Merge pull request #430 from jdegenstein/trapezoid_width

Trapezoid width is now fully controlled by width param

src/build123d/objects_sketch.py

@@ -621,13 +621,32 @@ def __init__(
  reduction_right = (
  0 if right_side_angle == 90 else height / tan(radians(right_side_angle))
  )
- if reduction_left + reduction_right >= width:
+
+ top_width_left = width / 2
+ top_width_right = width / 2
+ bot_width_left = width / 2
+ bot_width_right = width / 2
+
+ if reduction_left > 0:
+ top_width_left -= reduction_left
+ else:
+ bot_width_left += reduction_left
+
+ if reduction_right > 0:
+ top_width_right -= reduction_right
+ else:
+ bot_width_right += reduction_right
+
+ if (bot_width_left + bot_width_right) < 0:
+ raise ValueError("Trapezoid bottom invalid - change angles")
+ if (top_width_left + top_width_right) < 0:
  raise ValueError("Trapezoid top invalid - change angles")
+
  pts = []
- pts.append(Vector(-width / 2, -height / 2))
- pts.append(Vector(width / 2, -height / 2))
- pts.append(Vector(width / 2 - reduction_right, height / 2))
- pts.append(Vector(-width / 2 + reduction_left, height / 2))
+ pts.append(Vector(-bot_width_left, -height / 2))
+ pts.append(Vector(bot_width_right, -height / 2))
+ pts.append(Vector(top_width_right, height / 2))
+ pts.append(Vector(-top_width_left, height / 2))
  pts.append(pts[0])
  face = Face.make_from_wires(Wire.make_polygon(pts))
  super().__init__(face, rotation, self.align, mode)

tests/test_build_sketch.py

@@ -382,6 +382,18 @@ def test_trapezoid(self):
  with BuildSketch() as test:
  Trapezoid(6, 2, 30)
 
+ with self.assertRaises(ValueError):
+ with BuildSketch() as test:
+ Trapezoid(6, 2, 150)
+
+ with BuildSketch() as test:
+ t = Trapezoid(12,8,135,90)
+ self.assertEqual(t.width, 12)
+ self.assertEqual(t.trapezoid_height, 8)
+ self.assertEqual(t.left_side_angle, 135)
+ self.assertEqual(t.right_side_angle, 90)
+ self.assertAlmostEqual(test.sketch.area, 8 * (12 + 4) / 2, 5)
+
  def test_triangle(self):
  tri = Triangle(a=3, b=4, c=5)
  self.assertAlmostEqual(tri.area, (3 * 4) / 2, 5)