Tweak slime bounce parameters

Instead of preserving 95% of speed, preserves 97.5%
Instead of the min fall height being 2, its now a min fall velocity if less than 3 (meaning you can bounce from a 1 block jump)
Might help with #4871

src/main/java/slimeknights/tconstruct/library/utils/SlimeBounceHandler.java

@@ -10,6 +10,7 @@
 import net.minecraftforge.event.server.ServerStoppingEvent;
 import slimeknights.tconstruct.common.Sounds;
 
+import javax.annotation.Nullable;
 import java.util.IdentityHashMap;
 
 /** Logic for entities bouncing */
@@ -28,15 +29,15 @@ public static void init() {
    * @param entity  Entity to bounce
    */
   public static void addBounceHandler(LivingEntity entity) {
-    addBounceHandler(entity, 0d);
+    addBounceHandler(entity, null);
   }
 
   /**
    * Causes the entity to bounce, needed because the fall event will reset motion afterwards
    * @param entity  Entity to bounce
    * @param bounce  Bounce amount
    */
-  public static void addBounceHandler(LivingEntity entity, double bounce) {
+  public static void addBounceHandler(LivingEntity entity, @Nullable Vec3 bounce) {
     // no fake players PlayerTick event
     if (entity instanceof FakePlayer) {
       return;
@@ -45,7 +46,7 @@ public static void addBounceHandler(LivingEntity entity, double bounce) {
     BounceInfo info = BOUNCING_ENTITIES.get(entity);
     if (info == null) {
       BOUNCING_ENTITIES.put(entity, new BounceInfo(entity, bounce));
-    } else if (bounce != 0) {
+    } else if (bounce != null) {
       // updated bounce if needed
       info.bounce = bounce;
       // add one to the tick as there is a 1 tick delay between falling and ticking for many entities
@@ -71,8 +72,10 @@ private static void onLivingTick(LivingUpdateEvent event) {
 
       // if its the bounce tick, time to bounce. This is to circumvent the logic that resets y motion after landing
       if (entity.tickCount == info.bounceTick) {
-        Vec3 motion = entity.getDeltaMovement();
-        entity.setDeltaMovement(motion.x, info.bounce, motion.z);
+        if (info.bounce != null) {
+          entity.setDeltaMovement(info.bounce);
+          info.bounce = null;
+        }
         info.bounceTick = 0;
       }
 
@@ -93,11 +96,11 @@ private static void onLivingTick(LivingUpdateEvent event) {
         } else if (motionSq < info.lastMagSq) {
           info.stopMagTick = 0;
           // preserve 95% of former speed
-          double boost = Math.sqrt(info.lastMagSq / motionSq) * 0.95f;
+          double boost = Math.sqrt(info.lastMagSq / motionSq) * 0.975f;
           if (boost > 1) {
             entity.setDeltaMovement(motion.x * boost, motion.y, motion.z * boost);
             entity.hasImpulse = true;
-            info.lastMagSq = info.lastMagSq * 0.95f * 0.95f;
+            info.lastMagSq = info.lastMagSq * 0.975f * 0.975f;
             // play sound if we had a big angle change
             double newAngle = Mth.atan2(motion.z, motion.x);
             if (Math.abs(newAngle - info.lastAngle) > 1) {
@@ -132,8 +135,9 @@ private static void serverStopping(ServerStoppingEvent event) {
 
   /** Data class to keep track of bouncing info for an entity */
   private static class BounceInfo {
-    /** Velocity the entity should have, unused if 0 */
-    private double bounce;
+    /** Velocity the entity should have, unused if null */
+    @Nullable
+    private Vec3 bounce;
     /** Time to update the entities velocity */
     private int bounceTick;
     /** Tick to stop entity magnitude changes */
@@ -147,9 +151,9 @@ private static class BounceInfo {
     /** Last angle of motion, used for sound effects */
     private double lastAngle;
 
-    public BounceInfo(LivingEntity entity, double bounce) {
+    public BounceInfo(LivingEntity entity, @Nullable Vec3 bounce) {
       this.bounce = bounce;
-      if (bounce != 0) {
+      if (bounce != null) {
         // add one to the tick as there is a 1 tick delay between falling and ticking for many entities
         this.bounceTick = entity.tickCount + 1;
       } else {

src/main/java/slimeknights/tconstruct/tools/modifiers/ability/armor/BouncyModifier.java

@@ -24,7 +24,7 @@ public BouncyModifier() {
   private static void onFall(LivingFallEvent event) {
     LivingEntity living = event.getEntityLiving();
     // using fall distance as the event distance could be reduced by jump boost
-    if (living == null || living.fallDistance <= 2f) {
+    if (living == null || (living.getDeltaMovement().y > -0.3 && living.fallDistance < 3)) {
       return;
     }
     // can the entity bounce?
@@ -47,16 +47,17 @@ private static void onFall(LivingFallEvent event) {
       double gravity = living.getAttributeValue(ForgeMod.ENTITY_GRAVITY.get());
       double time = Math.sqrt(living.fallDistance / gravity);
       double velocity = gravity * time;
-      living.setDeltaMovement(motion.x / 0.95f, velocity, motion.z / 0.95f);
+      living.setDeltaMovement(motion.x / 0.975f, velocity, motion.z / 0.975f);
       living.hurtMarked = true;
 
       // preserve momentum
       SlimeBounceHandler.addBounceHandler(living);
     } else {
       // for non-players, need to defer the bounce
       // only slow down half as much when bouncing
-      living.setDeltaMovement(motion.x / 0.95f, motion.y * -0.9, motion.z / 0.95f);
-      SlimeBounceHandler.addBounceHandler(living, living.getDeltaMovement().y);
+      float factor = living.fallDistance < 2 ? -0.7f : -0.9f;
+      living.setDeltaMovement(motion.x / 0.975f, motion.y * factor, motion.z / 0.975f);
+      SlimeBounceHandler.addBounceHandler(living, living.getDeltaMovement());
     }
     // update airborn status
     event.setDistance(0.0F);