extends Node
# Portability for GLES2 vs GLES3 stuff
const INDEX_FORMAT := globals.INDEX_FORMAT

const snes_graphics := preload('res://scripts/loaders/snes/graphics.gd')
const snes_battle_bgs := preload('res://scripts/loaders/snes/battle_bgs.gd')
const gba_graphics := preload('res://scripts/loaders/gba/graphics.gd')
var shader_material = load('res://palette_mat.tres')
const TILE_RECT := Rect2(0, 0, 8, 8)

# Offsets

# Glyphs
const offset_glyphs_small := 0x1FF000  # 0x100 entries, 2bpp
const offset_glyphs_dialog := 0x03E800  # 0x100 entries, 1bpp
const offset_glyphs_kanji := 0x1BD000  # 0x1AA entries, 1bpp

# Images
const offset_title_ffv := 0x031243  # Type 02 headed compression, expands to 0x1000 bytes
const offset_title_dragon := 0x032D22  # Type 02 compression, expands to 0x1200 bytes
const offset_title_dragon_OAM := 0x033342  # Type 02 headed compression, expands to 0x0120 bytes
const num_Character_Battle_Sprite_Layouts := 11

# Arrays to store sprites in
var worldmap_palette_imgs = []
var worldmap_palette_textures = []
var worldmap_tile_individual_imgs = []
var worldmap_tile_atlas_textures = []
var worldmap_block_tile_ids = []
var worldmap_block_individual_imgs = []
var worldmap_block_individual_textures = []
var worldmap_block_atlas_imgs = []
var worldmap_block_atlas_textures = []
# var worldmap_tile_atlas_textures = []

#var character_battle_sprite_tiles = []
#var character_battle_sprite_palette_imgs = []
var character_battle_sprite_palette_textures = []
var character_battle_sprite_palette_disabled_texture: ImageTexture
var character_battle_sprite_palette_stone_texture: ImageTexture
var weapon_textures = {}

var character_status_palette_replacements = {
	'poison': {4: '$7EDB = #DEB5FF', 8: '$4DD3 = #9C739C'},  # Also kneel
	'zombie': {3: '$7FFF = #FFFFFF', 4: '$3AF5 = #ADBD73', 8: '$3210 = #848463'},  # Also kneel in menu
	# Darkness None
	'old': {5: '$5294 = #A5A5A5', 9: '$4210 = #848484'},
	# Sleep None, Paralyze None, Charm None
	'berserk': {4: '$013F = #FF4A00', 8: '$001F = #FF0000'},
	# Mute None, Image None
	'wall': {1: '$6A60 = #009CD6'},  # Strobe between normal ($1084 = #212121) and this aqua at 30Hz (2 frames each)
	'armor': {1: '$031F = #FFC600'},  # Strobe between normal ($1084 = #212121) and this orange at 30Hz (2 frames each)
	'shell': {1: '$0B64 = #21DE10'},  # Strobe between normal ($1084 = #212121) and this green 30Hz (2 frames each)
	'stop': {1: '$001A = #D60000'},  # Strobe between normal ($1084 = #212121) and this aqua at 30Hz (2 frames each)
	'haste': {1: '$017F = #FF5A00'},  # Strobe between normal ($1084 = #212121) and this orange at 30Hz (2 frames each)
	'slow': {1: '$7FFF = #FFFFFF'},  # Strobe between normal ($1084 = #212121) and this green 30Hz (2 frames each)
}

static func ByteArray(size: int) -> PoolByteArray:
	var arr := PoolByteArray()
	arr.resize(size)
	return arr

static func texture_from_image(image: Image, flags: int = 0) -> ImageTexture:
	var tex = ImageTexture.new()
	tex.create_from_image(image, flags)
	return tex

static func bgr555_to_color(short: int) -> Color:
	var color = Color()
	color.a = 1
	color.r = ((short & 0x1F) / 31.0)
	color.g = (((short >> 5) & 0x1F) / 31.0)
	color.b = (((short >> 10) & 0x1F) / 31.0)
	return color

