improved handling of fake players in boats and when pushed by slimeblocks. Fixes #507

src/main/java/carpet/mixins/EntityMixin.java

@@ -1,10 +1,16 @@
 package carpet.mixins;
 
 import carpet.fakes.EntityInterface;
+import carpet.patches.EntityPlayerMPFake;
 import net.minecraft.entity.Entity;
 import net.minecraft.util.math.MathHelper;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 @Mixin(Entity.class)
 public abstract class EntityMixin implements EntityInterface
@@ -15,8 +21,18 @@ public abstract class EntityMixin implements EntityInterface
     @Shadow
     public float prevYaw;
 
+    @Shadow public @Nullable abstract Entity getPrimaryPassenger();
+
+    @Shadow public World world;
+
     public float getMainYaw(float partialTicks)
     {
         return partialTicks == 1.0F ? this.yaw : MathHelper.lerp(partialTicks, this.prevYaw, this.yaw);
     }
+
+    @Inject(method = "isLogicalSideForUpdatingMovement", at = @At("HEAD"), cancellable = true)
+    private void isFakePlayer(CallbackInfoReturnable<Boolean> cir)
+    {
+        if (getPrimaryPassenger() instanceof EntityPlayerMPFake) cir.setReturnValue(!world.isClient);
+    }
 }

src/main/java/carpet/mixins/PistonBlockEntity_creativeNoClipMixin.java

@@ -1,29 +0,0 @@
-package carpet.mixins;
-
-import carpet.CarpetSettings;
-import net.minecraft.block.entity.PistonBlockEntity;
-import net.minecraft.entity.Entity;
-import net.minecraft.entity.player.PlayerEntity;
-import net.minecraft.util.math.Direction;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.Redirect;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
-
-@Mixin(PistonBlockEntity.class)
-public class PistonBlockEntity_creativeNoClipMixin
-{
-    @Inject(method = "method_23672", at = @At("HEAD"), cancellable = true)
-    private static void dontPushSpectators(Direction direction, Entity entity, double d, Direction direction2, CallbackInfo ci)
-    {
-        if (CarpetSettings.creativeNoClip && entity instanceof PlayerEntity && (((PlayerEntity) entity).isCreative()) && ((PlayerEntity) entity).abilities.flying) ci.cancel();
-    }
-
-    @Redirect(method = "pushEntities", at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/Entity;setVelocity(DDD)V"))
-    private void ignoreAccel(Entity entity, double x, double y, double z)
-    {
-        if (CarpetSettings.creativeNoClip && entity instanceof PlayerEntity && (((PlayerEntity) entity).isCreative()) && ((PlayerEntity) entity).abilities.flying) return;
-        entity.setVelocity(x,y,z);
-    }
-}

src/main/java/carpet/mixins/PistonBlockEntity_playerHandlingMixin.java

@@ -0,0 +1,69 @@
+package carpet.mixins;
+
+import carpet.CarpetSettings;
+import carpet.patches.EntityPlayerMPFake;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.Blocks;
+import net.minecraft.block.entity.PistonBlockEntity;
+import net.minecraft.block.piston.PistonBehavior;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.math.Direction;
+import net.minecraft.util.math.Vec3d;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(PistonBlockEntity.class)
+public abstract class PistonBlockEntity_playerHandlingMixin
+{
+    @Shadow private BlockState pushedBlock;
+
+    @Shadow public abstract Direction getMovementDirection();
+
+    @Inject(method = "method_23672", at = @At("HEAD"), cancellable = true)
+    private static void dontPushSpectators(Direction direction, Entity entity, double d, Direction direction2, CallbackInfo ci)
+    {
+        if (CarpetSettings.creativeNoClip && entity instanceof PlayerEntity && (((PlayerEntity) entity).isCreative()) && ((PlayerEntity) entity).abilities.flying) ci.cancel();
+    }
+
+    @Redirect(method = "pushEntities", at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/Entity;setVelocity(DDD)V"))
+    private void ignoreAccel(Entity entity, double x, double y, double z)
+    {
+        if (CarpetSettings.creativeNoClip && entity instanceof PlayerEntity && (((PlayerEntity) entity).isCreative()) && ((PlayerEntity) entity).abilities.flying) return;
+        entity.setVelocity(x,y,z);
+    }
+
+    @Redirect(method = "pushEntities", at = @At(
+            value = "INVOKE",
+            target = "Lnet/minecraft/entity/Entity;getPistonBehavior()Lnet/minecraft/block/piston/PistonBehavior;"
+    ))
+    private PistonBehavior moveFakePlayers(Entity entity)
+    {
+        if (entity instanceof EntityPlayerMPFake && pushedBlock.isOf(Blocks.SLIME_BLOCK))
+        {
+            Vec3d vec3d = entity.getVelocity();
+            double e = vec3d.x;
+            double f = vec3d.y;
+            double g = vec3d.z;
+            Direction direction = getMovementDirection();
+            switch(direction.getAxis()) {
+                case X:
+                    e = (double)direction.getOffsetX();
+                    break;
+                case Y:
+                    f = (double)direction.getOffsetY();
+                    break;
+                case Z:
+                    g = (double)direction.getOffsetZ();
+            }
+
+            entity.setVelocity(e, f, g);
+        }
+        return entity.getPistonBehavior();
+    }
+
+}

src/main/resources/carpet.mixins.json

@@ -180,7 +180,7 @@
     "WorldChunk_movableTEMixin",
     "PistonHandler_customStickyMixin",
     "PlayerEntity_creativeNoClipMixin",
-    "PistonBlockEntity_creativeNoClipMixin",
+    "PistonBlockEntity_playerHandlingMixin",
     "BlockItem_creativeNoClipMixin",
     "LivingEntity_creativeFlyMixin"