diff options
Diffstat (limited to 'src/main.zig')
| -rw-r--r-- | src/main.zig | 139 |
1 files changed, 122 insertions, 17 deletions
diff --git a/src/main.zig b/src/main.zig index 9043f8c..20202d0 100644 --- a/src/main.zig +++ b/src/main.zig @@ -4,6 +4,9 @@ const ray = @import("raylib.zig"); // @cInclude("raylib.h"); //}); +const print = std.debug.print; +const fs = std.fs; + const screenWidth: u32 = 64 * 10; const screenHeight: u32 = (32 * 10) + 24; const RndGen = std.rand.DefaultPrng; @@ -15,7 +18,7 @@ const Chip8 = struct { memory: [4096]u8 = [_]u8{0} ** 4096, V: [16]u8 = [_]u8{0} ** 16, I: u16 = 0, - pc: u16 = 0, + pc: u16 = 0x200, gfx: [64 * 32]bool = [_]bool{false} ** (64 * 32), delay_timer: u8 = 0, sound_timer: u8 = 0, @@ -24,36 +27,129 @@ const Chip8 = struct { key: u8 = 0, pub fn new() Chip8 { + // TODO Initialize registers and memory once return Chip8{}; } - pub fn load_game(file_name: []u8) []u8 { - // TODO: handle file reading here - //var file = try std.fs.cwd().openFile(file_name, .{}); - //defer file.close(); - return file_name; + pub fn load_game(self: *Chip8, file_name: []const u8) void { + const file = std.fs.cwd().openFile(file_name, .{ .mode = .read_write }) catch |err| { + print("{}\n", .{err}); + return; + }; + defer file.close(); + + var buf: [512 * 7]u8 = undefined; + const chars_read = file.readAll(&buf) catch |err| { + print("{}\n", .{err}); + return; + }; + + print("{s}\n", .{buf}); + for (buf) |char, index| { + if (index == chars_read) { + break; + } + print("{}: {}\n", .{ index, char }); + self.*.memory[index + 512] = char; + } + } + + pub fn emulate_cycles(self: *Chip8, cycles: u32) void { + var i: u32 = cycles; + while (i > 0) : (i -= 1) { + //print("{}\n", .{i}); + // Fetch Opcode + self.*.opcode = @intCast(u16, self.*.memory[self.*.pc]) << 8 | self.*.memory[self.*.pc + 1]; + // Decode Opcode + // Execute Opcode + switch (self.*.opcode & 0xF000) { + 0x0000 => { // 00E0: Clear Screen + self.*.gfx = [_]bool{false} ** (64 * 32); + self.*.pc += 2; + }, + 0xA000 => { // ANNN: Set I to adress NNN + self.*.I = self.*.opcode & 0x0FFF; + self.*.pc += 2; + }, + 0x1000 => { // 1NNN: Jump to NNN + //self.*.stack[self.*.sp] = self.*.pc; + self.*.pc = self.*.opcode & 0x0FFF; + }, + 0x6000 => { // 6XNN: Set VX to NN + self.*.V[@intCast(u8, self.*.opcode & 0x0F00 >> 8)] = @intCast(u8, self.*.opcode & 0x00FF); + self.*.pc += 2; + }, + 0x7000 => { // 7XNN: Add NN to VX (dont change carry flag) + self.*.V[@intCast(u8, self.*.opcode & 0x0F00 >> 8)] += @intCast(u8, self.*.opcode & 0x00FF); + self.*.pc += 2; + }, + 0xD000 => { // DXYN: Draw a sprite + const x: u16 = self.*.V[@intCast(u16, self.*.opcode & 0x0F00 >> 8)]; + const y: u16 = self.*.V[@intCast(u16, self.*.opcode & 0x00F0 >> 4)]; + const height: u16 = @intCast(u16, self.*.opcode & 0x000F); + var pixel: u16 = undefined; + + self.*.V[0xF] = 0; + var yline: u32 = 0; + while (yline < height) : (yline += 1) { + pixel = self.*.memory[self.*.I + yline]; + var xline: u32 = 0; + while (xline < 8) : (xline += 1) { + //while (times(&eight)) |width| { + if ((pixel & (@intCast(u32, 0x80) >> @intCast(u5, xline))) != 0) { + if (self.*.gfx[(x + xline + ((y + yline) * 64))] == true) { + self.*.V[0xF] = 1; + } + self.*.gfx[x + xline + ((y + yline) * 64)] = true; + } + } + } + self.*.pc += 2; + }, + else => { + // opcode not found + }, + } + // Update timers + _ = self; + } } }; -var chip8 = Chip8{}; +var chip8 = Chip8.new(); -pub fn main() void { +pub fn main() !void { setup_graphics(); defer ray.CloseWindow(); var exitWindow: bool = false; + chip8.load_game("roms/IBM_Logo.ch8"); + while (!ray.WindowShouldClose() and !exitWindow) { ray.BeginDrawing(); defer ray.EndDrawing(); - ray.ClearBackground(ray.RAYWHITE); exitWindow = ray.GuiWindowBox(ray.Rectangle{ .x = 0, .y = 0, .height = screenHeight, .width = screenWidth }, "CHIP-8"); + chip8.emulate_cycles(1); + update_screen(&chip8_screen, chip8.gfx); - ray.DrawTextureEx(chip8_screen.texture, ray.Vector2{ .x = 0, .y = 24 }, 0, 10, ray.WHITE); } } +fn pow(base: u32, power: u32) u32 { + var iter: u32 = 0; + var result: u32 = base; + while (iter < power) : (iter += 1) { + result = result * base; + } + return result; +} + +fn get_coords(x: u32, y: u32) u32 { + return y * 64 + x; +} + fn setup_graphics() void { //for (chip8_screen) |*pixel, index_usize| { @@ -63,22 +159,31 @@ fn setup_graphics() void { ray.InitWindow(screenWidth, screenHeight, "raylib [core] example - basic window"); chip8_screen = ray.LoadRenderTexture(64, 32); - ray.SetTargetFPS(60); + ray.SetTargetFPS(6); } fn update_screen(screen: *ray.RenderTexture, pixels: [2048]bool) void { + ray.ClearBackground(ray.RAYWHITE); ray.BeginTextureMode(screen.*); - for (pixels) |_, index_usize| { - var rnd: u8 = Rnd.random().int(u8); - if (rnd < (256 / 2)) { - rnd = 255; + for (pixels) |pixel, index_usize| { + //var rnd: u8 = Rnd.random().int(u8); + //if (rnd < (256 / 2)) { + // rnd = 255; + //} else { + // rnd = 0; + //} + + var on: u8 = undefined; + if (pixel) { + on = 255; } else { - rnd = 0; + on = 0; } var index: u32 = @intCast(u32, index_usize); //var index_char: u8 = @intCast(u8, @mod(@intCast(u32, index_usize), 256)); - ray.DrawRectangleRec(ray.Rectangle{ .x = @intToFloat(f32, @mod(index, 64)), .y = @intToFloat(f32, (index / 64)), .width = 1, .height = 1 }, ray.Color{ .r = rnd, .g = rnd, .b = rnd, .a = 255 }); + ray.DrawRectangleRec(ray.Rectangle{ .x = @intToFloat(f32, @mod(index, 64)), .y = @intToFloat(f32, (index / 64)), .width = 1, .height = 1 }, ray.Color{ .r = on, .g = on, .b = on, .a = 255 }); } ray.EndTextureMode(); + ray.DrawTextureEx(screen.texture, ray.Vector2{ .x = 0, .y = 24 }, 0, 10, ray.WHITE); } |