ref: b9a113a9f4712771e37313a4c8a76f7ef23cebb2
dir: /engine/overworld/clear_variables.asm/
ClearVariablesOnEnterMap:: ld a, SCREEN_HEIGHT_PX ldh [hWY], a ldh [rWY], a xor a ldh [hAutoBGTransferEnabled], a ld [wStepCounter], a ld [wLoneAttackNo], a ldh [hJoyPressed], a ldh [hJoyReleased], a ldh [hJoyHeld], a ld [wActionResultOrTookBattleTurn], a ld [wUnusedD5A3], a ld hl, wCardKeyDoorY ld [hli], a ld [hl], a ld hl, wWhichTrade ld bc, wStandingOnWarpPadOrHole - wWhichTrade call FillMemory ret