Pyclipr

Fixes for addPaths which were not correctly offsetting for polygon regions.
Updated example for clipper offset + visualisation

.github/workflows/pythonpublish.yml

@@ -14,7 +14,10 @@ jobs:
     strategy:
       matrix:
         python-version: [3.7, 3.8, 3.9, '3.10', '3.11', '3.12']
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-latest, macos-13, windows-latest]
+        exclude:
+        - os: ubuntu-latest
+            python-version: '3.12'
 
     steps:
     - uses: actions/checkout@v2

CHANGELOG.md

@@ -10,6 +10,20 @@ All notable changes to this project will be documented in this file.
 
 ### Changed
 
+
+## [0.1.5] - 2023-16-12
+
+### Added
+
+### Fixed
+
+- In `ClipperOffset::addPaths`, paths of each polygon are seperately constructed into a list of paths to ensure that these are correctly imported into ClipperOffset.
+- Scale factor has been applied when importing paths
+
+### Changed
+
+
+
 ## [0.1.4] - 2023-11-12
 
 Update release for PyClipr and updated dependencies to ClipperLib2 v.1.2. and Eigen 3.4.0 - dependent on

README.rst

@@ -81,7 +81,9 @@ by using either `execute` or `execute2` methods, respectively.
     po.scaleFactor = int(1000)
 
     # add the path - ensuring to use Polygon for the endType argument
-    po.addPath(np.array(path), pyclipr.JoinType.Miter, pyclipr.EndType.Polygon)
+    # addPaths is required when working with polygon - this is a list of correctly orientated paths for exterior
+    # and interior holes
+    po.addPaths([np.array(path)], pyclipr.JoinType.Miter, pyclipr.EndType.Polygon)
 
     # Apply the offsetting operation using a delta.
     offsetSquare = po.execute(10.0)
@@ -149,4 +151,4 @@ by using either `execute` or `execute2` methods, respectively.
     plt.fill(out[0][:, 0], out[0][:, 1],  facecolor='#75507b')
 
     # Plot the open path intersection
-    plt.plot(openPathsC[0][:,0], openPathsC[0][:,1],color='#222', linewidth=1.0, linestyle='dashed', marker='.',markersize=20.0)
+    plt.plot(openPathsC[0][:,0], openPathsC[0][:,1],color='#222', linewidth=1.0, linestyle='dashed', marker='.',markersize=20.0)

examples/example.py

@@ -4,8 +4,11 @@
 import pyclipr
 
 # Tuple definition of a path
-path = [(0.0, 0.), (0, 105.1234), (100, 105.1234), (100, 0), (0, 0)]
-path2 = [(1.0, 1.0), (1.0, 50), (100, 50), (100, 1.0), (1.0, 1.0)]
+path = np.array([(0.0, 0.), (0, 105.1234), (100, 105.1234), (100, 0), (0, 0)])
+path2 = np.array([(10.0, 10.0), (1.0, 50), (50.0, 50), (50., 10.0), (10.0, 10.0)])
+path2 = np.flipud(path2)
+
+path3 = np.array([(-10.0, -10.0), (70.0, -10), (70.0, 70), (-10., 70.0), (-10.0, -10.0)])
 
 """
 Create an offsetting PyClipr tool
@@ -14,16 +17,20 @@
 
 # Set the scale factor to convert to internal integer representation
 # Note the default is set to 1000 units
-po.scaleFactor = int(1000)
+po.scaleFactor = int(1e4)
 
 # add the path - ensuring to use Polygon for the endType argument
-po.addPath(np.array(path), pyclipr.JoinType.Miter, pyclipr.EndType.Polygon)
-
+po.addPaths([path, path2], pyclipr.JoinType.Miter, pyclipr.EndType.Polygon)
 """
 Apply the offsetting operation using a delta/offset
 NoteL this automatically scaled interally scaled within pyclipr.ClipperOffset
 """
-offsetSquare = po.execute(10.0)
+offsetOut = po.execute(-1.0)
+
+import pyslm.visualise
+handle = pyslm.visualise.plotPolygon([path, path2])
+pyslm.visualise.plotPolygon(offsetOut, handle=handle, lineColor='r')
+
 
 """
 Create a Pyclipr clipping tool
@@ -35,10 +42,10 @@
 Add the paths to the clipping object. Ensure the subject and clip arguments are set to differentiate
 the paths during the Boolean operation. The final argument specifies if the path is open.
 """
-pc.addPaths(offsetSquare, pyclipr.Subject)
+pc.addPaths(offsetOut, pyclipr.Subject)
 
 # Note it is possible to add a path as a numpy array (nx2) or as a list of tuples
-pc.addPath(np.array(path2), pyclipr.Clip)
+pc.addPath(np.array(path3), pyclipr.Clip)
 
 """
 Perform Polygon Clipping 
@@ -76,7 +83,7 @@
 pc2.addPath(((40, -10), (50, 130)), pyclipr.Subject, True)
 
 # The clipping object is usually set to the Polygon
-pc2.addPaths(offsetSquare, pyclipr.Clip, False)
+pc2.addPaths(offsetOut, pyclipr.Clip, False)
 
 """ 
 Test the return types for open path clipping with option enabled. When The returnOpenPaths argument is set to True
@@ -100,7 +107,7 @@
 plt.fill(pathPoly[:, 0], pathPoly[:, 1], 'b', alpha=0.1, linewidth=1.0, linestyle='dashed', edgecolor='#000')
 
 # Plot the offset square
-plt.fill(offsetSquare[0][:, 0], offsetSquare[0][:, 1],
+plt.fill(offsetOut[0][:, 0], offsetOut[0][:, 1],
          linewidth=1.0, linestyle='dashed', edgecolor='#333', facecolor='none')
 
