diff --git a/app/src/main/java/com/hippo/ehviewer/download/DownloadManager.kt b/app/src/main/java/com/hippo/ehviewer/download/DownloadManager.kt
index ad937fa05..91f31a887 100644
--- a/app/src/main/java/com/hippo/ehviewer/download/DownloadManager.kt
+++ b/app/src/main/java/com/hippo/ehviewer/download/DownloadManager.kt
@@ -20,6 +20,7 @@ import android.util.Log
 import android.util.SparseLongArray
 import androidx.collection.LongSparseArray
 import androidx.collection.keyIterator
+import com.google.android.material.math.MathUtils
 import com.hippo.ehviewer.AppConfig
 import com.hippo.ehviewer.EhDB
 import com.hippo.ehviewer.Settings
@@ -33,7 +34,6 @@ import com.hippo.ehviewer.spider.SpiderQueen.OnSpiderListener
 import com.hippo.ehviewer.spider.readCompatFromUniFile
 import com.hippo.ehviewer.spider.write
 import com.hippo.ehviewer.yorozuya.ConcurrentPool
-import com.hippo.ehviewer.yorozuya.MathUtils
 import com.hippo.ehviewer.yorozuya.SimpleHandler
 import com.hippo.ehviewer.yorozuya.collect.LongList
 import com.hippo.unifile.UniFile
diff --git a/app/src/main/java/com/hippo/ehviewer/ui/legacy/AddDeleteDrawable.java b/app/src/main/java/com/hippo/ehviewer/ui/legacy/AddDeleteDrawable.java
index 75a45e98d..067b4fc60 100644
--- a/app/src/main/java/com/hippo/ehviewer/ui/legacy/AddDeleteDrawable.java
+++ b/app/src/main/java/com/hippo/ehviewer/ui/legacy/AddDeleteDrawable.java
@@ -29,8 +29,8 @@ import android.graphics.drawable.Drawable;
 
 import androidx.annotation.Keep;
 
+import com.google.android.material.math.MathUtils;
 import com.hippo.ehviewer.R;
-import com.hippo.ehviewer.yorozuya.MathUtils;
 
 public class AddDeleteDrawable extends Drawable {
 
diff --git a/app/src/main/java/com/hippo/ehviewer/ui/legacy/FastScroller.kt b/app/src/main/java/com/hippo/ehviewer/ui/legacy/FastScroller.kt
index cc4500121..938a9949a 100644
--- a/app/src/main/java/com/hippo/ehviewer/ui/legacy/FastScroller.kt
+++ b/app/src/main/java/com/hippo/ehviewer/ui/legacy/FastScroller.kt
@@ -27,10 +27,10 @@ import android.view.View
 import android.view.ViewConfiguration
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.RecyclerView.AdapterDataObserver
+import com.google.android.material.math.MathUtils.dist
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.yorozuya.AnimationUtils
 import com.hippo.ehviewer.yorozuya.LayoutUtils.dp2pix
-import com.hippo.ehviewer.yorozuya.MathUtils.dist
 import com.hippo.ehviewer.yorozuya.SimpleAnimatorListener
 import com.hippo.ehviewer.yorozuya.SimpleHandler
 import kotlin.math.abs
diff --git a/app/src/main/java/com/hippo/ehviewer/ui/legacy/LayoutManagerUtils.kt b/app/src/main/java/com/hippo/ehviewer/ui/legacy/LayoutManagerUtils.kt
index a1e59ce86..adade8f42 100644
--- a/app/src/main/java/com/hippo/ehviewer/ui/legacy/LayoutManagerUtils.kt
+++ b/app/src/main/java/com/hippo/ehviewer/ui/legacy/LayoutManagerUtils.kt
@@ -20,7 +20,7 @@ import android.graphics.PointF
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.StaggeredGridLayoutManager
-import com.hippo.ehviewer.yorozuya.MathUtils
+import com.google.android.material.math.MathUtils
 import com.hippo.ehviewer.yorozuya.SimpleHandler
 import java.lang.reflect.InvocationTargetException
 import java.lang.reflect.Method
@@ -112,7 +112,7 @@ object LayoutManagerUtils {
             if (offset < max && max > 0) {
                 smoothScrollToPosition(
                     layoutManager, context, position,
-                    MathUtils.lerp(100, 25, (offset / max).toFloat())
+                    MathUtils.lerp(100F, 25F, (offset / max).toFloat()).toInt()
                 )
             } else {
                 scrollToPositionWithOffset(layoutManager, position, 0)
@@ -126,7 +126,7 @@ object LayoutManagerUtils {
             is LinearLayoutManager -> layoutManager.findFirstVisibleItemPosition()
             is StaggeredGridLayoutManager -> {
                 val positions = layoutManager.findFirstVisibleItemPositions(null)
-                MathUtils.min(*positions)
+                positions.min()
             }
 
