Fix 02-interrupts test

src/bin/main.rs

@@ -1,9 +1,6 @@
 use rmg_001::render::start_eventloop;
-use rmg_001::emulator::Emulator;
 
 fn main() -> std::io::Result<()> {
     start_eventloop();
-    /* let mut emulator = Emulator::new();
-    emulator.cpu_loop(); */
     Ok(())
 }

src/bus.rs

@@ -1,14 +1,10 @@
 use crate::utils::{
     get_bit,
-    set_bit,
     BitIndex,
     join_bytes
 };
 use crate::rom::ROM;
 use crate::ppu::{
-    PPU,
-    LCDStatus,
-    LCDStatusModeFlag,
     LCD_STATUS_ADDRESS,
     LCD_CONTROL_ADDRESS,
     LCD_Y_ADDRESS,
@@ -61,10 +57,10 @@ pub struct Bus {
 
 impl Bus {
     pub fn new() -> Self {
-        let game_rom = match ROM::load_file("ignore/tetris.gb".to_string()) {
+        // let game_rom = match ROM::load_file("ignore/mooneye/acceptance/if_ie_registers.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()) {
-        // let game_rom = match ROM::load_file("roms/cpu_instrs_individual/02-interrupts.gb".to_string()) {
+        let game_rom = match ROM::load_file("roms/cpu_instrs_individual/02-interrupts.gb".to_string()) {
         // let game_rom = match ROM::load_file("roms/cpu_instrs_individual/03-op sp,hl.gb".to_string()) {
         // let game_rom = match ROM::load_file("roms/cpu_instrs_individual/04-op r,imm.gb".to_string()) {
         // let game_rom = match ROM::load_file("roms/cpu_instrs_individual/05-op rp.gb".to_string()) {
@@ -111,9 +107,8 @@ impl Bus {
     }
 
     pub fn read(&self, address: u16) -> u8 {
-        if BANK_ZERO.in_range(address) || BANK_SWITCHABLE.in_range(address) {
+        if BANK_ZERO.in_range(address) || BANK_SWITCHABLE.in_range(address)  || EXTERNAL_RAM.in_range(address) {
             return self.game_rom.read(address);
-
         } else if address == INTERRUPT_ENABLE_ADDRESS || address == INTERRUPT_FLAG_ADDRESS {
             return 0b11100000 | self.data[address as usize];
         } else if address == JOYPAD_ADDRESS {
@@ -131,7 +126,8 @@ impl Bus {
             // print!("{}", data as char); 
         }
 
-        if BANK_ZERO.in_range(address) || BANK_SWITCHABLE.in_range(address) {
+        if BANK_ZERO.in_range(address) || BANK_SWITCHABLE.in_range(address) || EXTERNAL_RAM.in_range(address) {
+            self.game_rom.write(address, data);
             // println!("WRITING TO ROM");
         } else if WORK_RAM_1.in_range(address) || WORK_RAM_2.in_range(address) {
             self.data[address as usize] = data;
@@ -139,6 +135,8 @@ impl Bus {
             if address <= 0xDDFF {
                 self.data[(ECHO_RAM.begin() + (address - WORK_RAM_1.begin())) as usize] = data;
             }
+        } else if EXTERNAL_RAM.in_range(address) {
+            // self.game_rom.write(address, data);
         } else if ECHO_RAM.in_range(address) {
             self.data[address as usize] = data;
             self.data[(WORK_RAM_1.begin() + (address - ECHO_RAM.begin())) as usize] = data; // Copy to the working RAM

src/cpu.rs

@@ -871,10 +871,6 @@ impl CPU {
         self.cycles.0 += cycles.0;
     }
 
-    fn decrement_cycles(&mut self, cycles: Cycles) {
-        self.cycles.0 -= cycles.0;
-    }
-
     pub fn reset_cycles(&mut self) {
         self.cycles = Cycles(0);
     }
@@ -919,7 +915,7 @@ impl CPU {
     }
 
