os/src/Console.zig
2025-11-07 10:34:28 +00:00

163 lines
3.7 KiB
Zig

const std = @import("std");
const Self = @This();
pub fn init() Self {
var self = Self{};
self.clear();
return self;
}
const vga_width = 80;
const vga_height = 25;
const vga_size = vga_width * vga_height;
pub const ConsoleColor = enum(u8) {
black = 0,
blue = 1,
green = 2,
cyan = 3,
red = 4,
magenta = 5,
brown = 6,
light_gray = 7,
dark_gray = 8,
light_blue = 9,
light_green = 10,
light_cyan = 11,
light_red = 12,
light_magenta = 13,
light_brown = 14,
white = 15,
};
const default_color = vgaEntryColor(ConsoleColor.light_gray, ConsoleColor.black);
column: usize = 0,
color: u8 = default_color,
buffer: [*]volatile u16 = @ptrFromInt(0xb8000),
fn vgaEntryColor(fg: ConsoleColor, bg: ConsoleColor) u8 {
return @intFromEnum(fg) | (@intFromEnum(bg) << 4);
}
fn vgaEntry(uc: u8, new_color: u8) u16 {
const c: u16 = new_color;
return uc | (c << 8);
}
fn index(x: usize, y: usize) usize {
return y * vga_width + x;
}
pub fn setColor(self: *Self, fg: ConsoleColor, bg: ConsoleColor) void {
self.color = vgaEntryColor(fg, bg);
}
pub fn resetColor(self: *Self) void {
self.color = default_color;
}
pub fn clear(self: *Self) void {
@memset(self.buffer[0..vga_size], vgaEntry(' ', self.color));
}
fn clearRow(self: *Self, y: usize) void {
for (0..vga_width) |x| {
const i = index(x, y);
self.buffer[i] = vgaEntry(' ', self.color);
}
}
fn newLine(self: *Self) void {
for (1..vga_height) |y| {
for (0..vga_width) |x| {
const entry = self.getEntryAt(x, y);
self.putEntryAt(entry, x, y - 1);
}
}
self.clearRow(vga_height - 1);
self.column = 0;
}
pub fn putCharAt(self: *Self, c: u8, new_color: u8, x: usize, y: usize) void {
self.putEntryAt(vgaEntry(c, new_color), x, y);
}
fn putEntryAt(self: *Self, entry: u16, x: usize, y: usize) void {
const i = index(x, y);
self.buffer[i] = entry;
}
fn getEntryAt(self: *Self, x: usize, y: usize) u16 {
const i = index(x, y);
return self.buffer[i];
}
pub fn putChar(self: *Self, c: u8) void {
switch (c) {
'\n' => self.newLine(),
else => {
if (self.column >= vga_width) {
self.newLine();
}
const y = vga_height - 1;
const x = self.column;
self.putCharAt(c, self.color, x, y);
self.column += 1;
},
}
}
pub fn puts(self: *Self, data: []const u8) void {
for (data) |c| {
self.putChar(c);
}
}
const Writer = struct {
console: *Self,
interface: std.Io.Writer,
fn drain(io_w: *std.Io.Writer, data: []const []const u8, splat: usize) std.Io.Writer.Error!usize {
const self: *@This() = @fieldParentPtr("interface", io_w);
try self.puts(io_w.buffered());
io_w.end = 0;
for (data[0..data.len - 1]) |bytes| {
try self.puts(bytes);
}
const pattern = data[data.len - 1];
for (0..splat) |_| {
try self.puts(pattern);
}
return std.Io.Writer.countSplat(data, splat);
}
fn puts(self: *@This(), data: []const u8) std.Io.Writer.Error!void {
self.console.puts(data);
}
};
pub fn writer(self: *Self, buffer: []u8) Writer {
return .{
.console = self,
.interface = .{
.buffer = buffer,
.vtable = &.{
.drain = Writer.drain,
},
},
};
}
pub fn printf(self: *Self, comptime format: []const u8, args: anytype) void {
var buffer: [1024]u8 = undefined;
var w = self.writer(&buffer);
const io_w = &w.interface;
io_w.print(format, args) catch unreachable;
io_w.flush() catch unreachable;
}