From d6cf2aba690322b3a758393a8482d96840012ff5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Sat, 10 Jun 2023 11:50:43 +0100
Subject: [PATCH] chore: better genie code structure
---
src/gb.rs | 5 ++---
src/ppu.rs | 4 ++--
src/rom.rs | 37 ++++++++++++++++++++++++++-----------
3 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/src/gb.rs b/src/gb.rs
index 180d5235..d418355d 100644
--- a/src/gb.rs
+++ b/src/gb.rs
@@ -970,9 +970,8 @@ impl GameBoy {
pub fn load_rom(&mut self, data: &[u8]) -> &Cartridge {
let mut rom = Cartridge::from_data(data);
- //rom.add_genie_code("00A-17B-C49").unwrap(); // SML
- //rom.add_genie_code("008-60A-E6E").unwrap(); // SML
- rom.add_genie_code("001-40C-E6E").unwrap();
+ rom.add_genie_code("00A-17B-C49").unwrap(); // SML
+ rom.add_genie_code("008-60A-E6E").unwrap(); // SML
self.mmu().set_rom(rom);
self.mmu().rom()
}
diff --git a/src/ppu.rs b/src/ppu.rs
index 690da47c..724f953a 100644
--- a/src/ppu.rs
+++ b/src/ppu.rs
@@ -211,7 +211,7 @@ impl Display for ObjectData {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
write!(
f,
- "Index => {}\nX => {}\nY => {}\nTile => {}",
+ "Index: {}, X: {}, Y: {}, Tile: {}",
self.index, self.x, self.y, self.tile
)
}
@@ -249,7 +249,7 @@ impl Display for TileData {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
write!(
f,
- "Palette => {}\nVRAM Bank => {}\nX Flip => {}\nY Flip => {}",
+ "Palette: {}, VRAM Bank: {}, X Flip: {}, Y Flip: {}",
self.palette, self.vram_bank, self.xflip, self.yflip
)
}
diff --git a/src/rom.rs b/src/rom.rs
index 72572236..8e42666e 100644
--- a/src/rom.rs
+++ b/src/rom.rs
@@ -218,6 +218,10 @@ pub struct GameGenieCode {
}
impl GameGenieCode {
+ pub fn short_description(&self) -> String {
+ self.code.to_string()
+ }
+
pub fn description(&self) -> String {
format!(
"Code: {}, Address: 0x{:04x}, New Data: 0x{:04x}, Old Data: 0x{:04x}",
@@ -228,7 +232,7 @@ impl GameGenieCode {
impl Display for GameGenieCode {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
- write!(f, "{}", self.description())
+ write!(f, "{}", self.short_description())
}
}
@@ -315,8 +319,15 @@ impl Cartridge {
pub fn read(&self, addr: u16) -> u8 {
if self.genie_codes.contains_key(&addr) {
let genie_code = self.genie_codes.get(&addr).unwrap();
- debugln!("Applying Game Genie code: {}", game_genie_code);
- return genie_code.new_data;
+
+ // checks if the current data at the address is the same as the
+ // one that is expected by the Game Genie code, if that's the case
+ // applies the patch, otherwise returns the original strategy is
+ // going to be used
+ if genie_code.old_data == (self.mbc.read_rom)(self, addr) {
+ debugln!("Applying Game Genie code: {}", game_genie_code);
+ return genie_code.new_data;
+ }
}
match addr & 0xf000 {
@@ -432,24 +443,28 @@ impl Cartridge {
return Err("Invalid Game Genie code length");
}
- let new_data_slice = &code[0..=1];
+ let code_u = code.to_uppercase();
+
+ let new_data_slice = &code_u[0..=1];
let new_data = u8::from_str_radix(new_data_slice, 16).unwrap();
- let old_data_slice = format!("{}{}", &code[8..=8], &code[10..=10]);
- let old_data: u8 = (u8::from_str_radix(old_data_slice.as_str(), 16).unwrap() ^ 0xba) << 2;
+ let old_data_slice = format!("{}{}", &code_u[8..=8], &code_u[10..=10]);
+ let old_data: u8 = u8::from_str_radix(old_data_slice.as_str(), 16)
+ .unwrap()
+ .rotate_right(2)
+ ^ 0xba;
- let address_slice = format!("{}{}{}", &code[6..=6], &code[2..=2], &code[4..=5]);
+ let address_slice = format!("{}{}{}", &code_u[6..=6], &code_u[2..=2], &code_u[4..=5]);
let address = u16::from_str_radix(address_slice.as_str(), 16).unwrap() ^ 0xf000;
- let game_genie_code = GameGenieCode {
- code: String::from(code),
+ let genie_code = GameGenieCode {
+ code: code_u,
address,
new_data,
old_data,
};
- self.genie_codes.insert(address, game_genie_code);
-
+ self.genie_codes.insert(address, genie_code);
Ok(self.genie_codes.get(&address).unwrap())
}
}
--
GitLab