Add support for custom elytra (#7202)

patches/minecraft/net/minecraft/client/entity/player/ClientPlayerEntity.java.patch

@@ -46,6 +46,15 @@
        }
  
        if (flag1) {
+@@ -689,7 +697,7 @@
+ 
+       if (this.field_71158_b.field_78901_c && !flag7 && !flag && !this.field_71075_bZ.field_75100_b && !this.func_184218_aH() && !this.func_70617_f_()) {
+          ItemStack itemstack = this.func_184582_a(EquipmentSlotType.CHEST);
+-         if (itemstack.func_77973_b() == Items.field_185160_cR && ElytraItem.func_185069_d(itemstack) && this.func_226566_ei_()) {
++         if (itemstack.canElytraFly(this) && this.func_226566_ei_()) {
+             this.field_71174_a.func_147297_a(new CEntityActionPacket(this, CEntityActionPacket.Action.START_FALL_FLYING));
+          }
+       }
 @@ -985,4 +993,16 @@
           return this.field_204230_bP;
        }

patches/minecraft/net/minecraft/client/renderer/entity/layers/ElytraLayer.java.patch

@@ -0,0 +1,54 @@
+--- a/net/minecraft/client/renderer/entity/layers/ElytraLayer.java
++++ b/net/minecraft/client/renderer/entity/layers/ElytraLayer.java
+@@ -29,7 +29,7 @@
+ 
+    public void func_225628_a_(MatrixStack p_225628_1_, IRenderTypeBuffer p_225628_2_, int p_225628_3_, T p_225628_4_, float p_225628_5_, float p_225628_6_, float p_225628_7_, float p_225628_8_, float p_225628_9_, float p_225628_10_) {
+       ItemStack itemstack = p_225628_4_.func_184582_a(EquipmentSlotType.CHEST);
+-      if (itemstack.func_77973_b() == Items.field_185160_cR) {
++      if (shouldRender(itemstack, p_225628_4_)) {
+          ResourceLocation resourcelocation;
+          if (p_225628_4_ instanceof AbstractClientPlayerEntity) {
+             AbstractClientPlayerEntity abstractclientplayerentity = (AbstractClientPlayerEntity)p_225628_4_;
+@@ -38,10 +38,10 @@
+             } else if (abstractclientplayerentity.func_152122_n() && abstractclientplayerentity.func_110303_q() != null && abstractclientplayerentity.func_175148_a(PlayerModelPart.CAPE)) {
+                resourcelocation = abstractclientplayerentity.func_110303_q();
+             } else {
+-               resourcelocation = field_188355_a;
++               resourcelocation = getElytraTexture(itemstack, p_225628_4_);
+             }
+          } else {
+-            resourcelocation = field_188355_a;
++            resourcelocation = getElytraTexture(itemstack, p_225628_4_);
+          }
+ 
+          p_225628_1_.func_227860_a_();
+@@ -53,4 +53,29 @@
+          p_225628_1_.func_227865_b_();
+       }
+    }
++
++   /**
++    * Determines if the ElytraLayer should render.
++    * ItemStack and Entity are provided for modder convenience,
++    * For example, using the same ElytraLayer for multiple custom Elytra.
++    *
++    * @param stack  The Elytra ItemStack
++    * @param entity The entity being rendered.
++    * @return If the ElytraLayer should render.
++    */
++   public boolean shouldRender(ItemStack stack, T entity) {
++      return stack.func_77973_b() == Items.field_185160_cR;
++   }
++
++   /**
++    * Gets the texture to use with this ElytraLayer.
++    * This assumes the vanilla Elytra model.
++    *
++    * @param stack  The Elytra ItemStack.
++    * @param entity The entity being rendered.
++    * @return The texture.
++    */
++   public ResourceLocation getElytraTexture(ItemStack stack, T entity) {
++      return field_188355_a;
++   }
+ }

patches/minecraft/net/minecraft/entity/LivingEntity.java.patch

@@ -360,7 +360,16 @@
              if (map == null) {
                 map = Maps.newEnumMap(EquipmentSlotType.class);
              }
-@@ -2658,8 +2693,16 @@
+@@ -2434,6 +2469,8 @@
+       boolean flag = this.func_70083_f(7);
+       if (flag && !this.field_70122_E && !this.func_184218_aH() && !this.func_70644_a(Effects.field_188424_y)) {
+          ItemStack itemstack = this.func_184582_a(EquipmentSlotType.CHEST);
++         flag = itemstack.canElytraFly(this) && itemstack.elytraFlightTick(this, this.field_184629_bo);
++         if (false) //Forge: Moved to ElytraItem
+          if (itemstack.func_77973_b() == Items.field_185160_cR && ElytraItem.func_185069_d(itemstack)) {
+             flag = true;
+             if (!this.field_70170_p.field_72995_K && (this.field_184629_bo + 1) % 20 == 0) {
+@@ -2658,8 +2695,16 @@
  
