(feat) Hobby Splines

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "solidpython"
-version = "1.1.3"
+version = "1.1.4"
 description = "Python interface to the OpenSCAD declarative geometry language"
 authors = ["Evan Jones <[email protected]>"]
 homepage = "https://github.com/SolidCode/SolidPython"

solid/examples/hobby_splines_example.py

@@ -0,0 +1,56 @@
+import sys
+import os
+from solid import polygon, scad_render_to_file
+from solid.splines import SEGMENTS, bezier_points, control_points
+from solid.examples.path_extrude_example import circle_points
+from euclid3 import Vector3, Point3
+
+from solid import splines
+from solid.utils import right, extrude_along_path
+
+SCALE = 30
+OMEGA = 1.0
+SUBDIVISIONS = 12
+SEGMENTS = 12
+
+
+def assembly():
+    knot_points = [
+        Point3(0, 0, -1),
+        Point3(1, -2, -2),
+        Point3(2, 0, 1),
+        Point3(3, -1, 2),
+        Point3(3, 1, -2),
+    ]
+    knot_points = [kp * SCALE for kp in knot_points]
+    path = splines.hobby_points(knot_points, OMEGA, close_loop=True)
+    path_open = splines.hobby_points(knot_points, OMEGA, close_loop=False)
+    bzp = []  # Closed Hobby spline control points used to make beziers
+    bzp_open = []  # Open Hobby spline control for same thing
+    for i in range(0, len(path) - 3, 3):
+        # Controls take the form of: Knot, control vec, control vec, knot
+        controls = path[i : i + 4]
+        controls_open = path_open[i : i + 4]
+        bzp += bezier_points(controls, subdivisions=SUBDIVISIONS)
+        if len(controls_open) == 4:
+            # PATH_OPEN may have fewer segments than PATH so assume last valid
+            # group of 4 points is the final segment of the open curve
+            bzp_open += bezier_points(controls_open, subdivisions=SUBDIVISIONS)
+
+    assembly = polygon(bzp) + right(5 * SCALE)(
+        extrude_along_path(circle_points(0.3 * SCALE, SEGMENTS), bzp)
+        + right(5 * SCALE)(
+            extrude_along_path(circle_points(0.3 * SCALE, SEGMENTS), bzp_open)
+            + right(5 * SCALE)(polygon(bzp_open))
+        )
+    )
+    return assembly
+
+
+if __name__ == "__main__":
+    out_dir = sys.argv[1] if len(sys.argv) > 1 else os.curdir
+
+    a = assembly()
+
+    out_path = scad_render_to_file(a, out_dir=out_dir, include_orig_code=True)
+    print(f"{__file__}: SCAD file written to: \n{out_path}")