(scene.frame_current))
 578             frame_group.insert(0, fill_group)
 579         else:
 580             lineset_group.insert(0, fill_group)
 581
 582         # write SVG to file
 583         indent_xml(root)
 584         tree.write(self.filepath, encoding='ascii', xml_declaration=True)
 585
 586
 587 def stroke_inside_stroke(a, b):
 588     box_a = BoundingBox.from_sequence(svert.point for svert in a)
 589     box_b = BoundingBox.from_sequence(svert.point for svert in b)
 590     return box_a.inside(box_b)
 591
 592
 593 def diffuse_from_stroke(stroke, curvemat=CurveMaterialF0D()):
 594     material = curvemat(Interface0DIterator(stroke))
 595     return material.diffuse
 596
 597 # - Callbacks - #
 598 class ParameterEditorCallback(object):
 599     """Object to store callbacks for the Parameter Editor in"""
 600     def lineset_pre(self, scene, layer, lineset):
 601         raise NotImplementedError()
 602
 603     def modifier_post(self, scene, layer, lineset):
 604         raise NotImplementedError()
 605
 606     def lineset_post(self, scene, layer, lineset):
 607         raise NotImplementedError()
 608
 609
 610
 611 class SVGPathShaderCallback(ParameterEditorCallback):
 612     @classmethod
 613     def poll(cls, scene, linestyle):
 614         return scene.render.use_freestyle and scene.svg_export.use_svg_export and linestyle.use_export_strokes
 615
 616     @classmethod
 617     def modifier_post(cls, scene, layer, lineset):
 618         if not cls.poll(scene, lineset.linestyle):
 619             return []
 620
 621         split = scene.svg_export.split_at_invisible
 622         stroke_color_mode = lineset.linestyle.stroke_color_mode
 623         cls.shader = SVGPathShader.from_lineset(
 624                 lineset, create_path(scene),
 625                 render_height(scene), split, stroke_color_mode, scene.frame_current, name=layer.name + '_' + lineset.name)
 626         return [cls.shader]
 627
 628     @classmethod
 629     def lineset_post(cls, scene, layer, lineset):
 630         if not cls.poll(scene, lineset.linestyle):
 631             return []
 632         cls.shader.write()
 633
 634
 635 class SVGFillShaderCallback(ParameterEditorCallback):
 636     @classmethod
 637     def poll(cls, scene, linestyle):
 638         return scene.render.use_freestyle and scene.svg_export.use_svg_export and scene.svg_export.object_fill and linestyle.use_export_fills
 639
 640     @classmethod
 641     def lineset_post(cls, scene, layer, lineset):
 642         if not cls.poll(scene, lineset.linestyle):
 643             return
 644
 645         # reset the stroke selection (but don't delete the already generated strokes)
 646         Operators.reset(delete_strokes=False)
 647         # Unary Predicates: visible and correct edge nature
 648         upred = AndUP1D(
 649             QuantitativeInvisibilityUP1D(0),
 650             OrUP1D(ExternalContourUP1D(),
 651                    pyNatureUP1D(Nature.BORDER)),
 652             )
 653         # select the new edges
 654         Operators.select(upred)
 655         # Binary Predicates
 656         bpred = AndBP1D(
 657             MaterialBP1D(),
 658             NotBP1D(pyZDiscontinuityBP1D()),
 659             )
 660         bpred = OrBP1D(bpred, AndBP1D(NotBP1D(bpred), AndBP1D(SameShapeIdBP1D(), MaterialBP1D())))
 661         # chain the edges
 662         Operators.bidirectional_chain(ChainPredicateIterator(upred, bpred))
 663         # export SVG
 664         collector = StrokeCollector()
 665         Operators.create(TrueUP1D(), [collector])
 666
 667         builder = SVGFillBuilder(create_path(scene), render_height(scene), layer.name + '_' + lineset.name)
 668         builder.write(collector.strokes)
 669         # make strokes used for filling invisible
 670         for stroke in collector.strokes:
 671             for svert in stroke:
 672                 svert.attribute.visible = False
 673
 674
 675
 676 def indent_xml(elem, level=0, indentsize=4):
 677     """Prettifies XML code (used in SVG exporter) """
 678     i = "\n" + level * " " * indentsize
 679     if len(elem):
 680         if not elem.text or not elem.text.strip():
 681             elem.text = i + " " * indentsize
 682         if not elem.tail or not elem.tail.strip():
 683             elem.tail = i
 684         for elem in elem:
 685             indent_xml(elem, level + 1)
 686         if not elem.tail or not elem.tail.strip():
 687             elem.tail = i
 688     elif level and (not elem.tail or not elem.tail.strip()):
 689         elem.tail = i
 690
 691
 692 def register_namespaces(namespaces=namespaces):
 693     for name, url in namespaces.items():
 694         if name != 'svg': # creates invalid xml
 695             et.register_namespace(name, url)
 696
 697 @persistent
 698 def handle_versions(self):
 699     # We don't modify startup file because it assumes to
 700     # have all the default values only.
