def _parse_structure_data_block(self, rom: Rom):
structure_block_offset = rom.little_endian(STRUCTURE_DATA_OFFSETS +
OFFSET_SIZE *
self.world_index)
self.structure_block_start = WORLD_MAP_BASE_OFFSET + structure_block_offset
# the indexes into the y_pos list, where the levels for the n-th screen start
y_pos_start_by_screen = rom.read(self.structure_block_start, 4)
level_y_pos_list_start = WORLD_MAP_BASE_OFFSET + rom.little_endian(
LEVEL_Y_POS_LISTS + OFFSET_SIZE * self.world_index)
level_x_pos_list_start = WORLD_MAP_BASE_OFFSET + rom.little_endian(
LEVEL_X_POS_LISTS + OFFSET_SIZE * self.world_index)
level_y_pos_list_end = level_x_pos_list_start - level_y_pos_list_start
self.level_count_s1 = y_pos_start_by_screen[1] - y_pos_start_by_screen[
0]
self.level_count_s2 = y_pos_start_by_screen[2] - y_pos_start_by_screen[
1]
self.level_count_s3 = y_pos_start_by_screen[3] - y_pos_start_by_screen[
2]
self.level_count_s4 = level_y_pos_list_end - y_pos_start_by_screen[3]
def test_little_endian():
rom_bytes = bytearray(b"\x00\x01\x02\x03\x04\x05\x06\x00")
rom = Rom(rom_bytes)
assert rom.little_endian(0) == (0x01 << 8) + 0x00
assert rom.little_endian(6) == (0x00 << 8) + 0x06