static func generate_palette_rgbf(rom: File, offset: int, length: int = 16) -> Image:
	rom.seek(offset)
	var img := Image.new()
	var rows := length/16
	img.create(16, rows, false, Image.FORMAT_RGBF)
	img.lock()
	for y in rows:
		for x in 16:
			var color = bgr555_to_color(rom.get_16())
			img.set_pixel(x, y, color)
	img.unlock()
	return img

static func generate_palette_rgb8(rom: File, offset: int, length: int = 16) -> Image:
	# Safe for GLES2 only!
	# Implicit sRGB -> linear conversion on ImageTexture creation from RGB8 Image ruins this in GLES3 mode
	rom.seek(offset)
	var data = ByteArray(length*3)
	# img.lock()
	for i in length:
		var color := bgr555_to_color(rom.get_16())
		var j: int = i*3
		data[j] = color.r8
		data[j+1] = color.g8
		data[j+2] = color.b8
	var img := Image.new()
	img.create_from_data(16, length/16, false, Image.FORMAT_RGB8, data)
	return img

static func generate_palette_rgb5_a1(rom: File, offset: int, length: int = 16) -> Image:
	var data = ByteArray(length*2)
	rom.seek(offset)
	for i in range(length):
		var bgr555 := rom.get_16()
		var r := bgr555 & 0x1F
		var g := (bgr555 >> 5) & 0x1F
		var b := (bgr555 >> 10) & 0x1F
		var rgb5_a1 := (r << 11) | (g << 6) | (b << 1) | 1
		data[i*2] = rgb5_a1 & 0xFF
		data[(i*2)+1] = rgb5_a1 >> 8
	var img := Image.new()
	img.create_from_data(16, length/16, false, Image.FORMAT_RGBA5551, data)
	return img

static func generate_palette(rom: File, offset: int, length: int = 16) -> Image:
	if length < 16:
		length = 16
	return generate_palette_rgb8(rom, offset, length)

static func generate_palette_from_colorarray(colors: PoolColorArray, format:=Image.FORMAT_RGBF) -> Image:
	var img := Image.new()
	var rows := len(colors)/16
	img.create(16, rows, false, format)
	img.lock()
	var i := 0
	for y in rows:
		for x in 16:
			img.set_pixel(x, y, colors[i])
			i += 1
	img.unlock()
	return img

static func make_tile_atlas(tile_images) -> Image:
	var image = Image.new()
	image.create(128, 128, false, INDEX_FORMAT)
	var tile = 0
	for y in tile_images.size()/16:
		for x in 16:
			image.blit_rect(tile_images[tile], TILE_RECT, Vector2(x*8, y*8))
			tile += 1
	return image


# func snes_load_worldmap(rom: File):
# 	# Load Worldmap Graphics
# 	var worldmap_tile_counts = [256, 256, 128]  # Only 128 underwater tiles
# 	for world_ts in 3:  # Bartz/Combined World, Galuf World, Underwater  (world tilesets, not to be confused with the 5 world maps)
# 		var tile_count: int = worldmap_tile_counts[world_ts]
# 		var image := generate_palette(rom, Common.SNES_PSX_addresses['worldmap_palettes']['SNES'] + (world_ts*0x100), 0x100)
# 		worldmap_palette_imgs.append(image)
# 		worldmap_palette_textures.append(texture_from_image(image))

# 		var tile_palettes = []
# 		rom.seek(Common.SNES_PSX_addresses['worldmap_tiles.bias']['SNES'] + (world_ts*0x100))
# 		for pal in 256:
# 			tile_palettes.append(rom.get_8())

# 		var tile_images = []
# 		# var tile_textures = []
# 		rom.seek(Common.SNES_PSX_addresses['worldmap_tiles']['SNES'] + (world_ts*0x2000))
# 		for tile in tile_count:
# 			var tiledata := rom.get_buffer(32)
# 			image = snes_graphics.mode7_compressed_to_tile(tiledata, tile_palettes[tile])
# 			tile_images.append(image)
# 			# tile_textures.append(texture_from_image(image))
# 		if world_ts == 0:  # Waterfall hack: lay it out vertically, pushing out dummy tiles
# 			tile_images[0x97] = tile_images[0x88]
# 			tile_images[0x98] = tile_images[0x87]
# 		worldmap_tile_individual_imgs.append(tile_images)
# 		worldmap_tile_atlas_textures.append(texture_from_image(make_tile_atlas(tile_images)))


