Added shader packs

tools/packsrc/Multiscale MIP Fluid/shaders/Buffer C.frag

@@ -0,0 +1,82 @@
+#define CURL_CH w
+#define CURL_SAMPLER iChannel0
+#define DEGREE VORTICITY_SCALES
+
+#define CURL(d) textureLod(CURL_SAMPLER, fract(uv+(d+0.0)), mip).CURL_CH
+#define D(d) abs(textureLod(CURL_SAMPLER, fract(uv+d), mip).CURL_CH)
+
+void tex(vec2 uv, inout mat3 mc, inout float curl, int degree) {
+    vec2 texel = 1.0/iResolution.xy;
+    float stride = float(1 << degree);
+    float mip = float(degree);
+    vec4 t = stride * vec4(texel, -texel.y, 0);
+
+    float d =    D( t.ww); float d_n =  D( t.wy); float d_e =  D( t.xw);
+    float d_s =  D( t.wz); float d_w =  D(-t.xw); float d_nw = D(-t.xz);
+    float d_sw = D(-t.xy); float d_ne = D( t.xy); float d_se = D( t.xz);
+    
+    mc =  mat3(d_nw, d_n, d_ne,
+               d_w,  d,   d_e,
+               d_sw, d_s, d_se);
+    
+    curl = CURL();
+    
+}
+
+float reduce(mat3 a, mat3 b) {
+    mat3 p = matrixCompMult(a, b);
+    return p[0][0] + p[0][1] + p[0][2] +
+           p[1][0] + p[1][1] + p[1][2] +
+           p[2][0] + p[2][1] + p[2][2];
+}
+
+vec2 confinement(vec2 fragCoord)
+{
+	vec2 uv = fragCoord.xy / iResolution.xy;
+    
+    float k0 = CONF_ISOTROPY;
+    float k1 = 1.0 - 2.0*(CONF_ISOTROPY);
+
+    mat3 conf_x = mat3(
+       -k0, -k1, -k0,
+        0.0, 0.0, 0.0,
+        k0,  k1,  k0
+    );
+
+    mat3 conf_y = mat3(
+       -k0,  0.0,  k0,
+       -k1,  0.0,  k1,
+       -k0,  0.0,  k0
+    );
+    
+    mat3 mc;
+    vec2 v = vec2(0);
+    float curl;
+    
+    float cacc = 0.0;
+    vec2 nacc = vec2(0);
+    float wc = 0.0;
+    for (int i = 0; i < DEGREE; i++) {
+        tex(uv, mc, curl, i);
+        float w = CONF_W_FUNCTION;
+        vec2 n = w * normz(vec2(reduce(conf_x, mc), reduce(conf_y, mc)));
+        v += curl * n;
+        cacc += curl;
+        nacc += n;
+        wc += w;
+    }
+
+    #ifdef PREMULTIPLY_CURL
+        return v / wc;
+    #else
+    	return nacc * cacc / wc;
+    #endif
+
+}
+
+void mainImage( out vec4 fragColor, in vec2 fragCoord )
+{
+    fragColor = vec4(confinement(fragCoord),0,0);
+    // Adding a very small amount of noise on init fixes subtle numerical precision blowup problems
+    if (iFrame==0) fragColor=1e-6*rand4(fragCoord, iResolution.xy, iFrame);
+}