#version 300 es
precision highp float;

// Welcome to OneShader!
// This is a standard GLSL Fragment Shader.

uniform float iTime;
uniform vec2  iResolution;

// TRY THIS: Create a UI slider by uncommenting the line below:
// uniform float speed; // value=1, min=0, max=5, step=0.001

out vec4 fragColor;

void main() {
    // Screen coordinate (from [-aspect, -1] to [aspect, 1])
    vec2 q   = (2. * gl_FragCoord.xy - iResolution) / iResolution.y;

    // Pixel color
    // Note: If you enabled the 'speed' slider above, multiply iTime by speed!
    vec3 col = .5 + .5 * sin((vec3(normalize(q), length(q)) + iTime) * 6.283);

    // Output
    fragColor = vec4(col, 1.);
}