     pub fn check_interrupts(&mut self, bus: &mut Bus) -> Option<Interrupt> {
-        if bus.read(INTERRUPT_ENABLE_ADDRESS) & bus.read(INTERRUPT_FLAG_ADDRESS) != 0 {
+        if (bus.read(INTERRUPT_ENABLE_ADDRESS) & 0b00011111) & (bus.read(INTERRUPT_FLAG_ADDRESS) & 0b00011111) != 0 {
             self.is_halted = false;
         }
         if !self.ime {
@@ -2132,7 +2128,16 @@ mod tests {
         let mut cpu = CPU::new();
         let mut bus = Bus::new();
         cpu.exec(Opcode::DI, &mut bus);
-        assert_eq!(bus.read(0xFFFF), 0x00);
+        assert_eq!(cpu.ime, false);
+        assert_eq!(cpu.registers.get(Register::PC), 0x101);
+    }
+
+    #[test]
+    fn test_ei_instructions() {
+        let mut cpu = CPU::new();
+        let mut bus = Bus::new();
+        cpu.exec(Opcode::EI, &mut bus);
+        assert_eq!(cpu.ime, true);
         assert_eq!(cpu.registers.get(Register::PC), 0x101);
     }
 

src/emulator.rs

@@ -1,4 +1,4 @@
-use std::{thread, time};
+// use std::{thread, time};
 use winit_input_helper::WinitInputHelper;
 use winit::event::{VirtualKeyCode};
 
@@ -6,7 +6,7 @@ use crate::cpu::{CPU, Cycles, Interrupt};
 use crate::ppu::PPU;
 use crate::bus::Bus;
 use crate::timer::Timer;
-use crate::joypad::{Joypad, Button, JOYPAD_ADDRESS};
+use crate::joypad::{Button};
 
 pub struct Emulator {
     cpu: CPU,

src/joypad.rs

@@ -1,4 +1,3 @@
-use crate::bus::{Bus};
 use crate::utils::{BitIndex, get_bit};
 
 pub const JOYPAD_ADDRESS: u16 = 0xFF00;

src/ppu.rs

@@ -2,9 +2,8 @@ use crate::utils::{
     BitIndex,
     get_bit,
     set_bit,
-    to_bit_index,
 };
-use crate::bus::{Bus, AddressRange, BANK_ZERO, VIDEO_RAM, SPRITE_ATTRIBUTE_TABLE};
+use crate::bus::{Bus, SPRITE_ATTRIBUTE_TABLE};
 use crate::cpu::{Cycles, Interrupt};
 
 pub const LCD_WIDTH: u32 = 160;
@@ -93,7 +92,6 @@ pub enum LCDStatus {
 pub struct PPU {
     prev_state: bool,
     cycles: Cycles,
-    rgba_frame: [[u8; 4]; FRAME_BUFFER_LENGTH as usize],
     sprite_buffer: Vec<Sprite>,
 }
 
@@ -114,11 +112,14 @@ impl Sprite {
     }
 
     pub fn get_pixel(&self, lcd_x: u8, lcd_y: u8, bus: &Bus) -> Option<Pixel> {
-        todo!("Implement sprite flipping");
         if lcd_x < self.x.saturating_sub(8) || lcd_x >= self.x {
             return None;
         }
 
+        if self.over_bg {
+            // todo!("Implement over_bg sprite property");
+        }
+
         let height: u8 = match self.is_long {
             true => 16,
             false => 8,
@@ -127,8 +128,25 @@ impl Sprite {
         let x = lcd_x.saturating_sub(self.x.saturating_sub(8));
         let y = lcd_y.saturating_sub(self.y .saturating_sub(16));
 
+        let x = match self.x_flip {
+            true => 7 - x,
+            false => x,
+        };
+        let y = match self.y_flip {
+            true => height - 1 - y,
+            false => y,
+        };
+
+        let mut tile_number = self.tile_number;
+
+        if self.is_long && x <= 7 {
+            tile_number = tile_number & 0xFE;
+        } else if self.is_long && x > 7 {
+            tile_number = tile_number | 0x01;
+        }
+
         let tile_line = y.rem_euclid(height) * 2;
-        let addr = 0x8000 + (self.tile_number as u16 * 16) + tile_line as u16;
+        let addr = 0x8000 + (tile_number as u16 * 16) + tile_line as u16;
 
