tangential->contour, fix legacy, remove unused params

1 files changed, 536 insertions, 0 deletions

diff --git a/lib/stitches/contour_fill.py b/lib/stitches/contour_fill.py
new file mode 100644
index 00000000..916285d8
--- /dev/null
+++ b/lib/stitches/contour_fill.py
@@ -0,0 +1,536 @@
+from collections import namedtuple
+from itertools import chain
+
+import networkx as nx
+import numpy as np
+import trimesh
+from shapely.geometry import GeometryCollection, MultiPolygon, Polygon, LineString, MultiLineString, Point
+from shapely.geometry.polygon import orient
+from shapely.ops import nearest_points
+from shapely.ops import polygonize
+
+from .running_stitch import running_stitch
+from ..i18n import _
+from ..stitch_plan import Stitch
+from ..stitches import constants
+from ..utils import DotDict
+from ..utils.geometry import cut, reverse_line_string, roll_linear_ring
+from ..utils.geometry import ensure_geometry_collection, ensure_multi_polygon
+
+
+class Tree(nx.DiGraph):
+    # This lets us do tree.nodes['somenode'].parent instead of the default
+    # tree.nodes['somenode']['parent'].
+    node_attr_dict_factory = DotDict
+
+    def __init__(self, *args, **kwargs):
+        self.__node_num = 0
+        super().__init__(**kwargs)
+
+    def generate_node_name(self):
+        node = self.__node_num
+        self.__node_num += 1
+
+        return node
+
+
+nearest_neighbor_tuple = namedtuple(
+    "nearest_neighbor_tuple",
+    [
+        "nearest_point_parent",
+        "nearest_point_child",
+        "proj_distance_parent",
+        "child_node",
+    ],
+)
+
+
+def _offset_linear_ring(ring, offset, resolution, join_style, mitre_limit):
+    result = Polygon(ring).buffer(-offset, resolution, cap_style=2, join_style=join_style, mitre_limit=mitre_limit, single_sided=True)
+    result = ensure_multi_polygon(result)
+
+    rings = GeometryCollection([poly.exterior for poly in result.geoms])
+    rings = rings.simplify(constants.simplification_threshold, False)
+
+    return _take_only_valid_linear_rings(rings)
+
+
+def _take_only_valid_linear_rings(rings):
+    """
+    Removes all geometries which do not form a "valid" LinearRing.
+
+    A "valid" ring is one that does not form a straight line.
+    """
+
+    valid_rings = []
+
+    for ring in ensure_geometry_collection(rings).geoms:
+        if len(ring.coords) > 3 or (len(ring.coords) == 3 and ring.coords[0] != ring.coords[-1]):
+            valid_rings.append(ring)
+
+    return GeometryCollection(valid_rings)
+
+
+def _orient_linear_ring(ring, clockwise=True):
+    # Unfortunately for us, Inkscape SVGs have an inverted Y coordinate.
+    # Normally we don't have to care about that, but in this very specific
+    # case, the meaning of is_ccw is flipped.  It actually tests whether
+    # a ring is clockwise.  That makes this logic super-confusing.
+    if ring.is_ccw != clockwise:
+        return reverse_line_string(ring)
+    else:
+        return ring
+
+
+def _orient_tree(tree, clockwise=True):
+    """
+    Orient all linear rings in the tree.
+
+    Since naturally holes have the opposite point ordering than non-holes we
+    make all lines within the tree uniform (having all the same ordering
+    direction)
+    """
+
+    for node in tree.nodes.values():
+        node.val = _orient_linear_ring(node.val, clockwise)
+
+
+def offset_polygon(polygon, offset, join_style, clockwise):
+    """
+    Convert a polygon to a tree of isocontours.
+
+    An isocontour is an offset version of the polygon's boundary.  For example,
+    the isocontours of a circle are a set of concentric circles inside the
+    circle.
