forked from LeenkxTeam/LNXSDK
304 lines
10 KiB
Python
304 lines
10 KiB
Python
|
import collections
|
||
|
|
import itertools
|
||
|
|
import operator
|
||
|
|
import heapq
|
||
|
|
import copy
|
||
|
|
from .pack_algo import PackingAlgorithm
|
||
|
|
from .geometry import Point as P
|
||
|
|
from .geometry import HSegment, Rectangle
|
||
|
|
from .waste import WasteManager
|
||
|
|
|
||
|
|
|
||
|
|
class Skyline(PackingAlgorithm):
|
||
|
|
""" Class implementing Skyline algorithm as described by
|
||
|
|
Jukka Jylanki - A Thousand Ways to Pack the Bin (February 27, 2010)
|
||
|
|
|
||
|
|
_skyline: stores all the segments at the top of the skyline.
|
||
|
|
_waste: Handles all wasted sections.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, width, height, rot=True, *args, **kwargs):
|
||
|
|
"""
|
||
|
|
_skyline is the list used to store all the skyline segments, each
|
||
|
|
one is a list with the format [x, y, width] where x is the x
|
||
|
|
coordinate of the left most point of the segment, y the y coordinate
|
||
|
|
of the segment, and width the length of the segment. The initial
|
||
|
|
segment is allways [0, 0, surface_width]
|
||
|
|
|
||
|
|
Arguments:
|
||
|
|
width (int, float):
|
||
|
|
height (int, float):
|
||
|
|
rot (bool): Enable or disable rectangle rotation
|
||
|
|
"""
|
||
|
|
self._waste_management = False
|
||
|
|
self._waste = WasteManager(rot=rot)
|
||
|
|
super(Skyline, self).__init__(width, height, rot, merge=False, *args, **kwargs)
|
||
|
|
|
||
|
|
def _placement_points_generator(self, skyline, width):
|
||
|
|
"""Returns a generator for the x coordinates of all the placement
|
||
|
|
points on the skyline for a given rectangle.
|
||
|
|
|
||
|
|
WARNING: In some cases could be duplicated points, but it is faster
|
||
|
|
to compute them twice than to remove them.
|
||
|
|
|
||
|
|
Arguments:
|
||
|
|
skyline (list): Skyline HSegment list
|
||
|
|
width (int, float): Rectangle width
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
generator
|
||
|
|
"""
|
||
|
|
skyline_r = skyline[-1].right
|
||
|
|
skyline_l = skyline[0].left
|
||
|
|
|
||
|
|
# Placements using skyline segment left point
|
||
|
|
ppointsl = (s.left for s in skyline if s.left+width <= skyline_r)
|
||
|
|
|
||
|
|
# Placements using skyline segment right point
|
||
|
|
ppointsr = (s.right-width for s in skyline if s.right-width >= skyline_l)
|
||
|
|
|
||
|
|
# Merge positions
|
||
|
|
return heapq.merge(ppointsl, ppointsr)
|
||
|
|
|
||
|
|
def _generate_placements(self, width, height):
|
||
|
|
"""
|
||
|
|
Generate a list with
|
||
|
|
|
||
|
|
Arguments:
|
||
|
|
skyline (list): SkylineHSegment list
|
||
|
|
width (number):
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
tuple (Rectangle, fitness):
|
||
|
|
Rectangle: Rectangle in valid position
|
||
|
|
left_skyline: Index for the skyline under the rectangle left edge.
|
||
|
|
right_skyline: Index for the skyline under the rectangle right edte.
|
||
|
|
"""
|
||
|
|
skyline = self._skyline
|
||
|
|
|
||
|
|
points = collections.deque()
|
||
|
|
|
||
|
|
left_index = right_index = 0 # Left and right side skyline index
|
||
|
|
support_height = skyline[0].top
|
||
|
|
support_index = 0
|
||
|
|
|
||
|
|
placements = self._placement_points_generator(skyline, width)
|
||
|
|
for p in placements:
|
||
|
|
|
||
|
|
# If Rectangle's right side changed segment, find new support
|
||
|
|
if p+width > skyline[right_index].right:
|
||
|
|
for right_index in range(right_index+1, len(skyline)):
|
||
|
|
if skyline[right_index].top >= support_height:
|
||
|
|
support_index = right_index
|
||
|
|
support_height = skyline[right_index].top
|
||
|
|
if p+width <= skyline[right_index].right:
|
||
|
|
break
|
||
|
|
|
||
|
|
# If left side changed segment.
|
||
|
|
if p >= skyline[left_index].right:
