test snake game

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Candygoblen123 2024-05-17 14:15:10 -04:00
parent c441014511
commit 5bdfebdf13
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GPG Key ID: 577DA64EBEF10385
3 changed files with 270 additions and 184 deletions

View File

@ -1,3 +1,6 @@
import Foundation
import SDL
enum AddressingMode {
case Immediate
case ZeroPage
@ -61,7 +64,6 @@ class CPU {
return base &+ UInt16(register_y)
case .Indirect_X:
let base = memRead(programCounter)
let ptr = UInt8(base) &+ register_x
let lo = memRead(UInt16(ptr))
let hi = memRead(UInt16(ptr &+ 1))
@ -101,184 +103,189 @@ class CPU {
}
func run() {
run {
run {}
}
func run(callback: @escaping () -> ()) {
let opcodes = OPCODES_MAP
Timer.scheduledTimer(withTimeInterval: 0.00007, repeats: true) { [self] timer in
processOpcodes(callback: callback, opcodes: opcodes, timer: timer)
}
}
func run(callback: () -> ()) {
let opcodes = OPCODES_MAP
func processOpcodes(callback: () -> (), opcodes: [UInt8: OpCode], timer: Timer) {
callback()
let code = memRead(programCounter)
programCounter += 1
while true {
callback()
let code = memRead(programCounter)
programCounter += 1
let programCounterState = programCounter
guard let opcode = opcodes[code] else {fatalError("OpCode \(code) not recgonized!")}
// print(programCounter, opcode.mnemonic)
let programCounterState = programCounter
guard let opcode = opcodes[code] else {fatalError("OpCode \(code) not recgonized!")}
switch code {
/// LDA
case 0xa9, 0xa5, 0xb5, 0xad, 0xbd, 0xb9, 0xa1, 0xb1:
lda(opcode.mode)
/// STA
case 0x85, 0x95, 0x8d, 0x9d, 0x99, 0x81, 0x91:
sta(opcode.mode)
case 0xd8:
status.remove(.decimalMode)
case 0x58:
status.remove(.interruptDisable)
case 0xb8:
status.remove(.overflow)
case 0x18:
clearCarryFlag()
case 0x38:
setCarryFlag()
case 0x78:
status.insert(.interruptDisable)
case 0xf8:
status.insert(.decimalMode)
case 0x48:
stackPush(register_a)
case 0x68:
pla()
case 0x08:
php()
case 0x28:
plp()
case 0x69, 0x65, 0x75, 0x6d, 0x7d, 0x79, 0x61, 0x71:
adc(opcode.mode)
case 0xe9, 0xe5, 0xf5, 0xed, 0xfd, 0xf9, 0xe1, 0xf1:
sbc(opcode.mode)
case 0x29, 0x25, 0x35, 0x2d, 0x3d, 0x39, 0x21, 0x31:
and(opcode.mode)
case 0x49, 0x45, 0x55, 0x4d, 0x5d, 0x59, 0x41, 0x51:
eor(opcode.mode)
case 0x09, 0x05, 0x15, 0x0d, 0x1d, 0x19, 0x01, 0x11:
ora(opcode.mode)
case 0x4a:
lsrAccumulator()
case 0x46, 0x56, 0x4e, 0x5e:
_ = lsr(opcode.mode)
case 0x0a:
aslAccumulator()
case 0x06, 0x16, 0x0e, 0x1e:
_ = asl(opcode.mode)
case 0x2a:
rolAccumulator()
case 0x26, 0x36, 0x2e, 0x3e:
_ = rol(opcode.mode)
case 0x6a:
rorAccumulator()
case 0x66, 0x76, 0x6e, 0x7e:
_ = ror(opcode.mode)
case 0xe6, 0xf6, 0xee, 0xfe:
_ = inc(opcode.mode)
case 0xc8:
iny()
case 0xc6, 0xd6, 0xce, 0xde:
_ = dec(opcode.mode)
case 0xca:
dex()
case 0x88:
dey()
case 0xc9, 0xc5, 0xd5, 0xcd, 0xdd, 0xd9, 0xc1, 0xd1:
compare(mode: opcode.mode, compare_with: register_a)
case 0xc0, 0xc4, 0xcc:
compare(mode: opcode.mode, compare_with: register_y)
case 0xe0, 0xe4, 0xec:
compare(mode: opcode.mode, compare_with: register_x)
case 0x4c:
let memAddr = memReadU16(programCounter)
programCounter = memAddr
case 0x6c:
let memAddr = memReadU16(programCounter)
//6502 bug mode with with page boundary:
// if address $3000 contains $40, $30FF contains $80, and $3100 contains $50,
// the result of JMP ($30FF) will be a transfer of control to $4080 rather than $5080 as you intended
// i.e. the 6502 took the low byte of the address from $30FF and the high byte from $3000
let indirectRef: UInt16
if memAddr & 0x00ff == 0x00ff {
let lo = memRead(memAddr)
let hi = memRead(memAddr & 0x00ff)
indirectRef = UInt16(hi) << 8 | UInt16(lo)
} else {
indirectRef = memReadU16(memAddr)
}
programCounter = indirectRef
case 0x20:
stackPushU16(programCounter + 2 - 1)
let targetAddr = memReadU16(programCounter)
programCounter = targetAddr
case 0x60:
programCounter = stackPopU16() + 1
case 0x40:
status.rawValue = stackPop()
status.remove(.break1)
status.remove(.break2)
programCounter = stackPopU16()
case 0xd0:
branch(!status.contains(.zero))
case 0x70:
branch(status.contains(.overflow))
case 0x50:
branch(!status.contains(.overflow))
case 0x10:
branch(!status.contains(.negative))
case 0x30:
branch(status.contains(.negative))
case 0xf0:
branch(status.contains(.zero))
case 0xb0:
branch(status.contains(.carry))
case 0x90:
branch(!status.contains(.carry))
case 0x24, 0x2c:
bit(opcode.mode)
case 0x86, 0x96, 0x8e:
let addr = getOpperandAddress(opcode.mode)
memWrite(addr, data: register_x)
case 0x84, 0x94, 0x8c:
let addr = getOpperandAddress(opcode.mode)
memWrite(addr, data: register_y)
case 0xa2, 0xa6, 0xb6, 0xae, 0xbe:
ldx(opcode.mode)
case 0xa0, 0xa4, 0xb4, 0xac, 0xbc:
ldy(opcode.mode)
case 0xea:
continue
case 0xa8:
register_y = register_x
