diagonal rungs are drawing. just need tranches.

src/components/chart/DiagonalBuilder.vue

@@ -4,7 +4,7 @@
                 :get-model-value="getModelValue" :set-model-value="setModelValue"
                 :set-values="setLines" :set-weights="setWeights"
                 :std-width="stdWidth" :build-tranches="buildTranches">
-    <span>(Diagonals)</span>
+    <span>{{ endpoints }}</span>
 <!--
     <table>
       <tbody>
@@ -186,10 +186,11 @@ function setModelValue(model, value) {
 
 
 function dirtyLine(a, b) {
-  console.log('dirtyLine', a, b)
-  return a === b ? false :
+  const result = a === b ? false :
       a === null && b !== null || a !== null && b === null ||
       a[0].time !== b[0].time || a[0].price !== b[0].price || a[1].time !== b[1].time || a[1].price !== b[1].price
+  console.log('dirtyLine', result, a, b)
+  return result
 }