     private void func_184608_ct() {
        if (this.func_184587_cr()) {
@@ -379,7 +388,7 @@
              this.field_184627_bm.func_222121_b(this.field_70170_p, this, this.func_184605_cv());
              if (this.func_226299_p_()) {
                 this.func_226293_b_(this.field_184627_bm, 5);
-@@ -2707,8 +2750,10 @@
+@@ -2707,8 +2752,10 @@
     public void func_184598_c(Hand p_184598_1_) {
        ItemStack itemstack = this.func_184586_b(p_184598_1_);
        if (!itemstack.func_190926_b() && !this.func_184587_cr()) {
@@ -391,7 +400,7 @@
           if (!this.field_70170_p.field_72995_K) {
              this.func_204802_c(1, true);
              this.func_204802_c(2, p_184598_1_ == Hand.OFF_HAND);
-@@ -2768,6 +2813,9 @@
+@@ -2768,6 +2815,9 @@
           vector3d1 = vector3d1.func_178789_a(-this.field_70125_A * ((float)Math.PI / 180F));
           vector3d1 = vector3d1.func_178785_b(-this.field_70177_z * ((float)Math.PI / 180F));
           vector3d1 = vector3d1.func_72441_c(this.func_226277_ct_(), this.func_226280_cw_(), this.func_226281_cx_());
@@ -401,7 +410,7 @@
           this.field_70170_p.func_195594_a(new ItemParticleData(ParticleTypes.field_197591_B, p_195062_1_), vector3d1.field_72450_a, vector3d1.field_72448_b, vector3d1.field_72449_c, vector3d.field_72450_a, vector3d.field_72448_b + 0.05D, vector3d.field_72449_c);
        }
  
-@@ -2779,7 +2827,9 @@
+@@ -2779,7 +2829,9 @@
        } else {
           if (!this.field_184627_bm.func_190926_b() && this.func_184587_cr()) {
              this.func_226293_b_(this.field_184627_bm, 16);
@@ -412,7 +421,7 @@
              this.func_184602_cy();
           }
  
-@@ -2800,7 +2850,11 @@
+@@ -2800,7 +2852,11 @@
  
     public void func_184597_cx() {
        if (!this.field_184627_bm.func_190926_b()) {
@@ -424,7 +433,7 @@
           if (this.field_184627_bm.func_222122_m()) {
              this.func_184608_ct();
           }
-@@ -2949,8 +3003,8 @@
+@@ -2949,8 +3005,8 @@
        }
  
        BlockState blockstate = this.field_70170_p.func_180495_p(p_213342_1_);
@@ -435,7 +444,7 @@
        }
  
        this.func_213301_b(Pose.SLEEPING);
-@@ -2966,15 +3020,15 @@
+@@ -2966,15 +3022,15 @@
  
     private boolean func_213359_p() {
        return this.func_213374_dv().map((p_241350_1_) -> {
@@ -454,7 +463,7 @@
              Vector3d vector3d1 = BedBlock.func_220172_a(this.func_200600_R(), this.field_70170_p, p_241348_1_, 0).orElseGet(() -> {
                 BlockPos blockpos = p_241348_1_.func_177984_a();
                 return new Vector3d((double)blockpos.func_177958_n() + 0.5D, (double)blockpos.func_177956_o() + 0.1D, (double)blockpos.func_177952_p() + 0.5D);
-@@ -2993,7 +3047,9 @@
+@@ -2993,7 +3049,9 @@
     @OnlyIn(Dist.CLIENT)
     public Direction func_213376_dz() {
        BlockPos blockpos = this.func_213374_dv().orElse((BlockPos)null);
@@ -465,7 +474,7 @@
     }
  
     public boolean func_70094_T() {
-@@ -3062,4 +3118,58 @@
+@@ -3062,4 +3120,58 @@
     public void func_213334_d(Hand p_213334_1_) {
        this.func_213361_c(p_213334_1_ == Hand.MAIN_HAND ? EquipmentSlotType.MAINHAND : EquipmentSlotType.OFFHAND);
     }

