v4k-git-backup/demos/art/shadertoys/4tdSWr.fs

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2023-08-10 14:30:56 +00:00
// https://www.shadertoy.com/view/4tdSWr
const float cloudscale = 1.1;
const float speed = 0.03;
const float clouddark = 0.5;
const float cloudlight = 0.3;
const float cloudcover = 0.2;
const float cloudalpha = 8.0;
const float skytint = 0.5;
const vec3 skycolour1 = vec3(0.2, 0.4, 0.6);
const vec3 skycolour2 = vec3(0.4, 0.7, 1.0);
const mat2 m = mat2( 1.6, 1.2, -1.2, 1.6 );
vec2 hash( vec2 p ) {
p = vec2(dot(p,vec2(127.1,311.7)), dot(p,vec2(269.5,183.3)));
return -1.0 + 2.0*fract(sin(p)*43758.5453123);
}
float noise( in vec2 p ) {
const float K1 = 0.366025404; // (sqrt(3)-1)/2;
const float K2 = 0.211324865; // (3-sqrt(3))/6;
vec2 i = floor(p + (p.x+p.y)*K1);
vec2 a = p - i + (i.x+i.y)*K2;
vec2 o = (a.x>a.y) ? vec2(1.0,0.0) : vec2(0.0,1.0); //vec2 of = 0.5 + 0.5*vec2(sign(a.x-a.y), sign(a.y-a.x));
vec2 b = a - o + K2;
vec2 c = a - 1.0 + 2.0*K2;
vec3 h = max(0.5-vec3(dot(a,a), dot(b,b), dot(c,c) ), 0.0 );
vec3 n = h*h*h*h*vec3( dot(a,hash(i+0.0)), dot(b,hash(i+o)), dot(c,hash(i+1.0)));
return dot(n, vec3(70.0));
}
float fbm(vec2 n) {
float total = 0.0, amplitude = 0.1;
for (int i = 0; i < 7; i++) {
total += noise(n) * amplitude;
n = m * n;
amplitude *= 0.4;
}
return total;
}
// -----------------------------------------------
void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
vec2 p = fragCoord.xy / iResolution.xy;
vec2 uv = p*vec2(iResolution.x/iResolution.y,1.0);
float time = iGlobalTime * speed;
float q = fbm(uv * cloudscale * 0.5);
//ridged noise shape
float r = 0.0;
uv *= cloudscale;
uv -= q - time;
float weight = 0.8;
for (int i=0; i<8; i++){
r += abs(weight*noise( uv ));
uv = m*uv + time;
weight *= 0.7;
}
//noise shape
float f = 0.0;
uv = p*vec2(iResolution.x/iResolution.y,1.0);
uv *= cloudscale;
uv -= q - time;
weight = 0.7;
for (int i=0; i<8; i++){
f += weight*noise( uv );
uv = m*uv + time;
weight *= 0.6;
}
f *= r + f;
//noise colour
float c = 0.0;
time = iGlobalTime * speed * 2.0;
uv = p*vec2(iResolution.x/iResolution.y,1.0);
uv *= cloudscale*2.0;
uv -= q - time;
weight = 0.4;
for (int i=0; i<7; i++){
c += weight*noise( uv );
uv = m*uv + time;
weight *= 0.6;
}
//noise ridge colour
float c1 = 0.0;
time = iGlobalTime * speed * 3.0;
uv = p*vec2(iResolution.x/iResolution.y,1.0);
uv *= cloudscale*3.0;
uv -= q - time;
weight = 0.4;
for (int i=0; i<7; i++){
c1 += abs(weight*noise( uv ));
uv = m*uv + time;
weight *= 0.6;
}
c += c1;
vec3 skycolour = mix(skycolour2, skycolour1, p.y);
vec3 cloudcolour = vec3(1.1, 1.1, 0.9) * clamp((clouddark + cloudlight*c), 0.0, 1.0);
f = cloudcover + cloudalpha*f*r;
vec3 result = mix(skycolour, clamp(skytint * skycolour + cloudcolour, 0.0, 1.0), clamp(f + c, 0.0, 1.0));
fragColor = vec4( result, 1.0 );
}