# 		# Block definitions
# 		var block_images = []
# 		var block_textures = []
# 		var block_bank_start: int = Common.SNES_PSX_addresses['worldmap_blocks']['SNES'] + (world_ts*0x300)
# 		var block_tile_ids := PoolByteArray()
# 		for block in 0xC0:  # 192 blocks per world tileset
# 			image = Image.new()
# 			image.create(16, 16, false, INDEX_FORMAT)
# 			for tile in 4:
# 				rom.seek(block_bank_start + block + (tile * 0xC0))  # Horrible interleaving scheme
# 				var src_idx := rom.get_8()
# 				block_tile_ids.append(src_idx)
# 				if src_idx < tile_count:
# 					image.blit_rect(tile_images[src_idx], Rect2(0, 0, 8, 8), Vector2((tile%2)*8, (tile/2)*8))
# 			block_images.append(image)
# 			block_textures.append(texture_from_image(image))
# 		worldmap_block_individual_imgs.append(block_images)
# 		worldmap_block_individual_textures.append(block_textures)
# 		worldmap_block_tile_ids.append(block_tile_ids)
# 		# Make block atlas
# 		image = Image.new()
# 		image.create(16*16, 16*12, false, INDEX_FORMAT)
# 		for block in 0xC0:
# 			image.blit_rect(block_images[block], Rect2(0, 0, 16, 16), Vector2((block%16)*16, (block/16)*16))
# 		worldmap_block_atlas_imgs.append(image)
# 		worldmap_block_atlas_textures.append(texture_from_image(image))

# 		# # DEBUG: Make tile atlas
# 		# image = Image.new()
# 		# image.create(16*8, (tile_count/16)*8, false, INDEX_FORMAT)
# 		# for tile in tile_count:
# 		# 	image.blit_rect(tile_images[tile], Rect2(0, 0, 8, 8), Vector2((tile%16)*8, (tile/16)*8))
# 		# worldmap_tile_atlas_textures.append(texture_from_image(image))

# 	MapLoader.update_worldmap_block_tile_ids(worldmap_block_tile_ids)


# func snes_load_battle_sprites(rom: File):
# 	# Load Battle sprites
# 	rom.seek(Common.SNES_PSX_addresses['character_battle_sprite_layouts']['SNES'])
# 	var battle_strip_layouts = rom.get_buffer(num_Character_Battle_Sprite_Layouts * 6)
# 	# Character Battle Sprite Tiles
# 	for strip in range(0, 22*5):
# 		var tiles = []
# 		for i in range(0, 32*48, 32):
# 			tiles.append(snes_graphics.get_tile(rom, Common.SNES_PSX_addresses['character_battle_sprite_tiles']['SNES'] + (strip*32*48) + i, 32))
# 		var strip_image = Image.new()
# 		strip_image.create(16, 24 * num_Character_Battle_Sprite_Layouts, false, INDEX_FORMAT)
# 		for i in range(6 * num_Character_Battle_Sprite_Layouts):
# 			strip_image.blit_rect(tiles[battle_strip_layouts[i]], Rect2(0, 0, 8, 8), Vector2((i%2) * 8, (i/2) * 8))
# 		strip_images.append(strip_image)
# 		strip_textures.append(texture_from_image(strip_image))

# 	# Character Battle Sprite Palettes
# 	for palette in range(0, 22*5):
# 		character_battle_sprite_palette_textures.append(texture_from_image(generate_palette(rom, Common.SNES_PSX_addresses['character_battle_sprite_palettes']['SNES'] + (palette*32))))
# 	character_battle_sprite_palette_disabled_texture = texture_from_image(generate_palette(rom, Common.SNES_PSX_addresses['character_battle_sprite_disabled_palette']['SNES']))
# 	character_battle_sprite_palette_stone_texture = texture_from_image(generate_palette(rom, Common.SNES_PSX_addresses['character_battle_sprite_stone_palette']['SNES']))

