Add LCDControlRegister for LCD control bit manipulation

Introduce a new `LCDControlRegister` struct to manage and manipulate individual bits of the LCD control register. Implement `From<u8>` and `Into<u8>` conversions for seamless integration with byte-level operations. This enhances code clarity and simplifies bitwise operations related to LCD control.
This commit is contained in:
2025-05-14 16:33:35 +01:00
parent b8c49682e2
commit 03c3c8a4ac

View File

@@ -1,6 +1,61 @@
#[derive(Clone, Copy, Debug)]
#[derive(PartialEq)]
const LCD_ENABLED_BIT: u8 = 7;
const WINDOW_TILE_MAP_AREA_BIT: u8 = 6;
const WINDOW_ENABLE_BIT: u8 = 5;
const BG_AND_WINDOW_TILE_DATA_AREA_BIT: u8 = 4;
const BG_TILE_MAP_AREA_BIT: u8 = 3;
const OBJECT_SIZE_BIT: u8 = 2;
const OBJECT_ENABLE_BIT: u8 = 1;
const BG_AND_WINDOW_ENABLE_BIT: u8 = 0;
#[derive(Clone, Copy, Debug, PartialEq)]
pub(crate) struct LCDControlRegister {
pub(crate) lcd_enabled: bool,
pub(crate) window_tile_map_area: bool,
pub(crate) window_enable: bool,
pub(crate) bg_and_window_tile_area: bool,
pub(crate) bg_tile_map_area: bool,
pub(crate) object_size: bool,
pub(crate) object_enable: bool,
pub(crate) bg_and_window_enable: bool,
}
impl From<LCDControlRegister> for u8 {
fn from(flag: LCDControlRegister) -> u8 {
(if flag.lcd_enabled { 1 } else { 0 }) << LCD_ENABLED_BIT |
(if flag.window_tile_map_area { 1 } else { 0 }) << WINDOW_TILE_MAP_AREA_BIT |
(if flag.window_enable { 1 } else { 0 }) << WINDOW_ENABLE_BIT |
(if flag.bg_and_window_tile_area{ 1 } else { 0 }) << BG_AND_WINDOW_TILE_DATA_AREA_BIT |
(if flag.bg_tile_map_area { 1 } else { 0 }) << BG_TILE_MAP_AREA_BIT |
(if flag.object_size { 1 } else { 0 }) << OBJECT_SIZE_BIT |
(if flag.object_enable { 1 } else { 0 }) << OBJECT_ENABLE_BIT |
(if flag.bg_and_window_enable { 1 } else { 0 }) << BG_AND_WINDOW_ENABLE_BIT
}
}
impl From<u8> for LCDControlRegister {
fn from(byte: u8) -> Self {
let lcd_enabled = ((byte >> LCD_ENABLED_BIT) & 0b1) != 0;
let window_tile_map_area = ((byte >> WINDOW_TILE_MAP_AREA_BIT) & 0b1) != 0;
let window_enable = ((byte >> WINDOW_ENABLE_BIT) & 0b1) != 0;
let bg_and_window_tile_area = ((byte >> BG_AND_WINDOW_TILE_DATA_AREA_BIT) & 0b1) != 0;
let bg_tile_map_area = ((byte >> BG_TILE_MAP_AREA_BIT) & 0b1) != 0;
let object_size = ((byte >> OBJECT_SIZE_BIT) & 0b1) != 0;
let object_enable = ((byte >> OBJECT_ENABLE_BIT) & 0b1) != 0;
let bg_and_window_enable = ((byte >> BG_AND_WINDOW_ENABLE_BIT) & 0b1) != 0;
LCDControlRegister {
lcd_enabled,
window_tile_map_area,
window_enable,
bg_and_window_tile_area,
bg_tile_map_area,
object_size,
object_enable,
bg_and_window_enable,
}
}
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub(crate) struct FlagsRegister {
pub(crate) zero: bool,
pub(crate) subtract: bool,
@@ -8,6 +63,7 @@ pub(crate) struct FlagsRegister {
pub(crate) carry: bool
}
const ZERO_FLAG_BYTE_POSITION: u8 = 7;
const SUBTRACT_FLAG_BYTE_POSITION: u8 = 6;
const HALF_CARRY_FLAG_BYTE_POSITION: u8 = 5;