// deform technique from iq: https://www.shadertoy.com/view/Xdf3Rn
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
float time = iTime * 1.; // adjust time
vec2 p = (-iResolution.xy + 2.0*fragCoord)/iResolution.x; // center coordinates
float r2 = dot(p,p);
float r = sqrt(r2);
vec2 uv = p/r2;
// animate
uv += 10.0 * cos( vec2(0.6,0.3) + vec2(0.1,0.13) * 2. * sin(time) );
// uv = p; // switch back to normal coords to test drawing
////////////////////////////////////
// custom drawing
uv += vec2(0., 2. * cos(uv.y * 8.)); // warp coordinates a little more
uv = abs(sin(uv * 0.3)); // draw horizontal stripes
float color = smoothstep(0.2, 0.8, abs(sin(time + uv.y * 3.)));
color = min(color, smoothstep(0.1, 0.95, abs(sin(time + uv.y * 4.))) );
color += 0.75;
// brighten everything
vec3 col = vec3(
// oscillate color components
0.6 + 0.1 * cos(time + color * 1.),
0.5 * color,
0.9 + 0.2 * sin(time + color * 1.1)
);
// reverse vignette
col *= r*1.5 * color;
col += pow(length(p)/2., 2.);
fragColor = vec4( col, 1.0 );
}