# 	weapon_textures['Fist'] = texture_from_image(snes_graphics.get_tile(rom, Common.SNES_PSX_addresses['tiles_fist']['SNES'], 24))


# var json_sprite_blocks: Dictionary = Common.load_json('res://data/sprite_blocks.json')  # This needs error handling later
# var sprite_blocks := {}
# func snes_load_map_sprites(rom: File):
# 	# Main palettes
# 	var map_palettes = []
# 	for i in 4:
# 		map_palettes.append(generate_palette(rom, 0x1FFC00 + 32*i))

# 	for k in json_sprite_blocks.keys():
# 		var v = json_sprite_blocks[k]
# 		var start: int = v['start'].hex_to_int()
# 		var bpp := int(v['bpp'])
# 		var definitions = v['definitions']
# 		var total_tiles := 0
# 		for defn in definitions:
# 			total_tiles += defn[0] * defn[1] * defn[2]
# 		print_debug('Processing sprite block "%s" - starts at $%06X with %d %dbpp tiles' % [k, start, total_tiles, bpp])
# 		rom.seek(start)
# 		var tiles := []
# 		match bpp:
# 			1:
# 				for i in total_tiles:
# 					tiles.append(snes_graphics._1plane_to_tile(rom.get_buffer(8)))
# 			2:
# 				for i in total_tiles:
# 					tiles.append(snes_graphics._2plane_to_tile(rom.get_buffer(16)))
# 			3:
# 				for i in total_tiles:
# 					tiles.append(snes_graphics._3plane_to_tile(rom.get_buffer(24)))
# 			4:
# 				for i in total_tiles:
# 					tiles.append(snes_graphics._4plane_to_tile(rom.get_buffer(32)))
# 			_:
# 				print_debug('Invalid bpp "%s" in sprite blocks json' % bpp)
# 		sprite_blocks[k] = tiles

# func load_snes_rom(rom: File):
# 	snes_load_battle_sprites(rom)
# 	snes_load_worldmap(rom)
# 	# snes_load_map_sprites(rom)

