Sources/CPU/CPU.swift

@@ -131,6 +131,7 @@ class CPU {
         status = [.interruptDisable, .break2]
 
         programCounter = self.memReadU16(0xFFFC)
+        print(programCounter)
     }
 
     //func loadAndRun(_ program: [UInt8]) {
@@ -150,14 +151,16 @@ class CPU {
     //}
 
     func run() {
-        run(onCycle: {}, onComplete: {})
+        run(onCycle: { print(dumpCpuState(self)) }, onComplete: {})
     }
 
     func run(onCycle: @escaping () -> (), onComplete: @escaping () -> ())  {
         let opcodes = OPCODES_MAP
         while true {
             if bus.pollNMI() != nil {
+                print(programCounter)
                 interrupt(.NMI)
+                print(programCounter)
             }
             processOpcodes(onCycle: onCycle, opcodes: opcodes) {
                 onComplete()
@@ -194,6 +197,7 @@ class CPU {
 
         let programCounterState = programCounter
         guard let opcode = opcodes[code] else {fatalError("OpCode \(code) not recgonized!")}
+        // print(programCounter, opcode.mnemonic)
 
         switch code {
         /// LDA

Sources/PPU/NesPPU.swift

@@ -28,6 +28,7 @@ class NesPPU {
     func tick(_ cycles: UInt8) -> Bool {
         self.cycles += Int(cycles)
         if self.cycles >= 341 {
+            //print(self.cycles)
             self.cycles = self.cycles - 341
             self.scanline += 1
 
@@ -36,6 +37,7 @@ class NesPPU {
                 status.setSpriteZeroHit(false)
                 if ctrl.generateVblankNMI() {
                     nmiInterrupt = 1
+                    print("interrupt")
                 }
             }
 
@@ -114,6 +116,7 @@ class NesPPU {
 
     func writeToData(_ data: UInt8) {
         let addr = addr.get()
+        print("\(addr): \(data)")
         switch addr {
         case 0...0x1fff:
             print("Attempt to write to chr rom space \(addr)!")

Sources/PPU/Registers/ControlRegister.swift

@@ -46,28 +46,4 @@ struct ControlRegister: OptionSet {
             0x1000
         }
     }
-
-    func spritePatternAddr() -> Int {
-        if !self.contains(.SPRITE_PATTERN_ADDR) {
-            0
-        } else {
-            0x1000
-        }
-    }
-
-    func spriteSize() -> Int {
-        if !self.contains(.SPRITE_SIZE) {
-            8
-        } else {
-            16
-        }
-    }
-
-    func masterSlaveSelect() -> Int {
-        if !self.contains(.SPRITE_SIZE) {
-            0
-        } else {
-            1
-        }
-    }
 }

Sources/Render/Render.swift

@@ -2,117 +2,36 @@ class Render {
     static func render(_ ppu: NesPPU, frame: Frame) {
         let bank = ppu.ctrl.backgroundPatternAddr()
 
-        for i in 0..<0x03c0 { // FIXME: For now, just use first nametable
+        for i in 0..<0x03c0 { // For now, just use first nametable
             let tileAddr = UInt16(ppu.vram[i])
-            let tileLoc = (col: i % 32, row: i / 32)
+            //print(ppu.vram)
+            let tileX = i % 32
+            let tileY = i / 32
             let tile = ppu.chrRom[(bank + Int(tileAddr) * 16)...(bank + Int(tileAddr) * 16 + 15)]
-            let bgPalette = getBgPalette(ppu, tileLoc: tileLoc)
 
-            // MARK: Draw Background
             for y in 0...7 {
                 var upper = tile[tile.startIndex + y]
                 var lower = tile[tile.startIndex + y + 8]
 
