Implements PPU background rendering (#18)

* Implements PPU background renderer
* Adds performance tests for Bus and improves performance
* Improves performance of the Bus

.swiftpm/xcode/xcshareddata/xcbaselines/SwiftNESTests.xcbaseline/27EA854B-A785-4A10-BB95-9D604E1EEB91.plist

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+ <key>classNames</key>
+ <dict>
+ <key>BusTests</key>
+ <dict>
+ <key>testReadPerformance()</key>
+ <dict>
+ <key>com.apple.XCTPerformanceMetric_WallClockTime</key>
+ <dict>
+ <key>baselineAverage</key>
+ <real>0.0275</real>
+ <key>baselineIntegrationDisplayName</key>
+ <string>Local Baseline</string>
+ </dict>
+ </dict>
+ <key>testWritePerformance()</key>
+ <dict>
+ <key>com.apple.XCTPerformanceMetric_WallClockTime</key>
+ <dict>
+ <key>baselineAverage</key>
+ <real>0.0281</real>
+ <key>baselineIntegrationDisplayName</key>
+ <string>Local Baseline</string>
+ </dict>
+ </dict>
+ </dict>
+ </dict>
+</dict>
+</plist>

.swiftpm/xcode/xcshareddata/xcbaselines/SwiftNESTests.xcbaseline/Info.plist

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+ <key>runDestinationsByUUID</key>
+ <dict>
+ <key>27EA854B-A785-4A10-BB95-9D604E1EEB91</key>
+ <dict>
+ <key>localComputer</key>
+ <dict>
+ <key>busSpeedInMHz</key>
+ <integer>0</integer>
+ <key>cpuCount</key>
+ <integer>1</integer>
+ <key>cpuKind</key>
+ <string>Apple M1</string>
+ <key>cpuSpeedInMHz</key>
+ <integer>0</integer>
+ <key>logicalCPUCoresPerPackage</key>
+ <integer>8</integer>
+ <key>modelCode</key>
+ <string>MacBookAir10,1</string>
+ <key>physicalCPUCoresPerPackage</key>
+ <integer>8</integer>
+ <key>platformIdentifier</key>
+ <string>com.apple.platform.macosx</string>
+ </dict>
+ <key>targetArchitecture</key>
+ <string>arm64</string>
+ <key>targetDevice</key>
+ <dict>
+ <key>modelCode</key>
+ <string>iPhone13,3</string>
+ <key>platformIdentifier</key>
+ <string>com.apple.platform.iphonesimulator</string>
+ </dict>
+ </dict>
+ </dict>
+</dict>
+</plist>

.swiftpm/xcode/xcshareddata/xcschemes/SwiftNES.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
- LastUpgradeVersion = "1110"
+ LastUpgradeVersion = "1240"
  version = "1.3">
  <BuildAction
  parallelizeBuildables = "YES"

Package.swift

@@ -1,10 +1,10 @@
-// swift-tools-version:5.1
-// The swift-tools-version declares the minimum version of Swift required to build this package.
+// swift-tools-version:5.9
 
 import PackageDescription
 
 let package = Package(
  name: "SwiftNES",
+ platforms: [.macOS(.v13)],
  products: [
  // Products define the executables and libraries produced by a package, and make them visible to other packages.
  .library(

Sources/SwiftNES/AddressableDevice.swift

@@ -23,29 +23,34 @@
 import Foundation
 
 /// A protocol that describes a device that is addressable on a system bus.
-protocol AddressableDevice: class {
+protocol AddressableDevice: AnyObject {
  /// Returns whether or not the device responds to the specified address.
  ///
- /// - parameter address: The address.
- /// - returns: Whether or not the device responds to the address.
+ /// - Parameters:
+ /// - address: The address.
+ /// - Returns: Whether or not the device responds to the address.
  func respondsTo(_ address: Address) -> Bool
+
+ var addressRange: AddressRange { get }
 }
 
 /// A protocol that describes a device that is addressable on a system bus and can be read from.
 protocol AddressableReadDevice: AddressableDevice {
  /// Reads from the addressable device at the specified address.
  ///
- /// - parameter address: The address to read from.
- /// - returns: The value stored at the address.
+ /// - Parameters:
+ /// - address: The address to read from.
+ /// - Returns: The value stored at the address.
  func read(from address: Address) -> Value
 }
 
