Allow undying items using a sponge

It's much less aggressive than dunking it in a cauldron, so won't damage
any of your precious electronics.

I had this idea back in 2017 (dan200/ComputerCraft#230). Can't believe
it took me almost 6 years to implement.

projects/common/src/main/java/dan200/computercraft/data/RecipeProvider.java

@@ -65,6 +65,7 @@ class RecipeProvider extends net.minecraft.data.recipes.RecipeProvider {
         addSpecial(add, ModRegistry.RecipeSerializers.PRINTOUT.get());
         addSpecial(add, ModRegistry.RecipeSerializers.DISK.get());
         addSpecial(add, ModRegistry.RecipeSerializers.DYEABLE_ITEM.get());
+        addSpecial(add, ModRegistry.RecipeSerializers.DYEABLE_ITEM_CLEAR.get());
         addSpecial(add, ModRegistry.RecipeSerializers.TURTLE_UPGRADE.get());
         addSpecial(add, ModRegistry.RecipeSerializers.POCKET_COMPUTER_UPGRADE.get());
     }

projects/common/src/main/java/dan200/computercraft/shared/ModRegistry.java

@@ -19,6 +19,7 @@ import dan200.computercraft.shared.command.arguments.ComputerArgumentType;
 import dan200.computercraft.shared.command.arguments.ComputersArgumentType;
 import dan200.computercraft.shared.command.arguments.RepeatArgumentType;
 import dan200.computercraft.shared.command.arguments.TrackingFieldArgumentType;
+import dan200.computercraft.shared.common.ClearColourRecipe;
 import dan200.computercraft.shared.common.ColourableRecipe;
 import dan200.computercraft.shared.common.DefaultBundledRedstoneProvider;
 import dan200.computercraft.shared.common.HeldItemMenu;
@@ -351,6 +352,7 @@ public final class ModRegistry {
         }
 
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<ColourableRecipe>> DYEABLE_ITEM = simple("colour", ColourableRecipe::new);
+        public static final RegistryEntry<SimpleCraftingRecipeSerializer<ClearColourRecipe>> DYEABLE_ITEM_CLEAR = simple("clear_colour", ClearColourRecipe::new);
         public static final RegistryEntry<TurtleRecipe.Serializer> TURTLE = REGISTRY.register("turtle", TurtleRecipe.Serializer::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<TurtleUpgradeRecipe>> TURTLE_UPGRADE = simple("turtle_upgrade", TurtleUpgradeRecipe::new);
         public static final RegistryEntry<SimpleCraftingRecipeSerializer<PocketComputerUpgradeRecipe>> POCKET_COMPUTER_UPGRADE = simple("pocket_computer_upgrade", PocketComputerUpgradeRecipe::new);

projects/common/src/main/java/dan200/computercraft/shared/common/ClearColourRecipe.java

@@ -0,0 +1,84 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.common;
+
+import dan200.computercraft.shared.ModRegistry;
+import net.minecraft.core.NonNullList;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.inventory.CraftingContainer;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.item.crafting.CraftingBookCategory;
+import net.minecraft.world.item.crafting.CustomRecipe;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.level.Level;
+
+/**
+ * Craft a wet sponge with a {@linkplain IColouredItem dyable item} to remove its dye.
+ */
+public final class ClearColourRecipe extends CustomRecipe {
+    public ClearColourRecipe(ResourceLocation id, CraftingBookCategory category) {
+        super(id, category);
+    }
+
+    @Override
+    public boolean matches(CraftingContainer inv, Level world) {
+        var hasColourable = false;
+        var hasSponge = false;
+        for (var i = 0; i < inv.getContainerSize(); i++) {
+            var stack = inv.getItem(i);
+            if (stack.isEmpty()) continue;
+
+            if (stack.getItem() instanceof IColouredItem colourable) {
+                if (hasColourable) return false;
+                if (colourable.getColour(stack) == -1) return false;
+                hasColourable = true;
+            } else if (stack.getItem() == Items.WET_SPONGE) {
+                if (hasSponge) return false;
+                hasSponge = true;
+            } else {
+                return false;
+            }
+        }
+
+        return hasColourable && hasSponge;
+    }
+
+    @Override
+    public ItemStack assemble(CraftingContainer inv) {
+        var colourable = ItemStack.EMPTY;
+
+        for (var i = 0; i < inv.getContainerSize(); i++) {
+            var stack = inv.getItem(i);
+            if (stack.getItem() instanceof IColouredItem) colourable = stack;
+        }
+
+        if (colourable.isEmpty()) return ItemStack.EMPTY;
+
+        var stack = ((IColouredItem) colourable.getItem()).withColour(colourable, -1);
+        stack.setCount(1);
+        return stack;
+    }
+
+    @Override
+    public NonNullList<ItemStack> getRemainingItems(CraftingContainer container) {
+        var remaining = NonNullList.withSize(container.getContainerSize(), ItemStack.EMPTY);
+        for (var i = 0; i < remaining.size(); i++) {
+            if (container.getItem(i).getItem() == Items.WET_SPONGE) remaining.set(i, new ItemStack(Items.WET_SPONGE));
+        }
+        return remaining;
+    }
+
+    @Override
+    public boolean canCraftInDimensions(int x, int y) {
+        return x * y >= 2;
+    }
+
+    @Override
+    public RecipeSerializer<ClearColourRecipe> getSerializer() {
+        return ModRegistry.RecipeSerializers.DYEABLE_ITEM_CLEAR.get();
+    }
+}

projects/common/src/main/java/dan200/computercraft/shared/common/ColourableRecipe.java

@@ -74,7 +74,7 @@ public final class ColourableRecipe extends CustomRecipe {
     }
 
     @Override
-    public RecipeSerializer<?> getSerializer() {
+    public RecipeSerializer<ColourableRecipe> getSerializer() {
         return ModRegistry.RecipeSerializers.DYEABLE_ITEM.get();
     }
 }

projects/fabric/src/generated/resources/data/computercraft/recipes/clear_colour.json

@@ -0,0 +1 @@
+{"type": "computercraft:clear_colour", "category": "misc"}

projects/forge/src/generated/resources/data/computercraft/recipes/clear_colour.json

@@ -0,0 +1 @@
+{"type": "computercraft:clear_colour", "category": "misc"}