Prove shove-in-rooms recovers ordering drops but does not create density

Add true_density.dsn: NET_C is a full-height wall on the sole signal layer, so plain room routing drops a net under every net ordering (an order-independent obstruction, verified over all permutations), unlike rooms_shove_channel whose plain drop fits under a reorder. Test that shove recovers nothing on this board (shoves == 0, same routed set as plain) while staying DRC-clean, and that the only difference from the recoverable shove_channel is the wall's span. shove relocates a blocker into existing free space; where the wall leaves no headroom there is nowhere to relocate to, so it cannot manufacture density. The recover/fail boundary is the free-space boundary.
2026-07-13 11:34:31 -06:00
parent 9cf2392c4b
commit 99c3d20de5
2 changed files with 171 additions and 0 deletions
@@ -0,0 +1,64 @@
+(pcb "true_density.dsn"
+  (parser
+    (string_quote ")
+    (space_in_quoted_tokens on)
+    (host_cad "freeroute-test")
+    (host_version "1.0")
+  )
+  (resolution um 10)
+  (unit um)
+  (structure
+    (layer F.Cu
+      (type signal)
+      (property
+        (index 0)
+      )
+    )
+    (layer B.Cu
+      (type power)
+      (property
+        (index 1)
+      )
+    )
+    (boundary
+      (path pcb 0  0 0  200000 0  200000 -30000  0 -30000  0 0)
+    )
+    (rule
+      (width 2000)
+      (clearance 2000)
+    )
+  )
+  (library
+    (padstack Rect_Pad
+      (shape (rect F.Cu -1000 -1000 1000 1000))
+      (attach off)
+    )
+    (image PAD
+      (pin Rect_Pad 1 0 0)
+    )
+  )
+  (placement
+    (component PAD
+      (place A1 7000 -15000 front 0)
+      (place A2 193000 -15000 front 0)
+      (place C1 100000 -500 front 0)
+      (place C2 100000 -29500 front 0)
+    )
+  )
+  (network
+    (net NET_A
+      (pins A1-1 A2-1)
+    )
+    (net NET_C
+      (pins C1-1 C2-1)
+    )
+    (class default
+      (rule
+        (width 2000)
+        (clearance 2000)
+      )
+    )
+  )
+  (wiring
+  )
+)