+
+    This function takes a polygon (which may have holes) as input and creates
+    isocontours until the polygon is filled completely.  The isocontours are
+    returned as a Tree, with a parent-child relationship indicating that the
+    parent isocontour contains the child isocontour.
+
+    Arguments:
+        polygon - The shapely Polygon which may have holes
+        offset - The spacing between isocontours
+        join_style - Join style used when offsetting the Polygon border to create
+                     isocontours.  Can be round, mitered or bevel, as defined by
+                     shapely:
+                       https://shapely.readthedocs.io/en/stable/manual.html#shapely.geometry.JOIN_STYLE
+        clockwise - If True, isocontour points are in clockwise order; if False, counter-clockwise.
+
+    Return Value:
+        Tree - see above
+    """
+
+    ordered_polygon = orient(polygon, -1)
+    tree = Tree()
+    tree.add_node('root', type='node', parent=None, val=ordered_polygon.exterior)
+    active_polygons = ['root']
+    active_holes = [[]]
+
+    for hole in ordered_polygon.interiors:
+        hole_node = tree.generate_node_name()
+        tree.add_node(hole_node, type="hole", val=hole)
+        active_holes[0].append(hole_node)
+
+    while len(active_polygons) > 0:
+        current_poly = active_polygons.pop()
+        current_holes = active_holes.pop()
+
+        outer, inners = _offset_polygon_and_holes(tree, current_poly, current_holes, offset, join_style)
+        polygons = _match_polygons_and_holes(outer, inners)
+
+        for polygon in polygons.geoms:
+            new_polygon, new_holes = _convert_polygon_to_nodes(tree, polygon, parent_polygon=current_poly, child_holes=current_holes)
+
+            if new_polygon is not None:
+                active_polygons.append(new_polygon)
+                active_holes.append(new_holes)
+
+        for previous_hole in current_holes:
+            # If the previous holes are not
+            # contained in the new holes they
+            # have been merged with the
+            # outer polygon
+            if not tree.nodes[previous_hole].parent:
+                tree.nodes[previous_hole].parent = current_poly
+                tree.add_edge(current_poly, previous_hole)
+
+    _orient_tree(tree, clockwise)
+    return tree
+
+
+def _offset_polygon_and_holes(tree, poly, holes, offset, join_style):
+    outer = _offset_linear_ring(
+        tree.nodes[poly].val,
+        offset,
+        resolution=5,
+        join_style=join_style,
+        mitre_limit=10,
+    )
+
+    inners = []
+    for hole in holes:
+        inner = _offset_linear_ring(
+            tree.nodes[hole].val,
+            -offset,  # take negative offset for holes
+            resolution=5,
+            join_style=join_style,
+            mitre_limit=10,
+        )
+        if not inner.is_empty:
+            inners.append(Polygon(inner.geoms[0]))
+
+    return outer, inners
+
+
+def _match_polygons_and_holes(outer, inners):
+    result = MultiPolygon(polygonize(outer.geoms))
+    if len(inners) > 0:
+        result = ensure_geometry_collection(result.difference(MultiPolygon(inners)))
+
+    return result
+
+
+def _convert_polygon_to_nodes(tree, polygon, parent_polygon, child_holes):
+    polygon = orient(polygon, -1)
+
+    if polygon.area < 0.1:
+        return None, None
+
+    polygon = polygon.simplify(constants.simplification_threshold, False)
+    valid_rings = _take_only_valid_linear_rings(polygon.exterior)
+
+    try:
+        exterior = valid_rings.geoms[0]
+    except IndexError:
+        return None, None
+
+    node = tree.generate_node_name()
+    tree.add_node(node, type='node', parent=parent_polygon, val=exterior)
+    tree.add_edge(parent_polygon, node)
+
+    hole_nodes = []
+    for hole in polygon.interiors:
+        hole_node = tree.generate_node_name()
+        tree.add_node(hole_node, type="hole", val=hole)
+        for previous_hole in child_holes:
+            if Polygon(hole).contains(Polygon(tree.nodes[previous_hole].val)):
+                tree.nodes[previous_hole].parent = hole_node
+                tree.add_edge(hole_node, previous_hole)
+        hole_nodes.append(hole_node)
+
+    return node, hole_nodes
+
+
+def _get_nearest_points_closer_than_thresh(travel_line, next_line, threshold):
+    """
+    Find the first point along travel_line that is within threshold of next_line.
