Files
glsl_playground/weird/fbm.glsl

68 lines
1.5 KiB
GLSL

#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
float random (in vec2 st) {
return fract(sin(dot(st.xy,
vec2(12.9898,78.233)))*
43758.5453123);
}
float noise (in vec2 st) {
vec2 i = floor(st);
vec2 f = fract(st);
float a = random(i);
float b = random(i + vec2(1.0, 0.0));
float c = random(i + vec2(0.0, 1.0));
float d = random(i + vec2(1.0, 1.0));
vec2 u = f * f * (3.0 - 2.0 * f);
return mix(a, b, u.x) +
(c - a)* u.y * (1.0 - u.x) +
(d - b) * u.x * u.y;
}
#define OCTAVES 10
float fbm (in vec2 st) {
float value = 0.0;
float amplitud = .5;
float frequency = 0.;
for (int i = 0; i < OCTAVES; i++) {
value += amplitud * noise(st);
st *= 2.;
amplitud *= .7;
}
return value;
}
vec3 circle(in vec2 _st, in float _radius, vec3 color){
vec2 dist = _st-vec2(0.5);
return color-smoothstep(_radius-(_radius*0.02),
_radius+(_radius*0.02),
dot(dist,dist)*4.0);
}
void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st*=5.;
st.x *= u_resolution.x/u_resolution.y;
vec3 color = vec3(0.);
color += fbm(st*3.0);
float resmin = min(u_resolution.x, u_resolution.y);
color -= smoothstep(0.44, 0.48, distance(gl_FragCoord.xy/resmin, (u_resolution/2.)/resmin));
gl_FragColor = vec4(color,1.0);
}