shader_type spatial;

uniform sampler2D noise;

uniform vec4 color : hint_color;
uniform vec2 center = vec2(.5, .5);
uniform float radial_scale = 1.0;
uniform float length_scale = 1.0;

uniform float divide_factor = 1.0;

void vertex() {
    vec2 delta = UV - center;
    float radius = length(delta) * 2.0 * radial_scale - .15;
    float angle = atan(delta.x, delta.y) * 1.0 / 6.28 * length_scale;

    float depth = radius / divide_factor;
    depth = clamp(1.0 - depth, 0.0, 1.0);

    depth = pow(depth, 2.0) * 1.0;

    VERTEX.y -= depth;
    NORMAL.y -= depth;

    COLOR.x = radius;
    COLOR.y = angle;
    COLOR.z = depth;
}

void fragment() {
    vec2 delta = UV - center;
    float angle = atan(delta.x, delta.y) * 1.0 / 6.28 * length_scale;

    float scaling_distance = COLOR.x * 1.5;

    vec2 uvs = vec2(scaling_distance + TIME * .12, scaling_distance + angle);
    float whirpool = step(texture(noise, uvs).x, .5);

    if(COLOR.z < .01 || whirpool > .5) {
        ALBEDO = color.rgb * (1.0 - COLOR.z * 1.4);

        if(COLOR.z >= .01) {
            ALBEDO.r += .03;
        }
    } else {
        ALBEDO.rgb = color.rgb * .35;
    }

    ROUGHNESS = 1.0;
}