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--- tutorial:fluids [2019/09/24 11:28] – client side operations (rendering) alexiy
+++ tutorial:fluids [2020/01/18 15:40] – Update tutorial to 1.15.1 + some cleanup virtuoel
@@ Line 1: / Line 1: @@
 ====== Creating a fluid ======
 ===== Overview =====
 Here we'll cover creation of a custom fluid. If you plan to create several fluids, it is recommended to make an abstract basic fluid class where you'll set necessary defaults that will be shared in its subclasses. We'll also make it generate in the world like lakes.
 ===== Making an abstract fluid =====
-Vanilla fluids extend **net.minecraft.fluid.BaseFluid** class, and so will our abstract fluid. It can be like this:
+Vanilla fluids extend ''net.minecraft.fluid.BaseFluid'', and so shall we.
-<code java>
+<code java [enable_line_numbers="true"]>
-public abstract class BasicFluid extends BaseFluid
+public abstract class TutorialFluid extends BaseFluid
 {
-    /**
+	/**
-     * @return does it produce infinite fluid (like water)?
+	 * @return is the given fluid an instance of this fluid?
-     */
+	 */
-    @Override
+	@Override
-    protected boolean isInfinite()
+	public boolean matchesType(Fluid fluid)
-    {
+	{
-        return false;
+		return fluid == getStill() || fluid == getFlowing();
-    }
+	}
-    // make it transparent
+	/**
-    @Override
+	 * @return is the fluid infinite like water?
-    protected BlockRenderLayer getRenderLayer()
+	 */
-    {
+	@Override
-        return BlockRenderLayer.TRANSLUCENT;
+	protected boolean isInfinite()
-    }
+	{
+		return false;
-    /**
+	}
-     *
-     * @return an associated item that "holds" this fluid
+	/**
-     */
+	 * Perform actions when fluid flows into a replaceable block. Water drops
-    @Override
+	 * the block's loot table. Lava plays the "block.lava.extinguish" sound.
-    public abstract Item getBucketItem();
+	 */
+	@Override
-    /**
+	protected void beforeBreakingBlock(IWorld world, BlockPos pos, BlockState state)
-     *
+	{
-     * @return a blockstate of the associated {@linkplain net.minecraft.block.FluidBlock} with {@linkplain net.minecraft.block.FluidBlock#LEVEL}
+		final BlockEntity blockEntity = state.getBlock().hasBlockEntity() ? world.getBlockEntity(pos) : null;
-     */
+		Block.dropStacks(state, world.getWorld(), pos, blockEntity);
-    @Override
+	}
-    protected abstract BlockState toBlockState(FluidState var1);
+	/**
-    /**
+	 * Lava returns true if its FluidState is above a certain height and the
-     *
+	 * Fluid is Water.
-     * @return flowing static instance of this fluid
+	 *
-     */
+	 * @return if the given Fluid can flow into this FluidState?
-    @Override
+	 */
-    public abstract Fluid getFlowing();
+	@Override
+	protected boolean method_15777(FluidState fluidState, BlockView blockView, BlockPos blockPos, Fluid fluid, Direction direction)
-    /**
+	{
-     *
+		return false;
-     * @return still static instance of this fluid
+	}
-     */
-    @Override
+	/**
-    public abstract Fluid getStill();
+	 * Possibly related to the distance checks for flowing into nearby holes?
+	 * Water returns 4. Lava returns 2 in the Overworld and 4 in the Nether.
-    // how much does the height of the fluid block decreases
+	 */
-    @Override
+	@Override
-    protected int getLevelDecreasePerBlock(ViewableWorld var1)
+	protected int method_15733(WorldView worldView)
-    {
+	{
-        return 1;
+		return 4;
-    }
+	}
-    /**
+	/**
-     *
+	 * Water returns 1. Lava returns 1 in the Overworld and 2 in the Nether.
-     * @return update rate
+	 */
-     */
+	@Override
-    @Override
+	protected int getLevelDecreasePerBlock(WorldView worldView)
-    public int getTickRate(ViewableWorld var1)
+	{
-    {
+		return 1;
-        return 5;
+	}
-    }
+	/**
-    @Override
+	 * Water returns 5. Lava returns 30 in the Overworld and 10 in the Nether.
