Impl Joypad

Sources/Data/Bus.swift

@@ -1,7 +1,8 @@
 class Bus {
     var cpuVram: [UInt8] = .init(repeating: 0, count: 2048)
     var prgRom: [UInt8]
-    var ppu: NesPPU
+    let ppu: NesPPU
+    let joypad1: Joypad
     var cycles: Int = 0
     var gameloopCallback: (NesPPU) -> ()
 
@@ -12,20 +13,18 @@ class Bus {
     fileprivate let ROM_ADDRESS_START: UInt16 = 0x8000
     fileprivate let ROM_ADDRESS_END: UInt16 = 0xFFFF
 
-    init(_ rom: Rom, gameloopCallback: @escaping (NesPPU) -> ()) {
+    init(rom: Rom, joypad1: Joypad, gameloopCallback: @escaping (NesPPU) -> ()) {
         ppu = NesPPU(rom.character, rom.screenMirror)
         self.prgRom = rom.program
         self.gameloopCallback = gameloopCallback
+        self.joypad1 = joypad1
+
     }
 
     func tick(_ cycles: UInt8) {
         self.cycles += Int(cycles)
-        let nmiBefore = ppu.nmiInterrupt != nil
+        let newFrame = self.ppu.tick(cycles * 3)
-        //print(nmiBefore)
+        if newFrame {
-        self.ppu.tick(cycles * 3)
-        let nmiAfter = ppu.nmiInterrupt != nil
-        //print(nmiAfter)
-        if !nmiBefore && nmiAfter {
             gameloopCallback(ppu)
         }
 
@@ -55,7 +54,7 @@ extension Bus: Memory {
         case 0x4000...0x4015:
             return 0 // Ignore APU
         case 0x4016:
-            return 0 // Ignore Joy 1
+            return joypad1.read()
         case 0x4017:
             return 0 // Ignore Joy 2
         case 0x2008...PPU_REGISTERS_MIRRORS_END:
@@ -96,7 +95,7 @@ extension Bus: Memory {
         case 0x4000...0x4013, 0x4015:
             return // Ignore APU
         case 0x4016:
-            return // ignore Joy 1
+            joypad1.write(data)
         case 0x4017:
             return // Ignore Joy 2
         case 0x4014:

Sources/Joypad.swift

@@ -0,0 +1,44 @@
+struct JoypadButton: OptionSet {
+    var rawValue: UInt8
+
+    static let RIGHT = JoypadButton(rawValue: 0b10000000)
+    static let LEFT = JoypadButton(rawValue: 0b01000000)
+    static let DOWN = JoypadButton(rawValue: 0b00100000)
+    static let UP = JoypadButton(rawValue: 0b00010000)
+    static let START = JoypadButton(rawValue: 0b00001000)
+    static let SELECT = JoypadButton(rawValue: 0b00000100)
+    static let BUTTON_B = JoypadButton(rawValue: 0b00000010)
+    static let BUTTON_A = JoypadButton(rawValue: 0b00000001)
+}
+
+class Joypad {
+    var strobe = false
+    var buttonIndex: UInt8 = 0
+    var buttonStatus = JoypadButton()
+
+    func write(_ data: UInt8) {
+        strobe = data & 1 == 1
+        if strobe {
+            buttonIndex = 0
+        }
+    }
+
+    func read() -> UInt8 {
+        if buttonIndex > 7 {
+            return 1
+        }
+        let response = (buttonStatus.rawValue & (1 << buttonIndex)) >> buttonIndex
+        if !strobe {
+            buttonIndex += 1
+        }
+        return response
+    }
+
+    func setButton(_ button: JoypadButton, pressed: Bool) {
+        if pressed {
+            buttonStatus.insert(button)
+        } else {
+            buttonStatus.remove(button)
+        }
+    }
+}

Sources/Render/Render.swift

@@ -13,7 +13,7 @@ class Render {
                 var upper = tile[tile.startIndex + y]
                 var lower = tile[tile.startIndex + y + 8]
 
-                for x in (0...7).reversed() {
+                for x in [7,6,5,4,3,2,1,0] {
                     let value = (1 & lower) << 1 | (1 & upper)
                     upper = upper >> 1
                     lower = lower >> 1
@@ -32,6 +32,7 @@ class Render {
                     frame.setPixel((tileLoc.col * 8 + x, tileLoc.row * 8 + y), rgb)
                 }
             }
+        }
 
