324 lines
10 KiB
Plaintext
324 lines
10 KiB
Plaintext
// needs to be compiled with -m -C="-lraylib"
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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_create[] : CHIP8
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let c: CHIP8 = new CHIP8
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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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let fonts: Array = [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] = array.nth(fonts, i)
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mem.free(fonts)
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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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return c
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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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let high: i64 = c->memory[c->pc] as i64
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let low: i64 = c->memory[c->pc + 1] as i64
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c->pc = c->pc + 2
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let ins: i64 = (high << 8) | low
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let nnn: i64 = ins & 0x0fff
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let kk: i64 = ins & 0x00ff
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let n: i64 = ins & 0x000f
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let x: i64 = (ins >> 8) & 0x0f
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let y: i64 = (ins >> 4) & 0x0f
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let op: i64 = (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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let high: i64 = c->memory[c->pc] as i64
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let low: i64 = c->memory[c->pc + 1] as i64
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c->pc = c->pc + 2
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let ins: i64 = (high << 8) | low
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let nnn: i64 = ins & 0x0fff
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let kk: i64 = ins & 0x00ff
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let n: i64 = ins & 0x000f
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let x: i64 = (ins >> 8) & 0x0f
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let y: i64 = (ins >> 4) & 0x0f
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let op: i64 = (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 = array.nth(c->stack, 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 = c->sp + 1
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array.set(c->stack, 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 = 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 = 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 = 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] = 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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let 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 = 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] = (math.abs(os.urandom_i64()) % 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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let pixel_x: u8 = (c->reg[x] + col) % 64
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let pixel_y: u8 = (c->reg[y] + row) % 32
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let offset: i64 = 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(array.nth(c->keyboard_map, c->reg[x] as i64))
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c->pc = c->pc + 2
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else if kk == 0xa1
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if !IsKeyDown(array.nth(c->keyboard_map, c->reg[x] as i64))
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c->pc = 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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let key_pressed: bool = false
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while !key_pressed && !WindowShouldClose()
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for i in 0..16
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if IsKeyDown(array.nth(c->keyboard_map, 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->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 chip8_free[c: CHIP8] : void
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mem.free(c->memory)
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array.free(c->stack)
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mem.free(c->reg)
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array.free(c->keyboard)
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mem.free(c->display)
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array.free(c->keyboard_map)
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mem.free(c)
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func main[argc: i64, argv: ptr] : i64
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let path: str = 0 as str
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let disassemble: bool = false
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for i in 1..argc
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let arg: str = mem.read64(argv + i * 8) as str
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if str.equal(arg, "-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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let c: CHIP8 = chip8_create()
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let buffer: io.Buffer = must(io.read_binary_file?(path))
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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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chip8_disassemble(c, 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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chip8_step(c)
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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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