patches/minecraft/net/minecraft/entity/player/PlayerEntity.java.patch

@@ -257,6 +257,15 @@
           return false;
        } else {
           if (p_225503_1_ >= 2.0F) {
+@@ -1434,7 +1467,7 @@
+    public boolean func_226566_ei_() {
+       if (!this.field_70122_E && !this.func_184613_cA() && !this.func_70090_H() && !this.func_70644_a(Effects.field_188424_y)) {
+          ItemStack itemstack = this.func_184582_a(EquipmentSlotType.CHEST);
+-         if (itemstack.func_77973_b() == Items.field_185160_cR && ElytraItem.func_185069_d(itemstack)) {
++         if (itemstack.canElytraFly(this)) {
+             this.func_226567_ej_();
+             return true;
+          }
 @@ -1475,6 +1508,10 @@
     }
  

patches/minecraft/net/minecraft/item/ElytraItem.java.patch

@@ -0,0 +1,20 @@
+--- a/net/minecraft/item/ElytraItem.java
++++ b/net/minecraft/item/ElytraItem.java
+@@ -35,4 +35,17 @@
+          return ActionResult.func_226251_d_(itemstack);
+       }
+    }
++
++   @Override
++   public boolean canElytraFly(ItemStack stack, net.minecraft.entity.LivingEntity entity) {
++      return ElytraItem.func_185069_d(stack);
++   }
++
++   @Override
++   public boolean elytraFlightTick(ItemStack stack, net.minecraft.entity.LivingEntity entity, int flightTicks) {
++      if (!entity.field_70170_p.field_72995_K && (flightTicks + 1) % 20 == 0) {
++         stack.func_222118_a(1, entity, e -> e.func_213361_c(net.minecraft.inventory.EquipmentSlotType.CHEST));
++      }
++      return true;
++   }
+ }

src/main/java/net/minecraftforge/common/extensions/IForgeItem.java

@@ -819,4 +819,33 @@ public interface IForgeItem
         return stack.getItem() == Blocks.CARVED_PUMPKIN.asItem();
     }
 
+    /**
+     * Used to determine if the player can use Elytra flight.
+     * This is called Client and Server side.
+     *
+     * @param stack The ItemStack in the Chest slot of the entity.
+     * @param entity The entity trying to fly.
+     * @return True if the entity can use Elytra flight.
+     */
+    default boolean canElytraFly(ItemStack stack, LivingEntity entity)
+    {
+        return false;
+    }
+
+    /**
+     * Used to determine if the player can continue Elytra flight,
+     * this is called each tick, and can be used to apply ItemStack damage,
+     * consume Energy, or what have you.
+     * For example the Vanilla implementation of this, applies damage to the
+     * ItemStack every 20 ticks.
+     *
+     * @param stack       ItemStack in the Chest slot of the entity.
+     * @param entity      The entity currently in Elytra flight.
+     * @param flightTicks The number of ticks the entity has been Elytra flying for.
+     * @return True if the entity should continue Elytra flight or False to stop.
+     */
+    default boolean elytraFlightTick(ItemStack stack, LivingEntity entity, int flightTicks)
+    {
+        return false;
+    }
 }

src/main/java/net/minecraftforge/common/extensions/IForgeItemStack.java

@@ -476,4 +476,32 @@ public interface IForgeItemStack extends ICapabilitySerializable<CompoundNBT>
     {
         return getStack().getItem().isEnderMask(getStack(), player, endermanEntity);
     }
+
+    /**
+     * Used to determine if the player can use Elytra flight.
+     * This is called Client and Server side.
+     *
+     * @param entity The entity trying to fly.
+     * @return True if the entity can use Elytra flight.
+     */
+    default boolean canElytraFly(LivingEntity entity)
+    {
+        return getStack().getItem().canElytraFly(getStack(), entity);
+    }
+
+    /**
+     * Used to determine if the player can continue Elytra flight,
+     * this is called each tick, and can be used to apply ItemStack damage,
+     * consume Energy, or what have you.
+     * For example the Vanilla implementation of this, applies damage to the
+     * ItemStack every 20 ticks.
+     *
+     * @param entity      The entity currently in Elytra flight.
+     * @param flightTicks The number of ticks the entity has been Elytra flying for.
+     * @return True if the entity should continue Elytra flight or False to stop.
+     */
+    default boolean elytraFlightTick(LivingEntity entity, int flightTicks)
+    {
+        return getStack().getItem().elytraFlightTick(getStack(), entity, flightTicks);
+    }
 }

