lines.frag

// Author @patriciogv - 2015 - patricio.io

#ifdef GL_ES
precision mediump float;
#endif

// Copyright (c) Patricio Gonzalez Vivo, 2015 - http://patriciogonzalezvivo.com/
// I am the sole copyright owner of this Work.
//
// You cannot host, display, distribute or share this Work in any form,
// including physical and digital. You cannot use this Work in any
// commercial or non-commercial product, website or project. You cannot
// sell this Work and you cannot mint an NFTs of it.
// I share this Work for educational purposes, and you can link to it,
// through an URL, proper attribution and unmodified screenshot, as part
// of your educational material. If these conditions are too restrictive
// please contact me and we'll definitely work it out.

const float PI = 3.1415926535897932384626433832795;

uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;

mat2 rotate2d(float angle){
    return mat2(cos(angle),-sin(angle),
                sin(angle),cos(angle));
}

float stripes(vec2 st){
    st = rotate2d( PI*-0.25 ) * st*10.;
    return step(.5,1.0-smoothstep(.3,1.,abs(sin(st.x*PI))));
}

void main(){
    vec2 st = gl_FragCoord.xy/u_resolution.xy;
    st.x *= u_resolution.x/u_resolution.y;

    vec3 color = vec3(stripes(st));
    gl_FragColor = vec4(color, 1.0);
}