|
||
|
|
left_index +=1
|
||
|
|
|
||
|
|
# Find new support if the previous one was shifted out.
|
||
|
|
if support_index < left_index:
|
||
|
|
support_index = left_index
|
||
|
|
support_height = skyline[left_index].top
|
||
|
|
for i in range(left_index, right_index+1):
|
||
|
|
if skyline[i].top >= support_height:
|
||
|
|
support_index = i
|
||
|
|
support_height = skyline[i].top
|
||
|
|
|
||
|
|
# Add point if there is enought room at the top
|
||
|
|
if support_height+height <= self.height:
|
||
|
|
points.append((Rectangle(p, support_height, width, height),\
|
||
|
|
left_index, right_index))
|
||
|
|
|
||
|
|
return points
|
||
|
|
|
||
|
|
def _merge_skyline(self, skylineq, segment):
|
||
|
|
"""
|
||
|
|
Arguments:
|
||
|
|
skylineq (collections.deque):
|
||
|
|
segment (HSegment):
|
||
|
|
"""
|
||
|
|
if len(skylineq) == 0:
|
||
|
|
skylineq.append(segment)
|
||
|
|
return
|
||
|
|
|
||
|
|
if skylineq[-1].top == segment.top:
|
||
|
|
s = skylineq[-1]
|
||
|
|
skylineq[-1] = HSegment(s.start, s.length+segment.length)
|
||
|
|
else:
|
||
|
|
skylineq.append(segment)
|
||
|
|
|
||
|
|
def _add_skyline(self, rect):
|
||
|
|
"""
|
||
|
|
Arguments:
|
||
|
|
seg (Rectangle):
|
||
|
|
"""
|
||
|
|
skylineq = collections.deque([]) # Skyline after adding new one
|
||
|
|
|
||
|
|
for sky in self._skyline:
|
||
|
|
if sky.right <= rect.left or sky.left >= rect.right:
|
||
|
|
self._merge_skyline(skylineq, sky)
|
||
|
|
continue
|
||
|
|
|
||
|
|
if sky.left < rect.left and sky.right > rect.left:
|
||
|
|
# Skyline section partially under segment left
|
||
|
|
self._merge_skyline(skylineq,
|
||
|
|
HSegment(sky.start, rect.left-sky.left))
|
||
|
|
sky = HSegment(P(rect.left, sky.top), sky.right-rect.left)
|
||
|
|
|
||
|
|
if sky.left < rect.right:
|
||
|
|
if sky.left == rect.left:
|
||
|
|
self._merge_skyline(skylineq,
|
||
|
|
HSegment(P(rect.left, rect.top), rect.width))
|
||
|
|
# Skyline section partially under segment right
|
||
|
|
if sky.right > rect.right:
|
||
|
|
self._merge_skyline(skylineq,
|
||
|
|
HSegment(P(rect.right, sky.top), sky.right-rect.right))
|
||
|
|
sky = HSegment(sky.start, rect.right-sky.left)
|
||
|
|
|
||
|
|
if sky.left >= rect.left and sky.right <= rect.right:
|
||
|
|
# Skyline section fully under segment, account for wasted space
|
||
|
|
if self._waste_management and sky.top < rect.bottom:
|
||
|
|
self._waste.add_waste(sky.left, sky.top,
|
||
|
|
sky.length, rect.bottom - sky.top)
|
||
|
|
else:
|
||
|
|
# Segment
|
||
|
|
self._merge_skyline(skylineq, sky)
|
||
|
|
|
||
|
|
# Aaaaand ..... Done
|
||
|
|
self._skyline = list(skylineq)
|
||
|
|
|
||
|
|
def _rect_fitness(self, rect, left_index, right_index):
|
||
|
|
return rect.top
|
||
|
|
|
||
|
|
def _select_position(self, width, height):
|
||
|
|
"""
|
||
|
|
Search for the placement with the bes fitness for the rectangle.
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
tuple (Rectangle, fitness) - Rectangle placed in the fittest position
|
||
|
|
None - Rectangle couldn't be placed
|
||
|
|
"""
|
||
|
|
positions = self._generate_placements(width, height)
|
||
|
|
if self.rot and width != height:
|
||
|
|
positions += self._generate_placements(height, width)
|
||
|
|
if not positions:
|
||
|
|
return None, None
|
||
|
|
return min(((p[0], self._rect_fitness(*p))for p in positions),
|
||
|
|
key=operator.itemgetter(1))
|
||
|
|
|
||
|
|
def fitness(self, width, height):
|
||
|
|
"""Search for the best fitness
|
||
|
|
"""
|
||
|
|
assert(width > 0 and height >0)
|
||
|
|
if width > max(self.width, self.height) or\
|
||
|
|
height > max(self.height, self.width):
