cartridge-refactor (#10)

* refactor

* update dir structure

emulator/src/cartridge/cartridge.rs

@@ -0,0 +1,103 @@
+use crate::cartridge::common::consts::NES_FILE_MAGIC_BYTES;
+use crate::cartridge::common::enums::Nes;
+use crate::cartridge::file_loader::{FileLoadable, NesRomReadError};
+use crate::cartridge::formats::i_nes::Ines;
+use crate::cartridge::formats::nes_2::Nes2;
+use crate::cartridge::registers::chr_rom::ChrRom;
+use crate::cartridge::registers::prg_rom::PrgRom;
+use byteorder::ReadBytesExt;
+use std::fs::File;
+use std::io::{BufReader, Read, Seek, SeekFrom};
+use std::path::Path;
+
+pub trait CartridgeData {
+    fn prg_rom(&self) -> &PrgRom;
+    fn chr_rom(&self) -> &ChrRom;
+}
+
+pub struct Cartridge {
+    data: Box<dyn CartridgeData>,
+}
+
+impl Cartridge {
+    // prepare cartridge with FileLoadable trait
+
+    pub fn from_file<P: AsRef<Path>>(path: P) -> anyhow::Result<Cartridge> {
+        let mut file = BufReader::new(File::open(&path)?);
+        let nes_type = Cartridge::nes_type_from_file(&mut file)?;
+        // reset file pointer
+        file.seek(SeekFrom::Start(0))?;
+        match nes_type {
+            Nes::Ines => {
+                let ines = Ines::from_file(path)?;
+                Ok(Cartridge {
+                    data: Box::new(ines),
+                })
+            }
+            Nes::Nes2 => {
+                let nes2 = Nes2::from_file(path)?;
+                Ok(Cartridge {
+                    data: Box::new(nes2),
+                })
+            }
+        }
+    }
+
+    fn nes_type_from_file<R: Read + Seek>(file: &mut R) -> anyhow::Result<Nes> {
+        let mut header = [0; 16];
+        file.read_exact(&mut header)?;
+        // Is it a NES file?
+        if header[0..4] != NES_FILE_MAGIC_BYTES {
+            return Err(NesRomReadError::MissingMagicBytes.into());
+        }
+        // NES 2.0
+        if (header[7] & 0x0C) == 0x08 {
+            // reset file pointer
+            file.seek(SeekFrom::Start(0))?;
+            return Ok(Nes::Nes2);
+        }
+        Ok(Nes::Ines)
+    }
+}
+
+impl CartridgeData for Cartridge {
+    fn prg_rom(&self) -> &PrgRom {
+        self.data.prg_rom()
+    }
+
+    fn chr_rom(&self) -> &ChrRom {
+        self.data.chr_rom()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_from_file() {
+        // Super Mario Bros
+        // check if the file is in the resources folder
+        let is_file = std::path::Path::new("resources/smb.nes").exists();
+        // issue a warning if the file is not found
+        if !is_file {
+            println!("resources/smb.nes not found");
+            return;
+        }
+        let cartridge = Cartridge::from_file("resources/smb.nes");
+        assert!(cartridge.is_ok());
+        let cartridge = cartridge.unwrap();
+
+        let prg_rom = cartridge.prg_rom();
+
+        let chr_rom = cartridge.chr_rom();
+
+        assert_eq!(
+            prg_rom.size(),
+            2 * crate::cartridge::file_loader::PRG_UNIT_SIZE as usize
+        );
+        assert_eq!(
+            chr_rom.size(),
+            1 * crate::cartridge::file_loader::CHR_UNIT_SIZE as usize
+        );
+    }
+}

emulator/src/cartridge/common/consts.rs

@@ -0,0 +1,3 @@
+pub const NES_FILE_MAGIC_BYTES: [u8; 4] = ['N' as u8, 'E' as u8, 'S' as u8, 0x1A];
+pub const PRG_UNIT_SIZE: u16 = 16;
+pub const CHR_UNIT_SIZE: u16 = 8;

