diff options
| -rw-r--r-- | embroider.py | 85 |
1 files changed, 50 insertions, 35 deletions
diff --git a/embroider.py b/embroider.py index 1b6f2c0f..660fd168 100644 --- a/embroider.py +++ b/embroider.py @@ -649,43 +649,58 @@ class Embroider(inkex.Effect): return [patch] def intersect_region_with_grating(self, shpath, row_spacing_px, angle): - #dbg.write("bounds = %s\n" % str(shpath.bounds)) - rotated_shpath = affinity.rotate(shpath, angle, use_radians = True) - bbox = rotated_shpath.bounds - delta = row_spacing_px * 50 # *2 should be enough but isn't. TODO: find out why, and if this always works. - bbox = affinity.rotate(shgeo.LinearRing(((bbox[0] - delta, bbox[1] - delta), (bbox[2] + delta, bbox[1] - delta), (bbox[2] + delta, bbox[3] + delta), (bbox[0] - delta, bbox[3] + delta))), -angle, use_radians = True).coords - - p0 = PyEmb.Point(bbox[0][0], bbox[0][1]) - p1 = PyEmb.Point(bbox[1][0], bbox[1][1]) - p2 = PyEmb.Point(bbox[3][0], bbox[3][1]) - count = (p2 - p0).length() / row_spacing_px - p_inc = (p2 - p0).mul(1 / count) - count += 2 + # the max line length I'll need to intersect the whole shape is the diagonal + (minx, miny, maxx, maxy) = shpath.bounds + length = (PyEmb.Point(maxx, maxy) - PyEmb.Point(minx, miny)).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 = PyEmb.Point(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 = PyEmb.Point((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 = affinity.rotate(shpath, angle, origin='center', use_radians = True).bounds + start -= center.y + end -= center.y + + # don't start right at the edge or we'll make a ridiculous single + # stitch + start += row_spacing_px / 2.0 rows = [] - steps = 0 - while (steps < count): - try: - steps += 1 - p0 += p_inc - p1 += p_inc - endpoints = [p0.as_tuple(), p1.as_tuple()] - shline = shgeo.LineString(endpoints) - res = shline.intersection(shpath) - if (isinstance(res, shgeo.MultiLineString)): - runs = map(shapelyLineSegmentToPyTuple, res.geoms) - else: - runs = [shapelyLineSegmentToPyTuple(res)] - if self.hatching and len(rows) > 0: - rows.append([(rows[-1][0][1], runs[0][0])]) - rows.append(runs) - except Exception, ex: - dbg.write("--------------\n") - dbg.write("%s\n" % ex) - dbg.write("%s\n" % shline) - dbg.write("%s\n" % shpath) - dbg.write("==============\n") - continue + + while start < end: + p0 = center + normal.mul(start) + direction.mul(half_length) + p1 = center + normal.mul(start) - direction.mul(half_length) + endpoints = [p0.as_tuple(), p1.as_tuple()] + shline = shgeo.LineString(endpoints) + + res = shline.intersection(shpath) + + if (isinstance(res, shgeo.MultiLineString)): + runs = map(shapelyLineSegmentToPyTuple, res.geoms) + else: + runs = [shapelyLineSegmentToPyTuple(res)] + + if self.hatching and len(rows) > 0: + rows.append([(rows[-1][0][1], runs[0][0])]) + + rows.append(runs) + + start += row_spacing_px return rows def visit_segments_one_by_one(self, rows): |