Ex: 6 - Sine Cosine

#version 300 es
#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 u_resolution;
uniform float u_time;
out vec4 outColor;

float circeShape(vec2 position, float radius) {
    return step(radius, length(position - vec2(0.5)));
}

void main() {
    vec2 coord = gl_FragCoord.xy / u_resolution.x;
    vec3 color = vec3(0.0);

    vec2 translate = vec2(sin(u_time / 10.0), cos(u_time));
    coord += translate * 0.5;

    color += vec3(circeShape(coord, 0.3));

    outColor = vec4(color, 1.0);
}