Anchor crouch collision to player feet

README.md

@@ -1,4 +1,4 @@
-# Sable Gravity 0.7.4
+# Sable Gravity 0.7.5
 
 Sable Gravity is a multidimensional gravity-frame kernel for moving and arbitrarily rotated
 Sable ships. A frame owns a dimension-qualified identity, a local coordinate system, a rigid

gradle.properties

@@ -2,7 +2,7 @@ org.gradle.jvmargs=-Xmx2G
 org.gradle.daemon=false
 org.gradle.parallel=true
 mod_id=sablegravity
-mod_version=0.7.4-player-recovery
+mod_version=0.7.5-foot-anchor
 minecraft_version=1.21.1
 neo_version=21.1.228
 sable_version=2.0.3+mc1.21.1

src/main/java/dev/nightly/sablegravity/mixin/EntityAabbIsolationMixin.java

@@ -1,15 +1,12 @@
 package dev.nightly.sablegravity.mixin;
 
 import dev.nightly.sablegravity.SableGravityState;
-import dev.nightly.sablegravity.physics.SableFrameOrientation;
 import dev.nightly.sablegravity.physics.SableLocalPlayerPhysics;
-import dev.nightly.sablegravity.physics.SableOrientedBounds;
 import dev.nightly.sablegravity.physics.SableParentWorldCollision;
 import dev.ryanhcode.sable.sublevel.SubLevel;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.phys.Vec3;
-import org.joml.Quaterniond;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Unique;
 import org.spongepowered.asm.mixin.injection.At;
@@ -17,8 +14,6 @@ import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
-import java.util.UUID;
-
 /**
  * Keeps Entity.bb as metadata/broadphase only while arbitrary gravity is active. This mixin has
  * higher priority than Sable's Entity mixin so the semantic-flag restoration point is inserted
@@ -26,8 +21,6 @@ import java.util.UUID;
  */
 @Mixin(value = Entity.class, priority = 3000)
 public abstract class EntityAabbIsolationMixin {
-    @Unique private Vec3 sablegravity$localFeetBeforeResize;
-    @Unique private UUID sablegravity$frameBeforeResize;
     @Unique private boolean sablegravity$insideMove;
 
     @Inject(method = "collide", at = @At("HEAD"), cancellable = true)
@@ -82,90 +75,8 @@ public abstract class EntityAabbIsolationMixin {
         sablegravity$insideMove = false;
     }
 
-    @Inject(method = "refreshDimensions", at = @At("HEAD"))
-    private void sablegravity$captureFeetBeforeResize(CallbackInfo ci) {
-        Entity self = (Entity) (Object) this;
-        if (!(self instanceof Player player) || !usesOrientedBody(player)) {
-            sablegravity$clearResizeAnchor();
-            return;
-        }
-
-        SubLevel frame = currentFrame(player);
-        if (!validFrame(player, frame)) {
-            sablegravity$clearResizeAnchor();
-            return;
-        }
-
-        // A pose transition belongs to the Sable frame, not to parent-world space. Anchoring the
-        // transient resize to a world point lets a simultaneously moving/rotating frame turn
-        // crouch into a visible teleport or tangent slide. Store the invariant local feet point.
-        Quaterniond orientation = SableFrameOrientation.getFrameOrientation(frame, 1.0F);
-        Vec3 worldFeet = SableOrientedBounds.worldFeet(player, orientation);
-        sablegravity$localFeetBeforeResize = frame.logicalPose()
-            .transformPositionInverse(worldFeet);
-        sablegravity$frameBeforeResize = frame.getUniqueId();
-    }
-
-    @Inject(method = "refreshDimensions", at = @At("TAIL"))
-    private void sablegravity$restoreFeetAfterResize(CallbackInfo ci) {
-        Entity self = (Entity) (Object) this;
-        if (!(self instanceof Player player)
-            || sablegravity$localFeetBeforeResize == null) {
-            sablegravity$clearResizeAnchor();
-            return;
-        }
-
-        SubLevel frame = currentFrame(player);
-        if (!validFrame(player, frame)
-            || !frame.getUniqueId().equals(sablegravity$frameBeforeResize)) {
-            sablegravity$clearResizeAnchor();
-            return;
-        }
-
-        Quaterniond orientation = SableFrameOrientation.getFrameOrientation(frame, 1.0F);
-        Vec3 physicalFeet = frame.logicalPose().transformPosition(
-            sablegravity$localFeetBeforeResize
-        );
-        Vec3 rawPosition = SableOrientedBounds.rawPositionForFeet(
-            player,
-            physicalFeet,
-            orientation
-        );
-        if (Double.isFinite(rawPosition.x)
-            && Double.isFinite(rawPosition.y)
-            && Double.isFinite(rawPosition.z)) {
-            player.setPos(rawPosition);
-        }
-        sablegravity$clearResizeAnchor();
-    }
-
-    @Unique
-    private static boolean usesOrientedBody(Player player) {
-        if (!((SableGravityState) player).sablegravity$isEnabled()) {
-            return false;
-        }
-        return player.isLocalPlayer();
-    }
-
-    @Unique
-    private static SubLevel currentFrame(Player player) {
-        if (player.isLocalPlayer()) {
-            SubLevel attached = SableLocalPlayerPhysics.getAttachedFrameIfPresent(player);
-            if (validFrame(player, attached)) {
-                return attached;
-            }
-        }
-        return null;
-    }
-
     @Unique
     private static boolean validFrame(Player player, SubLevel frame) {
         return frame != null && !frame.isRemoved() && frame.getLevel() == player.level();
     }
-
-    @Unique
-    private void sablegravity$clearResizeAnchor() {
-        sablegravity$localFeetBeforeResize = null;
-        sablegravity$frameBeforeResize = null;
-    }
 }

