void main()
{
    float rad = 0.2 + (sin(iTime * 1.0) * 0.5 + 0.5) * 0.3;
    color = vec4(1.0f, 0.5f, 0.2f, 1.0f) * circle(uv, vec2(0.0), rad, 0.05);
    color += vec4(uv + .5, 1., 1.) * .2;
}