cubic bezier (#65)

* cubic bezieré

* apiDump + add android license to be compliant to Apache 2.0

* Fix small oopsie

* Apache licensing

Co-authored-by: MoonTidez <79183852+MoonTidez@users.noreply.github.com>

3 files changed, 105 insertions, 2 deletions

diff --git a/src/main/java/cc/polyfrost/oneconfig/gui/SideBar.java b/src/main/java/cc/polyfrost/oneconfig/gui/SideBar.java
index ebfc8cb..b25a8e3 100644
--- a/src/main/java/cc/polyfrost/oneconfig/gui/SideBar.java
+++ b/src/main/java/cc/polyfrost/oneconfig/gui/SideBar.java
@@ -1,6 +1,7 @@
 package cc.polyfrost.oneconfig.gui;
 
 import cc.polyfrost.oneconfig.gui.animations.Animation;
+import cc.polyfrost.oneconfig.gui.animations.CubicBezier;
 import cc.polyfrost.oneconfig.gui.animations.DummyAnimation;
 import cc.polyfrost.oneconfig.gui.animations.EaseInOutQuart;
 import cc.polyfrost.oneconfig.gui.elements.BasicButton;
@@ -94,7 +95,7 @@ public class SideBar {
     private void moveSideBar(BasicButton button) {
         if (button.equals(buttons.get(selected))) return;
         buttons.get(selected).setColorPalette(ColorPalette.TERTIARY);
-        moveAnimation = new EaseInOutQuart(300, buttons.get(selected).y - y, button.y - y, false);
+        moveAnimation = new CubicBezier(0.76f, 0, 0.24f, 1, 300, buttons.get(selected).y - y, button.y - y, false);
         sizeAnimation = new DummyAnimation(36);
         selected = buttons.indexOf(button);
     }
diff --git a/src/main/java/cc/polyfrost/oneconfig/gui/animations/Animation.java b/src/main/java/cc/polyfrost/oneconfig/gui/animations/Animation.java
index 30fcc4e..77556b5 100644
--- a/src/main/java/cc/polyfrost/oneconfig/gui/animations/Animation.java
+++ b/src/main/java/cc/polyfrost/oneconfig/gui/animations/Animation.java
@@ -33,7 +33,7 @@ public abstract class Animation {
      */
     public float get(float deltaTime) {
         timePassed += deltaTime;
-        if (timePassed >= duration) timePassed = duration;
+        if (timePassed >= duration) return start + change;
         return animate(timePassed / duration) * change + start;
     }
 
diff --git a/src/main/java/cc/polyfrost/oneconfig/gui/animations/CubicBezier.java b/src/main/java/cc/polyfrost/oneconfig/gui/animations/CubicBezier.java
new file mode 100644
index 0000000..f7848da
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/gui/animations/CubicBezier.java
@@ -0,0 +1,102 @@
+/* This file contains an adaptation of code from The Android Open Source
+ * Project found at <https://cs.android.com/>
+ * For the avoidance of doubt, this file is still licensed under the terms
+ * of OneConfig's Licensing.
+ *
+ *                 LICENSE NOTICE FOR ADAPTED CODE
+ *
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use the 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.
+ *
+ * Significant changes (as required by the Apache 2.0):
+ * - Changed variable names
+ * - Code adapted from Kotlin to Java
+ * - Removed variables defining premade easing functions
+ * - Added constructor for JDT and OneConfig's animation system
+ *
+ * As per the terms of the Apache 2.0 License, a copy of the License
+ * is found at `src/main/resources/licenses/Android-License.txt`.
+ */
+
+package cc.polyfrost.oneconfig.gui.animations;
+
+public class CubicBezier extends Animation {
+    private static final float CubicErrorBound = 0.001f;
+    protected final float P0;
+    protected final float P1;
+    protected final float P2;
+    protected final float P3;
+
+    /**
+     * @param P0       First control point X
+     * @param P1       First control point Y
+     * @param P2       Second control point X
+     * @param P3       Second control point Y
+     * @param duration The duration of the animation
+     * @param start    The start of the animation
+     * @param end      The end of the animation
+     * @param reverse  Reverse the animation
+     */
+    public CubicBezier(float P0, float P1, float P2, float P3, float duration, float start, float end, boolean reverse) {
+        super(duration, start, end, reverse);
+        this.P0 = P0;
+        this.P1 = P1;
+        this.P2 = P2;
+        this.P3 = P3;
+    }
+
+    /**
+     * This constructor should be used with JDT's getCubicBezier method
+     *
+     * @param points   The control points
+     * @param duration The duration of the animation
+     * @param start    The start of the animation
+     * @param end      The end of the animation
+     * @param reverse  Reverse the animation
+     */
+    public CubicBezier(float[] points, float duration, float start, float end, boolean reverse) {
+        this(points[0], points[1], points[2], points[3], duration, start, end, reverse);
+    }
+
+    /**
+     * Adapted from <a href="https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:compose/animation/animation-core/src/commonMain/kotlin/androidx/compose/animation/core/Easing.kt">Android</a>
+     * Under Apache 2.0 license
+     *
+     * @param x The current point
+     * @return The value
+     */
+    @Override
+    protected float animate(float x) {
+        float start = 0.0f;
+        float end = 1.0f;
+        while (true) {
+            float midpoint = (start + end) / 2;
+            float estimate = evaluateCubic(P0, P2, midpoint);
+            if (Math.abs(x - estimate) < CubicErrorBound)
+                return evaluateCubic(P1, P3, midpoint);
+            if (estimate < x) start = midpoint;
+            else end = midpoint;
+        }
+    }
+
+    /**
+     * Adapted from <a href="https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:compose/animation/animation-core/src/commonMain/kotlin/androidx/compose/animation/core/Easing.kt">Android</a>
+     * Under Apache 2.0 license
+     */
+    private float evaluateCubic(float a, float b, float m) {
+        return 3 * a * (1 - m) * (1 - m) * m +
+                3 * b * (1 - m) * /*    */ m * m +
+                /*                      */ m * m * m;
+    }
+}