update blobs

Plugins/ZShell/Blobs/shaders/blob.frag

@@ -63,13 +63,17 @@ float smaxSharpA(float a, float b, float k) {
 void main() {
   vec2 pixel = vec2(paddedX, paddedY) + qt_TexCoord0 * vec2(paddedW, paddedH);
 
-  float mergedSdf = 1e10;
+  // Phase 1: compute per-rect SDF, track owner. We can't smin yet because
+  // excluded pairs need to skip the smooth blend, which requires pairwise pass
+  // below.
+  float dArr[16];
   int owner = -2;
   float minDist = 1e10;
 
   for (int i = 0; i < rectCount; i++) {
-    vec4 rect = rectData[i * 5];      // cx, cy, hw, hh
-    vec4 props = rectData[i * 5 + 1]; // radius, offsetX, offsetY, minEig
+    vec4 rect = rectData[i * 5]; // cx, cy, hw, hh
+    vec4 props =
+        rectData[i * 5 + 1]; // excludeMask(int bits), offsetX, offsetY, minEig
     vec4 invDm = rectData[i * 5 + 2]; // inverse deform matrix
     vec4 sh = rectData[i * 5 + 3];    // screenHalfX, screenHalfY, 0, 0
     vec4 radii =
@@ -81,8 +85,10 @@ void main() {
     // AABB early-out: skip rects far from this pixel
     vec2 extent = sh.xy + vec2(smoothFactor * 1.5);
     if (abs(pixel.x - center.x) > extent.x ||
-        abs(pixel.y - center.y) > extent.y)
+        abs(pixel.y - center.y) > extent.y) {
+      dArr[i] = 1e10;
       continue;
+    }
 
     // Apply pre-computed inverse deformation to the evaluation point
     mat2 invDeform = mat2(invDm.xy, invDm.zw);
@@ -138,13 +144,38 @@ void main() {
       d *= scale;
     }
 
-    mergedSdf = smin(mergedSdf, d, smoothFactor);
+    dArr[i] = d;
     if (d < smoothFactor && d < minDist) {
       minDist = d;
       owner = i;
     }
   }
 
+  // Phase 2: hard-min baseline over all rects.
+  float mergedSdf = 1e10;
+  for (int i = 0; i < rectCount; i++) {
+    mergedSdf = min(mergedSdf, dArr[i]);
+  }
+
+  // Phase 3: pair-wise smin contributions, skipping excluded pairs. Pair smin
+  // <= min, so taking the min over all non-excluded pair smins gives the
+  // smoothly-merged SDF.
+  for (int i = 0; i < rectCount; i++) {
+    if (dArr[i] >= 1e9)
+      continue;
+    int excludeMask = floatBitsToInt(rectData[i * 5 + 1].x);
+    for (int j = i + 1; j < rectCount; j++) {
+      if (dArr[j] >= 1e9)
+        continue;
+      if ((excludeMask & (1 << j)) != 0)
+        continue;
+      // smin only deviates from min within smoothFactor
+      if (abs(dArr[i] - dArr[j]) >= smoothFactor)
+        continue;
+      mergedSdf = min(mergedSdf, smin(dArr[i], dArr[j], smoothFactor));
+    }
+  }
+
   if (hasInverted != 0) {
     float dOuter = sdBox(pixel, invertedOuter.xy, invertedOuter.zw) - 1.0;
     float dInner =