327 lines
9.8 KiB
Plaintext
327 lines
9.8 KiB
Plaintext
// needs to be compiled with -m -C "-lraylib"
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include "std/io.zr"
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include "std/os.zr"
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extern InitWindow
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extern SetTargetFPS
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extern WindowShouldClose
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extern BeginDrawing
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extern ClearBackground
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extern DrawRectangle
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extern EndDrawing
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extern IsKeyDown
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struct CHIP8
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memory: ptr
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pc: i64
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stack: Array
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sp: i64
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reg: ptr
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I: i64
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delay_timer: u8
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sound_timer: u8
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keyboard: Array
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display: ptr
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keyboard_map: Array
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func CHIP8.init[c: CHIP8] : void
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c->memory = mem.alloc(4096)
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mem.zero(c->memory, 4096)
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c->display = mem.alloc(64*32)
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mem.zero(c->display, 64*32)
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c->reg = mem.alloc(16)
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mem.zero(c->reg, 16)
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c->stack = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
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c->keyboard = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
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fonts := [0xf0, 0x90, 0x90, 0x90, 0xf0, 0x20, 0x60, 0x20, 0x20, 0x70, 0xf0, 0x10, 0xf0, 0x80, 0xf0, 0xf0, 0x10, 0xf0, 0x10, 0xf0, 0x90, 0x90, 0xf0, 0x10, 0x10, 0xf0, 0x80, 0xf0, 0x10, 0xf0, 0xf0, 0x80, 0xf0, 0x90, 0xf0, 0xf0, 0x10, 0x20, 0x40, 0x40, 0xf0, 0x90, 0xf0, 0x90, 0xf0, 0xf0, 0x90, 0xf0, 0x10, 0xf0, 0xf0, 0x90, 0xf0, 0x90, 0x90, 0xe0, 0x90, 0xe0, 0x90, 0xe0, 0xf0, 0x80, 0x80, 0x80, 0xf0, 0xe0, 0x90, 0x90, 0x90, 0xe0, 0xf0, 0x80, 0xf0, 0x80, 0xf0, 0xf0, 0x80, 0xf0, 0x80, 0x80]
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for i in 0..80
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c->memory[i] = fonts->nth(i)
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fonts->free()
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c->pc = 0x200
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// see KeyboardKey in raylib.h
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c->keyboard_map = [49, 50, 51, 52, 53, 265, 32, 263, 264, 262, 87, 69, 82, 84, 89, 85]
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func CHIP8.free[c: CHIP8] : void
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c->memory->free()
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c->stack->free()
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c->reg->free()
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c->keyboard->free()
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c->display->free()
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c->keyboard_map->free()
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(c as ptr)->free()
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func CHIP8.disassemble[c: CHIP8, ins_count: i64] : void
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for i in 0..ins_count
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io.printf("0x%x: ", c->pc)
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high := c->memory[c->pc] as i64
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low := c->memory[c->pc + 1] as i64
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c->pc += 2
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ins := (high << 8) | low
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nnn := ins & 0x0fff
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kk := ins & 0x00ff
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n := ins & 0x000f
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x := (ins >> 8) & 0x0f
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y := (ins >> 4) & 0x0f
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op := (ins >> 12) & 0x0f
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if op == 0x0
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if nnn == 0x0e0
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io.println("CLS")
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else if nnn == 0x0ee
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io.println("RET")
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else
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io.printf("SYS %d\n", nnn)
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else if op == 0x1
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io.printf("JP 0x%x\n", nnn)
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else if op == 0x2
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io.printf("CALL %d\n", nnn)
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else if op == 0x3
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io.printf("SE V%x, %d\n", x, kk)
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else if op == 0x4
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io.printf("SNE V%x, %d\n", x, kk)
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else if op == 0x5
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io.printf("SE V%x, V%x\n", x, y)
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else if op == 0x6
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io.printf("LD V%x, %d\n", x, kk)
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else if op == 0x7
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io.printf("ADD V%x, %d\n", x, kk)
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else if op == 0x8
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if n == 0x0
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io.printf("LD V%x, V%x\n", x, y)
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else if n == 0x1
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io.printf("OR V%x, V%x\n", x, y)
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else if n == 0x2
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io.printf("AND V%x, V%x\n", x, y)
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else if n == 0x3
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io.printf("XOR V%x, V%x\n", x, y)
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else if n == 0x4
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io.printf("ADD V%x, V%x\n", x, y)
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else if n == 0x5
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io.printf("SUB V%x, V%x\n", x, y)
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else if n == 0x6