             else -> throw IllegalStateException("Can't do getFirstVisibleItemPosition for " + layoutManager.javaClass.name)
@@ -138,7 +138,7 @@ object LayoutManagerUtils {
             is LinearLayoutManager -> layoutManager.findLastVisibleItemPosition()
             is StaggeredGridLayoutManager -> {
                 val positions = layoutManager.findLastVisibleItemPositions(null)
-                MathUtils.max(*positions)
+                positions.max()
             }
 
             else -> throw IllegalStateException("Can't do getLastVisibleItemPosition for " + layoutManager.javaClass.name)
diff --git a/app/src/main/java/com/hippo/ehviewer/ui/legacy/SimpleGridLayout.kt b/app/src/main/java/com/hippo/ehviewer/ui/legacy/SimpleGridLayout.kt
index b5d04e57a..67e10affe 100644
--- a/app/src/main/java/com/hippo/ehviewer/ui/legacy/SimpleGridLayout.kt
+++ b/app/src/main/java/com/hippo/ehviewer/ui/legacy/SimpleGridLayout.kt
@@ -19,7 +19,6 @@ import android.content.Context
 import android.util.AttributeSet
 import android.view.ViewGroup
 import com.hippo.ehviewer.R
-import com.hippo.ehviewer.yorozuya.MathUtils.ceilDivide
 import com.hippo.ehviewer.yorozuya.ViewUtils
 
 /**
@@ -72,7 +71,7 @@ open class SimpleGridLayout : ViewGroup {
     }
 
     override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
-        val maxRowCount = ceilDivide(childCount, mColumnCount)
+        val maxRowCount = (childCount + mColumnCount - 1) / mColumnCount
         if (mRowHeights == null || mRowHeights!!.size != maxRowCount) {
             mRowHeights = IntArray(maxRowCount)
         }
diff --git a/app/src/main/java/com/hippo/ehviewer/ui/legacy/WindowInsetsAnimationHelper.java b/app/src/main/java/com/hippo/ehviewer/ui/legacy/WindowInsetsAnimationHelper.java
index 9adb4316b..e352391de 100644
--- a/app/src/main/java/com/hippo/ehviewer/ui/legacy/WindowInsetsAnimationHelper.java
+++ b/app/src/main/java/com/hippo/ehviewer/ui/legacy/WindowInsetsAnimationHelper.java
@@ -24,7 +24,7 @@ import androidx.annotation.NonNull;
 import androidx.core.view.WindowInsetsAnimationCompat;
 import androidx.core.view.WindowInsetsCompat;
 
-import com.hippo.ehviewer.yorozuya.MathUtils;
+import com.google.android.material.math.MathUtils;
 
