From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Helvetica Volubi <suisuroru@blue-millennium.fun>
Date: Sat, 26 Jul 2025 12:45:01 +0800
Subject: [PATCH] Leaves: Vanilla Fluid Pushing

Co-authored by: Fortern <blueten.ki@gmail.com>
As part of: Leaves (https://github.com/LeavesMC/Leaves/blob/d4854b69b2775f6d0929c63db84de45294cdd375/leaves-server/minecraft-patches/features/0129-Vanilla-Fluid-Pushing.patch)
Licensed under: GPL-3.0 (https://www.gnu.org/licenses/gpl-3.0.html)

diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
index 76ee76c7c6abeb14f379b73188305903be5d2df6..0a2bdd4cb84abe58ce891cf39a63c658e3cd8298 100644
--- a/net/minecraft/world/entity/Entity.java
+++ b/net/minecraft/world/entity/Entity.java
@@ -5588,8 +5588,82 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
         return Mth.lerp(partialTick, this.yRotO, this.yRot);
     }
 
+    // Leaves start - vanilla fluid pushing
+    private boolean vanillaUpdateFluidHeightAndDoFluidPushing(final TagKey<Fluid> fluidTag, final double motionScale) {
+        if (this.touchingUnloadedChunk()) {
+            return false;
+        } else {
+            AABB aabb = this.getBoundingBox().deflate(0.001);
+            int floor = Mth.floor(aabb.minX);
+            int ceil = Mth.ceil(aabb.maxX);
+            int floor1 = Mth.floor(aabb.minY);
+            int ceil1 = Mth.ceil(aabb.maxY);
+            int floor2 = Mth.floor(aabb.minZ);
+            int ceil2 = Mth.ceil(aabb.maxZ);
+            double d = 0.0;
+            boolean isPushedByFluid = this.isPushedByFluid();
+            boolean flag = false;
+            Vec3 vec3 = Vec3.ZERO;
+            int i = 0;
+            BlockPos.MutableBlockPos mutableBlockPos = new BlockPos.MutableBlockPos();
+
+            for (int i1 = floor; i1 < ceil; i1++) {
+                for (int i2 = floor1; i2 < ceil1; i2++) {
+                    for (int i3 = floor2; i3 < ceil2; i3++) {
+                        mutableBlockPos.set(i1, i2, i3);
+                        FluidState fluidState = this.level().getFluidState(mutableBlockPos);
+                        if (fluidState.is(fluidTag)) {
+                            double d1 = i2 + fluidState.getHeight(this.level(), mutableBlockPos);
+                            if (d1 >= aabb.minY) {
+                                flag = true;
+                                d = Math.max(d1 - aabb.minY, d);
+                                if (isPushedByFluid) {
+                                    Vec3 flow = fluidState.getFlow(this.level(), mutableBlockPos);
+                                    if (d < 0.4) {
+                                        flow = flow.scale(d);
+                                    }
+
+                                    vec3 = vec3.add(flow);
+                                    i++;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+
+            if (vec3.length() > 0.0) {
+                if (i > 0) {
+                    vec3 = vec3.scale(1.0 / i);
+                }
+
+                if (!(this instanceof Player)) {
+                    vec3 = vec3.normalize();
+                }
+
+                Vec3 deltaMovement = this.getDeltaMovement();
+                vec3 = vec3.scale(motionScale);
+                double d2 = 0.003;
+                if (Math.abs(deltaMovement.x) < 0.003 && Math.abs(deltaMovement.z) < 0.003 && vec3.length() < 0.0045000000000000005) {
+                    vec3 = vec3.normalize().scale(0.0045000000000000005);
+                }
+
+                this.setDeltaMovement(this.getDeltaMovement().add(vec3));
+            }
+
+            this.fluidHeight.put(fluidTag, d);
+            return flag;
+        }
+    }
+    // Leaves end - vanilla fluid pushing
+
     // Paper start - optimise collisions
     public boolean updateFluidHeightAndDoFluidPushing(final TagKey<Fluid> fluid, final double flowScale) {
+        // Leaves start - vanilla fluid pushing
+        if (me.earthme.luminol.config.modules.fixes.CollisionBehaviorConfig.vanillaFluidPushing) {
+            return vanillaUpdateFluidHeightAndDoFluidPushing(fluid, flowScale);
+        }
+        // Leaves end - vanilla fluid pushing
         if (this.touchingUnloadedChunk()) {
             return false;
         }