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Add startPoint and endPoint support to TSP solver and Python wrapper; add tests

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- Enhanced the C++ TSP solver to accept optional start and end points, so the route can begin and/or end at the closest point to specified coordinates.
- Updated the Python pybind11 wrapper and PathUtils.sort_locations_tsp to support startPoint and endPoint as named parameters.
- Added a new Python test suite (TestTSPSolver.py) to verify correct handling of start/end points and integration with PathUtils.
- Registered the new test in TestCAMApp.py and CMakeLists.txt for automatic test discovery.
This commit is contained in:
Billy Huddleston
2025-10-17 15:03:10 -04:00
parent f9347c781b
commit 428948699a
7 changed files with 373 additions and 9 deletions
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154
src/Mod/CAM/App/tsp_solver.cpp
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@@ -55,16 +55,41 @@ void twoOptSwap(std::vector<int>& path, size_t i, size_t k)
}
} // namespace
std::vector<int> TSPSolver::solve(const std::vector<TSPPoint>& points)
/**
* @brief Solve the Traveling Salesperson Problem using 2-opt algorithm
*
* This implementation handles optional start and end point constraints:
* - If startPoint is provided, the path will begin at the point closest to startPoint
* - If endPoint is provided, the path will end at the point closest to endPoint
* - If both are provided, the path will respect both constraints while optimizing the middle path
* - The algorithm ensures all points are visited exactly once
*/
std::vector<int> TSPSolver::solve(const std::vector<TSPPoint>& points,
const TSPPoint* startPoint,
const TSPPoint* endPoint)
{
size_t n = points.size();
if (n == 0) {
return {};
}
// Start with a simple nearest neighbor path
std::vector<bool> visited(n, false);
std::vector<int> path;
// If startPoint provided, find the closest point to it
size_t current = 0;
if (startPoint) {
double minDist = std::numeric_limits<double>::max();
for (size_t i = 0; i < n; ++i) {
double d = dist(points[i], *startPoint);
if (d < minDist) {
minDist = d;
current = i;
}
}
}
path.push_back(static_cast<int>(current));
visited[current] = true;
for (size_t step = 1; step < n; ++step) {
@@ -101,5 +126,132 @@ std::vector<int> TSPSolver::solve(const std::vector<TSPPoint>& points)
}
}
}
// Handle end point constraint if specified
if (endPoint) {
// If both start and end points are specified, we need to handle them differently
if (startPoint) {
// Find the closest points to start and end
size_t startIdx = 0;
size_t endIdx = 0;
double minStartDist = std::numeric_limits<double>::max();
double minEndDist = std::numeric_limits<double>::max();
// Find the indices of the closest points to both start and end points
for (size_t i = 0; i < n; ++i) {
// Find closest to start
double dStart = dist(points[i], *startPoint);
if (dStart < minStartDist) {
minStartDist = dStart;
startIdx = i;
}
// Find closest to end
double dEnd = dist(points[i], *endPoint);
if (dEnd < minEndDist) {
minEndDist = dEnd;
endIdx = i;
}
}
// If start and end are different points, create a new path
if (startIdx != endIdx) {
// Create a new path starting with the start point and ending with the end point
// This ensures both constraints are met
std::vector<bool> visited(n, false);
std::vector<int> newPath;
// Add start point
newPath.push_back(static_cast<int>(startIdx));
visited[startIdx] = true;
// Add all other points except end point using nearest neighbor algorithm
// This builds a path that starts at startIdx and visits all intermediate points
size_t current = startIdx;
for (size_t step = 1; step < n - 1; ++step) {
double minDist = std::numeric_limits<double>::max();
size_t next = n; // Invalid index (n is out of bounds)
for (size_t i = 0; i < n; ++i) {
if (!visited[i] && i != endIdx) {
double d = dist(points[current], points[i]);
if (d < minDist) {
minDist = d;
next = i;
}
}
}
if (next == n) {
break; // No more points to add
}
current = next;
newPath.push_back(static_cast<int>(current));
visited[current] = true;
}
// Add end point as the final stop in the path
newPath.push_back(static_cast<int>(endIdx));
// Apply 2-opt optimization while preserving the start and end points
// The algorithm only swaps edges between interior points
bool improved = true;
while (improved) {
improved = false;
// Start from 1 and end before the last point to preserve start/end constraints
for (size_t i = 1; i < newPath.size() - 1; ++i) {
for (size_t k = i + 1; k < newPath.size() - 1; ++k) {
// Calculate improvement in distance if we swap these edges
double delta = dist(points[newPath[i - 1]], points[newPath[k]])
+ dist(points[newPath[i]], points[newPath[k + 1]])
- dist(points[newPath[i - 1]], points[newPath[i]])
- dist(points[newPath[k]], points[newPath[k + 1]]);
// If the swap reduces the total distance, make the swap
if (delta < -Base::Precision::Confusion()) {
std::reverse(newPath.begin() + static_cast<long>(i),
newPath.begin() + static_cast<long>(k) + 1);
improved = true;
}
}
}
}
path = newPath;
}
// If start and end are the same point, keep path as is
}
else {
// Only end point specified (no start point constraint)
// Find the point in the current path that's closest to the desired end point
double minDist = std::numeric_limits<double>::max();
size_t endIdx = 0;
for (size_t i = 0; i < n; ++i) {
double d = dist(points[path[i]], *endPoint);
if (d < minDist) {
minDist = d;
endIdx = i;
}
}
// Rotate the path so that endIdx is at the end
// This preserves the relative order of points while ensuring the path ends
// at the point closest to the specified end coordinates
if (endIdx != n - 1) {
std::vector<int> newPath;
// Start with points after endIdx
for (size_t i = endIdx + 1; i < n; ++i) {
newPath.push_back(path[i]);
}
// Then add points from beginning up to and including endIdx
for (size_t i = 0; i <= endIdx; ++i) {
newPath.push_back(path[i]);
}
path = newPath;
}
}
}
return path;
}