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io.printf("SHR V%x\n", x)
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else if n == 0x7
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io.printf("SUBN V%x, V%x\n", x, y)
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else if n == 0xE
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io.printf("SHL V%x\n", x)
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else
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io.printf("??? (%x)\n", ins)
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else if op == 0x9
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io.printf("SNE V%x, V%x\n", x, y)
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else if op == 0xa
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io.printf("LD I, 0x%x\n", nnn)
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else if op == 0xb
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io.printf("JP V0, %d\n", nnn)
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else if op == 0xc
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io.printf("RND V%x, %d\n", x, kk)
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else if op == 0xd
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io.printf("DRW V%x, V%x, %d\n", x, y, n)
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else if op == 0xe
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if kk == 0x9e
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io.printf("SKP V%x\n", x)
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else if kk == 0xa1
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io.printf("SKNP V%x\n", x)
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else
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io.printf("??? (%x)\n", ins)
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else if op == 0xf
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if kk == 0x07
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io.printf("LD V%x, DT\n", x)
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else if kk == 0x0A
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io.printf("LD V%x, K\n", x)
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else if kk == 0x15
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io.printf("LD DT, V%x\n", x)
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else if kk == 0x18
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io.printf("LD ST, V%x\n", x)
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else if kk == 0x1E
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io.printf("ADD I, V%x\n", x)
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else if kk == 0x29
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io.printf("LD F, V%x\n", x)
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else if kk == 0x33
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io.printf("LD B, V%x\n", x)
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else if kk == 0x55
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io.printf("LD [I], V%x\n", x)
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else if kk == 0x65
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io.printf("LD V%x, [I]\n", x)
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else
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io.printf("??? (%x)\n", ins)
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else
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io.printf("??? (%x)\n", ins)
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func CHIP8.step[c: CHIP8] : void
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high := c->memory[c->pc] as i64
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low := c->memory[c->pc + 1] as i64
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c->pc += 2
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ins := (high << 8) | low
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nnn := ins & 0x0fff
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kk := ins & 0x00ff
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n := ins & 0x000f
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x := (ins >> 8) & 0x0f
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y := (ins >> 4) & 0x0f
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op := (ins >> 12) & 0x0f
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if op == 0x0
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if nnn == 0x0e0
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mem.zero(c->display, 64 * 32)
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else if nnn == 0x0ee
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c->pc = c->stack->nth(c->sp)
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c->sp = c->sp - 1
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else if op == 0x1
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c->pc = nnn
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else if op == 0x2
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c->sp += 1
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c->stack->set(c->sp, c->pc)
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c->pc = nnn
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else if op == 0x3
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if c->reg[x] == kk
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c->pc += 2
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else if op == 0x4
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if c->reg[x] != kk
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c->pc += 2
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else if op == 0x5
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if c->reg[x] == c->reg[y]
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c->pc += 2
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else if op == 0x6
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c->reg[x] = kk
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else if op == 0x7
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c->reg[x] += kk
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else if op == 0x8
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if n == 0x0
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c->reg[x] = c->reg[y]
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else if n == 0x1
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c->reg[x] = c->reg[x] | c->reg[y]
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else if n == 0x2
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c->reg[x] = c->reg[x] & c->reg[y]
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else if n == 0x3
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c->reg[x] = c->reg[x] ^ c->reg[y]
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else if n == 0x4
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res : u8 = c->reg[x] + c->reg[y]
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c->reg[0xf] = (res > 0xff) as u8
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c->reg[x] = res
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else if n == 0x5
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c->reg[0xf] = (c->reg[x] > c->reg[y]) as u8
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c->reg[x] = c->reg[x] - c->reg[y]
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else if n == 0x6
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c->reg[0xf] = c->reg[x] & 0x1
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c->reg[x] = c->reg[x] >> 1