+
+    Input:
+        travel_line - The "parent" line for which the distance should
+                      be minimized to enter next_line
+        next_line - contains the next_line which need to be entered
+        threshold - The distance between travel_line and next_line needs
+                    to below threshold to be a valid point for entering
+
+    Return value:
+        tuple or None
+            - the tuple structure is:
+              (point in travel_line, point in next_line)
+            - None is returned if there is no point that satisfies the threshold.
+    """
+
+    # We'll buffer next_line and find the intersection with travel_line.
+    # Then we'll return the very first point in the intersection,
+    # matched with a corresponding point on next_line.  Fortunately for
+    # us, intersection of a Polygon with a LineString yields pieces of
+    # the LineString in the same order as the input LineString.
+    threshold_area = next_line.buffer(threshold)
+    portion_within_threshold = travel_line.intersection(threshold_area)
+
+    if portion_within_threshold.is_empty:
+        return None
+    else:
+        # Projecting with 0 lets us avoid distinguishing between LineString and
+        # MultiLineString.
+        parent_point = Point(portion_within_threshold.interpolate(0))
+        return nearest_points(parent_point, next_line)
+
+
+def _create_nearest_points_list(
+        travel_line, tree, children, threshold, threshold_hard):
+    """Determine the best place to enter each of parent's children
+
+    Arguments:
+        travel_line - The "parent" line for which the distance should
+                      be minimized to enter each child
+        children - children of travel_line that need to be entered
+        threshold - The distance between travel_line and a child should
+                    to be below threshold to be a valid point for entering
+        threshold_hard - As a last resort, we can accept an entry point
+                         that is this far way
+
+    Return value:
+        list of nearest_neighbor_tuple - indicating where to enter each
+                                         respective child
+    """
+
+    children_nearest_points = []
+
+    for child in children:
+        result = _get_nearest_points_closer_than_thresh(travel_line, tree.nodes[child].val, threshold)
+        if result is None:
+            # where holes meet outer borders a distance
+            # up to 2 * used offset can arise
+            result = _get_nearest_points_closer_than_thresh(travel_line, tree.nodes[child].val, threshold_hard)
+
+        proj = travel_line.project(result[0])
+        children_nearest_points.append(
+            nearest_neighbor_tuple(
+                nearest_point_parent=result[0],
+                nearest_point_child=result[1],
+                proj_distance_parent=proj,
+                child_node=child,
+            )
+        )
+
+    return children_nearest_points
+
+
+def _find_path_inner_to_outer(tree, node, offset, starting_point,
+                              avoid_self_crossing, forward=True):
+    """Find a stitch path for this ring and its children.
+
+    Strategy: A connection from parent to child is made as fast as possible to
+    reach the innermost child as fast as possible in order to stitch afterwards
+    from inner to outer.
+
+    This function calls itself recursively to find a stitch path for each child
+    (and its children).
+
+    Arguments:
+        tree - a Tree of isocontours (as returned by offset_polygon)
+        offset - offset that was passed to offset_polygon
+        starting_point - starting point for stitching
+        avoid_self_crossing - if True, tries to generate a path that does not
+                              cross itself.
+        forward - if True, this ring will be stitched in its natural direction
+                  (used internally by avoid_self_crossing)
+
+    Return value:
+        LineString -- the stitching path
+    """
+
+    current_node = tree.nodes[node]
+    current_ring = current_node.val
+
+    if not forward and avoid_self_crossing:
+        current_ring = reverse_line_string(current_ring)
+
+    # reorder the coordinates of this ring so that it starts with
+    # a point nearest the starting_point
+    start_distance = current_ring.project(starting_point)
+    current_ring = roll_linear_ring(current_ring, start_distance)
+    current_node.val = current_ring
+
+    # Find where along this ring to connect to each child.
