SakuraMC/patches/server/0019-Optimise-Fast-Movement.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <40902469+Samsuik@users.noreply.github.com>
Date: Fri, 13 Oct 2023 14:36:19 +0100
Subject: [PATCH] Optimise Fast Movement


diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index c518dc036459b925e384fed8cdf81d89b081a19e..11b137cad5455a46064fafe73fd0ab60ffb537a3 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -1236,6 +1236,95 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
     }
     // Paper end - detailed watchdog information
 
+    // Sakura start - stripped back movement method for basic entities
+    public void moveBasic(MoverType movementType, Vec3 movement) {
+        io.papermc.paper.util.TickThread.ensureTickThread("Cannot move an entity off-main");
+
+        if (this.noPhysics) {
+            this.setPos(this.getX() + movement.x, this.getY() + movement.y, this.getZ() + movement.z);
+        } else {
+            if (movementType == MoverType.PISTON) {  // Paper
+                movement = this.limitPistonMovement(movement);
+                if (movement.equals(Vec3.ZERO)) {
+                    return;
+                }
+            }
+
+            this.level().getProfiler().push("move");
+            if (this.stuckSpeedMultiplier.lengthSqr() > 1.0E-7D) {
+                movement = movement.multiply(this.stuckSpeedMultiplier);
+                this.stuckSpeedMultiplier = Vec3.ZERO;
+                this.setDeltaMovement(Vec3.ZERO);
+            }
+
+            // collideScan for optimised large movements
+            Vec3 vec3d1 = this.collideScan(movement);
+            double d0 = vec3d1.lengthSqr();
+
+            if (d0 > 1.0E-7D) {
+                // NOTE: if there are any blocks in the future that rely on fall distance make sure this is correct.
+                // The only block I am aware of is powdered snow that has a special case for falling blocks.
+                if (this.fallDistance != 0.0F && d0 >= 1.0D && !isFallingBlock) {
+                    BlockHitResult movingobjectpositionblock = this.level().clip(new ClipContext(this.position(), this.position().add(vec3d1), ClipContext.Block.FALLDAMAGE_RESETTING, ClipContext.Fluid.WATER, this));
+
+                    if (movingobjectpositionblock.getType() != HitResult.Type.MISS) {
+                        this.resetFallDistance();
+                    }
+                }
+
+                this.setPos(this.getX() + vec3d1.x, this.getY() + vec3d1.y, this.getZ() + vec3d1.z);
+            }
+
+            this.level().getProfiler().pop();
+            this.level().getProfiler().push("rest");
+            boolean flag = !Mth.equal(movement.x, vec3d1.x);
+            boolean flag1 = !Mth.equal(movement.z, vec3d1.z);
+
+            this.horizontalCollision = flag || flag1;
+            this.verticalCollision = movement.y != vec3d1.y;
+            this.verticalCollisionBelow = this.verticalCollision && movement.y < 0.0D;
+            if (this.horizontalCollision) {
+                this.minorHorizontalCollision = this.isHorizontalCollisionMinor(vec3d1);
+            } else {
+                this.minorHorizontalCollision = false;
+            }
+
+            this.setOnGroundWithKnownMovement(this.verticalCollisionBelow, vec3d1);
+            BlockPos blockposition = this.getOnPosLegacy();
+            BlockState iblockdata = this.level().getBlockState(blockposition);
+
+            this.checkFallDamage(vec3d1.y, this.onGround(), iblockdata, blockposition);
+            if (this.isRemoved()) {
+                this.level().getProfiler().pop();
+            } else {
+                if (this.horizontalCollision) {
+                    Vec3 vec3d2 = this.getDeltaMovement();
+
+                    this.setDeltaMovement(flag ? 0.0D : vec3d2.x, vec3d2.y, flag1 ? 0.0D : vec3d2.z);
+                }
+
+                Block block = iblockdata.getBlock();
+
+                if (movement.y != vec3d1.y) {
+                    block.updateEntityAfterFallOn(this.level(), this);
+                }
+
+                if (this.onGround()) {
+                    // used for slowing down entities on top of slime
+                    block.stepOn(this.level(), blockposition, iblockdata, this);
+                }
+
+                this.tryCheckInsideBlocks();
+
+                float f = this.getBlockSpeedFactor();
+
+                this.multiplyDeltaMovement((double) f, 1.0D, (double) f); // Sakura - reduce movement allocations
+                this.level().getProfiler().pop();
+            }
+        }
+    }
+    // Sakura end
+
     public void move(MoverType movementType, Vec3 movement) {
         final Vec3 originalMovement = movement; // Paper - Expose pre-collision velocity
         // Paper start - detailed watchdog information
@@ -1614,6 +1703,95 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
         return offsetFactor;
     }
 