|
||
|
|
return None
|
||
|
|
|
||
|
|
# If there is room in wasted space, FREE PACKING!!
|
||
|
|
if self._waste_management:
|
||
|
|
if self._waste.fitness(width, height) is not None:
|
||
|
|
return 0
|
||
|
|
|
||
|
|
# Get best fitness segment, for normal rectangle, and for
|
||
|
|
# rotated rectangle if rotation is enabled.
|
||
|
|
rect, fitness = self._select_position(width, height)
|
||
|
|
return fitness
|
||
|
|
|
||
|
|
def add_rect(self, width, height, rid=None):
|
||
|
|
"""
|
||
|
|
Add new rectangle
|
||
|
|
"""
|
||
|
|
assert(width > 0 and height > 0)
|
||
|
|
if width > max(self.width, self.height) or\
|
||
|
|
height > max(self.height, self.width):
|
||
|
|
return None
|
||
|
|
|
||
|
|
rect = None
|
||
|
|
# If Waste managment is enabled, first try to place the rectangle there
|
||
|
|
if self._waste_management:
|
||
|
|
rect = self._waste.add_rect(width, height, rid)
|
||
|
|
|
||
|
|
# Get best possible rectangle position
|
||
|
|
if not rect:
|
||
|
|
rect, _ = self._select_position(width, height)
|
||
|
|
if rect:
|
||
|
|
self._add_skyline(rect)
|
||
|
|
|
||
|
|
if rect is None:
|
||
|
|
return None
|
||
|
|
|
||
|
|
# Store rectangle, and recalculate skyline
|
||
|
|
rect.rid = rid
|
||
|
|
self.rectangles.append(rect)
|
||
|
|
return rect
|
||
|
|
|
||
|
|
def reset(self):
|
||
|
|
super(Skyline, self).reset()
|
||
|
|
self._skyline = [HSegment(P(0, 0), self.width)]
|
||
|
|
self._waste.reset()
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
class SkylineWMixin(Skyline):
|
||
|
|
"""Waste managment mixin"""
|
||
|
|
def __init__(self, width, height, *args, **kwargs):
|
||
|
|
super(SkylineWMixin, self).__init__(width, height, *args, **kwargs)
|
||
|
|
self._waste_management = True
|
||
|
|
|
||
|
|
|
||
|
|
class SkylineMwf(Skyline):
|
||
|
|
"""Implements Min Waste fit heuristic, minimizing the area wasted under the
|
||
|
|
rectangle.
|
||
|
|
"""
|
||
|
|
def _rect_fitness(self, rect, left_index, right_index):
|
||
|
|
waste = 0
|
||
|
|
for seg in self._skyline[left_index:right_index+1]:
|
||
|
|
waste +=\
|
||
|
|
(min(rect.right, seg.right)-max(rect.left, seg.left)) *\
|
||
|
|
(rect.bottom-seg.top)
|
||
|
|
|
||
|
|
return waste
|
||
|
|
|
||
|
|
def _rect_fitnes2s(self, rect, left_index, right_index):
|
||
|
|
waste = ((min(rect.right, seg.right)-max(rect.left, seg.left)) for seg in self._skyline[left_index:right_index+1])
|
||
|
|
return sum(waste)
|
||
|
|
|
||
|
|
class SkylineMwfl(Skyline):
|
||
|
|
"""Implements Min Waste fit with low profile heuritic, minimizing the area
|
||
|
|
wasted below the rectangle, at the same time it tries to keep the height
|
||
|
|
minimal.
|
||
|
|
"""
|
||
|
|
def _rect_fitness(self, rect, left_index, right_index):
|
||
|
|
waste = 0
|
||
|
|
for seg in self._skyline[left_index:right_index+1]:
|
||
|
|
waste +=\
|
||
|
|
(min(rect.right, seg.right)-max(rect.left, seg.left)) *\
|
||
|
|
(rect.bottom-seg.top)
|
||
|
|
|
||
|
|
return waste*self.width*self.height+rect.top
|
||
|
|
|
||
|
|
|
||
|
|
class SkylineBl(Skyline):
|
||
|
|
"""Implements Bottom Left heuristic, the best fit option is that which
|
||
|
|
results in which the top side of the rectangle lies at the bottom-most
|
||
|
|
position.
|
||
|
|
"""
|
||
|
|
def _rect_fitness(self, rect, left_index, right_index):
|
||
|
|
return rect.top
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
class SkylineBlWm(SkylineBl, SkylineWMixin):
|
||
|
|
pass
|
||
|
|
|
||
|
|
class SkylineMwfWm(SkylineMwf, SkylineWMixin):
|
||
|
|
pass
|
||
|
|
|
||
|
|
class SkylineMwflWm(SkylineMwfl, SkylineWMixin):
|
||
|
|
pass
|