example.glsl

// License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
// Created by S.Guillitte
uniform float u_time;
uniform vec2 u_resolution;

void main()
{
	float time=u_time*1.0;
	vec2 uv = (gl_FragCoord.xy / u_resolution.xx-0.5)*8.0;
    vec2 uv0=uv;
	float i0=1.0;
	float i1=1.0;
	float i2=1.0;
	float i4=0.0;
	for(int s=0;s<7;s++)
	{
		vec2 r;
		r=vec2(cos(uv.y*i0-i4+time/i1),sin(uv.x*i0-i4+time/i1))/i2;
        r+=vec2(-r.y,r.x)*0.3;
		uv.xy+=r;

		i0*=1.93;
		i1*=1.15;
		i2*=1.7;
		i4+=0.05+0.1*time*i1;
	}
    float r=sin(uv.x-time)*0.5+0.5;
    float b=sin(uv.y+time)*0.5+0.5;
    float g=sin((uv.x+uv.y+sin(time*0.5))*0.5)*0.5+0.5;
	gl_FragColor = vec4(r,g,b,1.0);
}

// void main()
// {
// 	float time=iGlobalTime*1.0;
// 	vec2 uv = (gl_FragCoord.xy / iResolution.xx-0.5)*8.0;
//     vec2 uv0=uv;
// 	float i0=1.0;
// 	float i1=1.0;
// 	float i2=1.0;
// 	float i4=0.0;
// 	for(int s=0;s<7;s++)
// 	{
// 		vec2 r;
// 		r=vec2(cos(uv.y*i0-i4+time/i1),sin(uv.x*i0-i4+time/i1))/i2;
//         r+=vec2(-r.y,r.x)*0.3;
// 		uv.xy+=r;

// 		i0*=1.93;
// 		i1*=1.15;
// 		i2*=1.7;
// 		i4+=0.05+0.1*time*i1;
// 	}
//     float r=sin(uv.x-time)*0.5+0.5;
//     float b=sin(uv.y+time)*0.5+0.5;
//     float g=sin((uv.x+uv.y+sin(time*0.5))*0.5)*0.5+0.5;
// 	gl_FragColor = vec4(r,g,b,1.0);
// }