Add new custom tweening functionality

Author: stringfromjava

.gitignore

@@ -88,6 +88,7 @@ www-test/
 
 
 ## NetBeans:
+
 /nbproject/private/
 /android/nbproject/private/
 /core/nbproject/private/
@@ -144,7 +145,7 @@ nbactions.xml
 nb-configuration.xml
 
 # VS Code
-/.vscode
+.vscode/
 
 ## OS-Specific:
 .DS_Store

core/build.gradle

@@ -10,6 +10,7 @@ dependencies {
   api "org.mini2Dx:universal-tween-engine:$universalTweenVersion"
 
   implementation "org.luaj:luaj-jse:3.0.1"
+  implementation 'org.jetbrains:annotations:15.0'
 
   if(enableGraalNative == 'true') {
     implementation "io.github.berstanio:gdx-svmhelper-annotations:$graalHelperVersion"

core/src/main/java/me/stringfromjava/funkin/game/menus/TitleScreen.java

@@ -16,7 +16,7 @@ public class TitleScreen extends FunkinScreen {
     @Override
     public void show() {
         super.show();
-        tickleFight = Funkin.playSound("shared/sounds/tickleFight.ogg");
+        tickleFight = new FunkinSound("shared/sounds/tickleFight.ogg");
         Funkin.playMusic("preload/music/freakyMenu/freakyMenu.ogg", 0.5f);
     }
 

core/src/main/java/me/stringfromjava/funkin/tween/FunkinTween.java

@@ -1,10 +1,60 @@
 package me.stringfromjava.funkin.tween;
 
+import me.stringfromjava.funkin.tween.settings.FunkinTweenSettings;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+
 /**
- * Core manager class for creating new tweens.
+ * Core class for creating new tweens to add nice and smooth animations to visual objects.
+ * <p>
+ * Note that this doesn't have to be used on sprites, it can be used on just about anything!
  */
-public final class FunkinTween {
+public class FunkinTween {
+
+    /**
+     * The global tween manager for the entire game.
+     */
+    public static FunkinTweenManager globalManager = new FunkinTweenManager();
+
+    /**
+     * The object to tween.
+     */
+    protected Object object;
+
+    /**
+     * The settings used for how the tween is handled and calculated (aka how it looks and animates).
+     */
+    protected FunkinTweenSettings tweenSettings;
+
+    private final ArrayList<Field> cachedFields;
+
+    /**
+     * @param object   The object to tween values.
+     * @param settings The settings that configure and determine how the tween should animate and last for.
+     */
+    public FunkinTween(Object object, FunkinTweenSettings settings) {
+        this.tweenSettings = settings;
+        this.cachedFields = new ArrayList<>();
+
+        Field[] allFields = object.getClass().getFields();
+        var neededFields = settings.getGoalFields();
+
+        // Due to how costly it is using Java reflect, we cache the fields we need
+        // before we actually do the real tweening functionality. This is so it
+        // doesn't cause lag while multiple tweens are being active.
+        for (Field field : allFields) {
+            String fName = field.getName();
+
+            if (!field.trySetAccessible() && !neededFields.contains(fName)) {
+                continue;
+            }
+
+            cachedFields.add(field);
+        }
+    }
 
-    private FunkinTween() {
+    public FunkinTweenSettings getTweenSettings() {
+        return tweenSettings;
     }
 }

core/src/main/java/me/stringfromjava/funkin/tween/FunkinTweenManager.java

@@ -0,0 +1,18 @@
+package me.stringfromjava.funkin.tween;
+
+import java.util.ArrayList;
+
+/**
+ * Core manager class for handling all {@link FunkinTween}s that are currently active.
+ */
+public final class FunkinTweenManager {
+
+    /**
+     * A list where all current active tweens are stored.
+     */
+    public final ArrayList<FunkinTween> activeTweens = new ArrayList<>();
+
+    public void update(float delta) {
+        // TODO: Iterate through every active tween and update them!
+    }
+}