 import java.util.HashMap;
 import java.util.List;
diff --git a/app/src/main/java/com/hippo/ehviewer/yorozuya/MathUtils.java b/app/src/main/java/com/hippo/ehviewer/yorozuya/MathUtils.java
deleted file mode 100644
index 104be69b4..000000000
--- a/app/src/main/java/com/hippo/ehviewer/yorozuya/MathUtils.java
+++ /dev/null
@@ -1,208 +0,0 @@
-/*
- * Copyright 2015 Hippo Seven
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.hippo.ehviewer.yorozuya;
-
-import java.util.Random;
-
-// Get most code from android.util.MathUtils
-public final class MathUtils {
-    private static final Random sRandom = new Random();
-
-    private MathUtils() {
-    }
-
-    public static float abs(float v) {
-        return v > 0 ? v : -v;
-    }
-
-    public static float log(float a) {
-        return (float) Math.log(a);
-    }
-
-    public static float max(float a, float b) {
-        return a > b ? a : b;
-    }
-
-    public static float max(int a, int b) {
-        return a > b ? a : b;
-    }
-
-    public static float max(float a, float b, float c) {
-        return a > b ? (a > c ? a : c) : (b > c ? b : c);
-    }
-
-    public static float max(int a, int b, int c) {
-        return a > b ? (a > c ? a : c) : (b > c ? b : c);
-    }
-
-    public static float max(float... arg) {
-        int length = arg.length;
-        if (length <= 0) {
-            throw new IllegalArgumentException("Empty argument");
-        } else {
-            float n = arg[0];
-            float m;
-            for (int i = 1; i < length; i++) {
-                m = arg[i];
-                if (m > n)
-                    n = m;
-            }
-            return n;
-        }
-    }
-
-    public static int max(int... arg) {
-        int length = arg.length;
-        if (length <= 0) {
-            throw new IllegalArgumentException("Empty argument");
-        } else {
-            int n = arg[0];
-            int m;
-            for (int i = 1; i < length; i++) {
-                m = arg[i];
-                if (m > n)
-                    n = m;
-            }
-            return n;
-        }
-    }
-
-    public static float min(float a, float b) {
-        return a < b ? a : b;
-    }
-
-    public static float min(int a, int b) {
-        return a < b ? a : b;
-    }
-
-    public static float min(float a, float b, float c) {
-        return a < b ? (a < c ? a : c) : (b < c ? b : c);
-    }
-
-    public static float min(int a, int b, int c) {
-        return a < b ? (a < c ? a : c) : (b < c ? b : c);
-    }
-
-    public static float min(float... args) {
-        int length = args.length;
-        if (length <= 0) {
-            throw new IllegalArgumentException("Empty argument");
-        } else {
-            float n = args[0];
-            float m;
-            for (int i = 1; i < length; i++) {
-                m = args[i];
-                if (m < n)
-                    n = m;
-            }
-            return n;
-        }
-    }
-
-    public static int min(int... args) {
-        int length = args.length;
-        if (length <= 0) {
-            throw new IllegalArgumentException("Empty argument");
-        } else {
-            int n = args[0];
-            int m;
-            for (int i = 1; i < length; i++) {
-                m = args[i];
-                if (m < n)
-                    n = m;
-            }
-            return n;
-        }
-    }
-
-    public static float dist(float x1, float y1, float x2, float y2) {
-        final float x = (x2 - x1);
-        final float y = (y2 - y1);
-        return (float) Math.hypot(x, y);
-    }
-
-    public static float dist(float x1, float y1, float z1, float x2, float y2, float z2) {
-        final float x = (x2 - x1);
-        final float y = (y2 - y1);
-        final float z = (z2 - z1);
-        return (float) Math.sqrt(x * x + y * y + z * z);
-    }
-
-    public static float cross(float v1x, float v1y, float v2x, float v2y) {
-        return v1x * v2y - v1y * v2x;
-    }
-
-    public static int lerp(int start, int stop, float amount) {
-        return start + (int) ((stop - start) * amount);
-    }
-
-    public static float lerp(float start, float stop, float amount) {
-        return start + (stop - start) * amount;
-    }
-
-    public static float map(float minStart, float minStop, float maxStart, float maxStop, float value) {
-        return maxStart + (maxStart - maxStop) * ((value - minStart) / (minStop - minStart));
-    }
-
-    /**
-     * Returns the input value x clamped to the range [min, max].
-     */
-    public static int clamp(int x, int min, int max) {
-        if (x > max) return max;
-        if (x < min) return min;
-        return x;
-    }
-
-    /**
-     * divide and ceil
-     */
-    public static int ceilDivide(int a, int b) {
-        return (a + b - 1) / b;
-    }
-
-    /**
-     * [0, howbig)
-     */
-    public static int random(int howbig) {
-        return (int) (sRandom.nextFloat() * howbig);
-    }
-
-    /**
-     * [howsmall, howbig)
-     */
-    public static int random(int howsmall, int howbig) {
-        if (howsmall >= howbig)
-            return howsmall;
-        return lerp(howsmall, howbig, sRandom.nextFloat());
-    }
-
-    /**
-     * [0, howbig)
-     */
-    public static float random(float howbig) {
-        return sRandom.nextFloat() * howbig;
-    }
-
-    /**
-     * [howsmall, howbig)
-     */
-    public static float random(float howsmall, float howbig) {
-        if (howsmall >= howbig)
-            return howsmall;
-        return lerp(howsmall, howbig, sRandom.nextFloat());
-    }
-}
diff --git a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/PageLoader.kt b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/PageLoader.kt
index 7e8f8fd30..dd0614373 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/PageLoader.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/PageLoader.kt
@@ -3,7 +3,6 @@ package eu.kanade.tachiyomi.ui.reader.loader
 import androidx.annotation.CallSuper
 import androidx.collection.lruCache
 import com.hippo.ehviewer.image.Image
-import com.hippo.ehviewer.yorozuya.MathUtils
 import com.hippo.ehviewer.yorozuya.OSUtils
 import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
@@ -23,7 +22,7 @@ abstract class PageLoader {
         (0 until size).map { ReaderPage(it) }
     }
 
-    private val mPreloads = MathUtils.clamp(com.hippo.ehviewer.Settings.preloadImage, 0, 100)
+    private val mPreloads = com.hippo.ehviewer.Settings.preloadImage.coerceIn(0, 100)
 
     abstract suspend fun awaitReady(): Boolean
     abstract val isReady: Boolean