Simplify usage of IItemRenderProperties::getArmorModel (#8349)

src/main/java/net/minecraftforge/client/ForgeHooksClient.java

@@ -26,6 +26,7 @@ import com.mojang.datafixers.util.Either;
 import net.minecraft.client.gui.chat.NarratorChatListener;
 import net.minecraft.client.gui.screens.inventory.tooltip.ClientTooltipComponent;
 import net.minecraft.client.gui.screens.multiplayer.JoinMultiplayerScreen;
+import net.minecraft.client.model.Model;
 import net.minecraft.client.model.geom.ModelLayerLocation;
 import net.minecraft.client.model.geom.builders.LayerDefinition;
 import net.minecraft.client.multiplayer.ClientLevel;
@@ -279,10 +280,24 @@ public class ForgeHooksClient
         renderType.set(layer);
     }
 
-    public static <A extends HumanoidModel<?>> A getArmorModel(LivingEntity entityLiving, ItemStack itemStack, EquipmentSlot slot, A _default)
+    public static Model getArmorModel(LivingEntity entityLiving, ItemStack itemStack, EquipmentSlot slot, HumanoidModel<?> _default)
     {
-        A model = RenderProperties.get(itemStack).getArmorModel(entityLiving, itemStack, slot, _default);
-        return model == null ? _default : model;
+        return RenderProperties.get(itemStack).getBaseArmorModel(entityLiving, itemStack, slot, _default);
+    }
+
+    /** Copies humanoid model properties from the original model to another, used for armor models */
+    @SuppressWarnings("unchecked")
+    public static <T extends LivingEntity> void copyModelProperties(HumanoidModel<T> original, HumanoidModel<?> replacement)
+    {
+        // this function does not make use of the <T> generic, so the unchecked cast should be safe
+        original.copyPropertiesTo((HumanoidModel<T>)replacement);
+        replacement.head.visible = original.head.visible;
+        replacement.hat.visible = original.hat.visible;
+        replacement.body.visible = original.body.visible;
+        replacement.rightArm.visible = original.rightArm.visible;
+        replacement.leftArm.visible = original.leftArm.visible;
+        replacement.rightLeg.visible = original.rightLeg.visible;
+        replacement.leftLeg.visible = original.leftLeg.visible;
     }
 
     //This properly moves the domain, if provided, to the front of the string before concatenating

src/main/java/net/minecraftforge/client/IItemRenderProperties.java

@@ -22,12 +22,16 @@ package net.minecraftforge.client;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.Font;
 import net.minecraft.client.model.HumanoidModel;
+import net.minecraft.client.model.Model;
 import net.minecraft.client.renderer.BlockEntityWithoutLevelRenderer;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
 public interface IItemRenderProperties
 {
     IItemRenderProperties DUMMY = new IItemRenderProperties()
@@ -53,13 +57,40 @@ public interface IItemRenderProperties
      * @param itemStack    The itemStack to render the model of
      * @param armorSlot    The slot the armor is in
      * @param _default     Original armor model. Will have attributes set.
-     * @return A ModelBiped to render instead of the default
+     * @return A HumanoidModel to render instead of the default, will have the relevant properties copied in {@link #getBaseArmorModel(LivingEntity, ItemStack, EquipmentSlot, HumanoidModel).
+     *         Returning null will cause the default to render.
+     * @see #getBaseArmorModel(LivingEntity, ItemStack, EquipmentSlot, HumanoidModel)
      */
-    default <A extends HumanoidModel<?>> A getArmorModel(LivingEntity entityLiving, ItemStack itemStack, EquipmentSlot armorSlot, A _default)
+    @Nullable
+    default HumanoidModel<?> getArmorModel(LivingEntity entityLiving, ItemStack itemStack, EquipmentSlot armorSlot, HumanoidModel<?> _default)
     {
         return null;
     }
 
+    /**
+     * Override this method to return a generic model rather than a {@link HumanoidModel}. More ideal for wrapping the original model or returning non-standard models like elytra wings.
+     * By default, this hook copies in the model properties from the default into the model returned by {@link #getArmorModel(LivingEntity, ItemStack, EquipmentSlot, HumanoidModel)},
+     * so if you override this method you are responsible for copying properties you care about
+     *
+     * @param entityLiving The entity wearing the armor
+     * @param itemStack    The itemStack to render the model of
+     * @param armorSlot    The slot the armor is in
+     * @param _default     Original armor model. Will have attributes set.
+     * @return A Model to render instead of the default
+     * @see #getArmorModel(LivingEntity, ItemStack, EquipmentSlot, HumanoidModel)
+     */
+    @Nonnull
+    default Model getBaseArmorModel(LivingEntity entityLiving, ItemStack itemStack, EquipmentSlot armorSlot, HumanoidModel<?> _default)
+    {
+        HumanoidModel<?> replacement = getArmorModel(entityLiving, itemStack, armorSlot, _default);
+        if (replacement != null && replacement != _default)
+        {
+            ForgeHooksClient.copyModelProperties(_default, replacement);
+            return replacement;
+        }
+        return _default;
+    }
+
     /**
      * Called when the client starts rendering the HUD, for whatever item the player
      * currently has as a helmet. This is where pumpkins would render there overlay.