src/main/java/dev/nightly/sablegravity/mixin/PlayerPoseFitMixin.java

@@ -6,6 +6,7 @@ import dev.nightly.sablegravity.physics.SableLocalCollisionProbe;
 import dev.nightly.sablegravity.physics.SableLocalPlayerPhysics;
 import dev.nightly.sablegravity.physics.SableOrientedBounds;
 import dev.nightly.sablegravity.physics.SableParentWorldCollision;
+import dev.ryanhcode.sable.Sable;
 import dev.ryanhcode.sable.sublevel.SubLevel;
 import net.minecraft.world.entity.EntityDimensions;
 import net.minecraft.world.entity.Pose;
@@ -27,11 +28,19 @@ public abstract class PlayerPoseFitMixin {
     ) {
         Player player = (Player) (Object) this;
         SableGravityState state = (SableGravityState) player;
-        if (!state.sablegravity$isEnabled() || !player.isLocalPlayer()) {
+        if (!state.sablegravity$isEnabled()
+            || (player.level().isClientSide() && !player.isLocalPlayer())) {
             return;
         }
 
-        SubLevel frame = SableLocalPlayerPhysics.getAttachedFrameIfPresent(player);
+        // The local client owns movement, but the server still owns pose/entity-data
+        // synchronization. Its upright parent-world fit test sees the rotated ship as unrelated
+        // terrain and rejects CROUCHING even though the exact ship-local OBB fits. Use the same
+        // frame-aware fit contract on both authoritative endpoints; remote client replicas only
+        // consume the synchronized pose and do not run this branch.
+        SubLevel frame = player.isLocalPlayer()
+            ? SableLocalPlayerPhysics.getAttachedFrameIfPresent(player)
+            : Sable.HELPER.getTrackingSubLevel(player);
         if (frame == null || frame.isRemoved() || frame.getLevel() != player.level()) {
             return;
         }

src/main/java/dev/nightly/sablegravity/mixin/SableCollisionYawMixin.java

@@ -14,6 +14,7 @@ import net.minecraft.world.phys.Vec3;
 import org.joml.Quaterniondc;
 import org.joml.Vector3d;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.Redirect;
@@ -66,7 +67,7 @@ public abstract class SableCollisionYawMixin {
         return SubLevelEntityCollision.getHitBoxYaw(pose);
     }
 