6
src/Mod/CAM/App/tsp_solver.h
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@@ -38,5 +38,9 @@ class TSPSolver
{
public:
// Returns a vector of indices representing the visit order using 2-Opt
static std::vector<int> solve(const std::vector<TSPPoint>& points);
// If startPoint or endPoint are provided, the path will start/end at the closest point to these
// coordinates
static std::vector<int> solve(const std::vector<TSPPoint>& points,
const TSPPoint* startPoint = nullptr,
const TSPPoint* endPoint = nullptr);
};

72
src/Mod/CAM/App/tsp_solver_pybind.cpp
View File

@@ -25,13 +25,72 @@
namespace py = pybind11;
std::vector<int> tspSolvePy(const std::vector<std::pair<double, double>>& points)
std::vector<int> tspSolvePy(const std::vector<std::pair<double, double>>& points,
const py::object& startPoint = py::none(),
const py::object& endPoint = py::none())
{
std::vector<TSPPoint> pts;
for (const auto& p : points) {
pts.emplace_back(p.first, p.second);
}
return TSPSolver::solve(pts);
// Handle optional start point
TSPPoint* pStartPoint = nullptr;
TSPPoint startPointObj(0, 0);
if (!startPoint.is_none()) {
try {
// Use py::cast to convert to standard C++ types
auto sp = startPoint.cast<std::vector<double>>();
if (sp.size() >= 2) {
startPointObj.x = sp[0];
startPointObj.y = sp[1];
pStartPoint = &startPointObj;
}
}
catch (py::cast_error&) {
// If casting fails, try accessing elements directly
try {
if (py::len(startPoint) >= 2) {
startPointObj.x = py::cast<double>(startPoint.attr("__getitem__")(0));
startPointObj.y = py::cast<double>(startPoint.attr("__getitem__")(1));
pStartPoint = &startPointObj;
}
}
catch (py::error_already_set&) {
// Ignore if we can't access the elements
}
}
}
// Handle optional end point
TSPPoint* pEndPoint = nullptr;
TSPPoint endPointObj(0, 0);
if (!endPoint.is_none()) {
try {
// Use py::cast to convert to standard C++ types
auto ep = endPoint.cast<std::vector<double>>();
if (ep.size() >= 2) {
endPointObj.x = ep[0];
endPointObj.y = ep[1];
pEndPoint = &endPointObj;
}
}
catch (py::cast_error&) {
// If casting fails, try accessing elements directly
try {
if (py::len(endPoint) >= 2) {
endPointObj.x = py::cast<double>(endPoint.attr("__getitem__")(0));
endPointObj.y = py::cast<double>(endPoint.attr("__getitem__")(1));
pEndPoint = &endPointObj;
}
}
catch (py::error_already_set&) {
// Ignore if we can't access the elements
}
}
}
return TSPSolver::solve(pts, pStartPoint, pEndPoint);
}
PYBIND11_MODULE(tsp_solver, m)
@@ -40,5 +99,12 @@ PYBIND11_MODULE(tsp_solver, m)
m.def("solve",
&tspSolvePy,
py::arg("points"),
"Solve TSP for a list of (x, y) points using 2-Opt, returns visit order");
py::arg("startPoint") = py::none(),
py::arg("endPoint") = py::none(),
"Solve TSP for a list of (x, y) points using 2-Opt, returns visit order.\n"
"Optional arguments:\n"
"- startPoint: Optional [x, y] point where the path should start (closest point will be "
"chosen)\n"
"- endPoint: Optional [x, y] point where the path should end (closest point will be "
"chosen)");
}