-    protected float getBlastResistance()
+	 */
-    {
+	@Override
-        return 100;
+	public int getTickRate(WorldView worldView)
-    }
+	{
+		return 5;
-    // this seems to determine fluid's spread speed (higher value means faster)
+	}
-    @Override
-    protected int method_15733(ViewableWorld var1)
+	/**
-    {
+	 * Water and Lava both return 100.0F.
-        return 4;
+	 */
-    }
+	@Override
+	protected float getBlastResistance()
-    // I don't know what this does, but it's present in the water fluid
+	{
-    @Override
+		return 100.0F;
-    protected void beforeBreakingBlock(IWorld iWorld_1, BlockPos blockPos_1, BlockState blockState_1) {
+	}
-        BlockEntity blockEntity_1 = blockState_1.getBlock().hasBlockEntity() ? iWorld_1.getBlockEntity(blockPos_1) : null;
-        Block.dropStacks(blockState_1, iWorld_1.getWorld(), blockPos_1, blockEntity_1);
-    }
-    // also don't know what it does
-    public boolean method_15777(FluidState fluidState_1, BlockView blockView_1, BlockPos blockPos_1, Fluid fluid_1, Direction direction_1) {
-        return direction_1 == Direction.DOWN;
-    }
-    /**
-     *
-     * @return is given fluid instance of this fluid?
-     */
-    @Override
-    public abstract boolean matchesType(Fluid fluid_1);
-    /**
-     * Required for entities to behave in this fluid like in water
-     */
-    @Override
-    public boolean matches(Tag<Fluid> tag_1)
-    {
-        return tag_1 == FluidTags.WATER;
-    }
 }
 </code>
 ===== Implementation =====
-Now let's make an actual fluid; it will have a //still// and //flowing// variants; will name it "Acid":
+Now let's make an actual fluid which'll have still and flowing variants. For this tutorial, we will call it Acid. The missing references will be filled in shortly.
-<code java>
+<code java [enable_line_numbers="true"]>
-public abstract class Acid extends BasicFluid
+public abstract class AcidFluid extends TutorialFluid
 {
-    @Override
+	@Override
-    public Item getBucketItem()
+	public Fluid getStill()
-    {
+	{
-        return null;
+		return <YOUR_STILL_FLUID_HERE>;
-    }
+	}
-    @Override
-    protected BlockState toBlockState(FluidState var1)
+	@Override
-    {
+	public Fluid getFlowing()
-        return null;
+	{
-    }
+		return <YOUR_FLOWING_FLUID_HERE>;
+	}
+	@Override
+	public Item getBucketItem()
+	{
+		return <YOUR_BUCKET_ITEM_HERE>;
+	}
+	@Override
+	protected BlockState toBlockState(FluidState fluidState)
+	{
+		// method_15741 converts the LEVEL_1_8 of the fluid state to the LEVEL_15 the fluid block uses
+		return <YOUR_FLUID_BLOCK_HERE>.getDefaultState().with(Properties.LEVEL_15, method_15741(fluidState));
+	}
+	public static class Flowing extends AcidFluid
+	{
+		@Override
+		protected void appendProperties(StateManager.Builder<Fluid, FluidState> builder)
+		{
+			super.appendProperties(builder);
+			builder.add(LEVEL);
+		}
+		@Override
+		public int getLevel(FluidState fluidState)
+		{
+			return fluidState.get(LEVEL);
+		}
+		@Override
+		public boolean isStill(FluidState fluidState)
+		{
+			return false;
+		}
+	}
+	public static class Still extends AcidFluid
+	{
+		@Override
+		public int getLevel(FluidState fluidState)
+		{
+			return 8;
+		}
+		@Override
+		public boolean isStill(FluidState fluidState)
+		{
+			return true;
+		}
+	}
+}
+</code>
-    @Override
+Next, we'll make static instances of still and flowing acid variants, and an acid bucket. In your ''ModInitializer'':
-    public Fluid getFlowing()
-    {
-        return null;
-    }
-    @Override
+<code java [enable_line_numbers="true"]>
-    public Fluid getStill()
+// ...
-    {
-        return null;
-    }
-    @Override
+public static BaseFluid STILL_ACID;
-    public boolean matchesType(Fluid fluid_1)
+public static BaseFluid FLOWING_ACID;
-    {
-        return false;
-    }
-    // still acid
+public static Item ACID_BUCKET;
-    public static class Still extends Acid
-    {
-        @Override
+// ...