 /// A protocol that describes a device that is addressable on a system bus and can be written to.
 protocol AddressableWriteDevice: AddressableDevice {
  /// Writes data to the addressable device at the specified address.
  ///
- /// - parameter data: The data to be written.
- /// - parameter address: The address to write to.
+ /// - Parameters:
+ /// - data: The data to be written.
+ /// - address: The address to write to.
  func write(_ data: Value, to address: Address)
 }
 

Sources/SwiftNES/AudioReceiver.swift

@@ -22,7 +22,7 @@
 
 import Foundation
 
-public protocol AudioReceiver: class {
+public protocol AudioReceiver: AnyObject {
  // TODO: Define an AudioReceiver.
  // TODO: Move protocol into an SDK package.
 }

Sources/SwiftNES/Bus.swift

@@ -27,47 +27,79 @@ final class Bus {
 
  // MARK: - Initializers
 
- /// Creates a bus with attached devices.
+ /// Initializes a bus with attached devices.
  ///
- /// - parameter addressableDevices: The devices that can be addressed via this bus.
- init(addressableDevices: [AddressableDevice]) {
- self.addressableReadDevices = addressableDevices.compactMap { $0 as? AddressableReadDevice }
- self.addressableWriteDevices = addressableDevices.compactMap { $0 as? AddressableWriteDevice }
+ /// - Parameters:
+ /// - addressableDevices: The devices that can be addressed via this bus.
+ init(addressableDevices: [any AddressableDevice]) throws {
+ // TODO: Verify that there are no overlapping devices.
+
+ let addressableReadDevices = addressableDevices.compactMap { $0 as? AddressableReadDevice }
+ let addressableWriteDevices = addressableDevices.compactMap { $0 as? AddressableWriteDevice }
+
+ self.addressableReadDeviceRanges = addressableReadDevices.map(\.addressRange)
+ self.addressableWriteDeviceRanges = addressableWriteDevices.map(\.addressRange)
+ self.addressableReadDevices = addressableReadDevices
+ self.addressableWriteDevices = addressableWriteDevices
  }
 
 
  // MARK: - Reading and writing
 
- /// Reads data from a device on the bus.
+ /// Read from or write to an address on the bus.
+ ///
+ /// - Parameters:
+ /// - address: The address to read from or write to..
+ /// - Returns: The value that was read from a device on the bus.
+ subscript(address: Address) -> Value {
+ get { read(from: address) }
+ set { write(newValue, to: address) }
+ }
+
+ /// Reads data from the specified address on the bus.
  ///
- /// - note: If a device does not respond to the address, `0` will be returned.
+ /// - Note: If a device does not respond to the address, `0` will be returned.
  ///
- /// - parameter address: The address to read from.
- /// - returns: The value that was read from a device on the bus.
+ /// - Parameters:
+ /// - address: The address to read from.
+ /// - Returns: The value that was read from a device on the bus.
  func read(from address: Address) -> Value {
- guard let deviceToReadFrom = addressableReadDevices
- .first(where: { $0.respondsTo(address) }) else { return 0 }
+ guard let deviceToReadFromIndex = addressableReadDeviceRanges
+ .firstIndex(where: { $0.contains(address) }) else { return 0 }
+
+ let deviceToReadFrom = addressableReadDevices[deviceToReadFromIndex]
 
  return deviceToReadFrom.read(from: address)
  }
- 
- /// Writes data to a device on the bus.
+
+ /// Writes data to the specified address on the bus.
  ///
- /// - note: If a device does not respond to the address, this method does nothing.
+ /// - Note: If a device does not respond to the address, this method does nothing.
  ///
- /// - parameter value: The value to write to the bus.
- /// - parameter address: The address to write to.
+ /// - Parameters:
+ /// - value: The value to write to the bus.
+ /// - address: The address to write to.
  func write(_ value: Value, to address: Address) {
- guard let deviceToWriteTo = addressableWriteDevices
- .first(where: { $0.respondsTo(address) }) else { return }
-
+ guard let deviceToWriteToIndex = addressableWriteDeviceRanges
+ .firstIndex(where: { $0.contains(address) }) else { return }
+
+ let deviceToWriteTo = addressableWriteDevices[deviceToWriteToIndex]
+
  deviceToWriteTo.write(value, to: address)
  }
- 
- 
+
+
  // MARK: - Private
 