128
src/Mod/CAM/CAMTests/TestTSPSolver.py Normal file
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@@ -0,0 +1,128 @@
# ***************************************************************************
# * Copyright (c) 2025 Billy Huddleston <billy@ivdc.com> *
# * *
# * This program is free software; you can redistribute it and/or modify *
# * it under the terms of the GNU Lesser General Public License (LGPL) *
# * as published by the Free Software Foundation; either version 2 of *
# * the License, or (at your option) any later version. *
# * for detail see the LICENCE text file. *
# * *
# * This program is distributed in the hope that it will be useful, *
# * but WITHOUT ANY WARRANTY; without even the implied warranty of *
# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
# * GNU Library General Public License for more details. *
# * *
# * You should have received a copy of the GNU Library General Public *
# * License along with this program; if not, write to the Free Software *
# * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
# * USA *
# * *
# ***************************************************************************
import FreeCAD
import math
import tsp_solver
import PathScripts.PathUtils as PathUtils
from CAMTests.PathTestUtils import PathTestBase
class TestTSPSolver(PathTestBase):
"""Test class for the TSP (Traveling Salesman Problem) solver."""
def setUp(self):
"""Set up test environment."""
# Create test points arranged in a simple pattern
self.square_points = [
(0, 0), # 0 - bottom left
(10, 0), # 1 - bottom right
(10, 10), # 2 - top right
(0, 10), # 3 - top left
]
self.random_points = [
(5, 5), # 0 - center
(8, 2), # 1
(3, 7), # 2
(1, 3), # 3
(9, 8), # 4
]
# Create dictionary points for PathUtils.sort_locations_tsp
self.dict_points = [{"x": x, "y": y} for x, y in self.random_points]
def test_simple_tsp(self):
"""Test TSP solver with a simple square of points."""
# Test the TSP solver on a simple square
route = tsp_solver.solve(self.square_points)
# Check that the route contains all points exactly once
self.assertEqual(len(route), len(self.square_points))
self.assertEqual(set(route), set(range(len(self.square_points))))
# Check that the route forms a logical path (each point is adjacent to previous)
total_distance = 0
for i in range(len(route) - 1):
pt1 = self.square_points[route[i]]
pt2 = self.square_points[route[i + 1]]
total_distance += math.sqrt((pt2[0] - pt1[0]) ** 2 + (pt2[1] - pt1[1]) ** 2)
# The path length should be 30 for a non-closed tour of a 10x10 square
# (10 + 10 + 10 = 30 for three sides of a square)
# Allow for small numerical errors
self.assertRoughly(total_distance, 30.0, 0.001)
def test_start_point(self):
"""Test that the path starts from the point closest to the specified start."""
# Force start point at (0, 0)
start_point = [0, 0]
route = tsp_solver.solve(self.random_points, startPoint=start_point)
# Based on observed behavior, the solver is choosing point 3
# This may be using a different distance metric or have different implementation details
closest_pt_idx = 3
self.assertEqual(route[0], closest_pt_idx)
def test_end_point(self):
"""Test that the path ends at the point closest to the specified end."""
# Force end point at (10, 10)
end_point = [10, 10]
route = tsp_solver.solve(self.random_points, endPoint=end_point)
# The last point should be the closest to (10, 10), which is point 4 (9, 8)
closest_pt_idx = 4
self.assertEqual(route[-1], closest_pt_idx)
def test_start_end_points(self):
"""Test that path respects both start and end points."""
start_point = [0, 0] # Solver should choose point 3 (1, 3) - closest to (0,0)
end_point = [10, 10] # Closest is point 4 (9, 8)
route = tsp_solver.solve(self.random_points, startPoint=start_point, endPoint=end_point)
self.assertEqual(route[0], 3) # Should start with point 3 (closest to start)
self.assertEqual(route[-1], 4) # Should end with point 4 (closest to end)
def test_path_utils_integration(self):
"""Test integration with PathUtils.sort_locations_tsp."""
keys = ["x", "y"]
start_point = [0, 0]
end_point = [10, 10]
# Test with both start and end points
sorted_locations = PathUtils.sort_locations_tsp(
self.dict_points, keys=keys, startPoint=start_point, endPoint=end_point
)
# First point should be closest to (0,0), which is point 3 (1,3)
self.assertRoughly(sorted_locations[0]["x"], 1, 0.001)
self.assertRoughly(sorted_locations[0]["y"], 3, 0.001)
# Last point should have coordinates closest to (10, 10)
self.assertRoughly(sorted_locations[-1]["x"], 9, 0.001)
self.assertRoughly(sorted_locations[-1]["y"], 8, 0.001)
if __name__ == "__main__":
import unittest
unittest.main()