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else if n == 0x7
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c->reg[0xf] = (c->reg[y] > c->reg[x]) as u8
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c->reg[x] = c->reg[y] - c->reg[x]
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else if n == 0xE
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c->reg[0xf] = (c->reg[x] & 0x80) >> 7
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c->reg[x] = c->reg[x] << 1
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else if op == 0x9
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if c->reg[x] != c->reg[y]
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c->pc += 2
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else if op == 0xa
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c->I = nnn
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else if op == 0xb
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c->pc = nnn + c->reg[0]
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else if op == 0xc
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c->reg[x] = (os.urandom_i64()->abs() % 256) & kk
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else if op == 0xd
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c->reg[0xf] = 0
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for row in 0..n
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for col in 0..8
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if (c->memory[c->I + row] & (0x80 >> col)) != 0
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pixel_x : u8 = (c->reg[x] + col) % 64
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pixel_y : u8 = (c->reg[y] + row) % 32
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offset := pixel_x as i64 + (pixel_y * 64)
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if c->display[offset] == 1
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c->reg[0xf] = 1
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c->display[offset] = c->display[offset] ^ 1
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else if op == 0xe
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if kk == 0x9e
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if IsKeyDown(c->keyboard_map->nth(c->reg[x] as i64))
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c->pc += 2
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else if kk == 0xa1
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if !IsKeyDown(c->keyboard_map->nth(c->reg[x] as i64))
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c->pc += 2
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else if op == 0xf
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if kk == 0x07
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c->reg[x] = c->delay_timer
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else if kk == 0x0A
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key_pressed := false
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while !key_pressed && !WindowShouldClose()
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for i in 0..16
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if IsKeyDown(c->keyboard_map->nth(i))
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key_pressed = true
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break
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else if kk == 0x15
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c->delay_timer = c->reg[x]
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else if kk == 0x18
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c->sound_timer = c->reg[x]
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else if kk == 0x1E
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c->I += c->reg[x]
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else if kk == 0x29
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c->I = c->reg[x] as i64 * 5
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else if kk == 0x33
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c->memory[c->I] = c->reg[x] / 100
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c->memory[c->I + 1] = (c->reg[x] / 10) % 10
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c->memory[c->I + 2] = c->reg[x] % 10
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else if kk == 0x55
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for i in 0..x+1
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c->memory[c->I + i] = c->reg[i]
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else if kk == 0x65
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for i in 0..x+1
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c->reg[i] = c->memory[c->I + i]
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func main[argc: i64, argv: ptr] : i64
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path := 0 as str
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disassemble := false
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for i in 1..argc
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arg := os.arg(argv, i)
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if arg->equal("-d")
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disassemble = true
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else
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path = arg
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if path as i64 == 0
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io.println("Usage: chip8 -d <path>")
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return 1
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c := new CHIP8
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c->init()
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buffer, ok := io.read_binary_file(path)
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if !ok
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panic("failed to read file")
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for i in 0..buffer->size
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c->memory[0x200 + i] = buffer->data[i]
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if disassemble
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c->disassemble(buffer->size / 2)
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return 0
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InitWindow(640, 320, "CHIP-8")
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SetTargetFPS(60)
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while !WindowShouldClose()
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if c->delay_timer > 0
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c->delay_timer = c->delay_timer - 1
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if c->sound_timer > 0
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c->sound_timer = c->sound_timer - 1
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// TODO: buzzer
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for i in 0..25
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c->step()
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BeginDrawing()
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ClearBackground(0xffffffff)
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for y in 0..32
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for x in 0..64
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if c->display[x + y * 64] == 1
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DrawRectangle(x * 10, y * 10, 10, 10, 0xff000000)
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EndDrawing()
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