From 615446faa7e3dc0f2b9aa1494d28b98bb0829c43 Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Thu, 9 Feb 2023 17:30:38 +1100
Subject: [PATCH] keypress interrupts

---
 src/processor/gpu.rs    | 18 ++++++++++--------
 src/processor/memory.rs |  9 ++++++---
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/processor/gpu.rs b/src/processor/gpu.rs
index 75cef70..b4549cb 100644
--- a/src/processor/gpu.rs
+++ b/src/processor/gpu.rs
@@ -147,7 +147,9 @@ impl CPU {
     }
 
     fn enter_vblank(&mut self) {
-        self.memory.update_pressed_keys(self.window.get_keys());
+        if self.memory.update_pressed_keys(self.window.get_keys()) {
+            self.memory.set(0xFF0F, set_bit(self.memory.get(0xFF0F), 4));
+        }
         self.gpu.mode = DrawMode::VBlank;
         self.render_window();
         self.memory.set(0xFF0F, set_bit(self.memory.get(0xFF0F), 0));
@@ -233,14 +235,14 @@ impl CPU {
         let pos_y = self.memory.get(0xFF4A);
         // subtracting 7 to get the Real Number...
         let pos_x = self.memory.get(0xFF4B);
-            self.render_tiles(
-                scanline,
-                &lcdc.window_tilemap,
-                &lcdc.tile_area,
-                palette,
+        self.render_tiles(
+            scanline,
+            &lcdc.window_tilemap,
+            &lcdc.tile_area,
+            palette,
             pos_x.wrapping_sub(7),
-                pos_y,
-                false,
+            pos_y,
+            false,
         );
     }
 
diff --git a/src/processor/memory.rs b/src/processor/memory.rs
index a714333..8c2e9c5 100644
--- a/src/processor/memory.rs
+++ b/src/processor/memory.rs
@@ -12,13 +12,13 @@ pub(crate) mod rom;
 
 pub(crate) type Address = u16;
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 enum JoypadBank {
     Action,
     Direction,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 struct Joypad {
     bank_sel: JoypadBank,
     down: bool,
@@ -275,7 +275,8 @@ impl Memory {
         }
     }
 
-    pub fn update_pressed_keys(&mut self, keys: Vec<Key>) {
+    pub fn update_pressed_keys(&mut self, keys: Vec<Key>) -> bool {
+        let old = self.joypad.clone();
         self.joypad.down = keys.contains(&Key::Down) || keys.contains(&Key::S);
         self.joypad.up = keys.contains(&Key::Up) || keys.contains(&Key::W);
         self.joypad.left = keys.contains(&Key::Left) || keys.contains(&Key::A);
@@ -284,5 +285,7 @@ impl Memory {
         self.joypad.select = keys.contains(&Key::Minus);
         self.joypad.a = keys.contains(&Key::Apostrophe);
         self.joypad.b = keys.contains(&Key::Semicolon);
+        self.joypad != old
+    }
     }
 }