Add waterlogged state to sea plants

src/main/java/com/minelittlepony/unicopia/mixin/MixinStateManager.java

@@ -0,0 +1,78 @@
+package com.minelittlepony.unicopia.mixin;
+
+import java.util.Map;
+import java.util.function.Function;
+
+import org.spongepowered.asm.mixin.*;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import net.minecraft.block.*;
+import net.minecraft.fluid.FluidState;
+import net.minecraft.fluid.Fluids;
+import net.minecraft.state.State;
+import net.minecraft.state.StateManager;
+import net.minecraft.state.StateManager.Factory;
+import net.minecraft.state.property.Properties;
+import net.minecraft.state.property.Property;
+
+@Mixin(StateManager.class)
+abstract class MixinStateManager<O, S extends State<O, S>> {
+    @Shadow
+    private @Final O owner;
+
+    @Inject(method = "getDefaultState", at = @At("RETURN"), cancellable = true)
+    private void onGetDefaultState(CallbackInfoReturnable<S> info) {
+        if ((owner instanceof SeagrassBlock
+                || owner instanceof TallSeagrassBlock
+                || owner instanceof KelpBlock
+                || owner instanceof KelpPlantBlock
+               ) && info.getReturnValue().contains(Properties.WATERLOGGED)) {
+            info.setReturnValue(info.getReturnValue().with(Properties.WATERLOGGED, true));
+        }
+    }
+}
+
+@Mixin(StateManager.Builder.class)
+abstract class MixinStateManagerBuilder<O, S extends State<O, S>> {
+    @Shadow
+    private @Final O owner;
+
+    @Shadow
+    private @Final Map<String, Property<?>> namedProperties;
+
+    @SuppressWarnings("unchecked")
+    @Inject(method = "build", at = @At("HEAD"))
+    private void build(Function<O, S> defaultStateGetter, Factory<O, S> factory, CallbackInfoReturnable<StateManager<O, S>> info) {
+        if (owner instanceof SeagrassBlock
+         || owner instanceof TallSeagrassBlock
+         || owner instanceof KelpBlock
+         || owner instanceof KelpPlantBlock
+        ) {
+            if (!namedProperties.containsValue(Properties.WATERLOGGED)) {
+                ((StateManager.Builder<O, S>)(Object)this).add(Properties.WATERLOGGED);
+            }
+        }
+    }
+}
+
+@Mixin(BlockState.class)
+abstract class MixinBlockState extends AbstractBlock.AbstractBlockState {
+    protected MixinBlockState() {
+        super(null, null, null);
+    }
+
+    @Override
+    public FluidState getFluidState() {
+        if (contains(Properties.WATERLOGGED) && (
+                getBlock() instanceof SeagrassBlock
+             || getBlock() instanceof TallSeagrassBlock
+             || getBlock() instanceof KelpBlock
+             || getBlock() instanceof KelpPlantBlock
+         )) {
+            return (get(Properties.WATERLOGGED) ? Fluids.WATER : Fluids.EMPTY).getDefaultState();
+        }
+        return super.getFluidState();
+    }
+}

src/main/resources/unicopia.mixin.json

@@ -32,6 +32,9 @@
     "MixinServerWorld",
     "MixinSheepEntity",
     "MixinShulkerEntity",
+    "MixinStateManager",
+    "MixinStateManagerBuilder",
+    "MixinBlockState",
     "MixinTargetPredicate",
     "MixinWorld",
     "MixinWorldChunk",