PPU optimization

src/bus.rs

@@ -57,7 +57,7 @@ pub struct Bus {
 
 impl Bus {
     pub fn new() -> Self {
-        let game_rom = match ROM::load_file("ignore/dr-mario.gb".to_string()) {
+        let game_rom = match ROM::load_file("ignore/tetris.gb".to_string()) {
         // let game_rom = match ROM::load_file("ignore/mooneye/emulator-only/mbc1/bits_bank1.gb".to_string()) {
         // let game_rom = match ROM::load_file("roms/cpu_instrs.gb".to_string()) {
         // let game_rom = match ROM::load_file("roms/cpu_instrs_individual/01-special.gb".to_string()) {

src/cpu.rs

@@ -831,8 +831,8 @@ pub enum Opcode {
 pub struct Cycles(pub usize); 
 
 impl Cycles {
-    pub fn to_t(&self) -> usize {
+    pub fn to_t(&self) -> Self {
-        self.0 * 4
+        Self(self.0 * 4)
     }
 }
 

src/emulator.rs

@@ -99,13 +99,13 @@ impl Emulator {
 
     pub fn run(&mut self, cpu_cycles: Cycles, frame_buffer: &mut [u8]) {
         self.cpu.reset_cycles();
-        while self.cpu.get_cycles().to_t() <= cpu_cycles.0 {
+        while self.cpu.get_cycles().to_t().0 <= cpu_cycles.0 {
             self.cpu.run(&mut self.bus);
             if self.bus.reset_timer {
                 self.bus.reset_timer = false;
                 self.timer.reset(&mut self.bus);
             }
-            self.ppu.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles(), frame_buffer);
+            self.ppu.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t(), frame_buffer);
             self.timer.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles());
 
             // 1 CPU cycle = 238.42ns
@@ -123,7 +123,7 @@ impl Emulator {
                 self.bus.reset_timer = false;
                 self.timer.reset(&mut self.bus);
             }
-            self.ppu.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles(), &mut frame);
+            self.ppu.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles().to_t(), &mut frame);
             self.timer.do_cycles(&mut self.bus, self.cpu.get_last_op_cycles());
 
             // exit = self.cpu.get_exec_calls_count() >= 1258895; // log 1

src/ppu.rs

@@ -186,42 +186,34 @@ impl PPU {
     }
 
     pub fn do_cycles(&mut self, bus: &mut Bus, cycles: Cycles, frame_buffer: &mut [u8]) {
-        let mut count = 0;
-        while count < cycles.to_t() {
-            self.cycle(bus, frame_buffer);
-            count += 1;
-        }
-    }
-
-    pub fn cycle(&mut self, bus: &mut Bus, frame_buffer: &mut [u8]) {
         if !PPU::get_lcd_control(bus, LCDControl::LCDEnable) {
-            self.increment_cycles(Cycles(1));
+            self.increment_cycles(cycles);
             return;
         }
 
         if PPU::get_lcd_y(bus) < 144 {
-            if self.cycles.0 == 0 {
+            if self.cycles.0 <= 80 && !PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::SearchingOAM)) {
                 // Mode 2 OAM scan
                 PPU::set_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::SearchingOAM), true);
                 self.stat_interrupt(bus);
                 self.oam_search(bus);
-            } else if self.cycles.0 == 80 + 1 {
+            } else if self.cycles.0 > 80 && self.cycles.0 <= 80 + 172 && !PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::TransferringToLCD)) {
                 // Mode 3 drawing pixel line. This could also last 289 cycles
                 self.draw_line(bus, frame_buffer);
                 PPU::set_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::TransferringToLCD), true);
-            } else if self.cycles.0 == 80 + 172 + 1 {
+            } else if self.cycles.0 > 80 + 172 && self.cycles.0 <= 80 + 172 + 204 && !PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::HBlank)) {
                 // Mode 0 Horizontal blank. This could last 87 or 204 cycles depending on the mode 3
                 PPU::set_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::HBlank), true);
                 self.stat_interrupt(bus);
             }
-        } else if PPU::get_lcd_y(bus) == 144 && self.cycles.0 == 0 {
+        } else if PPU::get_lcd_y(bus) >= 144 && !PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::VBlank)) {
             // Mode 1 Vertical blank
             bus.set_interrupt_flag(Interrupt::VBlank, true);
             PPU::set_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::VBlank), true);
             self.stat_interrupt(bus);
         }
 
-        self.increment_cycles(Cycles(1));
+        self.increment_cycles(cycles);
 
         // Horizontal scan completed
         if self.cycles.0 > 456 {

src/rom.rs

@@ -18,6 +18,7 @@ enum Region {
     NonJapanese,
 }
 
+#[derive(Debug, Copy, Clone)]
 enum MBC {
     NoMBC,
     MBC1,
@@ -159,6 +160,7 @@ impl ROM {
 
         let info = ROMInfo::from_bytes(&data);
         println!("has ram {}", info.has_ram);
+        println!("mbc {:?}", info.mbc);
         let ram = Vec::with_capacity(info.ram_size() as usize);
 
         Ok(Self {

src/timer.rs

@@ -31,7 +31,7 @@ impl Timer {
     
     pub fn do_cycles(&mut self, bus: &mut Bus, cycles: Cycles) {
         let mut count = 0;
-        while count < cycles.to_t() {
+        while count < cycles.to_t().0 {
             self.cycle(bus);
             count += 1;
         }