-    /** Rotates non-player bodies around their invariant raw feet position, never around the eye. */
+    /** Rotates gravity bodies around their invariant raw/network feet position, never the eye. */
     @Inject(
         method = "transformEntityBoundsCenter",
         at = @At("HEAD"),
@@ -80,12 +81,7 @@ public abstract class SableCollisionYawMixin {
         Vector3d center,
         CallbackInfo ci
     ) {
-        if (entity instanceof Player || orientation == null) {
+        if (!sablegravity$usesFeetAnchoredBody(entity, orientation)) {
-            return;
-        }
-        GravityEntityState state = (GravityEntityState) entity;
-        if (state.sablegravity$isInLocalSimulation()
-            || state.sablegravity$getFrameId() == null) {
             return;
         }
 
@@ -117,17 +113,39 @@ public abstract class SableCollisionYawMixin {
         float partialTicks,
         Quaterniondc orientation
     ) {
-        if (!(entity instanceof Player) && orientation != null) {
+        if (sablegravity$usesFeetAnchoredBody(entity, orientation)) {
-            GravityEntityState state = (GravityEntityState) entity;
+            return new Vector3d(
-            if (!state.sablegravity$isInLocalSimulation()
+                entity.getX(),
-                && state.sablegravity$getFrameId() != null) {
+                entity.getY() - partialTicks,
-                return new Vector3d(
+                entity.getZ()
-                    entity.getX(),
+            );
-                    entity.getY() - partialTicks,
-                    entity.getZ()
-                );
-            }
         }
         return companion.getFeetPos(entity, partialTicks, orientation);
     }
+
+    @Unique
+    private static boolean sablegravity$usesFeetAnchoredBody(
+        Entity entity,
+        Quaterniondc orientation
+    ) {
+        if (orientation == null) {
+            return false;
+        }
+
+        GravityEntityState state = (GravityEntityState) entity;
+        if (state.sablegravity$isInLocalSimulation()) {
+            return false;
+        }
+
+        if (entity instanceof Player player) {
+            if (!player.isLocalPlayer()
+                || !((SableGravityState) player).sablegravity$isEnabled()) {
+                return false;
+            }
+            SubLevel frame = SableLocalPlayerPhysics.getAttachedFrameIfPresent(player);
+            return frame != null && !frame.isRemoved() && frame.getLevel() == player.level();
+        }
+
+        return state.sablegravity$getFrameId() != null;
+    }
 }

src/main/java/dev/nightly/sablegravity/physics/SableLocalPlayerPhysics.java

@@ -130,11 +130,9 @@ public final class SableLocalPlayerPhysics {
     ) {
         SubLevel previousFrame = validFrame(player, ATTACHED_FRAMES.get(player));
 
-        // Sable's custom-orientation OBB is rotated around the eye, while vanilla stores the raw
+        // Raw/network position is the invariant physical feet point. The collision mixin rotates
-        // entity position at the unrotated feet. Switching the quaternion without rebasing the raw
+        // the OBB center around it, so attaching or changing pose never needs a packet-coordinate
-        // position moves the physical OBB bottom by up to twice the eye height. That exact offset
+        // rebase.
-        // was then reported as inheritedMotion (2.32 blocks in the supplied log) and launched the
-        // player. Preserve the physical feet point and change only the raw eye-anchor position.
         Vec3 physicalFeet;
         if (previousFrame != null) {
             physicalFeet = SableOrientedBounds.worldFeet(
@@ -238,8 +236,7 @@ public final class SableLocalPlayerPhysics {
         if (attached != null
             && !attached.isRemoved()
             && attached.getLevel() == player.level()) {
-            // Undo the eye-anchor raw-position rebase before vanilla resumes treating position()
+            // Keep the invariant physical feet when vanilla resumes upright collision.
-            // as the physical feet. Otherwise toggling gravity off visibly teleports the player.
             Vec3 physicalFeet = SableOrientedBounds.worldFeet(
                 player,
                 SableFrameOrientation.getFrameOrientation(attached, 1.0F)
@@ -324,7 +321,7 @@ public final class SableLocalPlayerPhysics {
         // Incrementally adding lastPose -> logicalPose deltas accumulated interpolation and
         // client/server round-off as a small tangent displacement every tick; the player had zero
         // local X/Z velocity but still slid off the deck. The local feet coordinate is the source
-        // of truth, so converge the raw eye-anchor position to its current logical-pose image.
+        // of truth, so converge raw/network feet to its current logical-pose image.
         Vec3 actualFrameMotion = applyCorrectedFrameMotion(player, frameMotion);
         LAST_FRAME_MOTION.put(player, actualFrameMotion);
         Vector3d inheritedVelocity =

src/main/java/dev/nightly/sablegravity/physics/SableOrientedBounds.java

@@ -9,7 +9,7 @@ import org.joml.Quaterniondc;
 import org.joml.Vector3d;
 
