From c09fe570316274d89d503148c873ba3479c3d5f4 Mon Sep 17 00:00:00 2001
From: Wire Segal <6596492+yrsegal@users.noreply.github.com>
Date: Tue, 3 Sep 2019 17:50:27 -0400
Subject: [PATCH] Add collisionExtendsVertically hook to allow modded blocks
 that extend collision into the block above similar to fences. (#6092)

---
 .../minecraft/net/minecraft/entity/Entity.java.patch   |  7 ++++++-
 .../entity/player/ServerPlayerEntity.java.patch        |  7 ++++++-
 .../minecraftforge/common/extensions/IForgeBlock.java  | 10 ++++++++++
 .../common/extensions/IForgeBlockState.java            |  9 +++++++++
 4 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/patches/minecraft/net/minecraft/entity/Entity.java.patch b/patches/minecraft/net/minecraft/entity/Entity.java.patch
index a8cc2adc6..2406f7f48 100644
--- a/patches/minecraft/net/minecraft/entity/Entity.java.patch
+++ b/patches/minecraft/net/minecraft/entity/Entity.java.patch
@@ -64,7 +64,7 @@
        float f = this.field_213325_aI.field_220315_a / 2.0F;
        float f1 = this.field_213325_aI.field_220316_b;
        this.func_174826_a(new AxisAlignedBB(p_70107_1_ - (double)f, p_70107_3_, p_70107_5_ - (double)f, p_70107_1_ + (double)f, p_70107_3_ + (double)f1, p_70107_5_ + (double)f));
-@@ -496,7 +508,7 @@
+@@ -496,11 +508,11 @@
           int k = MathHelper.func_76128_c(this.field_70161_v);
           BlockPos blockpos = new BlockPos(i, j, k);
           BlockState blockstate = this.field_70170_p.func_180495_p(blockpos);
@@ -73,6 +73,11 @@
              BlockPos blockpos1 = blockpos.func_177977_b();
              BlockState blockstate1 = this.field_70170_p.func_180495_p(blockpos1);
              Block block = blockstate1.func_177230_c();
+-            if (block.func_203417_a(BlockTags.field_219748_G) || block.func_203417_a(BlockTags.field_219757_z) || block instanceof FenceGateBlock) {
++            if (blockstate.collisionExtendsVertically(this.field_70170_p, blockpos, this)) {
+                blockstate = blockstate1;
+                blockpos = blockpos1;
+             }
 @@ -535,7 +547,7 @@
  
              this.field_70140_Q = (float)((double)this.field_70140_Q + (double)MathHelper.func_76133_a(func_213296_b(vec3d)) * 0.6D);
diff --git a/patches/minecraft/net/minecraft/entity/player/ServerPlayerEntity.java.patch b/patches/minecraft/net/minecraft/entity/player/ServerPlayerEntity.java.patch
index 7d2b04287..c6565c5e5 100644
--- a/patches/minecraft/net/minecraft/entity/player/ServerPlayerEntity.java.patch
+++ b/patches/minecraft/net/minecraft/entity/player/ServerPlayerEntity.java.patch
@@ -64,7 +64,7 @@
           return this;
        }
     }
-@@ -776,7 +778,7 @@
+@@ -776,11 +778,11 @@
        BlockPos blockpos = new BlockPos(i, j, k);
        if (this.field_70170_p.func_175667_e(blockpos)) {
           BlockState blockstate = this.field_70170_p.func_180495_p(blockpos);
@@ -73,6 +73,11 @@
              BlockPos blockpos1 = blockpos.func_177977_b();
              BlockState blockstate1 = this.field_70170_p.func_180495_p(blockpos1);
              Block block = blockstate1.func_177230_c();
+-            if (block.func_203417_a(BlockTags.field_219748_G) || block.func_203417_a(BlockTags.field_219757_z) || block instanceof FenceGateBlock) {
++            if (blockstate.collisionExtendsVertically(this.field_70170_p, blockpos, this)) {
+                blockpos = blockpos1;
+                blockstate = blockstate1;
+             }
 @@ -819,6 +821,7 @@
              this.field_71135_a.func_147359_a(new SOpenWindowPacket(container.field_75152_c, container.func_216957_a(), p_213829_1_.func_145748_c_()));
              container.func_75132_a(this);
diff --git a/src/main/java/net/minecraftforge/common/extensions/IForgeBlock.java b/src/main/java/net/minecraftforge/common/extensions/IForgeBlock.java
index 3d0eee135..85d90fb37 100644
--- a/src/main/java/net/minecraftforge/common/extensions/IForgeBlock.java
+++ b/src/main/java/net/minecraftforge/common/extensions/IForgeBlock.java
@@ -29,6 +29,7 @@ import javax.annotation.Nullable;
 import net.minecraft.block.Block;
 import net.minecraft.block.BedBlock;
 import net.minecraft.block.FarmlandBlock;
+import net.minecraft.block.FenceGateBlock;
 import net.minecraft.block.FireBlock;
 import net.minecraft.block.HorizontalBlock;
 import net.minecraft.block.IBeaconBeamColorProvider;
@@ -1024,4 +1025,13 @@ public interface IForgeBlock
         world.setBlockState(pos, Blocks.AIR.getDefaultState(), 3);
         getBlock().onExplosionDestroy(world, pos, explosion);
     }
+
+    /**
+     * Determines if this block's collision box should be treated as though it can extend above its block space.
+     * Use this to replicate fence and wall behavior.
+     */
+    default boolean collisionExtendsVertically(BlockState state, IBlockReader world, BlockPos pos, Entity collidingEntity)
+    {
+        return getBlock().isIn(BlockTags.FENCES) || getBlock().isIn(BlockTags.WALLS) || getBlock() instanceof FenceGateBlock;
+    }
 }
diff --git a/src/main/java/net/minecraftforge/common/extensions/IForgeBlockState.java b/src/main/java/net/minecraftforge/common/extensions/IForgeBlockState.java
index 80337d423..5741a7738 100644
--- a/src/main/java/net/minecraftforge/common/extensions/IForgeBlockState.java
+++ b/src/main/java/net/minecraftforge/common/extensions/IForgeBlockState.java
@@ -867,4 +867,13 @@ public interface IForgeBlockState
     {
         getBlockState().getBlock().onBlockExploded(getBlockState(), world, pos, explosion);
     }
+
+    /**
+     * Determines if this block's collision box should be treated as though it can extend above its block space.
+     * This can be used to replicate fence and wall behavior.
+     */
+    default boolean collisionExtendsVertically(IBlockReader world, BlockPos pos, Entity collidingEntity)
+    {
+        return getBlockState().getBlock().collisionExtendsVertically(getBlockState(), world, pos, collidingEntity);
+    }
 }