From 39548a2f9c64747ad7e673679297a9f8fef4752f Mon Sep 17 00:00:00 2001
From: Lumi Pakkanen <lumi.pakkanen@gmail.com>
Date: Fri, 12 Apr 2024 11:21:59 +0300
Subject: [PATCH] Truncate parallelotope ups and downs to match basis

ref #643
---
 src/stores/tempering.ts | 12 ++++--------
 src/utils.ts            |  7 +++++++
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/stores/tempering.ts b/src/stores/tempering.ts
index c4773638..e17e48ba 100644
--- a/src/stores/tempering.ts
+++ b/src/stores/tempering.ts
@@ -1,6 +1,6 @@
 import { FIFTH, MAX_GEO_SUBGROUP_SIZE, MAX_INTERACTIVE_SUBGROUP_SIZE, OCTAVE } from '@/constants'
 import { mosPatternsRank2FromCommas, mosPatternsRank2FromVals } from '@/tempering'
-import { computedAndError, splitText } from '@/utils'
+import { computedAndError, padEndOrTruncate, splitText } from '@/utils'
 import { isBright, mosPatterns as getMosPatterns, type MosInfo } from 'moment-of-symmetry'
 import { defineStore } from 'pinia'
 import { parseChord, parseVals, type TimeMonzo } from 'sonic-weave'
@@ -372,13 +372,9 @@ export const useLatticeStore = defineStore('lattice', () => {
     return parseChord(basisString.value)
   }, [])
 
-  watch(basis, () => {
-    while (ups.length < basis.value.length) {
-      ups.push(1)
-    }
-    while (downs.length < basis.value.length) {
-      downs.push(0)
-    }
+  watch(basis, (newValue) => {
+    padEndOrTruncate(ups, newValue.length, 1)
+    padEndOrTruncate(downs, newValue.length, 0)
   })
 
   const dimensions = computed(() => {
diff --git a/src/utils.ts b/src/utils.ts
index 316499cf..3be3ddb4 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -474,3 +474,10 @@ export function syncValues(values: Record<string, Ref>) {
     watch(value, (newValue) => window.localStorage.setItem(key, String(newValue)))
   }
 }
+
+export function padEndOrTruncate<T>(array: T[], targetLength: number, padValue: T) {
+  while (array.length < targetLength) {
+    array.push(padValue)
+  }
+  array.length = targetLength
+}