updateZeroAndNegativeFlags(register_y)
case 0xba:
register_x = stackPointer
updateZeroAndNegativeFlags(register_x)
case 0x8a:
register_a = register_x
updateZeroAndNegativeFlags(register_a)
case 0x9a:
stackPointer = register_x
case 0x98:
register_a = register_y
updateZeroAndNegativeFlags(register_a)
/// TAX
case 0xaa:
tax()
/// INX
case 0xe8:
inx()
/// BRK
case 0x00:
return
default: fatalError("TODO!")
switch code {
/// LDA
case 0xa9, 0xa5, 0xb5, 0xad, 0xbd, 0xb9, 0xa1, 0xb1:
lda(opcode.mode)
/// STA
case 0x85, 0x95, 0x8d, 0x9d, 0x99, 0x81, 0x91:
sta(opcode.mode)
case 0xd8:
status.remove(.decimalMode)
case 0x58:
status.remove(.interruptDisable)
case 0xb8:
status.remove(.overflow)
case 0x18:
clearCarryFlag()
case 0x38:
setCarryFlag()
case 0x78:
status.insert(.interruptDisable)
case 0xf8:
status.insert(.decimalMode)
case 0x48:
stackPush(register_a)
case 0x68:
pla()
case 0x08:
php()
case 0x28:
plp()
case 0x69, 0x65, 0x75, 0x6d, 0x7d, 0x79, 0x61, 0x71:
adc(opcode.mode)
case 0xe9, 0xe5, 0xf5, 0xed, 0xfd, 0xf9, 0xe1, 0xf1:
sbc(opcode.mode)
case 0x29, 0x25, 0x35, 0x2d, 0x3d, 0x39, 0x21, 0x31:
and(opcode.mode)
case 0x49, 0x45, 0x55, 0x4d, 0x5d, 0x59, 0x41, 0x51:
eor(opcode.mode)
case 0x09, 0x05, 0x15, 0x0d, 0x1d, 0x19, 0x01, 0x11:
ora(opcode.mode)
case 0x4a:
lsrAccumulator()
case 0x46, 0x56, 0x4e, 0x5e:
_ = lsr(opcode.mode)
case 0x0a:
aslAccumulator()
case 0x06, 0x16, 0x0e, 0x1e:
_ = asl(opcode.mode)
case 0x2a:
rolAccumulator()
case 0x26, 0x36, 0x2e, 0x3e:
_ = rol(opcode.mode)
case 0x6a:
rorAccumulator()
case 0x66, 0x76, 0x6e, 0x7e:
_ = ror(opcode.mode)
case 0xe6, 0xf6, 0xee, 0xfe:
_ = inc(opcode.mode)
case 0xc8:
iny()
case 0xc6, 0xd6, 0xce, 0xde:
_ = dec(opcode.mode)
case 0xca:
dex()
case 0x88:
dey()
case 0xc9, 0xc5, 0xd5, 0xcd, 0xdd, 0xd9, 0xc1, 0xd1:
compare(mode: opcode.mode, compare_with: register_a)
case 0xc0, 0xc4, 0xcc:
compare(mode: opcode.mode, compare_with: register_y)
case 0xe0, 0xe4, 0xec:
compare(mode: opcode.mode, compare_with: register_x)
case 0x4c:
let memAddr = memReadU16(programCounter)
programCounter = memAddr
case 0x6c:
let memAddr = memReadU16(programCounter)
//6502 bug mode with with page boundary:
// if address $3000 contains $40, $30FF contains $80, and $3100 contains $50,
// the result of JMP ($30FF) will be a transfer of control to $4080 rather than $5080 as you intended
// i.e. the 6502 took the low byte of the address from $30FF and the high byte from $3000
let indirectRef: UInt16
if memAddr & 0x00ff == 0x00ff {
let lo = memRead(memAddr)
let hi = memRead(memAddr & 0x00ff)
indirectRef = UInt16(hi) << 8 | UInt16(lo)
} else {
indirectRef = memReadU16(memAddr)
}
if programCounterState == programCounter {
programCounter += UInt16(opcode.len - 1)
}
programCounter = indirectRef
case 0x20:
stackPushU16(programCounter + 2 - 1)
let targetAddr = memReadU16(programCounter)
programCounter = targetAddr
case 0x60:
programCounter = stackPopU16() + 1
case 0x40:
status.rawValue = stackPop()
status.remove(.break1)
status.remove(.break2)
programCounter = stackPopU16()
case 0xd0:
branch(!status.contains(.zero))
case 0x70:
branch(status.contains(.overflow))
case 0x50:
branch(!status.contains(.overflow))
case 0x10:
branch(!status.contains(.negative))
case 0x30:
branch(status.contains(.negative))
case 0xf0:
branch(status.contains(.zero))
case 0xb0:
branch(status.contains(.carry))
case 0x90:
branch(!status.contains(.carry))
case 0x24, 0x2c:
bit(opcode.mode)
case 0x86, 0x96, 0x8e:
let addr = getOpperandAddress(opcode.mode)
memWrite(addr, data: register_x)
case 0x84, 0x94, 0x8c:
let addr = getOpperandAddress(opcode.mode)
memWrite(addr, data: register_y)
case 0xa2, 0xa6, 0xb6, 0xae, 0xbe:
ldx(opcode.mode)
case 0xa0, 0xa4, 0xb4, 0xac, 0xbc:
ldy(opcode.mode)
case 0xea:
return
case 0xa8:
register_y = register_x
updateZeroAndNegativeFlags(register_y)
case 0xba:
register_x = stackPointer
updateZeroAndNegativeFlags(register_x)
case 0x8a:
register_a = register_x
updateZeroAndNegativeFlags(register_a)
case 0x9a:
stackPointer = register_x
case 0x98:
register_a = register_y
updateZeroAndNegativeFlags(register_a)
/// TAX
case 0xaa:
tax()
/// INX
case 0xe8:
inx()
/// BRK
case 0x00:
timer.invalidate()
SDL_DestroyWindow(window)
SDL_Quit()
exit(0)
default: fatalError("TODO!")
}
if programCounterState == programCounter {
programCounter += UInt16(opcode.len - 1)
}
}
@ -323,7 +330,7 @@ class CPU {
status.remove(.carry)
}
let result = UInt8(sum)
let result = UInt8(truncatingIfNeeded: sum)
if (data ^ result) & (result ^ register_a) & 0x80 != 0 {
status.insert(.overflow)
@ -373,7 +380,6 @@ class CPU {
func branch(_ condition: Bool) {
if condition {
let addr = memRead(programCounter)
// print(addr)
let jump: Int8 = Int8(bitPattern: addr)
let jump_addr = programCounter &+ 1 &+ UInt16(bitPattern: Int16(jump))

