Cura/cura/ShapeArray.py
2017-04-03 14:48:31 +02:00

104 lines
4.2 KiB
Python
Executable File

import numpy
import copy
from UM.Math.Polygon import Polygon
## Polygon representation as an array
#
class ShapeArray:
def __init__(self, arr, offset_x, offset_y, scale = 1):
self.arr = arr
self.offset_x = offset_x
self.offset_y = offset_y
self.scale = scale
@classmethod
def fromPolygon(cls, vertices, scale = 1):
# scale
vertices = vertices * scale
# flip y, x -> x, y
flip_vertices = numpy.zeros((vertices.shape))
flip_vertices[:, 0] = vertices[:, 1]
flip_vertices[:, 1] = vertices[:, 0]
flip_vertices = flip_vertices[::-1]
# offset, we want that all coordinates have positive values
offset_y = int(numpy.amin(flip_vertices[:, 0]))
offset_x = int(numpy.amin(flip_vertices[:, 1]))
flip_vertices[:, 0] = numpy.add(flip_vertices[:, 0], -offset_y)
flip_vertices[:, 1] = numpy.add(flip_vertices[:, 1], -offset_x)
shape = [int(numpy.amax(flip_vertices[:, 0])), int(numpy.amax(flip_vertices[:, 1]))]
arr = cls.arrayFromPolygon(shape, flip_vertices)
return cls(arr, offset_x, offset_y)
## Return an offset and hull ShapeArray from a scenenode.
@classmethod
def fromNode(cls, node, min_offset, scale = 0.5):
# hacky way to undo transformation
transform = node._transformation
transform_x = transform._data[0][3]
transform_y = transform._data[2][3]
hull_verts = node.callDecoration("getConvexHull")
offset_verts = hull_verts.getMinkowskiHull(Polygon.approximatedCircle(min_offset))
offset_points = copy.deepcopy(offset_verts._points) # x, y
offset_points[:, 0] = numpy.add(offset_points[:, 0], -transform_x)
offset_points[:, 1] = numpy.add(offset_points[:, 1], -transform_y)
offset_shape_arr = ShapeArray.fromPolygon(offset_points, scale = scale)
hull_points = copy.deepcopy(hull_verts._points)
hull_points[:, 0] = numpy.add(hull_points[:, 0], -transform_x)
hull_points[:, 1] = numpy.add(hull_points[:, 1], -transform_y)
hull_shape_arr = ShapeArray.fromPolygon(hull_points, scale = scale) # x, y
return offset_shape_arr, hull_shape_arr
## Create np.array with dimensions defined by shape
# Fills polygon defined by vertices with ones, all other values zero
# Only works correctly for convex hull vertices
# Originally from: http://stackoverflow.com/questions/37117878/generating-a-filled-polygon-inside-a-numpy-array
@classmethod
def arrayFromPolygon(cls, shape, vertices):
base_array = numpy.zeros(shape, dtype=float) # Initialize your array of zeros
fill = numpy.ones(base_array.shape) * True # Initialize boolean array defining shape fill
# Create check array for each edge segment, combine into fill array
for k in range(vertices.shape[0]):
fill = numpy.all([fill, cls._check(vertices[k - 1], vertices[k], base_array)], axis=0)
# Set all values inside polygon to one
base_array[fill] = 1
return base_array
## Return indices that mark one side of the line, used by array_from_polygon
# Uses the line defined by p1 and p2 to check array of
# input indices against interpolated value
# Returns boolean array, with True inside and False outside of shape
# Originally from: http://stackoverflow.com/questions/37117878/generating-a-filled-polygon-inside-a-numpy-array
@classmethod
def _check(cls, p1, p2, base_array):
if p1[0] == p2[0] and p1[1] == p2[1]:
return
idxs = numpy.indices(base_array.shape) # Create 3D array of indices
p1 = p1.astype(float)
p2 = p2.astype(float)
if p2[0] == p1[0]:
sign = numpy.sign(p2[1] - p1[1])
return idxs[1] * sign
if p2[1] == p1[1]:
sign = numpy.sign(p2[0] - p1[0])
return idxs[1] * sign
# Calculate max column idx for each row idx based on interpolated line between two points
max_col_idx = (idxs[0] - p1[0]) / (p2[0] - p1[0]) * (p2[1] - p1[1]) + p1[1]
sign = numpy.sign(p2[0] - p1[0])
return idxs[1] * sign <= max_col_idx * sign