 701     if not bpy.data.is_saved:
 702         return
 703
 704     # Revision https://developer.blender.org/rBA861519e44adc5674545fa18202dc43c4c20f2d1d
 705     # changed the default for fills.
 706     # fix by Sergey https://developer.blender.org/T46150
 707     if bpy.data.version <= (2, 76, 0):
 708         for linestyle in bpy.data.linestyles:
 709             linestyle.use_export_fills = True
 710
 711
 712
 713 classes = (
 714     SVGExporterPanel,
 715     SVGExporterLinesetPanel,
 716     SVGExport,
 717     )
 718
 719
 720 def register():
 721     linestyle = bpy.types.FreestyleLineStyle
 722     linestyle.use_export_strokes = BoolProperty(
 723             name="Export Strokes",
 724             description="Export strokes for this Line Style",
 725             default=True,
 726             )
 727     linestyle.stroke_color_mode = EnumProperty(
 728             name="Stroke Color Mode",
 729             items=(
 730                 ('BASE', "Base Color", "Use the linestyle's base color", 0),
 731                 ('FIRST', "First Vertex", "Use the color of a stroke's first vertex", 1),
 732                 ('FINAL', "Final Vertex", "Use the color of a stroke's final vertex", 2),
 733                 ),
 734             default='BASE',
 735             )
 736     linestyle.use_export_fills = BoolProperty(
 737             name="Export Fills",
 738             description="Export fills for this Line Style",
 739             default=False,
 740             )
 741
 742     for cls in classes:
 743         bpy.utils.register_class(cls)
 744     bpy.types.Scene.svg_export = PointerProperty(type=SVGExport)
 745
 746
 747     # add callbacks
 748     bpy.app.handlers.render_init.append(render_init)
 749     bpy.app.handlers.render_write.append(render_write)
 750     bpy.app.handlers.render_pre.append(svg_export_header)
 751     bpy.app.handlers.render_complete.append(svg_export_animation)
 752
 753     # manipulate shaders list
 754     parameter_editor.callbacks_modifiers_post.append(SVGPathShaderCallback.modifier_post)
 755     parameter_editor.callbacks_lineset_post.append(SVGPathShaderCallback.lineset_post)
 756     parameter_editor.callbacks_lineset_post.append(SVGFillShaderCallback.lineset_post)
 757
 758     # register namespaces
 759     register_namespaces()
 760
 761     # handle regressions
 762     bpy.app.handlers.version_update.append(handle_versions)
 763
 764
 765 def unregister():
 766
 767     for cls in classes:
 768         bpy.utils.unregister_class(cls)
 769     del bpy.types.Scene.svg_export
 770     linestyle = bpy.types.FreestyleLineStyle
 771     del linestyle.use_export_strokes
 772     del linestyle.use_export_fills
 773
 774     # remove callbacks
 775     bpy.app.handlers.render_init.remove(render_init)
 776     bpy.app.handlers.render_write.remove(render_write)
 777     bpy.app.handlers.render_pre.remove(svg_export_header)
 778     bpy.app.handlers.render_complete.remove(svg_export_animation)
 779
 780     # manipulate shaders list
 781     parameter_editor.callbacks_modifiers_post.remove(SVGPathShaderCallback.modifier_post)
 782     parameter_editor.callbacks_lineset_post.remove(SVGPathShaderCallback.lineset_post)
 783     parameter_editor.callbacks_lineset_post.remove(SVGFillShaderCallback.lineset_post)
 784
 785     bpy.app.handlers.version_update.remove(handle_versions)
 786
 787
 788 if __name__ == "__main__":
 789     register()