002_simplex.frag

/*

    daily: 002
    author: Will Stallwood
    insta: https://www.instagram.com/willstall/
    
*/

#ifdef GL_ES
    precision mediump float; 
#endif

#define PI 3.14159265359
#define HALF_PI 1.57079632675
#define TWO_PI 6.283185307

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

vec3 palette(float t,vec3 a,vec3 b,vec3 c,vec3 d )
{
    return a + b * cos( TWO_PI * (c*t+d));
}

float random(float x)
{
    return fract(sin(x*100.00)*10000.0);
}

float random(vec2 st)
{
    return fract(
        dot(
            sin(st.x*100.00),
            sin(st.y*100.00)        
        )*10000.0);
}

float smoothCellRandom(float x,float scale)
{   
    float iPos = floor(x*scale);
    float fPos = fract(x*scale);

    return mix(random(iPos), random(iPos + 1.0), smoothstep(0.,1.,fPos));
}

float peakCellRandom(float x,float scale)
{   
    float iPos = floor(x*scale);
    float fPos = fract(x*scale);

    return mix(random(iPos), random(iPos + 1.0), fPos);
}

float cellRandom(float x,float scale)
{   
    float iPos = floor(x*scale);
    float fPos = fract(x*scale);

    return random(iPos);
}

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

    vec3 color = vec3(0.0);
    //    color.x = abs(sin(u_time));
    float t = u_time * .33;
    float scale = 20.0;

    float cell = cellRandom(st.x+t,scale);
    float r = floor(cell*st.y*scale);
    float f = st.y * abs(sin( cell*1000.0 + u_time));
    r *= f;
    r = 1.0 - step(1.0,r);
    r += 1.0-f;

    float d = smoothCellRandom(st.x+t,scale);
    // d *= r;
    d = r;

    vec3 a = vec3(0.5,0.5,0.5);
    vec3 b = vec3(0.5,0.5,0.5);
    vec3 c = vec3(0.0,.1,0.2);

    color = palette(d+fract(t)*2.0,vec3(0.5),a,b,c);
    // color += d;

    gl_FragColor = vec4(color,1.0);
}