-        public boolean isStill(FluidState fluidState)
-        {
-            return true;
-        }
-        /**
+@Override
-         * @return height of the fluid block
+public void onInitialize()
-         */
+{
-        @Override
+	// ...
-        public int getLevel(FluidState fluidState)
-        {
+	STILL_ACID = Registry.FLUID.add(new Identifier(MOD_ID, "acid"), new AcidFluid.Still());
-            return 8;
-        }
+	FLOWING_ACID = Registry.FLUID.add(new Identifier(MOD_ID, "flowing_acid"), new AcidFluid.Flowing());
-    }
+	ACID_BUCKET = Registry.ITEM.add(new Identifier(MOD_ID, "acid_bucket"), new BucketItem(STILL_ACID, new Item.Settings().recipeRemainder(Items.BUCKET).maxCount(1)));
+	// ...
+}
-    // flowing acid
+// ...
-    public static class Flowing extends  Acid
+</code>
-    {
-        @Override
+To make a custom fluid behave more like water or lava, you must add it to a corresponding fluid tag: For water, make a ''data/minecraft/tags/fluids/water.json'' file and write the identifiers of your fluids in there:
-        public boolean isStill(FluidState fluidState)
+<code json [enable_line_numbers="true"]>
-        {
+{
-            return false;
+	"replace": false,
-        }
+	"values":
+	[
-        /**
+		"your_mod_id:acid",
-         * @return height of the fluid block
+		"your_mod_id:flowing_acid"
-         */
+	]
-        @Override
-        public int getLevel(FluidState fluidState)
-        {
-            return fluidState.get(LEVEL);
-        }
-        @Override
-        protected void appendProperties(StateFactory.Builder<Fluid, FluidState> stateFactory$Builder_1)
-        {
-            super.appendProperties(stateFactory$Builder_1);
-            stateFactory$Builder_1.add(LEVEL);
-        }
-    }
 }
 </code>
-Next, we'll make static instances of still and flowing acid variants, and an acid bucket. In your **ModInitializer**:
+===== Making a fluid block =====
+Next we need to create a block which will represent acid in the world. ''net.minecraft.block.FluidBlock'' is the class we need to use, but since its constructor is protected, we can't construct it directly. Some ways to use it are to make a subclass or an anonymous subclass. Here we will be showing the latter. In your ''ModInitializer'':
-<code java>
+<code java [enable_line_numbers="true"]>
+// ...
+public static Block ACID;
-    public static Acid stillAcid;
-    public static Acid flowingAcid;
-    public static BucketItem acidBucket;
-    @Override
+// ...
-    public void onInitialize()
-    {
-        stillAcid = Registry.register(Registry.FLUID,new Identifier(MODID,"acid_still"),new Acid.Still());
-        flowingAcid = Registry.register(Registry.FLUID,new Identifier(MODID,"acid_flowing"),new Acid.Flowing());
-        acidBucket=new BucketItem(stillAcid,new Item.Settings().maxCount(1));
-        Registry.register(Registry.ITEM,new Identifier(MODID,"acid_bucket"),acidBucket);
-    }
-</code>
-==== Making a fluid block ====
-Next we need to create a block which will represent acid in the world. **net.minecraft.block.FluidBlock** is the class we need to use, but for "mojang" reasons its constructor is protected. The solution is well-known - make a subclass of it and change the visibility of the constructor:
-<code java>
+@Override
-public class BaseFluidBlock extends FluidBlock
+public void onInitialize()
 {
-    public BaseFluidBlock(BaseFluid fluid, Settings settings)
+	// ...
-    {
-        super(fluid, settings);
+	ACID = Registry.BLOCK.add(new Identifier(MOD_ID, "acid"), new FluidBlock(STILL_ACID, FabricBlockSettings.copy(Blocks.WATER).build()){});
-    }
+	// ...
 }
+// ...
 </code>
-Now make a static block instance:
+Now that we have these static objects, we can go back to ''AcidFluid'' and fill in the overridden methods:
-<code java>
+<code java [enable_line_numbers="true"]>
-    ...
+public abstract class AcidFluid extends TutorialFluid
+{
-    public static FluidBlock acid;
+	@Override
+	public Fluid getStill()
-    @Override
+	{
-    public void onInitialize()
+		return TutorialMod.STILL_ACID;
-    {
+	}
-        ...