+    nearest_points_list = _create_nearest_points_list(
+        current_ring,
+        tree,
+        tree[node],
+        constants.offset_factor_for_adjacent_geometry * offset,
+        2.05 * offset
+    )
+    nearest_points_list.sort(key=lambda tup: tup.proj_distance_parent)
+
+    result_coords = []
+    if not nearest_points_list:
+        # We have no children, so we're at the center of a spiral.  Reversing
+        # the innermost ring gives a nicer visual appearance.
+        if not avoid_self_crossing:
+            current_ring = reverse_line_string(current_ring)
+    else:
+        # This is a recursive algorithm.  We'll stitch along this ring, pausing
+        # to jump to each child ring in turn and sew it before continuing on
+        # this ring.  We'll end back where we started.
+
+        result_coords.append(current_ring.coords[0])
+        distance_so_far = 0
+        for child_connection in nearest_points_list:
+            # Cut this ring into pieces before and after where this child will connect.
+            before, after = cut(current_ring, child_connection.proj_distance_parent - distance_so_far)
+            distance_so_far = child_connection.proj_distance_parent
+
+            # Stitch the part leading up to this child.
+            if before is not None:
+                result_coords.extend(before.coords)
+
+            # Stitch this child.  The child will start and end in the same
+            # place, which should be close to our current location.
+            child_path = _find_path_inner_to_outer(
+                tree,
+                child_connection.child_node,
+                offset,
+                child_connection.nearest_point_child,
+                avoid_self_crossing,
+                not forward
+            )
+            result_coords.extend(child_path.coords)
+
+            # Skip ahead a little bit on this ring before resuming.  This
+            # gives a nice spiral pattern, where we spiral out from the
+            # innermost child.
+            if after is not None:
+                skip, after = cut(after, offset)
+                distance_so_far += offset
+
+            current_ring = after
+
+    if current_ring is not None:
+        # skip a little at the end so we don't end exactly where we started.
+        remaining_length = current_ring.length
+        if remaining_length > offset:
+            current_ring, skip = cut(current_ring, current_ring.length - offset)
+
+        result_coords.extend(current_ring.coords)
+
+    return LineString(result_coords)
+
+
+def inner_to_outer(tree, offset, stitch_length, starting_point, avoid_self_crossing):
+    """Fill a shape with spirals, from innermost to outermost."""
+
+    stitch_path = _find_path_inner_to_outer(tree, 'root', offset, starting_point, avoid_self_crossing)
+    points = [Stitch(*point) for point in stitch_path.coords]
+    stitches = running_stitch(points, stitch_length)
+
+    return stitches
+
+
+def _reorder_linear_ring(ring, start):
+    distances = ring - start
+    start_index = np.argmin(np.linalg.norm(distances, axis=1))
+    return np.roll(ring, -start_index, axis=0)
+
+
+def _interpolate_linear_rings(ring1, ring2, max_stitch_length, start=None):
+    """
+    Interpolate between two LinearRings
+
+    Creates a path from start_point on ring1 and around the rings, ending at a
+    nearby point on ring2.  The path will smoothly transition from ring1 to
+    ring2 as it travels around the rings.
+
+    Inspired by interpolate() from https://github.com/mikedh/pocketing/blob/master/pocketing/polygons.py
+
+    Arguments:
+        ring1 -- LinearRing start point will lie on
+        ring2 -- LinearRing end point will lie on
+        max_stitch_length -- maximum stitch length (used to calculate resampling accuracy)
+        start -- Point on ring1 to start at, as a tuple
+
+    Return value: Path interpolated between two LinearRings, as a LineString.
+    """
+
+    # Resample the two LinearRings so that they are the same number of points
+    # long.  Then take the corresponding points in each ring and interpolate
+    # between them, gradually going more toward ring2.