 # Plot the intersection

python/pyclipr/module.cpp

@@ -27,7 +27,6 @@ typedef Eigen::Matrix<double,Eigen::Dynamic,2>   EigenVec2d;
 typedef Eigen::Matrix<double,Eigen::Dynamic,3>   EigenVec3d;
 
 
-
 static void myZCB(const Clipper2Lib::Point64& e1bot, const Clipper2Lib::Point64& e1top,
                   const Clipper2Lib::Point64& e2bot, const Clipper2Lib::Point64& e2top,
                   Clipper2Lib::Point64& pt) {
@@ -112,7 +111,7 @@ void applyScaleFactor(const Clipper2Lib::PolyPath64 & polyPath,
     {
         Clipper2Lib::Path64 path = polyPath[i]->Polygon();
         Clipper2Lib::PolyPathD pathD;
-        newPath.SetScale(1.0/scaleFactor);
+        newPath.SetScale(1.0 / double(scaleFactor));
 
         auto newChild = newPath.AddChild(path);
 
@@ -194,8 +193,8 @@ class Clipper : public Clipper2Lib::Clipper64 {
             EigenVec1d eigPathZ(path.size(), 1);
 
             for (uint64_t i=0; i < path.size(); i++) {
-                eigPath(i,0) = double(path[i].x) / scaleFactor;
-                eigPath(i,1) = double(path[i].y) / scaleFactor;
+                eigPath(i,0) = double(path[i].x) / double(scaleFactor);
+                eigPath(i,1) = double(path[i].y) / double(scaleFactor);
 
                 if(returnZ)
                     eigPathZ(i, 0) = path[i].z;
@@ -221,8 +220,8 @@ class Clipper : public Clipper2Lib::Clipper64 {
                 EigenVec2d eigPath(path.size(), 2);
 
                 for (uint64_t i=0; i<path.size(); i++) {
-                    eigPath(i,0) = double(path[i].x) / scaleFactor;
-                    eigPath(i,1) = double(path[i].y) / scaleFactor;
+                    eigPath(i,0) = double(path[i].x) / double(scaleFactor);
+                    eigPath(i,1) = double(path[i].y) / double(scaleFactor);
 
                     if(returnZ) {
                         //std::cout << "OP: assign z" << path[i].z;
@@ -266,8 +265,8 @@ class Clipper : public Clipper2Lib::Clipper64 {
                 EigenVec1d eigPathZ(path.size(), 1);
 
                 for (uint64_t i=0; i<path.size(); i++) {
-                    eigPath(i,0) = double(path[i].x) / scaleFactor;
-                    eigPath(i,1) = double(path[i].y) / scaleFactor;
+                    eigPath(i,0) = double(path[i].x) / double(scaleFactor);
+                    eigPath(i,1) = double(path[i].y) / double(scaleFactor);
 
                     if(returnZ)
                         eigPathZ(i) = path[i].z;
@@ -322,7 +321,6 @@ class ClipperOffset : public Clipper2Lib::ClipperOffset {
 
         auto r = path.unchecked<2>();
 
-
         if(path.shape(1) == 2) {
             for(uint64_t i=0; i < path.shape(0); i++)
                 p.push_back(Clipper2Lib::Point64(r(i,0) * scaleFactor, r(i,1) * scaleFactor));
@@ -340,9 +338,35 @@ class ClipperOffset : public Clipper2Lib::ClipperOffset {
                   const Clipper2Lib::EndType endType = Clipper2Lib::EndType::Polygon)
     {
 
-        for(auto path : paths)
-            addPath(path, joinType, endType);
+        std::vector<Clipper2Lib::Path64> closedPaths;
+
+        for(auto path : paths) {
+
+            Clipper2Lib::Path64 p;
+
+            if (path.ndim() != 2)
+                throw std::runtime_error("Number of dimensions must be two");
+
+            if (!(path.shape(1) == 2 || path.shape(1) == 3))
+                throw std::runtime_error("Path must be nx2, or nx3");
 
+            // Resize the path list
+            p.reserve(path.shape(0));
+
+            auto r = path.unchecked<2>();
+
+            if(path.shape(1) == 2) {
+                for(uint64_t i=0; i < path.shape(0); i++)
+                    p.push_back(Clipper2Lib::Point64(r(i,0) * scaleFactor, r(i,1) * scaleFactor));
+            } else {
+                for(uint64_t i=0; i < path.shape(0); i++)
+                    p.push_back(Clipper2Lib::Point64(r(i,0) * scaleFactor, r(i,1) * scaleFactor, r(i,2)));
+            }
+
+            closedPaths.push_back(p);
+
+        }
+        this->AddPaths(closedPaths, joinType, endType);
     }
 
     void clear() { this->Clear(); }
@@ -360,8 +384,8 @@ class ClipperOffset : public Clipper2Lib::ClipperOffset {
             EigenVec2d eigPath(path.size(), 2);
 
             for (uint64_t i=0; i<path.size(); i++) {
-                eigPath(i,0) = double(path[i].x) / scaleFactor;
-                eigPath(i,1) = double(path[i].y) / scaleFactor;
+                eigPath(i,0) = double(path[i].x) / double(scaleFactor);
+                eigPath(i,1) = double(path[i].y) / double(scaleFactor);
             }
 
             closedOut.push_back(eigPath);

setup.py

@@ -76,7 +76,7 @@ def build_extension(self, ext):
 
 setup(
     name='pyclipr',
-    version='0.1.4',
+    version='0.1.5',
     author='Luke Parry',
     author_email='[email protected]',
     url='https://github.com/drlukeparry/pyclipr',