Ryan Malloy
7f81c1f4ce
Add channel_pack.dsn: three nets whose pads spread wider than a wall gap, so they must converge and pack into lanes. Plain room routing (shove on or off) drops >= 1 net under every net ordering; the packer connects all three under every ordering, DRC-clean (search tree and independent emitted-copper check). The falsifiable boundary test sweeps the gap width for N=3 and N=4 and asserts the packer connects all N iff the gap meets the geometric feasibility width (N-1)*(width+clearance) + 2*(half_width+clearance), never routes fewer than greedy below it, and never false-packs. Determinism, endpoints-on-pads, valid SES, and pack=False-equals-default (additive) are covered.
DSN test fixtures
Hand-crafted minimal Specctra DSN files, written to exercise the parser. They
are modeled on the real fixtures shipped in the upstream FreeRouting repo
(fixtures/empty_board.dsn and fixtures/SMD-routing-issue-demo.dsn) so the
grammar and formatting match what kicad-cli pcb export specctra-dsn and
FreeRouting itself produce, but they were typed fresh here (no upstream file is
copied into this tree).
empty_board.dsn— the smallest valid board: parser, resolution, unit, and a structure with two signal layers and apcbboundary path. Modeled on FreeRoutingfixtures/empty_board.dsn.smd_demo.dsn— a fuller board exercising every scope the parser handles: quoted board/padstack/image names,via, defaultrule(width + clearance with a(type smd_smd)pair), akeepout, padstacks (rect and circle pads), images with pins, placement withfront/rotation, nets withComp-Pinreferences, and aclasswithcircuit/use_viaand arule. Modeled on FreeRoutingfixtures/SMD-routing-issue-demo.dsn.