+	@Override
+	public Fluid getFlowing()
-        acid=new BaseFluidBlock(stillAcid,FabricBlockSettings.of(Material.WATER).dropsNothing().build());
+	{
-        Registry.register(Registry.BLOCK,new Identifier(MODID,"acid_block"),acid);
+		return TutorialMod.FLOWING_ACID;
-    }
+	}
+	@Override
+	public Item getBucketItem()
+	{
+		return TutorialMod.ACID_BUCKET;
+	}
+	@Override
+	protected BlockState toBlockState(FluidState fluidState)
+	{
+		// method_15741 converts the LEVEL_1_8 of the fluid state to the LEVEL_15 the fluid block uses
+		return TutorialMod.ACID.getDefaultState().with(Properties.LEVEL_15, method_15741(fluidState));
+	}
+	// ...
+}
 </code>
-Now when we have these static objects, we go back to **Acid** class and complete the overridden methods:
+===== Rendering setup =====
+For your fluids to have textures or be tinted with a color, you will need to register a ''FluidRenderHandler'' for them. Here, we will reuse water's textures and just change the tint color applied to them. To make sure the textures are rendered as translucent, you can use Fabric's ''BlockRenderLayerMap''.
-<code java>
+<code java [enable_line_numbers="true"]>
-public abstract class Acid extends BasicFluid
+public class TutorialModClient implements ClientModInitializer
 {
-    @Override
+	// ...
-    public Item getBucketItem()
-    {
+	@Override
-        return [ModInitializer].acidBucket;
+	public void onInitializeClient()
-    }
+	{
+		// ...
-    @Override
-    protected BlockState toBlockState(FluidState fluidState)
+		setupFluidRendering(TutorialMod.STILL_ACID, TutorialMod.FLOWING_ACID, new Identifier("minecraft", "water"), 0x4CC248);
-    {
+		BlockRenderLayerMap.INSTANCE.putFluids(RenderLayer.getTranslucent(), TutorialMod.STILL_ACID, TutorialMod.FLOWING_ACID);
-        //don't ask me what **method_15741** does...
-        return [ModInitializer].acid.getDefaultState().with(FluidBlock.LEVEL,method_15741(fluidState));
+		// ...
-    }
+	}
-    @Override
+	// ...
-    public Fluid getFlowing()
-    {
+	public static void setupFluidRendering(final Fluid still, final Fluid flowing, final Identifier textureFluidId, final int color)
-        return [ModInitializer].flowingAcid;
+	{
-    }
+		final Identifier stillSpriteId = new Identifier(textureFluidId.getNamespace(), "block/" + textureFluidId.getPath() + "_still");
+		final Identifier flowingSpriteId = new Identifier(textureFluidId.getNamespace(), "block/" + textureFluidId.getPath() + "_flow");
-    @Override
-    public Fluid getStill()
+		// If they're not already present, add the sprites to the block atlas
-    {
+		ClientSpriteRegistryCallback.event(SpriteAtlasTexture.BLOCK_ATLAS_TEX).register((atlasTexture, registry) ->
-        return [ModInitializer].stillAcid;
+		{
-    }
+			registry.register(stillSpriteId);
+			registry.register(flowingSpriteId);
-    @Override
+		});
-    public boolean matchesType(Fluid fluid_1)
-    {
+		final Identifier fluidId = Registry.FLUID.getId(still);
-        return fluid_1==[ModInitializer].flowingAcid || fluid_1==[ModInitializer].stillAcid;
+		final Identifier listenerId = new Identifier(fluidId.getNamespace(), fluidId.getPath() + "_reload_listener");
-    }
+		final Sprite[] fluidSprites = new Sprite[] { null, null };
-    ...
+		ResourceManagerHelper.get(ResourceType.CLIENT_RESOURCES).registerReloadListener(new SimpleSynchronousResourceReloadListener()
-}
+		{
+			@Override
+			public Identifier getFabricId()
+			{
+				return listenerId;
+			}
+			/**
+			 * Get the sprites from the block atlas when resources are reloaded
+			 */
+			@Override
+			public void apply(ResourceManager resourceManager)
+			{
+				final Function<Identifier, Sprite> atlas = MinecraftClient.getInstance().getSpriteAtlas(SpriteAtlasTexture.BLOCK_ATLAS_TEX);
+				fluidSprites[0] = atlas.apply(stillSpriteId);
+				fluidSprites[1] = atlas.apply(flowingSpriteId);
+			}
+		});
+		// The FluidRenderer gets the sprites and color from a FluidRenderHandler during rendering
+		final FluidRenderHandler renderHandler = new FluidRenderHandler()
+		{
+			@Override
+			public Sprite[] getFluidSprites(BlockRenderView view, BlockPos pos, FluidState state)
+			{
+				return fluidSprites;
+			}
+			@Override
+			public int getFluidColor(BlockRenderView view, BlockPos pos, FluidState state)
+			{
+				return color;
+			}
+		};
+		FluidRenderHandlerRegistry.INSTANCE.register(still, renderHandler);
+		FluidRenderHandlerRegistry.INSTANCE.register(flowing, renderHandler);
+	}
+	// ...
