From a893988c10736d324330fbdcacabd6ac862500e1 Mon Sep 17 00:00:00 2001
From: Astatin <git@astatin.live>
Date: Wed, 3 Sep 2025 14:27:00 +0200
Subject: Add a post assembly script to round up ROM size (fixes ROM banking on
 some emulator)

---
 Makefile                       |   1 +
 init.gbasm                     |   2 +-
 map/loading/dungeoninfos.gbasm |   2 +-
 map/maps/test.ldtk             |   2 +-
 map/maps/test/png/Level_0.png  | Bin 0 -> 9470 bytes
 scripts/round-rom-size.py      |  34 ++++++++++++++++++++++++++++++++++
 sprites/bg/moss.png            | Bin 187 -> 190 bytes
 tileset.gbasm                  |   2 +-
 8 files changed, 39 insertions(+), 4 deletions(-)
 create mode 100644 map/maps/test/png/Level_0.png
 create mode 100644 scripts/round-rom-size.py

diff --git a/Makefile b/Makefile
index c5af677..e038331 100644
--- a/Makefile
+++ b/Makefile
@@ -24,6 +24,7 @@ map/maps.gbasm: $(subst .ldtk,.map.gbasm,$(wildcard ./map/maps/*.ldtk))
 build/main.rom: build/main.rom.unsigned
 	cp build/main.rom.unsigned build/main.rom
 	python scripts/set_checksums.py build/main.rom
+	python scripts/round-rom-size.py build/main.rom
 
 build/main.rom.unsigned: main.gbasm tileset.gbasm text.gbasm dialogues/text.gbasm map/maps.gbasm $(wildcard ./*.gbasm) $(wildcard ./**/*.gbasm) $(wildcard ./**/**/*.gbasm) $(wildcard ./music/*.vgm)
 	mkdir -p build
diff --git a/init.gbasm b/init.gbasm
index 9495df7..08fab8f 100644
--- a/init.gbasm
+++ b/init.gbasm
@@ -32,7 +32,7 @@ Header:
 .Licensee_code_new: .DB $00, $00
 .SGB_Flag: .DB $00
 .MBC: .DB $01
-.ROM_size: .DB $08
+.ROM_size: .DB $00 ; Will be set after assembly by build scripts
 .RAM_size: .DB $00 ; The .sav cartridge kind of ram
 .Destination_code: .DB $01 ; Overseas
 .Licensee_code_old: .DB $00
diff --git a/map/loading/dungeoninfos.gbasm b/map/loading/dungeoninfos.gbasm
index 7d00d1a..bc46100 100644
--- a/map/loading/dungeoninfos.gbasm
+++ b/map/loading/dungeoninfos.gbasm
@@ -86,10 +86,10 @@ Load_Dungeon_Infos: ; pointer to Dungeon struct in HL, bank in A
 	RET
 
 Load_Dungeon_Spawn_patterns: ; pointer to Dungeon struct in HL bank in A
+	.CHANGE_BANK_TO_A
 	LD A, $mem_dungeon_flags
 	BIT 2, A
 	RET Z
-	.CHANGE_BANK_TO_A
 	LD A, L
 	ADD $0a
 	LD L, A
diff --git a/map/maps/test.ldtk b/map/maps/test.ldtk
index 65c4999..56b5fbb 100644
--- a/map/maps/test.ldtk
+++ b/map/maps/test.ldtk
@@ -30,7 +30,7 @@
 	"externalLevels": false,
 	"exportTiled": false,
 	"simplifiedExport": false,
-	"imageExportMode": "None",
+	"imageExportMode": "OneImagePerLevel",
 	"exportLevelBg": true,
 	"pngFilePattern": null,
 	"backupOnSave": false,
diff --git a/map/maps/test/png/Level_0.png b/map/maps/test/png/Level_0.png
new file mode 100644
index 0000000..e2518e3
Binary files /dev/null and b/map/maps/test/png/Level_0.png differ
diff --git a/scripts/round-rom-size.py b/scripts/round-rom-size.py
new file mode 100644
index 0000000..a59a11f
--- /dev/null
+++ b/scripts/round-rom-size.py
@@ -0,0 +1,34 @@
+import sys
+import os
+
+if len(sys.argv) != 2:
+    raise ValueError("Rom file must be specified as first argument")
+
+rom_filename = sys.argv[1]
+current_filesize = os.path.getsize(rom_filename)
+
+i = 0
+for n in range(0, 9):
+    if current_filesize <= 32768 * (1 << n):
+        break
+    i += 1
+
+missing = (32768 * (1 << i)) - current_filesize
+
+print("Original file size =", current_filesize, "bytes")
+print("ROM size =", hex(i), "({} bytes)".format(32768 * (1 << i)))
+
+rom_file = open(rom_filename, 'r+b')
+
+rom_file.seek(0x148)
+
+rom_file.write(bytes(bytearray([i])))
+
+rom_file.close()
+
+rom_file = open(rom_filename, 'a+b')
+
+
+rom_file.write(bytes(bytearray([0]*missing)))
+
+rom_file.close()
diff --git a/sprites/bg/moss.png b/sprites/bg/moss.png
index 4e5f07c..a91d996 100644
Binary files a/sprites/bg/moss.png and b/sprites/bg/moss.png differ
diff --git a/tileset.gbasm b/tileset.gbasm
index 32410a3..d1126a7 100644
--- a/tileset.gbasm
+++ b/tileset.gbasm
@@ -77,7 +77,7 @@ BG_Tile_Image_Data:
 	.DB $00, $00, $00, $00, $00, $00, $00, $00, $33, $00, $7f, $00, $dd, $00, $00, $00 ; 0x49
 
 	; Moss
-	.DB $00, $00, $00, $01, $00, $03, $03, $1c, $1f, $20, $3b, $40, $3f, $40, $77, $88 ; 0x4a
+	.DB $00, $00, $00, $01, $01, $02, $01, $1c, $1f, $20, $3b, $40, $3f, $40, $77, $88 ; 0x4a
 	.DB $00, $00, $00, $e0, $e0, $1c, $dc, $02, $fc, $02, $f4, $0a, $fa, $01, $be, $01 ; 0x4b
 	.DB $7f, $80, $33, $40, $7f, $80, $5f, $80, $6d, $90, $3b, $40, $1f, $20, $00, $1f ; 0x4c
 	.DB $fe, $01, $76, $01, $fe, $01, $9c, $42, $f0, $0c, $e0, $10, $a0, $10, $00, $e0 ; 0x4d
-- 
cgit v1.2.3-70-g09d2