// Author: Sol Sarratea @solquemal

// Title: Fundamentales - Figura simple

​

precision mediump float;

uniform float u_time;

uniform vec2 u_resolution;

vec2 uv(){

    /* Devuelve las posiciones del canvas en rango [-1.,1.]x[-1.,1.] */

    vec2 pos = gl_FragCoord.xy/u_resolution; 

    pos.x *= u_resolution.y/u_resolution.x;

    pos = pos *2.-1.;

    return pos;

}

​

vec2 uvN(){

    /* Devuelve las posiciones del canvas en rango [0.,1.]x[0.,1.] */

    vec2 pos = gl_FragCoord.xy/u_resolution; 

    pos.x *= u_resolution.y/u_resolution.x;  

    return pos;

}

​

float sdSegment( in vec2 p, in vec2 a, in vec2 b )

{

    vec2 pa = p-a, ba = b-a;

    float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 );

    return length( pa - ba*h );

}

​

float verEjes(vec2 pos,float verX, float verY){

    float ejes; 

    ejes += (1.-step(0.009, distance(pos.x,0.)))*verY;

    ejes += (1.-step(0.009, distance(pos.y,0.)))*verX;

    return ejes;

}

​

float verDistAlOrigen(vec2 pos, float radio){

    float d = sdSegment(pos, vec2(0.), radio*vec2(-cos(u_time), -sin(u_time)));

    d = smoothstep(0.01,0.009,d);

    return d;

}

​

float verDistAlEjeY(vec2 pos, float radio){

    float d = sdSegment(pos, vec2(0.), radio*vec2(cos(u_time), 0.));

    d = smoothstep(0.01,0.009,d);

    return d;

}

​

float verDistAlEjeX(vec2 pos, float radio){

    float d = sdSegment(pos, vec2(0.), radio*vec2(0., sin(u_time)));

    d = smoothstep(0.01,0.009,d);

    return d;

}

​

float caminoCirculo(float radio){

    float d = smoothstep(0.02,0.,length(uv())-radio);

    d -=smoothstep(0.,-0.02,length(uv())-radio);

    return d;

}

​

void main() {

    vec2 pos = uv(); vec3 color; float circulo;

​

    float punto = smoothstep(0.5,0.49, length(pos));

    color += punto;

    gl_FragColor = vec4(color, 1.); 

​

}

​

​