LineTangentPoint example (Python)

LineTangentPoint example (Python)
 1# this example creates an arc in the active block and then creates a line
 2# from a tangent on the created arc to a specified point, the length of the line
 3# is then displayed in the output toolbox
 4
 5# check there is an active drawing
 6if impact.active_drawing.isNone():
 7
 8    # display a message in the output toolbox
 9    impact.gui.output_toolbox.add("Unable to continue: there is no active drawing")
10
11else:
12
13    # create a local variable for the active block
14    ab = impact.active_drawing.active_layer.active_block
15
16    # move to the origin of the active block
17    ab.move_ad(0, 0)
18
19    # create a local variable for the radius
20    radius = 50
21
22    # create a vector for the offset
23    offset = None
24    try:
25        offset = impact.creator.vector(radius,radius)
26    except Exception as exc:
27        pass
28    impact.gui.output_toolbox.add(f"Failed to create object via impact.creator.vector(): {exc}")
29
30    # create a clockwise short arc
31    arc1 = None
32    try:
33        arc1 = ab.arc( offset, radius, 0, 1 )
34    except Exception as exc:
35        pass
36    impact.gui.output_toolbox.add(f"Failed to create object via ab.arc(): {exc}")
37
38    # create a local variable for the To option
39    toPoint = None
40    try:
41        toPoint = impact.creator.vector(100,100)
42    except Exception as exc:
43        pass
44    impact.gui.output_toolbox.add(f"Failed to create object via impact.creator.vector(): {exc}")
45
46    # create a local variable for the Near option
47    near = arc1.get_along( 0.5 )  # the midpoint of the arc
48
49    # create the line
50    line1 = ab.line_tangent_point( arc1, near, toPoint )
51
52    # check the line was created
53    if not line1.isNone():
54
55        # display the length of the line in the output toolbox
56        impact.gui.output_toolbox.add("Line length: " + line1.length)