libvaxis/src/InternalScreen.zig
Tim Culverhouse d2f02897dc render: use different internal model of screen
We use two screens: one which the user provides a slice of bytes for the
graphemes, and the user owns the bytes. We copy those bytes to our
internal model so that we can compare between frames

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
2024-01-22 20:09:35 -06:00

73 lines
1.8 KiB
Zig

const std = @import("std");
const assert = std.debug.assert;
const Style = @import("cell.zig").Style;
const Cell = @import("cell.zig").Cell;
const log = std.log.scoped(.internal_screen);
const InternalScreen = @This();
pub const InternalCell = struct {
char: std.ArrayList(u8) = undefined,
style: Style = .{},
pub fn eql(self: InternalCell, cell: Cell) bool {
return std.mem.eql(u8, self.char.items, cell.char.grapheme) and std.meta.eql(self.style, cell.style);
}
};
width: usize = 0,
height: usize = 0,
buf: []InternalCell = undefined,
cursor_row: usize = 0,
cursor_col: usize = 0,
cursor_vis: bool = false,
/// sets each cell to the default cell
pub fn init(alloc: std.mem.Allocator, w: usize, h: usize) !InternalScreen {
var screen = InternalScreen{};
screen.buf = try alloc.alloc(InternalCell, w * h);
for (screen.buf, 0..) |_, i| {
screen.buf[i] = .{
.char = try std.ArrayList(u8).initCapacity(alloc, 1),
};
}
screen.width = w;
screen.height = h;
return screen;
}
pub fn deinit(self: *InternalScreen, alloc: std.mem.Allocator) void {
for (self.buf, 0..) |_, i| {
self.buf[i].char.deinit();
}
alloc.free(self.buf);
}
/// writes a cell to a location. 0 indexed
pub fn writeCell(
self: *InternalScreen,
col: usize,
row: usize,
char: []const u8,
style: Style,
) void {
if (self.width < col) {
// column out of bounds
return;
}
if (self.height < row) {
// height out of bounds
return;
}
const i = (row * self.width) + col;
assert(i < self.buf.len);
self.buf[i].char.clearRetainingCapacity();
self.buf[i].char.appendSlice(char) catch {
log.warn("couldn't write grapheme", .{});
};
self.buf[i].style = style;
}