src/test/java/net/minecraftforge/debug/item/CustomElytraTest.java

@@ -0,0 +1,132 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.debug.item;
+
+import net.minecraft.block.DispenserBlock;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.entity.player.AbstractClientPlayerEntity;
+import net.minecraft.client.renderer.entity.IEntityRenderer;
+import net.minecraft.client.renderer.entity.PlayerRenderer;
+import net.minecraft.client.renderer.entity.layers.ElytraLayer;
+import net.minecraft.client.renderer.entity.model.ElytraModel;
+import net.minecraft.client.renderer.entity.model.PlayerModel;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.inventory.EquipmentSlotType;
+import net.minecraft.item.*;
+import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.SoundEvent;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
+import net.minecraftforge.eventbus.api.IEventBus;
+import net.minecraftforge.fml.DistExecutor;
+import net.minecraftforge.fml.RegistryObject;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.thread.EffectiveSide;
+import net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent;
+import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
+import net.minecraftforge.registries.DeferredRegister;
+import net.minecraftforge.registries.ForgeRegistries;
+
+import javax.annotation.Nullable;
+
+@Mod(CustomElytraTest.MOD_ID)
+@Mod.EventBusSubscriber(bus = Mod.EventBusSubscriber.Bus.MOD, modid = CustomElytraTest.MOD_ID)
+public class CustomElytraTest
+{
+    public static final String MOD_ID = "custom_elytra_test";
+    private static final DeferredRegister<Item> ITEMS = DeferredRegister.create(ForgeRegistries.ITEMS, MOD_ID);
+    private static final RegistryObject<Item> TEST_ELYTRA = ITEMS.register("test_elytra",() -> new CustomElytra(new Item.Properties().maxDamage(100).group(ItemGroup.MISC)));
+
+    public CustomElytraTest()
+    {
+        final IEventBus modBus = FMLJavaModLoadingContext.get().getModEventBus();
+        ITEMS.register(modBus);
+        modBus.addListener(this::onClientSetup);
+    }
+
+    private void onClientSetup(FMLClientSetupEvent event)
+    {
+        registerElytraLayer();
+    }
+
+    @OnlyIn(Dist.CLIENT)
+    private void registerElytraLayer()
+    {
+        Minecraft.getInstance().getRenderManager().getSkinMap().values().forEach(player -> player.addLayer(new CustomElytraLayer(player)));
+    }
+
+    public static class CustomElytra extends Item
+    {
+
+        public CustomElytra(Properties properties)
+        {
+            super(properties);
+            DispenserBlock.registerDispenseBehavior(this, ArmorItem.DISPENSER_BEHAVIOR);
+        }
+
+        @Nullable
+        @Override
+        public EquipmentSlotType getEquipmentSlot(ItemStack stack)
+        {
+            return EquipmentSlotType.CHEST; //Or you could just extend ItemArmor
+        }
+
+        @Override
+        public boolean canElytraFly(ItemStack stack, LivingEntity entity)
+        {
+            return true;
+        }
+
+        @Override
+        public boolean elytraFlightTick(ItemStack stack, LivingEntity entity, int flightTicks)
+        {
+            //Adding 1 to ticksElytraFlying prevents damage on the very first tick.
+            if (!entity.world.isRemote && (flightTicks + 1) % 20 == 0)
+            {
+                stack.damageItem(1, entity, e -> e.sendBreakAnimation(EquipmentSlotType.CHEST));
+            }
+            return true;
+        }
+    }
+
+    @OnlyIn(Dist.CLIENT)
+    public static class CustomElytraLayer extends ElytraLayer<AbstractClientPlayerEntity, PlayerModel<AbstractClientPlayerEntity>>
+    {
+        private static final ResourceLocation TEXTURE_ELYTRA = new ResourceLocation(MOD_ID, "textures/entity/custom_elytra.png");
+
+        public CustomElytraLayer(IEntityRenderer<AbstractClientPlayerEntity, PlayerModel<AbstractClientPlayerEntity>> rendererIn)
+        {
+            super(rendererIn);
+        }
+
+        @Override
+        public boolean shouldRender(ItemStack stack, AbstractClientPlayerEntity entity)
+        {
+            return stack.getItem() == TEST_ELYTRA.get();
+        }
+
+        @Override
+        public ResourceLocation getElytraTexture(ItemStack stack, AbstractClientPlayerEntity entity)
+        {
+            return TEXTURE_ELYTRA;
+        }
+    }
+}

src/test/resources/META-INF/mods.toml

@@ -76,3 +76,5 @@ license="LGPL v2.1"
     modId="player_name_event_test"
 [[mods]]
     modId="modded_overworld_biomes_test"
+[[mods]]
+    modId="custom_elytra_test"

src/test/resources/assets/custom_elytra_test/models/item/test_elytra.json

@@ -0,0 +1,6 @@
+{
+  "parent": "item/generated",
+  "textures": {
+    "layer0": "custom_elytra_test:item/custom_elytra"
+  }
+}