From b6813ad14d2a0596c994779cfa112c7372fa5951 Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sat, 5 Jan 2019 18:14:29 -0500
Subject: [PATCH] Add multipart container hasSolidTopSurface implementation

---
 .../container/AbstractContainerBlock.java     | 16 ++++++++++++++
 .../simplemultipart/util/ShapeUtils.java      | 21 +++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/src/main/java/net/shadowfacts/simplemultipart/container/AbstractContainerBlock.java b/src/main/java/net/shadowfacts/simplemultipart/container/AbstractContainerBlock.java
index 3902768..d59f987 100644
--- a/src/main/java/net/shadowfacts/simplemultipart/container/AbstractContainerBlock.java
+++ b/src/main/java/net/shadowfacts/simplemultipart/container/AbstractContainerBlock.java
@@ -15,6 +15,7 @@ import net.shadowfacts.simplemultipart.client.util.RenderStateProvider;
 import net.shadowfacts.simplemultipart.util.MultipartHelper;
 import net.shadowfacts.simplemultipart.util.MultipartHitResult;
 import net.shadowfacts.simplemultipart.multipart.MultipartView;
+import net.shadowfacts.simplemultipart.util.ShapeUtils;
 
 import java.util.Set;
 
@@ -69,6 +70,21 @@ public abstract class AbstractContainerBlock extends Block implements BlockEntit
 		return shape == null ? VoxelShapes.empty() : shape;
 	}
 
+	@Override
+	@Deprecated
+	public boolean hasSolidTopSurface(BlockState state, BlockView world, BlockPos pos) {
+		MultipartContainer container = (MultipartContainer)world.getBlockEntity(pos);
+		if (container == null) {
+			return false;
+		}
+
+		return container.getParts().stream()
+				.anyMatch(view -> {
+					VoxelShape shape = view.getState().getBoundingShape(view);
+					return ShapeUtils.hasSolidSide(shape, Direction.UP);
+				});
+	}
+
 	@Override
 	public abstract AbstractContainerBlockEntity createBlockEntity(BlockView world);
 
diff --git a/src/main/java/net/shadowfacts/simplemultipart/util/ShapeUtils.java b/src/main/java/net/shadowfacts/simplemultipart/util/ShapeUtils.java
index f31563a..7ab390e 100644
--- a/src/main/java/net/shadowfacts/simplemultipart/util/ShapeUtils.java
+++ b/src/main/java/net/shadowfacts/simplemultipart/util/ShapeUtils.java
@@ -1,9 +1,13 @@
 package net.shadowfacts.simplemultipart.util;
 
 import net.minecraft.util.BooleanBiFunction;
+import net.minecraft.util.math.Direction;
 import net.minecraft.util.shape.VoxelShape;
 import net.minecraft.util.shape.VoxelShapes;
 
+import java.util.function.BiFunction;
+import java.util.function.DoubleFunction;
+
 /**
  * @author shadowfacts
  */
@@ -15,4 +19,21 @@ public class ShapeUtils {
 		return !overlap.isEmpty();
 	}
 
+	public static boolean hasSolidSide(VoxelShape shape, Direction side) {
+		BiFunction<VoxelShape, Direction.Axis, Double> getter = side.getDirection() == Direction.AxisDirection.NEGATIVE ? VoxelShape::getMinimum : VoxelShape::getMaximum;
+		if (getter.apply(shape, side.getAxis()) < 1) {
+			return false;
+		}
+		for (Direction.Axis axis : Direction.Axis.values()) {
+			if (axis == side.getAxis()) {
+				continue;
+			}
+
+			if (shape.getMinimum(axis) > 0 || shape.getMaximum(axis) < 1) {
+				return false;
+			}
+		}
+		return true;
+	}
+
 }