From d4b5bac4752edfac936a192272adda9ce5256462 Mon Sep 17 00:00:00 2001
From: Isaac Marovitz <isaacryu@icloud.com>
Date: Mon, 6 May 2024 20:46:31 -0400
Subject: [PATCH] Clear VRAM after Boot ROM

Fixes blank areas in some CGB Games
---
 src/components/mmu.rs     | 5 ++++-
 src/components/ppu/ppu.rs | 4 ++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/components/mmu.rs b/src/components/mmu.rs
index 7050bb1..5fe9808 100644
--- a/src/components/mmu.rs
+++ b/src/components/mmu.rs
@@ -167,7 +167,10 @@ impl Memory for MMU {
             0xFF04..=0xFF07 => self.timer.write(a, v),
             0xFF10..=0xFF3F => self.apu.write(a, v),
             0xFF0F => self.intf = Interrupts::from_bits_truncate(v),
-            0xFF50 => self.boot_rom_enabled = false,
+            0xFF50 => {
+                self.boot_rom_enabled = false;
+                self.ppu.clear_vram();
+            },
             // TODO: RP
             0xFF56 => { },
             0xFF51..=0xFF6F => self.ppu.write(a, v),
diff --git a/src/components/ppu/ppu.rs b/src/components/ppu/ppu.rs
index a61db2a..b173cef 100644
--- a/src/components/ppu/ppu.rs
+++ b/src/components/ppu/ppu.rs
@@ -445,6 +445,10 @@ impl PPU {
         }
     }
 
+    pub fn clear_vram(&mut self) {
+        self.vram = [0; 0x4000];
+    }
+
     fn read_vram(&self, a: u16, bank: usize) -> u8 {
         self.vram[(bank * 0x2000) + a as usize - 0x8000]
     }