# Cache these as they are shared between monsters
var monster_battle_sprite_palettes := {}  # offset -> 16 colour palette image
var monster_battle_sprite_palette_textures := {}  # offset -> 16 colour palette texture
var monster_battle_sprite_images := {}  # "tiles_offset:layout_id:large:bpp" -> tiles laid out in image
var monster_battle_sprite_textures := {}  # "tiles_offset:layout_id:large:bpp" -> tiles laid out in texture
func load_enemy_battle_sprites(data: Dictionary, buffer: StreamPeerBuffer):
	var PAL: int = Common.SNES_PSX_addresses.enemy_battle_sprite_palettes.SNES
	var TILES: int = Common.SNES_PSX_addresses.enemy_battle_sprite_tiles.SNES
	var Palette16Of555 = RomLoader.structdefs.Palette16Of555
	data.monster_battle_sprites = []
	for monster in data.enemy_battle_sprite_data:
		var entry = {}
		# Fetch or generate+cache palette
		var palette_offset = (monster.palette_offset_hi << 12) + (monster.palette_offset_lo << 4)
		if not (palette_offset in monster_battle_sprite_palettes):
			buffer.seek(palette_offset + PAL)
			var colors = PoolColorArray()
			for i in 16:
				colors.append(snes_graphics.bgr555_to_color(buffer.get_u16()))
			var image := generate_palette_from_colorarray(colors)
			monster_battle_sprite_palettes[palette_offset] = image
			monster_battle_sprite_palette_textures[palette_offset] = texture_from_image(image)
		entry['palette'] = monster_battle_sprite_palette_textures[palette_offset]
		# Fetch or generate+cache tiles and layout
		var bpp := 3 if monster.is_3bpp else 4
		var tiles_offset = (monster.tileset_offset_hi << 11) + (monster.tileset_offset_lo << 3)
		var key: String
		if monster.is_large_layout:
			var layout = data.enemy_battle_sprite_layouts_large[monster.layout_id]
			key = '%04X:%02X:1:%d' % [tiles_offset, monster.layout_id, bpp]
			if not (key in monster_battle_sprite_images):
				buffer.seek(tiles_offset + TILES)
				var image := Image.new()
				image.create(128, 128, false, INDEX_FORMAT)
				var max_col := 0
				var max_row := 0
				if bpp == 3:
					for y in 16:
						for x in 16:
							if (layout[y] & (0x8000 >> x)):
								image.blit_rect(snes_graphics._3plane_to_tile(buffer.get_data(24)[1]), TILE_RECT, Vector2(x, y)*8)
								if max_row < y:
									max_row = y
								if max_col < x:
									max_col = x
				else:
					for y in 16:
						for x in 16:
							if (layout[y] & (0x8000 >> x)):
								image.blit_rect(snes_graphics._4plane_to_tile(buffer.get_data(32)[1]), TILE_RECT, Vector2(x, y)*8)
								if max_row < y:
									max_row = y
								if max_col < x:
									max_col = x
				image.crop(8*(max_col+1), 8*(max_row+1))
				monster_battle_sprite_images[key] = image
				monster_battle_sprite_textures[key] = texture_from_image(image)
		else:
			var layout = data.enemy_battle_sprite_layouts_small[monster.layout_id]
			key = '%04X:%02X:0:%d' % [tiles_offset, monster.layout_id, bpp]
			if not (key in monster_battle_sprite_images):
				buffer.seek(tiles_offset + TILES)
				var image := Image.new()
				image.create(64, 64, false, INDEX_FORMAT)
				var max_col := 0
				var max_row := 0
				if bpp == 3:
					for y in 8:
						for x in 8:
							if (layout[y] & (0x80 >> x)):
								image.blit_rect(snes_graphics._3plane_to_tile(buffer.get_data(24)[1]), TILE_RECT, Vector2(x, y)*8)
								if max_row < y:
									max_row = y
								if max_col < x:
									max_col = x
				else:
					for y in 8:
						for x in 8:
							if (layout[y] & (0x80 >> x)):
								image.blit_rect(snes_graphics._4plane_to_tile(buffer.get_data(32)[1]), TILE_RECT, Vector2(x, y)*8)
								if max_row < y:
									max_row = y
								if max_col < x:
									max_col = x
				image.crop(8*(max_col+1), 8*(max_row+1))
				monster_battle_sprite_images[key] = image
				monster_battle_sprite_textures[key] = texture_from_image(image)
		entry['sprite'] = monster_battle_sprite_textures[key]
		# Save monster
		data.monster_battle_sprites.append(entry)


class BattleBackground:
	var tilemap_image: Image
	var tilemap_tex: Texture
	var palette_images: Array
	var palette_texs: Array
	var tile_atlas_images: Array
	var tile_atlas_texs: Array

var battle_backgrounds := []
func load_battle_bgs(data: Dictionary, buffer: StreamPeerBuffer):
	var bg_palettes = data.battle_background_palettes
	for map in snes_battle_bgs.get_all_battle_background_tilemaps(buffer, data):
		var bg := BattleBackground.new()
		bg.tilemap_image = map.tilemap_image
		bg.tilemap_tex = texture_from_image(bg.tilemap_image)
		var palette_images = []
		var palette_texs = []
		for ids in map.palette_ids:
			var pal_image := generate_palette_from_colorarray(bg_palettes[ids[0]] + bg_palettes[ids[1]])
			palette_images.append(pal_image)
			palette_texs.append(texture_from_image(pal_image))
		bg.palette_images = palette_images
		bg.palette_texs = palette_texs
		var tiles := []
		var ts: PoolByteArray = map.tileset
		var ts_l = len(ts)
		for i in 128:
			var start: int = i*32
			var end: int = start+31  # inclusive...
			if end >= ts_l:
				break
			tiles.append(snes_graphics._4plane_to_tile(ts.subarray(start, end)))
		if 'animated_tiles' in map:
			bg.tile_atlas_images = []
			bg.tile_atlas_texs = []
			var frames = []
			for frame in 4:
				frames.append(tiles.duplicate())
			for pair in map.animated_tiles:
				var frame = pair[0] >> 6
				var tile_dst = pair[0] & 0x3F
				var tile_src = pair[1]
				frames[frame][tile_dst] = tiles[tile_src]
			for frame in 4:
				var atlas_image = make_tile_atlas(frames[frame])
				bg.tile_atlas_images.append(atlas_image)
				bg.tile_atlas_texs.append(texture_from_image(atlas_image))
		else:
			var atlas_image = make_tile_atlas(tiles)
			bg.tile_atlas_images = [atlas_image]
			bg.tile_atlas_texs = [texture_from_image(atlas_image)]
		battle_backgrounds.append(bg)

