better design with selfmade shader

components/Shaders/Background/fragment.tsx

@@ -0,0 +1,82 @@
+
+export const fragmentShader = `
+uniform float u_intensity;
+uniform float u_time;
+uniform int width;
+uniform int height;
+
+varying vec2 vUv;
+varying float vDisplacement;
+
+//from Hash Functions for GPU Rendering (Jarzynski et al.)
+//http://www.jcgt.org/published/0009/03/02/
+vec3 pcg3d(uvec3 v)
+{
+    v = v * 1664525u + 1013904223u;
+    v.x += v.y*v.z; v.y += v.z*v.x; v.z += v.x*v.y;
+    v ^= v >> 16u;
+    v.x += v.y*v.z; v.y += v.z*v.x; v.z += v.x*v.y;
+    return vec3(v) * (1.0/float(0xffffffffu));
+}
+
+// convert texture coordinates to pixel
+float t2p(float t, int noOfPixels){
+    return t * float(noOfPixels) - 0.5;
+}
+
+#define M_PI 3.1415926535897932384626433832795
+vec2 randomGradient(uvec3 p){
+    vec3 _uv = pcg3d(p);
+    float r = sqrt(_uv[0]);
+    float phi = 2.0 * M_PI * _uv[1];
+    return vec2(r* cos(phi), r * sin(phi));
+}
+
+
+vec3 gradientNoise(vec2 pos, float gridSize){
+    vec2 gridPos = pos * gridSize;
+    uvec2 i = uvec2(gridPos);
+    vec2 f = fract(gridPos);
+
+    vec2 g11 = randomGradient(uvec3(i.x,i.y,1));
+    vec2 g12 = randomGradient(uvec3(i.x + 1u,i.y,1));
+    vec2 g21 = randomGradient(uvec3(i.x,i.y + 1u,1));
+    vec2 g22 = randomGradient(uvec3(i.x + 1u,i.y +1u,1));
+
+    float d11 = dot(g11, f);
+    float d12 = dot(g12, f - vec2(1.0, 0.0));
+    float d21 = dot(g21, f - vec2(0.0, 1.0));
+    float d22 = dot(g22, f - vec2(1.0, 1.0));
+
+    /*
+    vec3 f11 = vec3(d11);
+    vec3 f12 = vec3(d12);
+    vec3 f21 = vec3(d21);
+    vec3 f22 = vec3(d22);
+    */
+    
+    vec3 f11 = pcg3d(uvec3(i.x,i.y,0)) * (d11 + 1.0);
+    vec3 f12 = pcg3d(uvec3(i.x + 1u,i.y,0))* (d12 + 1.0);
+    vec3 f21 = pcg3d(uvec3(i.x,i.y + 1u,0))* (d21 + 1.0);
+    vec3 f22 = pcg3d(uvec3(i.x + 1u,i.y +1u,0))* (d22 + 1.0);
+    
+    f = smoothstep(0.0, 1.0, f);
+
+    vec3 q1 = mix(f11, f12, vec3(f.x));
+    vec3 q2 = mix(f21, f22, vec3(f.x));
+    vec3 p = mix(q1, q2, vec3(f.y));    
+    
+    return p;
+}
+
+
+void main() {
+    float distort = 2.0 * vDisplacement + u_intensity;
+    vec2 pos = vec2(u_time) /5.0 + vUv;
+    vec3 texColor = gradientNoise(pos, 4.0);
+    texColor.y = 0.0;
+    gl_FragColor = vec4(texColor, 1.0);
+}
+
+`
+