fix(scale): #20265 when dataZomm.filterMode is “empty” or ‘none’， the line graph is scaled to only one category, it is not filtered correctly

src/coord/Axis.ts

@@ -295,6 +295,9 @@ class Axis {
 }
 
 function fixExtentWithBands(extent: [number, number], nTick: number): void {
+    if (nTick <= 1) {
+        return;
+    }
     const size = extent[1] - extent[0];
     const len = nTick;
     const margin = size / len / 2;

src/scale/breakImpl.ts

@@ -99,7 +99,14 @@ class ScaleBreakContextImpl implements ScaleBreakContext {
         const elapsedSpan = this._elapsedExtent[1] - this._elapsedExtent[0];
         // The same logic as `Scale#normalize`.
         if (elapsedSpan === 0) {
-            return 0.5;
+            const elapsedVal = this.elapse(val);
+            if (isNaN(elapsedVal)) {
+                return NaN;
+            }
+            if (elapsedVal === this._elapsedExtent[0]) {
+                return 0.5;
+            }
+            return elapsedVal < this._elapsedExtent[0] ? -0.5 : 1.5;
         }
         return (this.elapse(val) - this._elapsedExtent[0]) / elapsedSpan;
     }

src/scale/helper.ts

@@ -151,7 +151,13 @@ function normalize(
     // Dont use optional arguments for performance consideration here.
 ): number {
     if (extent[1] === extent[0]) {
-        return 0.5;
+        if (isNaN(val)) {
+            return NaN;
+        }
+        if (val === extent[0]) {
+            return 0.5;
+        }
+        return val < extent[0] ? -0.5 : 1.5;
     }
     return (val - extent[0]) / (extent[1] - extent[0]);
 }