         // MARK: Draw Sprites
         for i in stride(from: 0, to: ppu.oamData.count, by: 4) {
@@ -52,7 +53,7 @@ class Render {
                 var upper = tile[tile.startIndex + y]
                 var lower = tile[tile.startIndex + y + 8]
 
-                    for x in (0...7).reversed() {
+                for x in [7,6,5,4,3,2,1,0] {
                     let value = (1 & lower) << 1 | (1 & upper)
                     upper = upper >> 1
                     lower = lower >> 1
@@ -83,7 +84,6 @@ class Render {
             }
         }
     }
-    }
 
     static func getBgPalette(_ ppu: NesPPU, tileLoc: (col: Int, row: Int)) -> [UInt8] {
         let attrTableIndex = tileLoc.row / 4 * 8 + tileLoc.col / 4

Sources/main.swift

@@ -21,87 +21,27 @@ SDL_RenderSetScale(canvas, 3.0, 3.0)
 var texture = SDL_CreateTexture(canvas, SDL_PIXELFORMAT_RGB24.rawValue, Int32(SDL_TEXTUREACCESS_TARGET.rawValue), 256, 240)
 
 var event = SDL_Event()
-var quit = false
-
-// func handleUserInput(_ cpu: CPU, event: inout SDL_Event) {
-//     while SDL_PollEvent(&event) > 0 {
-//         if event.type == SDL_QUIT.rawValue {
-//             SDL_DestroyWindow(window)
-//             SDL_Quit()
-//             exit(0)
-//         }
-//         if event.type == SDL_KEYDOWN.rawValue {
-//             switch SDL_KeyCode(UInt32(event.key.keysym.sym)) {
-//             case SDLK_ESCAPE:
-//                 SDL_DestroyWindow(window)
-//                 SDL_Quit()
-//                 exit(0)
-//             case SDLK_w:
-//                 cpu.memWrite(0xff, data: 0x77)
-//             case SDLK_a:
-//                 cpu.memWrite(0xff, data: 0x61)
-//             case SDLK_s:
-//                 cpu.memWrite(0xff, data: 0x73)
-//             case SDLK_d:
-//                 cpu.memWrite(0xff, data: 0x64)
-//             default:
-//                 continue
-//             }
-//         }
-//     }
-// }
-
-// func color(_ byte: UInt8) -> SDL_Color {
-//     switch byte{
-//     case 0:
-//         return SDL_Color(r: 0, g: 0, b: 0, a: 255)
-//     case 1:
-//         return SDL_Color(r: 255, g: 255, b: 255, a: 255)
-//     case 2, 9:
-//         return SDL_Color(r: 128, g: 128, b: 128, a: 255)
-//     case 3, 10:
-//         return SDL_Color(r: 255, g: 0, b: 0, a: 255)
-//     case 4, 11:
-//         return SDL_Color(r: 0, g: 255, b: 0, a: 255)
-//     case 5, 12:
-//         return SDL_Color(r: 0, g: 0, b: 255, a: 255)
-//     case 6, 13:
-//         return SDL_Color(r: 255, g: 0, b: 255, a: 255)
-//     case 7, 14:
-//         return SDL_Color(r: 255, g: 255, b: 0, a: 255)
-//     default:
-//         return SDL_Color(r: 0, g: 255, b: 255, a: 255)
-
-//     }
-// }
-
-// func readScreenState(_ cpu: CPU, frame: inout [UInt8]) -> Bool {
-
-//     var frame_idx = 0
-//     var update = false
-//     for i in 0x0200..<0x600 {
-//         let color_idx = cpu.memRead(UInt16(i))
-//         let color = color(color_idx)
-//         let (b1, b2, b3) = (color.r, color.b, color.g)
-//         if frame[frame_idx] != b1 || frame[frame_idx + 1] != b2 || frame[frame_idx + 2] != b3 {
-//            frame[frame_idx] = b1;
-//            frame[frame_idx + 1] = b2;
-//            frame[frame_idx + 2] = b3;
-//            update = true;
-//        }
-//         frame_idx += 3
-//     }
-//     return update
-// }
 