core/src/main/java/me/stringfromjava/funkin/tween/accessors/SpriteAccessor.java

@@ -0,0 +1,210 @@
+package me.stringfromjava.funkin.tween.settings;
+
+import me.stringfromjava.funkin.tween.FunkinTween;
+
+/**
+ * Class where all easer functions are stored, mostly used for tweening.
+ */
+public final class FunkinTweenEase {
+
+    // Easing constants for specific functions.
+    private static final float PI2 = (float) Math.PI / 2;
+    private static final float EL = (float) ((float) 2 * Math.PI / .45);
+    private static final float B1 = (float) ((float) 1 / 2.75);
+    private static final float B2 = (float) ((float) 2 / 2.75);
+    private static final float B3 = (float) ((float) 1.5 / 2.75);
+    private static final float B4 = (float) ((float) 2.5 / 2.75);
+    private static final float B5 = (float) ((float) 2.25 / 2.75);
+    private static final float B6 = (float) ((float) 2.625 / 2.75);
+    private static final float ELASTIC_AMPLITUDE = 1;
+    private static final float ELASTIC_PERIOD = 0.4f;
+
+    private FunkinTweenEase() {
+    }
+
+    public static float linear(float t) {
+        return t;
+    }
+
+    public static float quadIn(float t) {
+        return t * t;
+    }
+
+    public static float quadOut(float t) {
+        return -t * (t - 2);
+    }
+
+    public static float quadInOut(float t) {
+        return t <= .5 ? t * t * 2 : 1 - (--t) * t * 2;
+    }
+
+    public static float cubeIn(float t) {
+        return t * t * t;
+    }
+
+    public static float cubeOut(float t) {
+        return 1 + (--t) * t * t;
+    }
+
+    public static float cubeInOut(float t) {
+        return t <= .5 ? t * t * t * 4 : 1 + (--t) * t * t * 4;
+    }
+
+    public static float quartIn(float t) {
+        return t * t * t * t;
+    }
+
+    public static float quartOut(float t) {
+        return 1 - (t -= 1) * t * t * t;
+    }
+
+    public static float quartInOut(float t) {
+        return t <= .5 ? t * t * t * t * 8 : (float) ((1 - (t = t * 2 - 2) * t * t * t) / 2 + .5);
+    }
+
+    public static float quintIn(float t) {
+        return t * t * t * t * t;
+    }
+
+    public static float quintOut(float t) {
+        return (t = t - 1) * t * t * t * t + 1;
+    }
+
+    public static float quintInOut(float t) {
+        return ((t *= 2) < 1) ? (t * t * t * t * t) / 2 : ((t -= 2) * t * t * t * t + 2) / 2;
+    }
+
+    public static float smoothStepIn(float t) {
+        return 2 * smoothStepInOut(t / 2);
+    }
+
+    public static float smoothStepOut(float t) {
+        return 2 * smoothStepInOut((float) (t / 2 + 0.5)) - 1;
+    }
+
+    public static float smoothStepInOut(float t) {
+        return t * t * (t * -2 + 3);
+    }
+
+    public static float smootherStepIn(float t) {
+        return 2 * smootherStepInOut(t / 2);
+    }
+
+    public static float smootherStepOut(float t) {
+        return 2 * smootherStepInOut((float) (t / 2 + 0.5)) - 1;
+    }
+
+    public static float smootherStepInOut(float t) {
+        return t * t * t * (t * (t * 6 - 15) + 10);
+    }
+
+    public static float sineIn(float t) {
+        return (float) (-Math.cos(PI2 * t) + 1);
+    }
+
+    public static float sineOut(float t) {
+        return (float) Math.sin(PI2 * t);
+    }
+
+    public static float sineInOut(float t) {
+        return (float) (-Math.cos(Math.PI * t) / 2 + .5);
