From c692ed2b75ea5d4aac3a0786bb26fd239357b272 Mon Sep 17 00:00:00 2001
From: Assil Ksiksi <cyph0nik@gmail.com>
Date: Thu, 28 Jan 2021 23:32:14 -0500
Subject: [PATCH] Update PPU mode even if LCD is disabled

---
 emu/src/main.rs | 15 +++++++--------
 lib/src/cpu.rs  |  2 ++
 lib/src/ppu.rs  | 19 ++++++++++---------
 3 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/emu/src/main.rs b/emu/src/main.rs
index ff0bd7d..fd7ba09 100644
--- a/emu/src/main.rs
+++ b/emu/src/main.rs
@@ -19,19 +19,19 @@ use structopt::StructOpt;
 enum Args {
     #[structopt(about = "Run a ROM on the emulator")]
     Run {
-        #[structopt(parse(from_os_str))]
+        #[structopt(parse(from_os_str), help = "Path to ROM file")]
         rom_file: PathBuf,
 
-        #[structopt(default_value = "6", long)]
+        #[structopt(default_value = "4", long, help = "Emulation resolution multiplier")]
         scale: u32,
 
-        #[structopt(default_value = "1", long)]
+        #[structopt(default_value = "1", long, help = "Emulation speed multiplier")]
         speed: u8,
 
-        #[structopt(long)]
+        #[structopt(long, help = "Boot into the DMG boot ROM")]
         boot_rom: bool,
 
-        #[structopt(long)]
+        #[structopt(long, help = "Trace all instructions to a file in the current directory")]
         trace: bool,
     },
     #[structopt(about = "Inspect a ROM")]
@@ -248,7 +248,6 @@ fn gui(rom_file: PathBuf, scale: u32, speed: u8, boot_rom: bool, trace: bool) {
         if !paused {
             // Render a single frame
             handle_frame(&mut gameboy, &mut canvas, &mut texture, &mut joypad_events, outline);
-
         }
 
         let elapsed = frame_start.elapsed();
@@ -288,8 +287,8 @@ fn main() {
                     Ok(c) => c,
                 };
 
-                println!("\nTitle: {}", cartridge.title().unwrap());
-                println!("Manufacturer: {}", cartridge.manufacturer_code().unwrap());
+                println!("\nTitle: {}", cartridge.title().unwrap_or("N/A"));
+                println!("Manufacturer: {}", cartridge.manufacturer_code().unwrap_or("N/A"));
                 println!("GBC support: {}", cartridge.cgb());
                 println!("Cartridge type: {:?}", cartridge.cartridge_type().unwrap());
                 println!("ROM size: {:?}", cartridge.rom_size().unwrap());
diff --git a/lib/src/cpu.rs b/lib/src/cpu.rs
index 1a89929..1be5a27 100644
--- a/lib/src/cpu.rs
+++ b/lib/src/cpu.rs
@@ -234,6 +234,8 @@ impl Cpu {
 
         // Then write the instruction
         write!(f, "{:03}:{}:{:#06X} - {}\n\n", bank, memory_type, pc, inst).unwrap();
+
+        f.flush().unwrap();
     }
 
     /// Execute a single step of DMA (if active).
diff --git a/lib/src/ppu.rs b/lib/src/ppu.rs
index b529045..68ba775 100644
--- a/lib/src/ppu.rs
+++ b/lib/src/ppu.rs
@@ -512,16 +512,14 @@ impl Ppu {
         self.dot = dot;
         self.ly = line;
 
-        if self.lcdc.lcd_display_enable() {
-            // Update the internal PPU status
-            //
-            // This also returns which interrupts need to be triggered
-            let stat_mode_change = self.update_status(mode, interrupts);
+        // Update the internal PPU status
+        //
+        // This also returns which interrupts need to be triggered
+        let stat_mode_change = self.update_status(mode, interrupts);
 
-            if stat_mode_change {
-                // Render data to the frame
-                self.render();
-            }
+        if self.lcdc.lcd_display_enable() && stat_mode_change {
+            // Render data to the frame
+            self.render();
         }
     }
 
@@ -1133,6 +1131,7 @@ impl MemoryRead<u16, u8> for Ppu {
                     self.vram.read(addr)
                 } else {
                     // PPU returns 0xFF if VRAM is locked
+                    log::info!("Blocked VRAM read from 0x{:X}", addr);
                     0xFF
                 }
             }
@@ -1183,6 +1182,8 @@ impl MemoryWrite<u16, u8> for Ppu {
                 if !self.oam_locked() {
                     let idx = (addr - Self::OAM_START_ADDR) as usize;
                     self.oam[idx] = value;
+                } else {
+                    log::info!("Blocked OAM write to 0x{:X}: 0x{:X}", addr, value);
                 }
             }
             Self::LCDC_ADDR => {