View File

@ -61,8 +61,8 @@ extension CPU {
func sbc(_ mode: AddressingMode) {
let addr = getOpperandAddress(mode)
let data = memRead(addr)
let res = Int8(data) &* -1
addToRegisterA(UInt8(res &- 1))
let res = Int8(bitPattern: data) &* -1
addToRegisterA(UInt8(bitPattern: res &- 1))
}
func adc(_ mode: AddressingMode) {

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@ -2,6 +2,7 @@
// https://docs.swift.org/swift-book
import SDL
import Foundation
guard SDL_Init(SDL_INIT_VIDEO) == 0 else {
fatalError("SDL could not initialize! SDL_Error: \(String(cString: SDL_GetError()))")
@ -17,6 +18,81 @@ let canvas = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC.rawValue)
SDL_RenderSetScale(canvas, 10.0, 10.0)
var texture = SDL_CreateTexture(canvas, SDL_PIXELFORMAT_RGB24.rawValue, Int32(SDL_TEXTUREACCESS_TARGET.rawValue), 32, 32)
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
}
let gameCode: [UInt8] = [
0x20, 0x06, 0x06, 0x20, 0x38, 0x06, 0x20, 0x0d, 0x06, 0x20, 0x2a, 0x06, 0x60, 0xa9, 0x02, 0x85,
@ -41,19 +117,23 @@ let gameCode: [UInt8] = [
0xea, 0xca, 0xd0, 0xfb, 0x60
]
print(gameCode[32])
var cpu = CPU()
cpu.load(gameCode)
cpu.reset()
cpu.run {
// TODO:
// read user input and write it to mem[0xFF]
// update mem[0xFE] with new Random Number
// read mem mapped screen state
// render screen state
var screenState = [UInt8](repeating: 0, count: 32 * 3 * 32)
var rng = SystemRandomNumberGenerator()
cpu.run() {
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)
}
}
// Infinite loop otherwise the program will exit prematurely
RunLoop.main.run()