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Diffstat (limited to 'lib/stitches/fill.py')
| -rw-r--r-- | lib/stitches/fill.py | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/lib/stitches/fill.py b/lib/stitches/fill.py new file mode 100644 index 00000000..1b7377b0 --- /dev/null +++ b/lib/stitches/fill.py @@ -0,0 +1,245 @@ +from .. import PIXELS_PER_MM +from ..utils import cache, Point as InkstitchPoint +import shapely +import math +import sys + + +def legacy_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, flip, staggers): + rows_of_segments = intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing, flip) + groups_of_segments = pull_runs(rows_of_segments, shape, row_spacing) + + return [section_to_stitches(group, angle, row_spacing, max_stitch_length, staggers) + for group in groups_of_segments] + + +@cache +def east(angle): + # "east" is the name of the direction that is to the right along a row + return InkstitchPoint(1, 0).rotate(-angle) + + +@cache +def north(angle): + return east(angle).rotate(math.pi / 2) + + +def row_num(point, angle, row_spacing): + return round((point * north(angle)) / row_spacing) + + +def adjust_stagger(stitch, angle, row_spacing, max_stitch_length, staggers): + this_row_num = row_num(stitch, angle, row_spacing) + row_stagger = this_row_num % staggers + stagger_offset = (float(row_stagger) / staggers) * max_stitch_length + offset = ((stitch * east(angle)) - stagger_offset) % max_stitch_length + + return stitch - offset * east(angle) + +def stitch_row(stitches, beg, end, angle, row_spacing, max_stitch_length, staggers): + # We want our stitches to look like this: + # + # ---*-----------*----------- + # ------*-----------*-------- + # ---------*-----------*----- + # ------------*-----------*-- + # ---*-----------*----------- + # + # Each successive row of stitches will be staggered, with + # num_staggers rows before the pattern repeats. A value of + # 4 gives a nice fill while hiding the needle holes. The + # first row is offset 0%, the second 25%, the third 50%, and + # the fourth 75%. + # + # Actually, instead of just starting at an offset of 0, we + # can calculate a row's offset relative to the origin. This + # way if we have two abutting fill regions, they'll perfectly + # tile with each other. That's important because we often get + # abutting fill regions from pull_runs(). + + beg = InkstitchPoint(*beg) + end = InkstitchPoint(*end) + + row_direction = (end - beg).unit() + segment_length = (end - beg).length() + + # only stitch the first point if it's a reasonable distance away from the + # last stitch + if not stitches or (beg - stitches[-1]).length() > 0.5 * PIXELS_PER_MM: + stitches.append(beg) + + first_stitch = adjust_stagger(beg, angle, row_spacing, max_stitch_length, staggers) + + # we might have chosen our first stitch just outside this row, so move back in + if (first_stitch - beg) * row_direction < 0: + first_stitch += row_direction * max_stitch_length + + offset = (first_stitch - beg).length() + + while offset < segment_length: + stitches.append(beg + offset * row_direction) + offset += max_stitch_length + + if (end - stitches[-1]).length() > 0.1 * PIXELS_PER_MM: + stitches.append(end) + + +def intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing=None, flip=False): + # the max line length I'll need to intersect the whole shape is the diagonal + (minx, miny, maxx, maxy) = shape.bounds + upper_left = InkstitchPoint(minx, miny) + lower_right = InkstitchPoint(maxx, maxy) + length = (upper_left - lower_right).length() + half_length = length / 2.0 + + # Now get a unit vector rotated to the requested angle. I use -angle + # because shapely rotates clockwise, but my geometry textbooks taught + # me to consider angles as counter-clockwise from the X axis. + direction = InkstitchPoint(1, 0).rotate(-angle) + + # and get a normal vector + normal = direction.rotate(math.pi / 2) + + # I'll start from the center, move in the normal direction some amount, + # and then walk left and right half_length in each direction to create + # a line segment in the