- /// All attached devices on the bus.
- private let addressableReadDevices: [AddressableReadDevice]
- private let addressableWriteDevices: [AddressableWriteDevice]
+ /// The ranges of the addressable devices attached to the bus that can be read from.
+ private let addressableReadDeviceRanges: [AddressRange]
+
+ /// The ranges of the addressable devices attached to the bus that can be written to.
+ private let addressableWriteDeviceRanges: [AddressRange]
+
+ /// All of the addressable devices attached to the bus that can be read from.
+ private let addressableReadDevices: [any AddressableReadDevice]
+
+ /// All of the addressable devices attached to the bus that can be written to.
+ private let addressableWriteDevices: [any AddressableWriteDevice]
 }

Sources/SwiftNES/Cartridge.swift

@@ -23,7 +23,7 @@
 import Foundation
 
 /// An enumeration that defines the types of errors a cartridge can throw.
-enum CartridgeError: Error {
+public enum CartridgeError: Error {
  /// The data was not in the `iNES` format.
  case invalidDataFormat
 
@@ -44,7 +44,7 @@ public final class Cartridge {
  /// - parameter programStartAddress: Forces the starting address to a specified value.
  /// This is typically only used for testing purposes, as all cartridges should have their program start
  /// address set.
- init(data: Data, programStartAddress: Address? = nil) throws {
+ public init(data: Data, programStartAddress: Address? = nil) throws {
  var dataLocation = 0
 
  // Read the 16-byte header.
@@ -88,6 +88,9 @@ public final class Cartridge {
  // Create and store the mapper.
  mapper = try mapperType.init(programMemoryBanks: programMemoryBanks, characterMemoryBanks: characterMemoryBanks)
 
+ // Determine the mirroring mode.
+ mirroringMode = (header.mapper1 & 0x01) > 0 ? .vertical : .horizontal
+
  // If a program start address was specified, write it to the cartridge.
  if let programStartAddress = programStartAddress {
  write(UInt8(programStartAddress & 0x00ff), to: 0xfffc)
@@ -99,10 +102,11 @@ public final class Cartridge {
  ///
  /// - parameter string: A string containing program code. The program code must be compiled object
  /// code in hexadecimal format.
- init(string: String) throws {
+ public init(string: String) throws {
  programMemory = [Value](repeating: 0, count: 0x4000)
  characterMemory = []
  mapper = try Self.mapperTypes[0]!.init(programMemoryBanks: 1, characterMemoryBanks: 1)
+ mirroringMode = .horizontal
 
  let programCode = string.hexToUInt8
  programMemory.replaceSubrange(0..<programCode.count, with: programCode)
@@ -111,6 +115,16 @@ public final class Cartridge {
  }
 
 
+ // MARK: - Accessing information about the cartridge
+
+ enum MirroringMode {
+ case horizontal
+ case vertical
+ }
+
+ let mirroringMode: MirroringMode
+
+
  // MARK: - Reading and writing
 
  /// Reads from the specified address in the cartridge.

Sources/SwiftNES/CartridgeConnector.swift

@@ -46,10 +46,14 @@ final class CartridgeConnector: AddressableReadWriteDevice {
 
  // MARK: - AddressableReadWriteDevice
 
+ @inlinable
  func respondsTo(_ address: Address) -> Bool {
- return addressRange.contains(address)
+ addressRange.contains(address)
  }
 
+ /// The range of addresses that this connector responds to.
+ let addressRange: AddressRange
+
  func read(from address: Address) -> Value {
  guard respondsTo(address) else { return 0 }
 
@@ -61,10 +65,4 @@ final class CartridgeConnector: AddressableReadWriteDevice {
 
  cartridge?.write(value, to: address)
  }
-
-
- // MARK: - Private
-
- /// The range of addresses that this connector responds to.
- private let addressRange: AddressRange
 }

Sources/SwiftNES/DirectMemoryAccessController.swift

@@ -0,0 +1,45 @@
+// MIT License
+//
+// Copyright (c) 2020 Jerrod Putman
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+import Foundation
+
+struct ObjectAttributeEntry {
+ var y: UInt8
+ var id: UInt8
+ var attribute: UInt8
+ var x: UInt8
+}
+
+var objectAttributeMemory: [ObjectAttributeEntry] = []
+
+final class DirectMemoryAccessController {
+
+ init() {
+ page = 0
+ address = 0
+ data = 0
+ }
+
+ private var page: UInt8
+ private var address: UInt8
+ private var data: Value
+}