 /**
- * Canonical dimensions and the exact eye-anchored OBB used by Sable gravity entities.
+ * Canonical dimensions for the feet-anchored OBB used by Sable gravity entities.
  *
  * Minecraft's AABB type cannot encode an arbitrary orientation. The exact body is therefore
  * represented by a center, half extents and quaternion; {@link #worldEnvelope(Entity, Quaterniondc)}
@@ -32,58 +32,36 @@ public final class SableOrientedBounds {
         );
     }
 
-    /** Exact world-space OBB center matching Sable's transformEntityBoundsCenter contract. */
+    /** Exact world-space OBB center: raw entity position is always the physical feet point. */
     public static Vec3 worldCenter(Entity entity, Quaterniondc orientation) {
         double halfHeight = entity.getBbHeight() * 0.5D;
-        double anchorOffset = entity.getEyeHeight() - halfHeight;
         Vector3d rotatedOffset = orientation.transform(
-            new Vector3d(0.0D, anchorOffset, 0.0D),
+            new Vector3d(0.0D, halfHeight, 0.0D),
             new Vector3d()
         );
         Vec3 position = entity.position();
         return new Vec3(
-            position.x - rotatedOffset.x,
+            position.x + rotatedOffset.x,
-            position.y + entity.getEyeHeight() - rotatedOffset.y,
+            position.y + rotatedOffset.y,
-            position.z - rotatedOffset.z
+            position.z + rotatedOffset.z
         );
     }
 
-    /** Physical feet point after rotating the canonical body around the eye anchor. */
+    /** Raw/network position and physical feet are the same invariant point. */
     public static Vec3 worldFeet(Entity entity, Quaterniondc orientation) {
-        Vector3d rotatedEyeOffset = orientation.transform(
+        return entity.position();
-            new Vector3d(0.0D, entity.getEyeHeight(), 0.0D),
-            new Vector3d()
-        );
-        Vec3 position = entity.position();
-        return new Vec3(
-            position.x - rotatedEyeOffset.x,
-            position.y + entity.getEyeHeight() - rotatedEyeOffset.y,
-            position.z - rotatedEyeOffset.z
-        );
     }
 
     /**
-     * Converts a physical world-space feet point back to Minecraft's raw entity position for
+     * Converts physical feet to raw/network position. The orientation is intentionally irrelevant:
-     * Sable's eye-anchored custom orientation contract.
+     * pose and eye-height changes must never move the packet coordinate.
-     *
-     * <p>Sable rotates a custom entity OBB around the eye. Therefore {@code Entity.position()}
-     * is no longer the physical bottom-center of the OBB. Keeping the feet fixed while changing
-     * orientation requires moving the raw position by {@code Q * eyeOffset - worldEyeOffset}.</p>
      */
     public static Vec3 rawPositionForFeet(
         Entity entity,
         Vec3 physicalFeet,
         Quaterniondc orientation
     ) {
-        Vector3d rotatedEyeOffset = orientation.transform(
+        return physicalFeet;
-            new Vector3d(0.0D, entity.getEyeHeight(), 0.0D),
-            new Vector3d()
-        );
-        return new Vec3(
-            physicalFeet.x + rotatedEyeOffset.x,
-            physicalFeet.y + rotatedEyeOffset.y - entity.getEyeHeight(),
-            physicalFeet.z + rotatedEyeOffset.z
-        );
     }
 
     public static Vec3 localFeet(

src/main/resources/META-INF/neoforge.mods.toml

@@ -4,7 +4,7 @@ license = "All Rights Reserved"
 
 [[mods]]
 modId = "sablegravity"
-version = "0.7.4-player-recovery"
+version = "0.7.5-foot-anchor"
 displayName = "Sable Gravity Local Physics"
 authors = "Nightly"
 description = '''Sable ship-local player gravity and collision. Non-player entities remain on Sable's native lifecycle while the universal frame layer is rebuilt safely.'''