+    #
+    # This is a little less accurate than the method in interpolate(), but several
+    # orders of magnitude faster because we're not building and querying a KDTree.
+
+    num_points = int(20 * ring1.length / max_stitch_length)
+    ring1_resampled = trimesh.path.traversal.resample_path(np.array(ring1.coords), count=num_points)
+    ring2_resampled = trimesh.path.traversal.resample_path(np.array(ring2.coords), count=num_points)
+
+    if start is not None:
+        ring1_resampled = _reorder_linear_ring(ring1_resampled, start)
+        ring2_resampled = _reorder_linear_ring(ring2_resampled, start)
+
+    weights = np.linspace(0.0, 1.0, num_points).reshape((-1, 1))
+    points = (ring1_resampled * (1.0 - weights)) + (ring2_resampled * weights)
+    result = LineString(points)
+
+    return result.simplify(constants.simplification_threshold, False)
+
+
+def _check_and_prepare_tree_for_valid_spiral(tree):
+    """Check whether spiral fill is possible, and tweak if necessary.
+
+    Takes a tree consisting of isocontours. If a parent has more than one child
+    we cannot create a spiral. However, to make the routine more robust, we
+    allow more than one child if only one of the children has own children. The
+    other children are removed in this routine then. If the routine returns true,
+    the tree will have been cleaned up from unwanted children.
+
+    If even with these weaker constraints, a spiral is not possible, False is
+    returned.
+    """
+
+    def process_node(node):
+        children = set(tree[node])
+
+        if len(children) == 0:
+            return True
+        elif len(children) == 1:
+            child = children.pop()
+            return process_node(child)
+        else:
+            children_with_children = {child for child in children if tree[child]}
+            if len(children_with_children) > 1:
+                # Node has multiple children with children, so a perfect spiral is not possible.
+                # This False value will be returned all the way up the stack.
+                return False
+            elif len(children_with_children) == 1:
+                children_without_children = children - children_with_children
+                child = children_with_children.pop()
+                tree.remove_nodes_from(children_without_children)
+                return process_node(child)
+            else:
+                # None of the children has its own children, so we'll just take the longest.
+                longest = max(children, key=lambda child: tree[child]['val'].length)
+                shorter_children = children - {longest}
+                tree.remove_nodes_from(shorter_children)
+                return process_node(longest)
+
+    return process_node('root')
+
+
+def single_spiral(tree, stitch_length, starting_point):
+    """Fill a shape with a single spiral going from outside to center."""
+    return _spiral_fill(tree, stitch_length, starting_point, _make_spiral)
+
+
+def double_spiral(tree, stitch_length, starting_point):
+    """Fill a shape with a double spiral going from outside to center and back to outside. """
+    return _spiral_fill(tree, stitch_length, starting_point, _make_fermat_spiral)
+
+
+def _spiral_fill(tree, stitch_length, close_point, spiral_maker):
+    if not _check_and_prepare_tree_for_valid_spiral(tree):
+        raise ValueError(_("Shape cannot be filled with single or double spiral!"))
+
+    starting_point = close_point.coords[0]
+    rings = [tree.nodes[node].val for node in nx.dfs_preorder_nodes(tree, 'root')]
+    path = spiral_maker(rings, stitch_length, starting_point)
+    path = [Stitch(*stitch) for stitch in path]
+
+    return running_stitch(path, stitch_length)
+
+
+def _make_fermat_spiral(rings, stitch_length, starting_point):
+    forward = _make_spiral(rings[::2], stitch_length, starting_point)
+    back = _make_spiral(rings[1::2], stitch_length, starting_point)
+    back.reverse()
+
+    return chain(forward, back)
+
+
+def _make_spiral(rings, stitch_length, starting_point):
+    path = []
+
+    for ring1, ring2 in zip(rings[:-1], rings[1:]):
+        spiral_part = _interpolate_linear_rings(ring1, ring2, stitch_length, starting_point)
+        path.extend(spiral_part.coords)
+
+    return path