63 lines
1.3 KiB
GLSL
63 lines
1.3 KiB
GLSL
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
|
|
#define NP 30
|
|
|
|
uniform vec2 u_resolution;
|
|
uniform float u_time;
|
|
|
|
float random (vec2 _st) {
|
|
return fract(sin(dot(_st.xy, vec2(0.690,0.540)))*43758.817);
|
|
}
|
|
|
|
float random(float i) {
|
|
return fract(sin(i)*1e5);
|
|
}
|
|
|
|
float noise (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;
|
|
}
|
|
|
|
struct particle {
|
|
vec2 vel;
|
|
vec2 pos;
|
|
};
|
|
|
|
void update_particle(inout particle p) {
|
|
p.pos += p.vel;
|
|
}
|
|
|
|
vec3 show_particle(particle p, vec3 c) {
|
|
vec2 st = gl_FragCoord.xy/u_resolution.xy;
|
|
particle o = p;
|
|
update_particle(p);
|
|
return abs(st.x-p.pos.x)+abs(st.y-p.pos.y)<0.1?c:vec3(0.);
|
|
}
|
|
|
|
void main() {
|
|
vec2 st = gl_FragCoord.xy/u_resolution.xy;
|
|
vec3 color = vec3(0.);
|
|
|
|
for (int i = 1; i < NP; i++) {
|
|
vec2 pos = vec2(0.);
|
|
vec2 vel = vec2(noise(st*float(i)*u_time*0.3), noise(st*float(i)));
|
|
particle p = particle(vel, pos);
|
|
color += show_particle(p, vec3(.3));
|
|
}
|
|
|
|
gl_FragColor = vec4(color, 1.);
|
|
}
|