Add more improvements

src/graphics/rendering/shaders/distance-fs.glsl

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+#version 300 es
+
+precision lowp float;
+
+#define SURFACE_OFFSET 0.001
+ 
+uniform float maxMinDistance;
+uniform float distanceNdcPixelSize;
+in vec2 position;
+
+{macroDefinitions}
+
+{declarations}
+
+/*
+#endif
+#if BLOB_COUNT > 0
+    uniform struct {
+        vec2 headCenter;
+        vec2 leftFootCenter;
+        vec2 rightFootCenter;
+        float headRadius;
+        float footRadius;
+        float k;
+    }[BLOB_COUNT] blobs;
+
+    float smoothMin(float a, float b)
+    {
+        const float k = 2.0;
+        
+        a = pow(a, k);
+        b = pow(b, k);
+        return pow((a * b) / (a + b), 1.0 / k);
+    }
+
+    float circleMinDistance(vec2 circleCenter, float radius) {
+        return distance(position, circleCenter) - radius;
+    }
+
+    void blobMinDistance(inout float minDistance, inout float color) {
+        for (int i = 0; i < BLOB_COUNT; i++) {
+            float headDistance = circleMinDistance(blobs[i].headCenter, blobs[i].headRadius);
+            float leftFootDistance = circleMinDistance(blobs[i].leftFootCenter, blobs[i].footRadius);
+            float rightFootDistance = circleMinDistance(blobs[i].rightFootCenter, blobs[i].footRadius);
+
+            float res = min(
+                smoothMin(headDistance, leftFootDistance),
+                smoothMin(headDistance, rightFootDistance)
+            );
+
+            res = min(100.0, headDistance);
+            res = min(res, leftFootDistance);
+            res = min(res, rightFootDistance);
+            //color = mix(2.0, color, step(distanceUvPixelSize + SURFACE_OFFSET, res));
+            minDistance = min(minDistance, res);
+            color = mix(2.0, color, step(distanceNdcPixelSize + SURFACE_OFFSET, res));
+        }
+    }
+#endif
+*/
+
+out vec2 fragmentColor;
+
+void main() {
+    float minDistance = maxMinDistance;
+    float color = 1.0;
+
+    {functionCalls}
+
+    // minDistance / 2.0: NDC to UV scale
+    fragmentColor = vec2(minDistance / 2.0, color);
+}