         let tile_byte_1 = bus.read(addr);
         let tile_byte_2 = bus.read(addr + 1);
@@ -155,7 +173,6 @@ impl PPU {
         Self {
             prev_state: false,
             cycles: Cycles(0),
-            rgba_frame: [[0xFF, 0xFF, 0xFF, 0]; FRAME_BUFFER_LENGTH as usize],
             sprite_buffer: Vec::new(),
         }
     }
@@ -221,11 +238,9 @@ impl PPU {
 
     fn stat_interrupt(&mut self, bus: &mut Bus) {
         let state = self.prev_state;
-        self.prev_state = (
-            (PPU::get_lcd_status(bus, LCDStatus::Mode2OAMInterrupt)    && PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::SearchingOAM))) ||
+        self.prev_state = (PPU::get_lcd_status(bus, LCDStatus::Mode2OAMInterrupt)    && PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::SearchingOAM))) ||
             (PPU::get_lcd_status(bus, LCDStatus::Mode0HBlankInterrupt) && PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::HBlank))) ||
-            (PPU::get_lcd_status(bus, LCDStatus::Mode1VBlankInterrupt) && PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::VBlank)))
-        );
+            (PPU::get_lcd_status(bus, LCDStatus::Mode1VBlankInterrupt) && PPU::get_lcd_status(bus, LCDStatus::ModeFlag(LCDStatusModeFlag::VBlank)));
         if self.prev_state && !state {
             bus.set_interrupt_flag(Interrupt::LCDSTAT, true);
         }
@@ -251,7 +266,7 @@ impl PPU {
             // The gameboy only supports 10 sprites per line,
             // but since we are on an emulator we can avoud that limitation
             if self.sprite_buffer.len() >= 10 {
-                todo!("Make a setting for the 10 sprites per scanline");
+                // todo!("Make a setting for the 10 sprites per scanline");
                 // break;
             }
             let y = bus.read(addr);
@@ -269,7 +284,7 @@ impl PPU {
 
             let lcd_y = PPU::get_lcd_y(bus).saturating_add(16);
 
-            if lcd_y < y || lcd_y > (y + sprite_height) {
+            if lcd_y < y || lcd_y > (y + sprite_height - 1) {
                 addr += 4;
                 continue;
             }
@@ -334,11 +349,6 @@ impl PPU {
         control.get(byte)
     }
 
-    fn set_lcd_control(bus: &mut Bus, control: LCDControl, val: bool) {
-        let mut byte = bus.read(LCD_CONTROL_ADDRESS);
-        bus.force_write(LCD_CONTROL_ADDRESS, control.set(byte, val));
-    }
-
     pub fn get_lcd_status(bus: &Bus, status: LCDStatus) -> bool {
         let byte = bus.read(LCD_STATUS_ADDRESS);
         match status {
@@ -444,7 +454,7 @@ impl PPU {
             frame_buffer[idx + 1] = rgba[1];
             frame_buffer[idx + 2] = rgba[2];
             if let Some(window_pixel) = PPU::get_window_pixel(lcd_x, bus) {
-                let rgba = PPU::get_rgba(pixel);
+                let rgba = PPU::get_rgba(window_pixel);
                 frame_buffer[idx]     = rgba[0];
                 frame_buffer[idx + 1] = rgba[1];
                 frame_buffer[idx + 2] = rgba[2];

src/render.rs

@@ -1,11 +1,11 @@
 use crate::emulator::Emulator;
-use crate::cpu::{CPU, Cycles};
+use crate::cpu::{Cycles};
 use crate::ppu::{WIDTH, HEIGHT};
 
 use std::{thread, time};
 
 use log::error;
-use pixels::{Error, Pixels, SurfaceTexture};
+use pixels::{Pixels, SurfaceTexture};
 use winit::dpi::LogicalSize;
 use winit::event::{Event, VirtualKeyCode, WindowEvent};
 use winit::event_loop::{ControlFlow, EventLoop};
@@ -67,7 +67,7 @@ pub fn start_eventloop() {
                 emulator.run(Cycles(70224), pixels.get_frame());
                 // emulator.draw(pixels.get_frame());
 