1
src/Mod/CAM/CMakeLists.txt
View File

@@ -571,6 +571,7 @@ SET(Tests_SRCS
CAMTests/TestPostGCodes.py
CAMTests/TestPostMCodes.py
CAMTests/TestSnapmakerPost.py
CAMTests/TestTSPSolver.py
CAMTests/Tools/Bit/test-path-tool-bit-bit-00.fctb
CAMTests/Tools/Library/test-path-tool-bit-library-00.fctl
CAMTests/Tools/Shape/test-path-tool-bit-shape-00.fcstd

20
src/Mod/CAM/PathScripts/PathUtils.py
View File

@@ -613,14 +613,26 @@ def sort_locations(locations, keys, attractors=None):
return out
def sort_locations_tsp(locations, keys, attractors=None):
def sort_locations_tsp(locations, keys, attractors=None, startPoint=None, endPoint=None):
"""
Python wrapper for the C++ TSP solver. Takes a list of dicts (locations),
a list of keys (e.g. ['x', 'y']), and optional attractors.
Returns the sorted list of locations in TSP order, starting at (0,0).
a list of keys (e.g. ['x', 'y']), and optional parameters.
Parameters:
- locations: List of dictionaries with point coordinates
- keys: List of keys to use for coordinates (e.g. ['x', 'y'])
- attractors: Optional parameter (not used, kept for compatibility)
- startPoint: Optional starting point [x, y]
- endPoint: Optional ending point [x, y]
Returns the sorted list of locations in TSP order.
If startPoint is None, path starts from the first point in the original order.
"""
# Extract points from locations
points = [(loc[keys[0]], loc[keys[1]]) for loc in locations]
order = tsp_solver.solve(points)
order = tsp_solver.solve(points=points, startPoint=startPoint, endPoint=endPoint)
# Return the reordered locations
return [locations[i] for i in order]

1
src/Mod/CAM/TestCAMApp.py
View File

@@ -117,3 +117,4 @@ from CAMTests.TestCentroidLegacyPost import TestCentroidLegacyPost
from CAMTests.TestMach3Mach4LegacyPost import TestMach3Mach4LegacyPost
from CAMTests.TestSnapmakerPost import TestSnapmakerPost
from CAMTests.TestTSPSolver import TestTSPSolver