explore (P1 core): overworld map-connection browser

New EXPLORE entry in the SL0P menu renders any overworld map (LoadMapData, no
NPCs, OBJ layer disabled so even the player sprite is hidden), centered on the
map. U/D/L/R jump to the connected map in that direction when wCurMapConnections
has that flag, following the connection graph (verified Pallet<->Route 1). B
restores the origin map + coords and returns to the menu (movement intact).
Arrows/indicators next.

1 files changed, 90 insertions, 2 deletions

diff --git a/engine/slop_menu.asm b/engine/slop_menu.asm
index 38c5bdcf..fbcd222a 100644
--- a/engine/slop_menu.asm
+++ b/engine/slop_menu.asm
@@ -8,7 +8,7 @@
 ; To add an entry: add a "NAME" line to SlopMenuText, a `dw Handler` to
 ; SlopMenuHandlers, and bump SLOP_MENU_COUNT.
 
-DEF SLOP_MENU_COUNT EQU 12
+DEF SLOP_MENU_COUNT EQU 13
 
 SECTION "Slop Menu", ROMX
 
@@ -120,7 +120,8 @@ SlopMenuText:
 	next "HMS"
 	next "ITEMS"
 	next "NOWILD"
-	next "REPEL@"
+	next "REPEL"
+	next "EXPLORE@"
 SlopOnText:
 	db "ON@"
 SlopMenuHandlers:
@@ -136,6 +137,7 @@ SlopMenuHandlers:
 	dw GiveItemSubmenu
 	dw SlopToggleNoWild
 	dw SlopRepel
+	dw SlopExplore
 
 
 ; ===========================================================================
@@ -214,6 +216,92 @@ WarpMapTable:
 
 
 ; ===========================================================================
+; EXPLORE (P1): overworld map-connection browser. Renders the current map (no
+; NPCs), and U/D/L/R jump to the connected map in that direction if one exists
+; (via wCurMapConnections + the connection headers). B restores the original
+; map and returns to the SL0P menu. No warping yet - read-only browse.
+; ===========================================================================
+SlopExplore:
+; save origin map + coords on the stack
+	ld a, [wYCoord]
+	ld b, a
+	ld a, [wXCoord]
+	ld c, a
+	push bc
+	ld a, [wCurMap]
+	push af
+.render
+; seed safe coords (0,0 is in-bounds for any map), load the map to get its real
+; dimensions + connections, then re-render centered on the map.
+	xor a
+	ld [wYCoord], a
+	ld [wXCoord], a
+	call LoadMapData
+	ld a, [wCurMapHeight]
+	ld [wYCoord], a
+	ld a, [wCurMapWidth]
+	ld [wXCoord], a
+	call LoadMapData               ; render centered
+	ldh a, [rLCDC]                 ; hide ALL sprites (player + actors) via LCDC
+	res B_LCDC_OBJS, a
+	ldh [rLCDC], a
+	ld a, $90
+	ldh [hWY], a                   ; window off-screen -> the BG map is visible
+.input
+	call DelayFrame
+	call JoypadLowSensitivity
+	ldh a, [hJoyPressed]
+	ld d, a
+	bit B_PAD_B, d
+	jr nz, .exit
+	bit B_PAD_UP, d
+	jr z, .chkDown
+	ld a, [wCurMapConnections]
+	bit NORTH_F, a
+	jr z, .input
+	ld a, [wNorthConnectedMap]
+	ld [wCurMap], a
+	jr .render
+.chkDown
+	bit B_PAD_DOWN, d
+	jr z, .chkLeft
+	ld a, [wCurMapConnections]
+	bit SOUTH_F, a
+	jr z, .input
+	ld a, [wSouthConnectedMap]
+	ld [wCurMap], a
+	jr .render
+.chkLeft
+	bit B_PAD_LEFT, d
+	jr z, .chkRight
+	ld a, [wCurMapConnections]
+	bit WEST_F, a
+	jr z, .input
+	ld a, [wWestConnectedMap]
+	ld [wCurMap], a
+	jr .render
+.chkRight
+	bit B_PAD_RIGHT, d
+	jr z, .input
+	ld a, [wCurMapConnections]
+	bit EAST_F, a
+	jr z, .input
+	ld a, [wEastConnectedMap]
+	ld [wCurMap], a
+	jr .render
+.exit
+	pop af
+	ld [wCurMap], a               ; restore origin map
+	pop bc
+	ld a, b
+	ld [wYCoord], a
+	ld a, c
+	ld [wXCoord], a
+	call LoadMapData              ; reload the origin map
+	and a                         ; carry clear -> back to SL0P menu
+	ret
+
+; ===========================================================================
 ; ITEMS submenu: give 99 of the chosen item (stacks via GiveItem)
 ; ===========================================================================
 DEF GIVE_COUNT EQU 12