grating. + center = InkstitchPoint((minx + maxx) / 2.0, (miny + maxy) / 2.0) + + # I need to figure out how far I need to go along the normal to get to + # the edge of the shape. To do that, I'll rotate the bounding box + # angle degrees clockwise and ask for the new bounding box. The max + # and min y tell me how far to go. + + _, start, _, end = shapely.affinity.rotate(shape, angle, origin='center', use_radians=True).bounds + + # convert start and end to be relative to center (simplifies things later) + start -= center.y + end -= center.y + + height = abs(end - start) + + #print >> dbg, "grating:", start, end, height, row_spacing, end_row_spacing + + # offset start slightly so that rows are always an even multiple of + # row_spacing_px from the origin. This makes it so that abutting + # fill regions at the same angle and spacing always line up nicely. + start -= (start + normal * center) % row_spacing + + rows = [] + + current_row_y = start + + while current_row_y < end: + p0 = center + normal * current_row_y + direction * half_length + p1 = center + normal * current_row_y - direction * half_length + endpoints = [p0.as_tuple(), p1.as_tuple()] + grating_line = shapely.geometry.LineString(endpoints) + + res = grating_line.intersection(shape) + + if (isinstance(res, shapely.geometry.MultiLineString)): + runs = map(lambda line_string: line_string.coords, res.geoms) + else: + if res.is_empty or len(res.coords) == 1: + # ignore if we intersected at a single point or no points + runs = [] + else: + runs = [res.coords] + + if runs: + runs.sort(key=lambda seg: (InkstitchPoint(*seg[0]) - upper_left).length()) + + if flip: + runs.reverse() + runs = map(lambda run: tuple(reversed(run)), runs) + + rows.append(runs) + + if end_row_spacing: + current_row_y += row_spacing + (end_row_spacing - row_spacing) * ((current_row_y - start) / height) + else: + current_row_y += row_spacing + + return rows + +def section_to_stitches(group_of_segments, angle, row_spacing, max_stitch_length, staggers): + stitches = [] + first_segment = True + swap = False + last_end = None + + for segment in group_of_segments: + (beg, end) = segment + + if (swap): + (beg, end) = (end, beg) + + stitch_row(stitches, beg, end, angle, row_spacing, max_stitch_length, staggers) + + swap = not swap + + return stitches + + +def make_quadrilateral(segment1, segment2): + return shapely.geometry.Polygon((segment1[0], segment1[1], segment2[1], segment2[0], segment1[0])) + + +def is_same_run(segment1, segment2, shape, row_spacing): + line1 = shapely.geometry.LineString(segment1) + line2 = shapely.geometry.LineString(segment2) + + if line1.distance(line2) > row_spacing * 1.1: + return False + + quad = make_quadrilateral(segment1, segment2) + quad_area = quad.area + intersection_area = shape.intersection(quad).area + + return (intersection_area / quad_area) >= 0.9 + + +def pull_runs(rows, shape, row_spacing): + # Given a list of rows, each containing a set of line segments, + # break the area up into contiguous patches of line segments. + # + # This is done by repeatedly pulling off the first line segment in + # each row and calling that a shape. We have to be careful to make + # sure that the line segments are part of the same shape. Consider + # the letter "H", with an embroidery angle of 45 degrees. When + # we get to the bottom of the lower left leg, the next row will jump + # over to midway up the lower right leg. We want to stop there and + # start a new patch. + + # for row in rows: + # print >> sys.stderr, len(row) + + # print >>sys.stderr, "\n".join(str(len(row)) for row in rows) + + runs = [] + count = 0 + while (len(rows) > 0): + run = [] + prev = None + + for row_num in xrange(len(rows)): + row = rows[row_num] + first, rest = row[0], row[1:] + + # TODO: only accept actually adjacent rows here + if prev is not None and not is_same_run(prev, first, shape, row_spacing): + break + + run.append(first) + prev = first + + rows[row_num] = rest + + # print >> sys.stderr, len(run) + runs.append(run) + rows = [row for row in rows if len(row) > 0] + + count += 1 + + return runs + |