FIrst iteration of Koch Curve

koch.glsl

// Drawing Koch Curve - first iteration
//i- draw line 
//ii- uv symmetrical to y-axis
//ii- fold it

float reflection(inout vec2 pos, float angle){
    vec2 normal = vec2(sin(angle),cos(angle));
    float d = dot(pos, normal);
    pos -= normal*min(0.,d)*2.;

    return smoothstep(0.01,0.,abs(d));
}


float line (vec2 pos){
    float d = length(pos-vec2(clamp(pos.x,-1.,1.),0.));
    return smoothstep(0.01,0.,abs(d));
}



void  main() {
    vec2 pos = uv();
    vec4 color = vec4(0.);
    
    //Symmetrical to y
    pos.x = abs(pos.x);
    
    //3 units over the line
    pos.x -= .5;
    
    float angle = PI-PI/3.;
    float dist = reflection(pos,angle);
    //Visualize lines
    //color += dist*vec4(0.,1.,0,1.);
    
    color += line(pos);
    //color.rb += pos;
    
    gl_FragColor = color;
}