Implement scaling for display entities (#4111)

Author: DrZoddiak

src/mixins/java/org/spongepowered/common/mixin/api/minecraft/world/entity/DisplayMixin_API.java

@@ -24,11 +24,30 @@
  */
 package org.spongepowered.common.mixin.api.minecraft.world.entity;
 
+import net.minecraft.network.syncher.EntityDataAccessor;
 import net.minecraft.world.entity.Display;
+import org.joml.Vector3f;
 import org.spongepowered.api.entity.display.DisplayEntity;
+import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.math.vector.Vector3d;
 
 @Mixin(Display.class)
 public abstract class DisplayMixin_API extends EntityMixin_API implements DisplayEntity {
 
+    // @formatter:off
+    @Shadow @Final private static EntityDataAccessor<Vector3f> DATA_SCALE_ID;
+    // @formatter:on
+
+    @Override
+    public void setScale(Vector3d scale) {
+        entityData.set(DisplayMixin_API.DATA_SCALE_ID, new Vector3f((float) scale.x(), (float) scale.y(), (float) scale.z()));
+    }
+
+    @Override
+    public Vector3d scale() {
+        Vector3f scale = entityData.get(DisplayMixin_API.DATA_SCALE_ID);
+        return new Vector3d(scale.x, scale.y, scale.z);
+    }
 }

src/mixins/java/org/spongepowered/common/mixin/api/minecraft/world/entity/EntityMixin_API.java

@@ -30,6 +30,7 @@
 import net.minecraft.core.Registry;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.syncher.SynchedEntityData;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerPlayer;
@@ -87,6 +88,7 @@ public abstract class EntityMixin_API implements org.spongepowered.api.entity.En
     @Shadow protected UUID uuid;
     @Shadow @Final private net.minecraft.world.entity.EntityType<?> type;
     @Shadow private Level level;
+    @Shadow @Final protected SynchedEntityData entityData;
 
     @Shadow public abstract double shadow$getX();
     @Shadow public abstract double shadow$getY();

testplugins/src/main/java/org/spongepowered/test/entity/DisplayEntityTest.java

@@ -238,6 +238,7 @@ public void onRegisterCommand(final RegisterCommandEvent<Parameterized> event) {
                         player.world().spawnEntity(blockDisplay);
                         blockDisplay.offer(Keys.TELEPORT_DURATION, Ticks.of(20));
                         blockDisplay.setLocation(((ServerLocation) blockDisplay.location().add(0.0, 4.0, 0.0)));
+                        blockDisplay.setScale(new Vector3d(1.0,5.0,1.0));
 
 
                         textDisplay = createEntity(player.world(), EntityTypes.TEXT_DISPLAY, centerPos, forwardDir, col7, 0);