/*
    Hurry Curry! - a game about cooking
    Copyright (C) 2025 Hurry Curry! Contributors

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, version 3 of the License only.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

*/
shader_type spatial;

uniform float angle = .2;
uniform float frequency = .5;
uniform float width = .2;
uniform float speed = 1.;
uniform float alpha_fac = 1.;

void fragment() {
    ALBEDO = vec3(1., 1., 0.);
    vec2 uv = UV.xy;
    uv.x = abs(2. * uv.x - 1.);
    float alpha = step(
        mod(uv.y - TIME * speed + angle * uv.x, frequency), width
    );
    ALPHA = alpha * alpha_fac;
}