From 84babc4d69207a23a2db2cd700257d4c31a06056 Mon Sep 17 00:00:00 2001
From: Rekai Musuka <rekai@musuka.dev>
Date: Mon, 15 Mar 2021 21:59:53 -0500
Subject: [PATCH] fix: convert structs to bitfield structs in interrupt.rs

---
 src/interrupt.rs | 162 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 123 insertions(+), 39 deletions(-)

diff --git a/src/interrupt.rs b/src/interrupt.rs
index 4e97bcc..e4d7362 100644
--- a/src/interrupt.rs
+++ b/src/interrupt.rs
@@ -1,67 +1,151 @@
+use bitfield::bitfield;
+
 #[derive(Debug, Clone, Copy, Default)]
 pub struct Interrupt {
     pub flag: InterruptFlag,
     pub enable: InterruptEnable,
 }
 
-#[derive(Debug, Clone, Copy, Default)]
-pub struct InterruptEnable {
-    vblank: bool,
-    lcd_stat: bool,
-    timer: bool,
-    serial: bool,
-    joypad: bool,
+bitfield! {
+    pub struct InterruptEnable(u8);
+    impl Debug;
+    _vblank, _set_vblank: 0;
+    _lcd_stat, _set_lcd_stat: 1;
+    _timer, _set_timer: 2;
+    _serial, _set_serial: 3;
+    _joypad, _set_joypad: 4;
 }
+
+// TODO: Is this the correct behaviour? (I think not)
+impl InterruptEnable {
+    pub fn vblank(&self) -> bool {
+        self._vblank()
+    }
+
+    pub fn lcd_stat(&self) -> bool {
+        self._lcd_stat()
+    }
+
+    pub fn timer(&self) -> bool {
+        self._timer()
+    }
+
+    pub fn serial(&self) -> bool {
+        self._serial()
+    }
+
+    pub fn joypad(&self) -> bool {
+        self._joypad()
+    }
+
+    pub fn set_vblank(&self, flag: &mut InterruptFlag, value: bool) {
+        let prev = self._vblank();
+
+        if prev == false && value {
+            flag.set_vblank(true);
+        }
+
+        flag.set_vblank(value)
+    }
+
+    pub fn set_lcd_stat(&self, flag: &mut InterruptFlag, value: bool) {
+        let prev = self._lcd_stat();
+
+        if prev == false && value {
+            flag.set_lcd_stat(true);
+        }
+
+        flag.set_lcd_stat(value)
+    }
+
+    pub fn set_timer(&self, flag: &mut InterruptFlag, value: bool) {
+        let prev = self._timer();
+
+        if prev == false && value {
+            flag.set_timer(true);
+        }
+
+        flag.set_timer(value)
+    }
+
+    pub fn set_serial(&self, flag: &mut InterruptFlag, value: bool) {
+        let prev = self._serial();
+
+        if prev == false && value {
+            flag.set_serial(true);
+        }
+
+        flag.set_serial(value)
+    }
+
+    pub fn set_joypad(&self, flag: &mut InterruptFlag, value: bool) {
+        let prev = self._joypad();
+
+        if prev == false && value {
+            flag.set_joypad(true);
+        }
+
+        flag.set_joypad(value)
+    }
+}
+
+impl Copy for InterruptEnable {}
+impl Clone for InterruptEnable {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl Default for InterruptEnable {
+    fn default() -> Self {
+        Self(0)
+    }
+}
+
 impl From<u8> for InterruptEnable {
     fn from(byte: u8) -> Self {
-        Self {
-            vblank: (byte >> 0 & 0x01) == 0x01,
-            lcd_stat: (byte >> 1 & 0x01) == 0x01,
-            timer: (byte >> 2 & 0x01) == 0x01,
-            serial: (byte >> 3 & 0x01) == 0x01,
-            joypad: (byte >> 4 & 0x01) == 0x01,
-        }
+        Self(byte)
     }
 }
 
 impl From<InterruptEnable> for u8 {
-    fn from(flag: InterruptEnable) -> Self {
-        (flag.joypad as u8) << 4
-            | (flag.serial as u8) << 3
-            | (flag.timer as u8) << 2
-            | (flag.lcd_stat as u8) << 1
-            | (flag.vblank as u8) << 0
+    fn from(enable: InterruptEnable) -> Self {
+        enable.0
     }
 }
 
-#[derive(Debug, Clone, Copy, Default)]
-pub struct InterruptFlag {
-    vblank: bool,
-    lcd_stat: bool,
-    timer: bool,
-    serial: bool,
-    joypad: bool,
+bitfield! {
+    pub struct InterruptFlag(u8);
+    impl Debug;
+    pub vblank, set_vblank: 0;
+    pub lcd_stat, set_lcd_stat: 1;
+    pub timer, set_timer: 2;
+    pub serial, set_serial: 3;
+    pub joypad, set_joypad: 4;
+}
+
+impl Copy for InterruptFlag {}
+impl Clone for InterruptFlag {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl Default for InterruptFlag {
+    fn default() -> Self {
+        Self(0)
+    }
 }
 
 impl From<u8> for InterruptFlag {
     fn from(byte: u8) -> Self {
-        Self {
-            vblank: (byte >> 0 & 0x01) == 0x01,
-            lcd_stat: (byte >> 1 & 0x01) == 0x01,
-            timer: (byte >> 2 & 0x01) == 0x01,
-            serial: (byte >> 3 & 0x01) == 0x01,
-            joypad: (byte >> 4 & 0x01) == 0x01,
-        }
+        Self(byte)
     }
 }
 
 impl From<InterruptFlag> for u8 {
     fn from(flag: InterruptFlag) -> Self {
-        (flag.joypad as u8) << 4
-            | (flag.serial as u8) << 3
-            | (flag.timer as u8) << 2
-            | (flag.lcd_stat as u8) << 1
-            | (flag.vblank as u8) << 0
+        flag.0
     }
 }