The bag of holding will now affect the player's gravity (weight)

src/main/java/com/minelittlepony/unicopia/command/GravityCommand.java

@@ -54,7 +54,7 @@ class GravityCommand {
 
         Pony iplayer = Pony.of(player);
 
-        iplayer.getPhysics().setGravityModifier(gravity);
+        iplayer.getPhysics().setBaseGravityModifier(gravity);
         iplayer.setDirty();
 
         if (isSelf) {

src/main/java/com/minelittlepony/unicopia/entity/EntityPhysics.java

@@ -30,33 +30,34 @@ public class EntityPhysics<T extends Ponylike<?> & Owned<? extends Entity>> impl
 
     @Override
     public double calcGravity(double worldConstant) {
-        return worldConstant * gravity;
+        return worldConstant * getGravityModifier();
     }
 
     @Override
     public BlockPos getHeadPosition() {
 
-        pony.getOwner().onGround = false;
+        Entity entity = pony.getOwner();
 
-        int i = MathHelper.floor(pony.getOwner().getX());
-        int j = MathHelper.floor(pony.getOwner().getY() + pony.getOwner().getHeight() + 0.20000000298023224D);
-        int k = MathHelper.floor(pony.getOwner().getZ());
+        entity.onGround = false;
 
-        BlockPos blockPos = new BlockPos(i, j, k);
+        BlockPos pos = new BlockPos(
+                MathHelper.floor(entity.getX()),
+                MathHelper.floor(entity.getY() + entity.getHeight() + 0.20000000298023224D),
+                MathHelper.floor(entity.getZ())
+        );
 
-        if (pony.getOwner().world.getBlockState(blockPos).isAir()) {
-            BlockPos blockPos2 = blockPos.down();
-            BlockState blockState = pony.getOwner().world.getBlockState(blockPos2);
-            Block block = blockState.getBlock();
+        if (entity.world.getBlockState(pos).isAir()) {
+            BlockPos below = pos.down();
+            Block block = entity.world.getBlockState(below).getBlock();
             if (block.matches(BlockTags.FENCES) || block.matches(BlockTags.WALLS) || block instanceof FenceGateBlock) {
-                pony.getOwner().onGround = true;
-                return blockPos2;
+                entity.onGround = true;
+                return below;
             }
         } else {
             pony.getOwner().onGround = true;
         }
 
-        return blockPos;
+        return pos;
     }
 
     @Override
@@ -74,7 +75,7 @@ public class EntityPhysics<T extends Ponylike<?> & Owned<? extends Entity>> impl
     }
 
     @Override
-    public void setGravityModifier(float constant) {
+    public void setBaseGravityModifier(float constant) {
         gravity = constant;
     }
 

src/main/java/com/minelittlepony/unicopia/entity/Physics.java

@@ -10,7 +10,7 @@ public interface Physics extends NbtSerialisable {
 
     float getGravityModifier();
 
-    void setGravityModifier(float constant);
+    void setBaseGravityModifier(float constant);
 
     boolean isFlying();
 

src/main/java/com/minelittlepony/unicopia/entity/player/PlayerAttributes.java

@@ -3,7 +3,6 @@ package com.minelittlepony.unicopia.entity.player;
 import java.util.UUID;
 
 import com.minelittlepony.unicopia.Race;
-import com.minelittlepony.unicopia.container.HeavyInventory;
 import com.minelittlepony.unicopia.mixin.Walker;
 
 import net.minecraft.entity.attribute.ClampedEntityAttribute;
@@ -25,12 +24,11 @@ class PlayerAttributes {
     private static final EntityAttributeModifier PEGASUS_REACH =
             new EntityAttributeModifier(UUID.fromString("707b50a8-03e8-40f4-8553-ecf67025fd6d"), "Pegasus Reach", 1.5, Operation.ADDITION);
 