                 for x in (0...7).reversed() {
-                    let value = (1 & lower) << 1 | (1 & upper)
+                    let value = (1 & upper) << 1 | (1 & lower)
                     upper = upper >> 1
                     lower = lower >> 1
                     let rgb = switch value {
                         case 0:
-                            NESColor.SYSTEM_PALLETE[Int(ppu.paletteTable[0])]
+                            NESColor.SYSTEM_PALLETE[0x01]
                         case 1:
-                            NESColor.SYSTEM_PALLETE[Int(bgPalette[1])]
+                            NESColor.SYSTEM_PALLETE[0x23]
                         case 2:
-                            NESColor.SYSTEM_PALLETE[Int(bgPalette[2])]
+                            NESColor.SYSTEM_PALLETE[0x28]
                         case 3:
-                            NESColor.SYSTEM_PALLETE[Int(bgPalette[3])]
+                            NESColor.SYSTEM_PALLETE[0x31]
                         default:
                             fatalError("Invalid Pallete Color type")
                     }
-                    frame.setPixel((tileLoc.col * 8 + x, tileLoc.row * 8 + y), rgb)
+                    frame.setPixel((tileX * 8 + x, tileY * 8 + y), rgb)
-                }
-            }
-
-            // MARK: Draw Sprites
-            for i in stride(from: 0, to: ppu.oamData.count, by: 4) {
-                let tileIndex = UInt16(ppu.oamData[i + 1])
-                let tileX = Int(ppu.oamData[i + 3])
-                let tileY = Int(ppu.oamData[i])
-
-                let flipVert = ppu.oamData[i + 2] >> 7 & 1 == 1
-                let flipHori = ppu.oamData[i + 2] >> 6 & 1 == 1
-
-                let paletteIndex = ppu.oamData[i + 2] & 0b11
-                let spritePallete = getSpritePalette(ppu, paletteIndex: paletteIndex)
-
-                let bank = ppu.ctrl.spritePatternAddr()
-                let tile = ppu.chrRom[(bank + Int(tileIndex) * 16)...(bank + Int(tileIndex) * 16 + 15)]
-
-                for y in 0...7 {
-                    var upper = tile[tile.startIndex + y]
-                    var lower = tile[tile.startIndex + y + 8]
-
-                    for x in (0...7).reversed() {
-                        let value = (1 & lower) << 1 | (1 & upper)
-                        upper = upper >> 1
-                        lower = lower >> 1
-                        if (value == 0) {
-                            continue // skip coloring this pixel, it's transparent
-                        }
-                        let rgb = switch value {
-                        case 1:
-                            NESColor.SYSTEM_PALLETE[Int(spritePallete[1])]
-                        case 2:
-                            NESColor.SYSTEM_PALLETE[Int(spritePallete[2])]
-                        case 3:
-                            NESColor.SYSTEM_PALLETE[Int(spritePallete[3])]
-                        default:
-                            fatalError("Invalid Pallete Color type")
-                        }
-                        switch (flipHori, flipVert) {
-                        case (false, false):
-                            frame.setPixel((tileX + x, tileY + y), rgb)
-                        case (true, false):
-                            frame.setPixel((tileX + 7 - x, tileY + y), rgb)
-                        case (false, true):
-                            frame.setPixel((tileX + x, tileY + 7 - y), rgb)
-                        case (true, true):
-                            frame.setPixel((tileX + 7 - x, tileY + 7 - y), rgb)
-                        }
-                    }
                 }
             }
         }
     }
-
-    static func getBgPalette(_ ppu: NesPPU, tileLoc: (col: Int, row: Int)) -> [UInt8] {
-        let attrTableIndex = tileLoc.row / 4 * 8 + tileLoc.col / 4
-        let attrByte = ppu.vram[0x3c0 + attrTableIndex] // FIXME: still using hardcoded first nametable
-
-        let palleteIndex = switch (tileLoc.col % 4 / 2, tileLoc.row % 4 / 2) {
-        case (0,0):
-            attrByte & 0b11
-        case (1,0):
-            (attrByte >> 2) & 0b11
-        case (0,1):
-            (attrByte >> 4) & 0b11
-        case (1,1):
-            (attrByte >> 6) & 0b11
-        default:
-            fatalError("Invalid titleLoc. This should never happen!")
-        }
-
-        let palleteStartIndex = 1 + Int(palleteIndex) * 4
-        return [ppu.paletteTable[0], ppu.paletteTable[palleteStartIndex], ppu.paletteTable[palleteStartIndex + 1], ppu.paletteTable[palleteStartIndex + 2]]
-    }
-
-    static func getSpritePalette(_ ppu: NesPPU, paletteIndex: UInt8) -> [UInt8] {
-        let start = 0x11 + Int(paletteIndex * 4)
-        return [
-          0,
-          ppu.paletteTable[start],
-          ppu.paletteTable[start + 1],
-          ppu.paletteTable[start + 2]
-        ]
-    }
 }