-                thread::sleep(time::Duration::from_millis(10));
+                thread::sleep(time::Duration::from_millis(1));
                 window.request_redraw();
             },
             Event::RedrawRequested(_) => {

src/rom.rs

@@ -1,43 +1,215 @@
 use std::fs::File;
 use std::io::Read;
 
+use crate::bus::{
+    BANK_SWITCHABLE,
+    EXTERNAL_RAM,
+};
+
+pub const CARTRIDGE_TYPE_ADDRESS: u16 = 0x0147;
+pub const CGB_FLAG_ADDRESS: u16 = 0x0143;
+pub const SGB_FLAG_ADDRESS: u16 = 0x0146;
+pub const RAM_SIZE_ADDRESS: u16 = 0x0149;
+pub const ROM_SIZE_ADDRESS: u16 = 0x0148;
+pub const DESTINATION_CODE_ADDRESS: u16 = 0x014A;
+
+enum Region {
+    Japanese,
+    NonJapanese,
+}
+
+enum MBC {
+    NoMBC,
+    MBC1,
+    MBC2,
+    MBC3,
+    MBC4,
+    MBC5,
+    MBC6,
+    MBC7,
+    HuC1,
+    HuC3,
+    MMM01,
+    MBC1M,
+    PocketCamera,
+    BandaiTIMA5,
+}
+
+enum BankingMode {
+    Simple,
+    Advanced,
+}
+
 pub struct ROMInfo {
+    mbc: MBC,
+    publisher: String,
+    title: String,
+    cgb_only: bool,
+    sgb_features: bool,
+    has_ram: bool,
+    has_battery: bool,
+    has_timer: bool,
+    ram_banks: u8,
+    rom_banks: u16,
+    region: Region,
 }
 
 impl ROMInfo {
+    pub fn from_bytes(bytes: &[u8]) -> Self {
+        let rom_type = bytes[CARTRIDGE_TYPE_ADDRESS as usize];
+        Self {
+            mbc: match rom_type {
+                0x00 => MBC::NoMBC,
+                0x01 => MBC::MBC1,
+                0x02 => MBC::MBC1,
+                0x03 => MBC::MBC1,
+                0x05 => MBC::MBC2,
+                0x06 => MBC::MBC2,
+                0x08 => MBC::NoMBC,
+                0x09 => MBC::NoMBC,
+                0x0B => MBC::MMM01,
+                0x0C => MBC::MMM01,
+                0x0F => MBC::MBC3,
+                0x10 => MBC::MBC3,
+                0x11 => MBC::MBC3,
+                0x12 => MBC::MBC3,
+                0x13 => MBC::MBC3,
+                0x19 => MBC::MBC5,
+                0x1A => MBC::MBC5,
+                0x1B => MBC::MBC5,
+                0x1C => MBC::MBC5,
+                0x1D => MBC::MBC5,
+                0x1E => MBC::MBC5,
+                0x20 => MBC::MBC6,
+                0x22 => MBC::MBC7,
+                0xFC => MBC::PocketCamera,
+                0xFD => MBC::BandaiTIMA5,
+                0xFE => MBC::HuC3,
+                0xFF => MBC::HuC1,
+                _ => unreachable!(),
+            },
+            region: match bytes[DESTINATION_CODE_ADDRESS as usize] {
+                0x00 => Region::Japanese,
+                _ => Region::NonJapanese,
+            },
+            publisher: "".to_string(), // TODO: Extract publisher
+            title: "".to_string(), // TODO: Extract the game title
+            cgb_only: bytes[CGB_FLAG_ADDRESS as usize] == 0xC0,
+            sgb_features: bytes[SGB_FLAG_ADDRESS as usize] == 0x03,
+            has_ram: match rom_type {
+                0x02 | 0x03 | 0x08 | 0x09 | 0x0C | 0x0D | 0x10 | 0x12 |
+                0x13 | 0x1A | 0x1B | 0x1D | 0x1E | 0x22 | 0xFF => true,
+                _ => false,
+            },
+            has_battery: match rom_type {
+                0x03 | 0x06 | 0x09 | 0x0D | 0x0F | 0x10 |
+                0x13 | 0x1B | 0x1E | 0x22 | 0xFF => true,
+                _ => false,
+            },
+            has_timer: match rom_type {
+                0x0F | 0x10 => true,
+                _ => false,
+            },
+            ram_banks: match bytes[RAM_SIZE_ADDRESS as usize] {
+                0x00 | 0x01 => 0,
+                0x02 => 1,
+                0x03 => 4,
+                0x04 => 16,
+                0x05 => 8,
+                _ => unreachable!(),
+            },
+            rom_banks: match bytes[ROM_SIZE_ADDRESS as usize] {
+                0x00 => 2,
+                0x01 => 4,
+                0x02 => 8,
+                0x03 => 16,
+                0x04 => 32,
+                0x05 => 64,
+                0x06 => 128,
+                0x07 => 256,
+                0x08 => 512,
+                0x52 => 72,
+                0x53 => 80,
+                0x54 => 96,
+                _ => unreachable!(),
+            },
+        }
+    }
+
+    pub fn ram_size(&self) -> u16 {
+        0x4000 * self.ram_banks as u16
+    }
 }
 