+    }
+
+    public static float bounceIn(float t) {
+        return 1 - bounceOut(1 - t);
+    }
+
+    public static float bounceOut(float t) {
+        if (t < B1)
+            return (float) (7.5625 * t * t);
+        if (t < B2)
+            return (float) (7.5625 * (t - B3) * (t - B3) + .75);
+        if (t < B4)
+            return (float) (7.5625 * (t - B5) * (t - B5) + .9375);
+        return (float) (7.5625 * (t - B6) * (t - B6) + .984375);
+    }
+
+    public static float bounceInOut(float t) {
+        return t < 0.5
+            ? (1 - bounceOut(1 - 2 * t)) / 2
+            : (1 + bounceOut(2 * t - 1)) / 2;
+    }
+
+    public static float circIn(float t) {
+        return (float) -(Math.sqrt(1 - t * t) - 1);
+    }
+
+    public static float circOut(float t) {
+        return (float) Math.sqrt(1 - (t - 1) * (t - 1));
+    }
+
+    public static float circInOut(float t) {
+        return (float) (t <= .5 ? (Math.sqrt(1 - t * t * 4) - 1) / -2 : (Math.sqrt(1 - (t * 2 - 2) * (t * 2 - 2)) + 1) / 2);
+    }
+
+    public static float expoIn(float t) {
+        return (float) Math.pow(2, 10 * (t - 1));
+    }
+
+    public static float expoOut(float t) {
+        return (float) (-Math.pow(2, -10 * t) + 1);
+    }
+
+    public static float expoInOut(float t) {
+        return (float) (t < .5 ? Math.pow(2, 10 * (t * 2 - 1)) / 2 : (-Math.pow(2, -10 * (t * 2 - 1)) + 2) / 2);
+    }
+
+    public static float backIn(float t) {
+        return (float) (t * t * (2.70158 * t - 1.70158));
+    }
+
+    public static float backOut(float t) {
+        return (float) (1 - (--t) * (t) * (-2.70158 * t - 1.70158));
+    }
+
+    public static float backInOut(float t) {
+        t *= 2;
+        if (t < 1)
+            return (float) (t * t * (2.70158 * t - 1.70158) / 2);
+        t--;
+        return (float) ((1 - (--t) * (t) * (-2.70158 * t - 1.70158)) / 2 + .5);
+    }
+
+    public static float elasticIn(float t) {
+        return (float) -(ELASTIC_AMPLITUDE * Math.pow(2,
+            10 * (t -= 1)) * Math.sin((t - (ELASTIC_PERIOD / (2 * Math.PI) * Math.asin(1 / ELASTIC_AMPLITUDE))) * (2 * Math.PI) / ELASTIC_PERIOD));
+    }
+
+    public static float elasticOut(float t) {
+        return (float) (ELASTIC_AMPLITUDE * Math.pow(2,
+                    -10 * t) * Math.sin((t - (ELASTIC_PERIOD / (2 * Math.PI) * Math.asin(1 / ELASTIC_AMPLITUDE))) * (2 * Math.PI) / ELASTIC_PERIOD)
+                    + 1);
+    }
+
+    public static float elasticInOut(float t) {
+        if (t < 0.5) {
+            return (float) (-0.5 * (Math.pow(2, 10 * (t -= 0.5f)) * Math.sin((t - (ELASTIC_PERIOD / 4)) * (2 * Math.PI) / ELASTIC_PERIOD)));
+        }
+        return (float) (Math.pow(2, -10 * (t -= 0.5f)) * Math.sin((t - (ELASTIC_PERIOD / 4)) * (2 * Math.PI) / ELASTIC_PERIOD) * 0.5 + 1);
+    }
+
+    @FunctionalInterface
+    public interface FunkinTweenEaseFunction {
+        float compute(float t);
+    }
+
+    @FunctionalInterface
+    public interface FunkinTweenEaseStartCallback {
+        void run(FunkinTween tween);
+    }
+
+    @FunctionalInterface
+    public interface FunkinTweenEaseUpdateCallback {
+        void run(FunkinTween tween);
+    }
+
+    @FunctionalInterface
+    public interface FunkinTweenEaseCompleteCallback {
+        void run(FunkinTween tween);
+    }
+}