Implementation of https://github.com/nesbox/TIC-80/wiki/Code-examples-and-snippets#screen-wave-and-sky-gradient in Zig ⚡

screen_wave_and_sky_gradient.zig

const math = @import("std").math;
const tic = @import("tic80.zig");

export fn BDR(row: i32) void {
    const urow: u8 = @intCast(row);

    { // skygradient
        scanline(0x42, 0xFF -| urow, 0x99 +| urow);
    }

    { // screen wave
        if (row < 90) {
            tic.poke(0x3ff9, 0);
        } else {
            tic.poke(0x3ff9, @intFromFloat(
                5 + math.sin(tic.time() / 200 + @as(
                    f32,
                    @floatFromInt(row),
                ) / 5) * 10,
            ));
        }
    }
}

fn scanline(r: u8, g: u8, b: u8) void {
    tic.poke(0x3fc0, r);
    tic.poke(0x3fc1, g);
    tic.poke(0x3fc2, b);
}

Peek.2023-11-11.17-17.webm

Peek.2023-11-11.17-19.webm