feat: stub work ram

src/work_ram.rs

@@ -0,0 +1,82 @@
+#[derive(Debug, Clone)]
+pub struct WorkRAM {
+    bank: Box<[u8]>,
+}
+
+impl WorkRAM {
+    pub fn write_byte(&mut self, index: usize, byte: u8) {
+        self.bank[index] = byte;
+    }
+
+    pub fn read_byte(&self, index: usize) -> u8 {
+        self.bank[index]
+    }
+}
+
+impl Default for WorkRAM {
+    fn default() -> Self {
+        Self {
+            bank: vec![0u8; 4096].into_boxed_slice(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum BankNumber {
+    One,
+    Two,
+    Three,
+    Four,
+    Five,
+    Six,
+    Seven,
+}
+
+impl From<BankNumber> for usize {
+    fn from(bank_num: BankNumber) -> Self {
+        match bank_num {
+            BankNumber::One => 1,
+            BankNumber::Two => 2,
+            BankNumber::Three => 3,
+            BankNumber::Four => 4,
+            BankNumber::Five => 5,
+            BankNumber::Six => 6,
+            BankNumber::Seven => 7,
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct VariableWorkRAM {
+    current: BankNumber,
+    bank_n: Box<[[u8; 4096]]>, // 4K for Variable amount of Banks (Banks 1 -> 7) in Game Boy Colour
+}
+
+impl Default for VariableWorkRAM {
+    fn default() -> Self {
+        Self {
+            current: BankNumber::One,
+            bank_n: vec![[0u8; 4096]; 7].into_boxed_slice(),
+        }
+    }
+}
+
+impl VariableWorkRAM {
+    pub fn set_current_bank(&mut self, bank: BankNumber) {
+        self.current = bank;
+    }
+
+    pub fn get_current_bank(&self) -> BankNumber {
+        self.current
+    }
+
+    pub fn write_byte(&mut self, index: usize, byte: u8) {
+        let num: usize = self.current.into();
+        self.bank_n[num][index] = byte;
+    }
+
+    pub fn read_byte(&self, index: usize) -> u8 {
+        let num: usize = self.current.into();
+        self.bank_n[num][index]
+    }
+}