big bug squash

tests/drivers/grass_seam_bug217_test.lua

@@ -0,0 +1,63 @@
+-- Visual regression for #217: no phantom tall-grass tuft should be drawn
+-- over the player's head while crossing the Viridian City -> Route 1 seam.
+--
+-- The player walks south out of Viridian City's exit path (cellX = 20).  On
+-- the step off the south edge, crossConnection swaps in ROUTE_1 and parks the
+-- player one cell before the entry point at cellY = -1 (off the top edge) for
+-- the duration of the seam step.  ROUTE_1's border block back-fills that
+-- off-map row with the grass tile, so before the fix the "feet overdraw"
+-- painted an animated grass tuft over the player's head for ~5 frames.
+--
+-- Screenshots (paths come from SHOT_DIR):
+--   grass_seam_during.png  -- the seam step, map == ROUTE_1 and cellY < 0
+--   grass_seam_after.png   -- one clean frame after the step lands (cellY >= 0)
+--
+-- Run: POKEPORT_DRIVER=tests/drivers/grass_seam_bug217_test.lua \
+--      POKEPORT_IDENTITY=bug217 POKEPORT_TOUCH=0 love .
+return function(game)
+  local U = dofile("tests/drivers/util.lua")
+  -- a party + starter flag so the overworld is fully usable
+  game.save.flags.EVENT_GOT_STARTER = true
+  local Pokemon = require("src.pokemon.Pokemon")
+  table.insert(game.save.party, Pokemon.new(game.data, "CHARMANDER", 5))
+
+  local shotDir = os.getenv("SHOT_DIR") or "."
+  -- south exit path column; four cells above the bottom edge (cellY 35)
+  U.teleport(game, "VIRIDIAN_CITY", 20, 31, "down")
+  local ow = game.overworld
+
+  local shotDuring, shotAfter = false, false
+  for i = 1, 120 do
+    table.insert(game.input.pressQueue, "down")
+    game.input.state.down = true
+    coroutine.yield()
+    local p = ow.player
+    local inb = ow.map:inBounds(p.cellX, p.cellY)
+    U.log(("f=%d map=%-14s cell=(%d,%d) inb=%s grassCell=%s py=%d moving=%s")
+      :format(i, ow.map.id, p.cellX, p.cellY, tostring(inb),
+        tostring(ow.map:isGrassCell(p.cellX, p.cellY)), p.py, tostring(p.moving)))
+
+    -- BEFORE the fix this is exactly the frame the phantom grass draws:
+    -- map is now ROUTE_1 but the player is still parked off the top edge.
+    if not shotDuring and ow.map.id == "ROUTE_1" and p.cellY < 0 then
+      game.input.state.down = false
+      U.shot(game, shotDir .. "/grass_seam_during.png")
+      shotDuring = true
+      game.input.state.down = true
+    end
+
+    -- one clean frame after the seam step lands on the real map
+    if shotDuring and not shotAfter and ow.map.id == "ROUTE_1"
+       and p.cellY >= 0 and not p.moving then
+      game.input.state.down = false
+      U.shot(game, shotDir .. "/grass_seam_after.png")
+      shotAfter = true
+      break
+    end
+  end
+  game.input.state.down = false
+  U.wait(2)
+
+  if not shotDuring then U.log("WARN: never captured the seam step frame") end
+  if not shotAfter then U.log("WARN: never captured a landed frame") end
+end