-    private double loadStrength = 0;
+    public void applyAttributes(Pony pony) {
+        PlayerEntity entity = pony.getOwner();
+        Race race = pony.getSpecies();
 
-    public void applyAttributes(PlayerEntity entity, Race race) {
-        loadStrength = HeavyInventory.getContentsTotalWorth(entity.inventory, false);
-
-        ((Walker)entity.abilities).setWalkSpeed(0.1F - (float)(loadStrength / 100000));
+        ((Walker)entity.abilities).setWalkSpeed(0.1F - (float)pony.getInventory().getCarryingWeight());
 
         toggleAttribute(entity, EntityAttributes.ATTACK_DAMAGE, EARTH_PONY_STRENGTH, race.canUseEarth());
         toggleAttribute(entity, EntityAttributes.KNOCKBACK_RESISTANCE, EARTH_PONY_STRENGTH, race.canUseEarth());

src/main/java/com/minelittlepony/unicopia/entity/player/PlayerInventory.java

@@ -4,6 +4,7 @@ import java.util.Iterator;
 import java.util.Map;
 
 import com.google.common.collect.Maps;
+import com.minelittlepony.unicopia.container.HeavyInventory;
 import com.minelittlepony.unicopia.item.MagicGemItem;
 import com.minelittlepony.unicopia.magic.AddictiveMagicalItem;
 import com.minelittlepony.unicopia.magic.MagicalItem;
@@ -23,6 +24,8 @@ public class PlayerInventory implements Tickable, NbtSerialisable {
 
     private final Pony player;
 
+    private double carryingWeight;
+
     PlayerInventory(Pony player) {
         this.player = player;
     }
@@ -67,6 +70,7 @@ public class PlayerInventory implements Tickable, NbtSerialisable {
 
     @Override
     public synchronized void tick() {
+        carryingWeight = HeavyInventory.getContentsTotalWorth(player.getOwner().inventory, false);
 
         Iterator<Map.Entry<AddictiveMagicalItem, Entry>> iterator = dependencies.entrySet().iterator();
 
@@ -106,6 +110,10 @@ public class PlayerInventory implements Tickable, NbtSerialisable {
         return false;
     }
 
+    public double getCarryingWeight() {
+        return carryingWeight / 100000D;
+    }
+
     @Override
     public void toNBT(CompoundTag compound) {
         ListTag items = new ListTag();
@@ -115,6 +123,7 @@ public class PlayerInventory implements Tickable, NbtSerialisable {
         }
 
         compound.put("dependencies", items);
+        compound.putDouble("weight", carryingWeight);
     }
 
     @Override
@@ -130,6 +139,7 @@ public class PlayerInventory implements Tickable, NbtSerialisable {
                 dependencies.put(entry.item, entry);
             }
         });
+        carryingWeight = compound.getDouble("weight");
     }
 
     class Entry implements Tickable, NbtSerialisable {

src/main/java/com/minelittlepony/unicopia/entity/player/PlayerPhysics.java

@@ -42,6 +42,15 @@ public class PlayerPhysics extends EntityPhysics<Pony> implements Tickable, Moti
         dimensions = new PlayerDimensions(pony, this);
     }
 
+    @Override
+    public float getGravityModifier() {
+        float modifier = super.getGravityModifier();
+
+        modifier *= (1 + pony.getInventory().getCarryingWeight() * 3);
+
+        return modifier;
+    }
+
     private boolean checkCanFly() {
         if (pony.getOwner().abilities.creativeMode) {
             return true;

src/main/java/com/minelittlepony/unicopia/entity/player/Pony.java

@@ -246,7 +246,7 @@ public class Pony implements Caster<PlayerEntity>, Ponylike<PlayerEntity>, Trans
         mana.addExertion(-1);
         mana.addEnergy(-1);
 
-        attributes.applyAttributes(entity, getSpecies());
+        attributes.applyAttributes(this);
 
         if (dirty) {
             sendCapabilities(true);