 guard let bytes = NSData(contentsOfFile: "pacman.nes") else { fatalError("Rom not found") }
 var gameCode = [UInt8](repeating: 0, count: bytes.length)
 bytes.getBytes(&gameCode, length: bytes.length)
 
 let rom = try Rom(gameCode)
+let joypad1 = Joypad()
+
+let keyMap = [
+  SDLK_DOWN : JoypadButton.DOWN,
+  SDLK_UP : JoypadButton.UP,
+  SDLK_LEFT : JoypadButton.LEFT,
+  SDLK_RIGHT : JoypadButton.RIGHT,
+  SDLK_SPACE : JoypadButton.SELECT,
+  SDLK_RETURN : JoypadButton.START,
+  SDLK_a : JoypadButton.BUTTON_A,
+  SDLK_s : JoypadButton.BUTTON_B
+]
 
 var frame = Frame()
-let bus = Bus(rom) { ppu in
+let bus = Bus(rom: rom, joypad1: joypad1) { ppu in
     Render.render(ppu, frame: frame)
     SDL_UpdateTexture(texture, nil, frame.data, 256 * 3)
     SDL_RenderCopy(canvas, texture, nil, nil)
@@ -114,75 +54,24 @@ let bus = Bus(rom) { ppu in
              exit(0)
          }
         if event.type == SDL_KEYDOWN.rawValue {
-            switch SDL_KeyCode(UInt32(event.key.keysym.sym)) {
+            let keyCode = SDL_KeyCode(UInt32(event.key.keysym.sym))
+            switch keyCode {
             case SDLK_ESCAPE:
                 SDL_DestroyWindow(window)
                 SDL_Quit()
                 exit(0)
             default:
-                continue
+                guard let key = keyMap[keyCode] else { continue }
+                joypad1.setButton(key, pressed: true)
             }
         }
+        if event.type == SDL_KEYUP.rawValue {
+            guard let key = keyMap[SDL_KeyCode(UInt32(event.key.keysym.sym))] else { continue }
+            joypad1.setButton(key, pressed: false)
+        }
     }
 }
 
 let cpu = CPU(bus: bus)
 cpu.reset()
 cpu.run()
-
-// let tileFrame = TileViewer.showTile(chrRom: rom.character, bank: 1, tileNum: 0)
-// let tileFrame = TileViewer.showTileBank(chrRom: rom.character, bank: 1)
-
-// SDL_UpdateTexture(texture, nil, tileFrame.data, 256 * 3)
-// SDL_RenderCopy(canvas, texture, nil, nil)
-// SDL_RenderPresent(canvas)
-
-// while true {
-//     while SDL_PollEvent(&event) > 0 {
-//         if event.type == SDL_QUIT.rawValue {
-//              SDL_DestroyWindow(window)
-//              SDL_Quit()
-//              exit(0)
-//          }
-//         if event.type == SDL_KEYDOWN.rawValue {
-//             switch SDL_KeyCode(UInt32(event.key.keysym.sym)) {
-//             case SDLK_ESCAPE:
-//                 SDL_DestroyWindow(window)
-//                 SDL_Quit()
-//                 exit(0)
-//             default:
-//                 continue
-//             }
-//         }
-//     }
-// }
-
-// let bus = Bus(try! Rom(gameCode))
-
-//var cpu = CPU(bus: bus)
-//cpu.load(gameCode)
-//cpu.reset()
-//cpu.programCounter = 0xC000
-
-// var screenState = [UInt8](repeating: 0, count: 32 * 3 * 32)
-// var rng = SystemRandomNumberGenerator()
-// cpu.run(onCycle: {
-//     //print(dumpCpuState(cpu))
-//     handleUserInput(cpu, event: &event)
-//     cpu.memWrite(0xfe, data: UInt8.random(in: 1...16, using: &rng))
-
-//     if readScreenState(cpu, frame: &screenState) {
-//         SDL_UpdateTexture(texture, nil, screenState, 32 * 3)
-//         SDL_RenderCopy(canvas, texture, nil, nil)
-//         SDL_RenderPresent(canvas)
-//     }
-
-//     usleep(70)
-// }, onComplete: {
-//     SDL_DestroyWindow(window)
-//     SDL_Quit()
-//     exit(0)
-// })
-
-// Infinite loop otherwise the program will exit prematurely
-// RunLoop.main.run()