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continue improving 2d packing example

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Laurent Perron
2021-11-15 11:48:34 +01:00
parent 9b75a7118d
commit 5111c0d7b5
1 changed files with 16 additions and 22 deletions
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38
examples/python/packing_2d_sat.py
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@@ -69,9 +69,6 @@ def build_data():
return (data, max_height, max_width)
# pytype: disable=wrong-arg-types
def solve_with_duplicate_items(data, max_height, max_width):
"""Solve the problem by building 2 items (rotated or not) for each item."""
# Derived data (expanded to individual items).
@@ -97,7 +94,6 @@ def solve_with_duplicate_items(data, max_height, max_width):
model = cp_model.CpModel()
# Variables
x_starts = []
x_ends = []
y_starts = []
@@ -184,7 +180,7 @@ def solve_with_rotations(data, max_height, max_width):
# OR-Tools model.
model = cp_model.CpModel()
# Variables.
# Coordinate variables for each rectangle.
x_starts = []
x_sizes = []
x_ends = []
@@ -195,22 +191,19 @@ def solve_with_rotations(data, max_height, max_width):
y_intervals = []
for i in range(num_items):
sizes = [0, int(item_widths[i]), int(item_heights[i])]
# X coordinates.
x_starts.append(model.NewIntVar(0, max_width, f'x_start{i}'))
x_sizes.append(
model.NewIntVarFromDomain(
cp_model.Domain.FromValues(
[0, int(item_widths[i]),
int(item_heights[i])]), f'x_size{i}'))
model.NewIntVarFromDomain(cp_model.Domain.FromValues(sizes),
f'x_size{i}'))
x_ends.append(model.NewIntVar(0, max_width, f'x_end{i}'))
# Y coordinates.
y_starts.append(model.NewIntVar(0, max_height, f'y_start{i}'))
y_sizes.append(
model.NewIntVarFromDomain(
cp_model.Domain.FromValues(
[0, int(item_widths[i]),
int(item_heights[i])]), f'y_size{i}'))
model.NewIntVarFromDomain(cp_model.Domain.FromValues(sizes),
f'y_size{i}'))
y_ends.append(model.NewIntVar(0, max_height, f'y_end{i}'))
## Interval variables
@@ -221,6 +214,7 @@ def solve_with_rotations(data, max_height, max_width):
model.NewIntervalVar(y_starts[i], y_sizes[i], y_ends[i],
f'y_interval{i}'))
# is_used[i] == True if and only if item i is selected.
is_used = []
# Constraints.
@@ -228,21 +222,21 @@ def solve_with_rotations(data, max_height, max_width):
## for each item, decide is unselected, no_rotation, rotated.
for i in range(num_items):
not_selected = model.NewBoolVar(f'not_selected_{i}')
no_rotation = model.NewBoolVar(f'no_rotation{i}')
rotation = model.NewBoolVar(f'rotation{i}')
no_rotation = model.NewBoolVar(f'no_rotation_{i}')
rotated = model.NewBoolVar(f'rotated_{i}')
### Only one state can be chosen.
model.Add(not_selected + no_rotation + rotation == 1)
### Exactly one state must be chosen.
model.Add(not_selected + no_rotation + rotated == 1)
### Define max_height and width.
dim1 = int(item_widths[i])
dim2 = int(item_heights[i])
### Define height and width according to the state.
dim1 = item_widths[i]
dim2 = item_heights[i]
model.Add(x_sizes[i] == 0).OnlyEnforceIf(not_selected)
model.Add(y_sizes[i] == 0).OnlyEnforceIf(not_selected)
model.Add(x_sizes[i] == dim1).OnlyEnforceIf(no_rotation)
model.Add(y_sizes[i] == dim2).OnlyEnforceIf(no_rotation)
model.Add(x_sizes[i] == dim2).OnlyEnforceIf(rotation)
model.Add(y_sizes[i] == dim1).OnlyEnforceIf(rotation)
model.Add(x_sizes[i] == dim2).OnlyEnforceIf(rotated)
model.Add(y_sizes[i] == dim1).OnlyEnforceIf(rotated)
is_used.append(not_selected.Not())