static func bias_tile(unbiased: PoolByteArray, bias: int) -> Image:
	var image := Image.new()
	var biased = ByteArray(64)
	for i in 64:
		biased[i] = unbiased[i] + bias
	image.create_from_data(8, 8, false, INDEX_FORMAT, biased)
	return image

func load_from_structs(data: Dictionary):
	# Load Battle sprites
	for character_tiles in data.character_battle_sprite_tiles:
		for job_tiles in character_tiles:
			var strip_image = Image.new()
			# Should probably refactor later
			strip_image.create(16, 24 * num_Character_Battle_Sprite_Layouts, false, INDEX_FORMAT)
			for sprite in num_Character_Battle_Sprite_Layouts:
				var sprite_tiles: PoolByteArray = data.character_battle_sprite_layouts[sprite]
				for i in 6:
					strip_image.blit_rect(job_tiles[sprite_tiles[i]], TILE_RECT, Vector2((i%2) * 8, ((i/2) * 8) + (sprite * 24)))
			strip_images.append(strip_image)
			strip_textures.append(texture_from_image(strip_image))
	# Character Battle Sprite Palettes
	for character_palettes in data.character_battle_sprite_palettes:
		for job_palette in character_palettes:
			character_battle_sprite_palette_textures.append(texture_from_image(generate_palette_from_colorarray(job_palette)))
	character_battle_sprite_palette_disabled_texture = texture_from_image(generate_palette_from_colorarray(data.character_battle_sprite_disabled_palette))
	character_battle_sprite_palette_stone_texture = texture_from_image(generate_palette_from_colorarray(data.character_battle_sprite_stone_palette))
	weapon_textures['Fist'] = texture_from_image(data.tiles_fist)
	# Load World Map
	# Load Worldmap Graphics
	var worldmap_tile_counts = [256, 256, 128]  # Only 128 underwater tiles
	for world_ts in 3:  # Bartz/Combined World, Galuf World, Underwater  (world tilesets, not to be confused with the 5 world maps)
		var tile_count: int = worldmap_tile_counts[world_ts]
		var image := generate_palette_from_colorarray(data.worldmap_palettes[world_ts])
		worldmap_palette_imgs.append(image)
		worldmap_palette_textures.append(texture_from_image(image))
		var tile_biases: PoolByteArray = data.worldmap_tiles.bias[world_ts]
		var tile_images_unbiased = data.worldmap_tiles[world_ts]
		var tile_images := []
		for i in tile_count:
			tile_images.append(bias_tile(tile_images_unbiased[i].get_data(), tile_biases[i]))
		if world_ts == 0:  # Waterfall hack: lay it out vertically, pushing out dummy tiles
			tile_images[0x97] = tile_images[0x88]
			tile_images[0x98] = tile_images[0x87]
		worldmap_tile_individual_imgs.append(tile_images)
		worldmap_tile_atlas_textures.append(texture_from_image(make_tile_atlas(tile_images)))
		# Block definitions
		var block_images = []
		var block_textures = []
		var block_tile_ids := PoolByteArray()
		for block in 0xC0:  # 192 blocks per world tileset
			image = Image.new()
			image.create(16, 16, false, INDEX_FORMAT)
			for i in 4:
				var src_idx: int = data.worldmap_blocks[world_ts][i][block]
				block_tile_ids.append(src_idx)
				if src_idx < tile_count:
					image.blit_rect(tile_images[src_idx], TILE_RECT, Vector2((i%2)*8, (i/2)*8))
			block_images.append(image)
			block_textures.append(texture_from_image(image))
		worldmap_block_individual_imgs.append(block_images)
		worldmap_block_individual_textures.append(block_textures)
		worldmap_block_tile_ids.append(block_tile_ids)
		# Make block atlas
		# image = Image.new()
		# image.create(16*16, 16*12, false, INDEX_FORMAT)
		# for block in 0xC0:
		# 	image.blit_rect(block_images[block], Rect2(0, 0, 16, 16), Vector2((block%16)*16, (block/16)*16))
		# worldmap_block_atlas_imgs.append(image)
		# worldmap_block_atlas_textures.append(texture_from_image(image))