+}
 </code>
-Now we can assert that the Acid class is complete.
+If you want to use your own fluid textures, you can refer to vanilla's assets ((''assets/minecraft/blockstates/water.json''\\ ''assets/minecraft/models/block/water.json''\\ ''assets/minecraft/textures/block/water_still.png''\\ ''assets/minecraft/textures/block/water_still.png.mcmeta''\\ ''assets/minecraft/textures/block/water_flow.png''\\ ''assets/minecraft/textures/block/water_flow.png.mcmeta'')) as a template.
-===== Rendering setup =====
+===== Generation in the world =====
+To make lakes of acid generate in the world, you can create a ''net.minecraft.world.gen.feature.LakeFeature'' in your ''ModInitializer'' and then add it to the biomes you want it to generate in:
-Time to do client-side things. In your **ClientModInitializer** you need to specify locations of sprites for your fluids and define their rendering. I will reuse water textures and just change the color applied to them.
+<code java [enable_line_numbers="true"]>
+// ...
-<code java>
+public static LakeFeature ACID_LAKE;
-    @Override
-    public void onInitializeClient()
-    {
-        Identifier stillSpriteLocation=new Identifier("block/water_still");
-        Identifier dynamicSpriteLocation=new Identifier("block/water_flow");
-        // here I tell to use only 16x16 area of the water texture
-        FabricSprite stillAcidSprite = new FabricSprite(stillSpriteLocation,16,16);
-        // same, but 32
-        FabricSprite dynamicAcidSprite=new FabricSprite(dynamicSpriteLocation,32,32);
-        // adding the sprites to the block texture atlas
-        ClientSpriteRegistryCallback.event(SpriteAtlasTexture.BLOCK_ATLAS_TEX).register((spriteAtlasTexture, registry) -> {
-            registry.register(stillAcidSprite);
-            registry.register(dynamicAcidSprite);
-        });
-        // this renderer is responsible for drawing fluids in a world
+// ...
-        FluidRenderHandler acidRenderHandler=new FluidRenderHandler()
-        {
-            // return the sprites: still sprite goes first into the array, flowing/dynamic goes last
-            @Override
-            public Sprite[] getFluidSprites(ExtendedBlockView extendedBlockView, BlockPos blockPos, FluidState fluidState)
-            {
-                return new Sprite[]{stillAcidSprite,dynamicAcidSprite};
-            }
-            // apply light green color
+@Override
-            @Override
+public void onInitialize()
-            public int getFluidColor(ExtendedBlockView view, BlockPos pos, FluidState state)
+{
-            {
+	// ...
-                return 0x4cc248;
-            }
+	ACID_LAKE = Registry.register(Registry.FEATURE, new Identifier(MOD_ID, "acid_lake"), new LakeFeature(SingleStateFeatureConfig::deserialize));
-        };
+	// generate in swamps, similar to water lakes, but with a chance of 40 (the higher the number, the lower the generation chance)
-        // registering the same renderer for both fluid variants is intentional
+	Biomes.SWAMP.addFeature(
+		GenerationStep.Feature.LOCAL_MODIFICATIONS,
+		ACID_LAKE.configure(new SingleStateFeatureConfig(ACID.getDefaultState()))
+			.createDecoratedFeature(Decorator.WATER_LAKE.configure(new ChanceDecoratorConfig(40)))
+	);
+	// ...
+}
-        FluidRenderHandlerRegistry.INSTANCE.register([ModInitializer].stillAcid,acidRenderHandler);
+// ...
-        FluidRenderHandlerRegistry.INSTANCE.register([ModInitializer].flowingAcid,acidRenderHandler);
 </code>
-Then what's left to do is to create necessary Json files and textures, but you should know how to do that at this point.