micheleandCursor
6fc2ac583d
Use the vendored Hammerstad-Jensen/Cohn engine for microstrip, stripline, and coupled-diff advice. Skip OpenEMS/pcbnew and refuse CPWG rather than inventing a number. Co-authored-by: Cursor <cursoragent@cursor.com>
65 lines
3.2 KiB
Python
65 lines
3.2 KiB
Python
from __future__ import annotations
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import pytest
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from impedancefinder import net_walk
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from impedancefinder.model import Point2D, TraceSegment
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def test_pitch_must_be_positive():
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with pytest.raises(ValueError):
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net_walk.sample_net((), pitch_mm=0.0)
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def test_bend_chains_into_one_continuous_branch():
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# Two segments sharing an exact endpoint at (5, 0) -- a bend, not a via.
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first = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(0, 0), end=Point2D(5, 0), width_mm=0.2)
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second = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(5, 0), end=Point2D(5, 5), width_mm=0.2)
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branches = net_walk.sample_net((first, second), pitch_mm=1.0)
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assert len(branches) == 1
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distances = [s.distance_along_net_mm for s in branches[0].samples]
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assert distances == sorted(distances)
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assert distances[0] == 0.0
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assert distances[-1] == pytest.approx(10.0) # 5mm + 5mm, continuous
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def test_via_like_layer_change_stays_continuous():
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# A segment on F.Cu ending exactly where a segment on In1.Cu begins --
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# this is what a via looks like geometrically, with no ViaSpan needed
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# for net_walk to treat it as one continuous run.
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top = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(0, 0), end=Point2D(3, 0), width_mm=0.2)
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bottom = TraceSegment(net="SIG", layer="In1.Cu", start=Point2D(3, 0), end=Point2D(7, 0), width_mm=0.2)
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branches = net_walk.sample_net((top, bottom), pitch_mm=1.0)
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assert len(branches) == 1
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assert branches[0].samples[-1].distance_along_net_mm == pytest.approx(7.0)
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def test_t_junction_splits_into_three_branches_zeroed_at_the_junction():
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junction = Point2D(0, 0)
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spoke_a = TraceSegment(net="SIG", layer="F.Cu", start=junction, end=Point2D(3, 0), width_mm=0.2)
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spoke_b = TraceSegment(net="SIG", layer="F.Cu", start=junction, end=Point2D(0, 4), width_mm=0.2)
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spoke_c = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(-5, 0), end=junction, width_mm=0.2)
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branches = net_walk.sample_net((spoke_a, spoke_b, spoke_c), pitch_mm=1.0)
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assert len(branches) == 3
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lengths = sorted(branch.samples[-1].distance_along_net_mm for branch in branches)
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assert lengths == pytest.approx([3.0, 4.0, 5.0])
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# every branch must start at the junction, not at its far leaf
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assert all(branch.samples[0].distance_along_net_mm == 0.0 for branch in branches)
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def test_disconnected_segments_become_separate_branches():
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isolated_a = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(0, 0), end=Point2D(2, 0), width_mm=0.2)
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isolated_b = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(100, 0), end=Point2D(103, 0), width_mm=0.2)
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branches = net_walk.sample_net((isolated_a, isolated_b), pitch_mm=1.0)
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assert len(branches) == 2
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lengths = sorted(branch.samples[-1].distance_along_net_mm for branch in branches)
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assert lengths == pytest.approx([2.0, 3.0])
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def test_zero_length_segment_produces_a_single_sample():
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point_segment = TraceSegment(net="SIG", layer="F.Cu", start=Point2D(1, 1), end=Point2D(1, 1), width_mm=0.2)
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branches = net_walk.sample_net((point_segment,), pitch_mm=1.0)
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assert len(branches) == 1
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assert len(branches[0].samples) == 1
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assert branches[0].samples[0].distance_along_net_mm == 0.0
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