		# # DEBUG: Make tile atlas
		# image = Image.new()
		# image.create(16*8, (tile_count/16)*8, false, INDEX_FORMAT)
		# for tile in tile_count:
		# 	image.blit_rect(tile_images[tile], TILE_RECT, Vector2((tile%16)*8, (tile/16)*8))
		# worldmap_tile_atlas_textures.append(texture_from_image(image))

	MapLoader.update_worldmap_block_tile_ids(worldmap_block_tile_ids)

const gba_marker := 'FINAL FANTASY V      ADVANCE    SYGMAB'
const gba_marker_pos_US := 0x12FE10
const gba_marker_pos_EU := 0x131294
const gba_offset_battle_sprite_tiles := 504
const gba_offset_battle_sprite_palettes := 1064
const gba_offset_battle_sprite_layouts := 9435
func load_gba_rom(filename: String):
	var rom := File.new()
	var offset_marker: int
	var result = rom.open(filename, File.READ)
	if result != 0:
		print_debug('ROM failed to open: ', result)
		return

	rom.seek(gba_marker_pos_US)
	if rom.get_buffer(len(gba_marker)).get_string_from_ascii() == gba_marker:
		offset_marker = gba_marker_pos_US
	else:
		rom.seek(gba_marker_pos_EU)
		if rom.get_buffer(len(gba_marker)).get_string_from_ascii() == gba_marker:
			offset_marker = gba_marker_pos_EU
		else:
			print_debug('ROM does not match known US/EU ROMs, aborting')
			return

	# Battle Sprite Tiles
	rom.seek(offset_marker + gba_offset_battle_sprite_layouts)
	var battle_strip_layouts = rom.get_buffer(num_Character_Battle_Sprite_Layouts * 6)
	for strip in range(0, 26*5):
		var tiles = []
		rom.seek(offset_marker + gba_offset_battle_sprite_tiles + strip*4)
		var address = rom.get_32() - 0x08000000
		var tiledata = CommonGBA.LZ77_decompress(rom, address)
		tiledata.append(0)  # Slicing to end of array causes an engine crash. For shame!
		for i in range(8, 57*32+8, 32):
			tiles.append(gba_graphics._4bpp_to_tile(tiledata.subarray(i, i+32)))
		var strip_image = Image.new()
		strip_image.create(16, 24 * num_Character_Battle_Sprite_Layouts, false, INDEX_FORMAT)
		for i in range(6 * num_Character_Battle_Sprite_Layouts):
			strip_image.blit_rect(tiles[battle_strip_layouts[i]], TILE_RECT, Vector2((i%2) * 8, (i/2) * 8))
		strip_images.append(strip_image)
		strip_textures.append(texture_from_image(strip_image))

	# Character Battle Sprite Palettes
	for palette in range(0, 26*5):
		rom.seek(offset_marker + gba_offset_battle_sprite_palettes + palette*4)
		character_battle_sprite_palette_textures.append(texture_from_image(generate_palette(rom, rom.get_32() - 0x08000000 + 8)))
#	character_battle_sprite_palette_disabled_texture = texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Disabled_Palette))
#	character_battle_sprite_palette_stone_texture = texture_from_image(generate_palette(rom, offset_Character_Battle_Sprite_Stone_Palette))


var strip_images = []
var strip_textures = []
# func _ready():
	#pass