 pub struct ROM {
-    bytes: Vec<u8>,
+    data: Vec<u8>,
+    info: ROMInfo,
+    ram: Vec<u8>,
+    rom_bank: u16,
+    ram_bank: u8,
+    ram_enable: bool,
+    banking_mode: BankingMode,
 }
 
 impl ROM {
     pub fn load_file(filename: String) -> std::io::Result<Self> {
         let mut file = File::open(filename)?;
-        let mut bytes = vec![];
-        file.read_to_end(&mut bytes)?;
+        let mut data = vec![];
+        file.read_to_end(&mut data)?;
+
+        let info = ROMInfo::from_bytes(&data);
+        let ram = Vec::with_capacity(info.ram_size() as usize);
+
         Ok(Self {
-            bytes,
+            data,
+            info,
+            ram,
+            rom_bank: 1,
+            ram_bank: 0,
+            ram_enable: false,
+            banking_mode: BankingMode::Simple,
         })
     }
 
     pub fn read(&self, address: u16) -> u8 {
-        match self.bytes.get(address as usize) {
-            Some(val) => *val,
-            None => 0xFF,
+        match self.info.mbc {
+            MBC::MBC1 => {
+                if BANK_SWITCHABLE.in_range(address) {
+                    return self.data[(address + (BANK_SWITCHABLE.begin() * (self.rom_bank - 1))) as usize]
+                } else if EXTERNAL_RAM.in_range(address) {
+                    return self.ram[(address - EXTERNAL_RAM.begin() + (EXTERNAL_RAM.begin() * self.ram_bank as u16)) as usize]
                 }
+            },
+            _ => {},
+        }
+        self.data[address as usize]
     }
 
-    pub fn from_bytes(bytes: &[u8]) -> Self {
-        Self {
-            bytes: bytes.to_vec(),
-        }
-    }
+    pub fn write(&mut self, address: u16, data: u8) {
+        match self.info.mbc {
+            MBC::MBC1 => {
                 
-    pub fn print_content(&self, address: Option<u16>) {
-        match address {
-            Some(address) => println!("{:02X?}", self.read(address)),
-            None => println!("{:02X?}", self.bytes),
+                if address >= 0x0000 || address <= 0x1FFF { // RAM enable register
+                    self.ram_enable = match data & 0x0F {
+                        0x0A => true,
+                        _ => false,
                     };
+                    return;
+                } else if address >= 0x2000 || address <= 0x3FFF { // ROM bank number register
+                    self.rom_bank = data as u16 & 0b00011111;
+                    if self.rom_bank > self.info.rom_banks.saturating_sub(1) {
+                        self.rom_bank = self.info.rom_banks.saturating_sub(1);
+                    }
+                } else if address >= 0x4000 || address <= 0x5FFF { // ROM and RAM bank number register
+                    self.ram_bank = data & 0b11;
+                } else if address >= 0x6000 || address <= 0x7FFF { // Banking mode select
+                } else if EXTERNAL_RAM.in_range(address) {
+                    if !self.ram_enable {
+                        return;
+                    }
+                }
+            },
+            _ => {},
+        }
     }
 }