emulator/src/cartridge/common/mod.rs

@@ -0,0 +1,2 @@
+pub mod consts;
+pub mod enums;

emulator/src/i_nes.rs → emulator/src/cartridge/formats/i_nes.rs

@@ -1,10 +1,11 @@
-use crate::chr_rom::ChrRom;
-use crate::enums::Mirroring;
-use crate::file_loader::read_banks;
-use crate::file_loader::{
+use crate::cartridge::cartridge::CartridgeData;
+use crate::cartridge::common::enums::Mirroring;
+use crate::cartridge::file_loader::read_banks;
+use crate::cartridge::file_loader::{
     FileLoadable, NesRomReadError, CHR_UNIT_SIZE, NES_FILE_MAGIC_BYTES, PRG_UNIT_SIZE,
 };
-use crate::prg_rom::PrgRom;
+use crate::cartridge::registers::chr_rom::ChrRom;
+use crate::cartridge::registers::prg_rom::PrgRom;
 use std::fs::File;
 use std::io::{BufReader, Read};
 use std::path::Path;
@@ -148,10 +149,19 @@ impl FileLoadable for Ines {
     }
 }
 
+impl CartridgeData for Ines {
+    fn prg_rom(&self) -> &PrgRom {
+        &self.prg_rom
+    }
+
+    fn chr_rom(&self) -> &ChrRom {
+        self.chr_rom.as_ref().unwrap()
+    }
+}
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::i_nes::FileLoadable;
+    use crate::cartridge::formats::i_nes::FileLoadable;
     use std::io::Cursor;
 
     #[test]

emulator/src/cartridge/formats/mod.rs

@@ -0,0 +1,2 @@
+pub mod i_nes;
+pub mod nes_2;

emulator/src/nes_2.rs → emulator/src/cartridge/formats/nes_2.rs

@@ -1,4 +1,7 @@
-use crate::file_loader::{FileLoadable, NesRomReadError, NES_FILE_MAGIC_BYTES};
+use crate::cartridge::cartridge::CartridgeData;
+use crate::cartridge::file_loader::{FileLoadable, NesRomReadError, NES_FILE_MAGIC_BYTES};
+use crate::cartridge::registers::chr_rom::ChrRom;
+use crate::cartridge::registers::prg_rom::PrgRom;
 use std::fs::File;
 use std::io::{BufReader, Read};
 use std::path::Path;
@@ -8,7 +11,6 @@ struct Nes2Header {}
 pub struct Nes2 {
     header: Nes2Header,
 }
-
 impl Nes2 {
     fn header_from_file<R: Read>(file: &mut R) -> anyhow::Result<Nes2Header> {
         let mut header = [0; 16];
@@ -26,6 +28,16 @@ impl Nes2 {
     }
 }
 
+impl CartridgeData for Nes2 {
+    fn prg_rom(&self) -> &PrgRom {
+        unimplemented!()
+    }
+
+    fn chr_rom(&self) -> &ChrRom {
+        unimplemented!()
+    }
+}
+
 impl FileLoadable for Nes2 {
     fn from_file<P: AsRef<Path>>(path: P) -> anyhow::Result<Nes2> {
         let mut file = BufReader::new(File::open(path)?);

emulator/src/cartridge/mod.rs

@@ -0,0 +1,6 @@
+pub mod cartridge;
+
+pub mod common;
+pub mod file_loader;
+mod formats;
+mod registers;

emulator/src/cartridge/registers/mod.rs

@@ -0,0 +1,2 @@
+pub mod chr_rom;
+pub mod prg_rom;

emulator/src/lib.rs

@@ -1,15 +1,9 @@
 pub mod addressing;
 pub mod bus;
 pub mod cartridge;
-mod chr_rom;
 pub mod cpu;
 pub mod empty_device;
-mod enums;
-mod file_loader;
-mod i_nes;
 pub mod logging;
 pub mod memory;
 mod mirroring;
-mod nes_2;
 pub mod ppu;
-mod prg_rom;