Debug view improvements, warp animation

* Add a visible frame one tile beyond the normal screen in debug mode.

* Fix the display of motion paths for mounted traps in debug mode.

* Add an animation for the warp trap.

tests/test_traps.py

@@ -163,6 +163,41 @@ traps:
     assert warped
 
 
+def test_warp_flash_pulses_and_fades(make_game):
+    g = make_game("""
+name: t
+tile_size: 32
+map: |
+  ##########
+  #.......G#
+  #P.......#
+  ##########
+traps:
+  - type: warp
+    at: [4, 2]
+    to: [7, 1]
+""")
+    warp = g.level.traps[0]
+    assert warp._pulse == 0.0                     # dormant: no aura
+    place(g, 4, 2)                                # stand on the warp tile
+    step(g)                                       # -> teleports, aura flashes on
+    assert warp._pulse > 0.9
+
+    # The aura paints at BOTH the source and the destination — even though the
+    # warp is invisible and we're not in debug.
+    a = AssetStore("noassets")
+    surf = pygame.Surface((g.level.width, g.level.height))
+    surf.fill((0, 0, 0))
+    warp.render(surf, a)
+    assert surf.get_at(warp.base_rect.center)[:3] != (0, 0, 0)
+    assert surf.get_at(warp._dest_rect().center)[:3] != (0, 0, 0)
+
+    # It quickly fades back to nothing within the pulse window.
+    for _ in range(int(warp._PULSE_TIME / DT) + 2):
+        step(g)
+    assert warp._pulse == 0.0
+
+
 # --- phase block -------------------------------------------------------------
 def test_phase_block_intangible_until_triggered(make_game):
     g = make_game("""
@@ -304,6 +339,24 @@ traps:
     assert pb.alpha == 1.0 and pb.solid   # snapped fully visible for the freeze
 
 
+def test_debug_overscan_reveals_offmap_trap(make_level):
+    # In debug the play surface is enlarged and shifted (render_offset) so a trap
+    # placed just off the map is drawn into the overscan instead of being clipped.
+    from game import settings as S
+    lvl = make_level(
+        "name: t\ntile_size: 32\ndebug: true\nmap: |\n  #####\n  #...#\n  #####\n"
+        "traps:\n  - type: block\n    at: [5, 1]\n    deadly: true\n")   # col 5 = off-map
+    a = AssetStore("noassets")
+    m = S.DEBUG_VIEW_MARGIN * lvl.tile
+    lvl.render_offset = (m, m)
+    surf = pygame.Surface((lvl.width + 2 * m, lvl.height + 2 * m))
+    surf.fill((0, 0, 0))
+    lvl.draw(surf, a)
+    cx = 5 * lvl.tile + m + lvl.tile // 2
+    cy = 1 * lvl.tile + m + lvl.tile // 2
+    assert surf.get_at((cx, cy))[:3] != (0, 0, 0)   # off-map block painted in overscan
+
+
 # --- generic invisible flag --------------------------------------------------
 def test_invisible_flag_on_any_trap(make_level):
     lvl = make_level("""