From 2cc716f59e951549f73976b58a0d1015bd0863f2 Mon Sep 17 00:00:00 2001
From: Peter Fajdiga <peter.fajdiga@gmail.com>
Date: Fri, 25 Oct 2024 17:06:20 +0200
Subject: [PATCH] fillSpace: improve divisor selection

---
 src/lib/utils/fillSpace.ts         | 19 +++++++---
 src/tests/units/utils/fillSpace.ts | 58 ++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 5 deletions(-)

diff --git a/src/lib/utils/fillSpace.ts b/src/lib/utils/fillSpace.ts
index 3c72e3f..bf0be42 100644
--- a/src/lib/utils/fillSpace.ts
+++ b/src/lib/utils/fillSpace.ts
@@ -5,23 +5,19 @@ function fillSpace(availableSpace: number, items: { min: number, max: number }[]
 
 function findMeanSpaceFiller(availableSpace: number, items: { min: number, max: number }[]) {
     let mean = Math.floor(availableSpace / items.length);
-    while (true) {
+    for (let i = 0; true; i++) {
         let requiredSpace = 0;
-        let increasable = 0;
-        let decreasable = 0;
         let low = -Infinity;
         let high = Infinity;
         for (const item of items) {
             const size = clamp(mean, item.min, item.max);
             requiredSpace += size;
             if (mean > item.min) {
-                decreasable++;
                 if (size > low) {
                     low = size;
                 }
             }
             if (mean < item.max) {
-                increasable++;
                 if (size < high) {
                     high = size;
                 }
@@ -32,17 +28,30 @@ function findMeanSpaceFiller(availableSpace: number, items: { min: number, max:
         const error = requiredSpace - availableSpace;
         if (error > 0) {
             // need to decrease mean
+            let decreasable = 0;
+            for (const item of items) {
+                if (mean > item.min && low - error < item.max) {
+                    decreasable++;
+                }
+            }
             if (decreasable > 0) {
                 mean = Math.floor(low - error / decreasable);
             }
         } else if (error < 0) {
             // need to increase mean
+            let increasable = 0;
+            for (const item of items) {
+                if (mean < item.max && high - error > item.min) {
+                    increasable++;
+                }
+            }
             if (increasable > 0) {
                 mean = Math.floor(high - error / increasable);
             }
         }
 
         if (mean === oldMean) {
+            log(`findMeanSpaceFiller ${i} / ${items.length}`);
             return mean;
         }
     }
diff --git a/src/tests/units/utils/fillSpace.ts b/src/tests/units/utils/fillSpace.ts
index 50c9f91..fec54dc 100644
--- a/src/tests/units/utils/fillSpace.ts
+++ b/src/tests/units/utils/fillSpace.ts
@@ -95,6 +95,64 @@ tests.register("fillSpace", 1, () => {
             ],
             expected: [114, 93, 93, 93, 93, 93, 110, 110],
         },
+        {
+            availableSpace: 801,
+            items: [
+                { min: 114, max: 800 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 109, max: 800 },
+                { min: 10, max: 800 },
+            ],
+            expected: [114, 93, 93, 93, 93, 93, 111, 111],
+        },
+        {
+            availableSpace: 1029,
+            items: [
+                { min: 114, max: 800 },
+                { min: 114, max: 800 },
+                { min: 114, max: 800 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 10, max: 93 },
+                { min: 109, max: 800 },
+                { min: 10, max: 800 },
+            ],
+            expected: [114, 114, 114, 93, 93, 93, 93, 93, 111, 111],
+        },
+        {
+            availableSpace: 602,
+            items: [
+                { min: 10, max: 600 },
+                { min: 10, max: 600 },
+                { min: 10, max: 600 },
+            ],
+            expected: [200, 200, 200],
+        },
+        {
+            availableSpace: 602,
+            items: [
+                { min: 204, max: 600 },
+                { min: 202, max: 600 },
+                { min: 10, max: 600 },
+            ],
+            expected: [204, 202, 196],
+        },
+        {
+            availableSpace: 803,
+            items: [
+                { min: 204, max: 600 },
+                { min: 10, max: 600 },
+                { min: 10, max: 600 },
+                { min: 10, max: 600 },
+            ],
+            expected: [204, 199, 199, 199],
+        },
     ];
 
     for (const testCase of testCases) {