+    // Sakura start
+    private Vec3 collideScan(Vec3 movement) {
+        if (movement.x == 0.0 && movement.y == 0.0 && movement.z == 0.0) {
+            return movement;
+        }
+
+        final boolean scan = movement.lengthSqr() >= 12.0;
+        final List<AABB> potentialCollisionsBB = new it.unimi.dsi.fastutil.objects.ObjectArrayList<>(4);
+        final List<VoxelShape> potentialCollisionsVoxel = new it.unimi.dsi.fastutil.objects.ObjectArrayList<>(1);
+        final AABB currBoundingBox = getBoundingBox();
+
+        if (scan) {
+            return scanAndCollide(movement, currBoundingBox, potentialCollisionsVoxel, potentialCollisionsBB);
+        } else {
+            final AABB bb = currBoundingBox.expandTowards(movement.x, movement.y, movement.z);
+            collectCollisions(bb, potentialCollisionsVoxel, potentialCollisionsBB);
+            return io.papermc.paper.util.CollisionUtil.performCollisions(movement, currBoundingBox, potentialCollisionsVoxel, potentialCollisionsBB);
+        }
+    }
+
+    private Vec3 scanAndCollide(Vec3 movement, AABB currBoundingBox, List<VoxelShape> voxelList, List<AABB> bbList) {
+        double x = movement.x;
+        double y = movement.y;
+        double z = movement.z;
+
+        final boolean xSmaller = Math.abs(x) < Math.abs(z);
+
+        if (y != 0.0) {
+            y = scanY(currBoundingBox, y, voxelList, bbList);
+
+            if (y != 0.0) {
+                currBoundingBox = io.papermc.paper.util.CollisionUtil.offsetY(currBoundingBox, y);
+            }
+        }
+
+        if (xSmaller && z != 0.0) {
+            z = scanZ(currBoundingBox, z, voxelList, bbList);
+
+            if (z != 0.0) {
+                currBoundingBox = io.papermc.paper.util.CollisionUtil.offsetZ(currBoundingBox, z);
+            }
+        }
+
+        if (x != 0.0) {
+            x = scanX(currBoundingBox, x, voxelList, bbList);
+
+            if (x != 0.0) {
+                currBoundingBox = io.papermc.paper.util.CollisionUtil.offsetX(currBoundingBox, x);
+            }
+        }
+
+        if (!xSmaller && z != 0.0) {
+            z = scanZ(currBoundingBox, z, voxelList, bbList);
+        }
+
+        return new Vec3(x, y, z);
+    }
+
+    private void collectCollisions(AABB collisionBox, List<VoxelShape> voxelList, List<AABB> bbList) {
+        // Copied from the collide method below
+        io.papermc.paper.util.CollisionUtil.getCollisions(
+            level, this, collisionBox, voxelList, bbList,
+            io.papermc.paper.util.CollisionUtil.COLLISION_FLAG_CHECK_BORDER | this.getExtraCollisionFlags(), // Sakura
+            null, null
+        );
+    }
+
+    private double scanX(AABB currBoundingBox, double x, List<VoxelShape> voxelList, List<AABB> bbList) {
+        AABB scanBox = currBoundingBox.expandTowards(x, 0.0, 0.0);
+        collectCollisions(scanBox, voxelList, bbList);
+        x = io.papermc.paper.util.CollisionUtil.performAABBCollisionsX(currBoundingBox, x, bbList);
+        return io.papermc.paper.util.CollisionUtil.performVoxelCollisionsX(currBoundingBox, x, voxelList);
+    }
+
+    private double scanY(AABB currBoundingBox, double y, List<VoxelShape> voxelList, List<AABB> bbList) {
+        AABB scanBox = currBoundingBox.expandTowards(0.0, y, 0.0);
+        collectCollisions(scanBox, voxelList, bbList);
+        y = io.papermc.paper.util.CollisionUtil.performAABBCollisionsY(currBoundingBox, y, bbList);
+        return io.papermc.paper.util.CollisionUtil.performVoxelCollisionsY(currBoundingBox, y, voxelList);
+    }
+
+    private double scanZ(AABB currBoundingBox, double z, List<VoxelShape> voxelList, List<AABB> bbList) {
+        AABB scanBox = currBoundingBox.expandTowards(0.0, 0.0, z);
+        collectCollisions(scanBox, voxelList, bbList);
+        z = io.papermc.paper.util.CollisionUtil.performAABBCollisionsZ(currBoundingBox, z, bbList);
+        return io.papermc.paper.util.CollisionUtil.performVoxelCollisionsZ(currBoundingBox, z, voxelList);
+    }
+    // Sakura end
+
     private Vec3 collide(Vec3 movement) {
         // Paper start - optimise collisions
         final boolean xZero = movement.x == 0.0;
diff --git a/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java b/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
index 7a1cc86185b9f4b6aa82cb2dd92500063b9f0736..0e60e3f694dd4d52ce92290148ff043e834d7c4c 100644
--- a/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/FallingBlockEntity.java
@@ -198,7 +198,7 @@ public class FallingBlockEntity extends Entity {
                 this.addDeltaMovement(0.0D, -0.04D, 0.0D); // Sakura - reduce movement allocations
             }
 
-            this.move(MoverType.SELF, this.getDeltaMovement());
+            this.moveBasic(MoverType.SELF, this.getDeltaMovement()); // Sakura - optimise simple entity movement
             // Paper start - Configurable falling blocks height nerf
             if (this.level().paperConfig().fixes.fallingBlockHeightNerf.test(v -> this.getY() > v)) {
                 if (this.dropItem && this.level().getGameRules().getBoolean(GameRules.RULE_DOENTITYDROPS)) {
diff --git a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
index 2800af98260ebdab107466c596d2ec8cba6088fe..7ff11a09234606508dac8347af281885b0a1f7e1 100644
--- a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
+++ b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
@@ -119,7 +119,7 @@ public class PrimedTnt extends Entity implements TraceableEntity {
             this.addDeltaMovement(0.0D, -0.04D, 0.0D); // Sakura - reduce movement allocations
         }
 
-        this.move(MoverType.SELF, this.getDeltaMovement());
+        this.moveBasic(MoverType.SELF, this.getDeltaMovement()); // Sakura - optimise simple entity movement
         // Paper start - Configurable TNT height nerf
         if (this.level().paperConfig().fixes.tntEntityHeightNerf.test(v -> this.getY() > v)) {
             this.discard(EntityRemoveEvent.Cause.OUT_OF_WORLD);