added marker lines and boxes with client synchro fixes.

src/main/java/carpet/mixins/DebugRenderer_scarpetRenderMixin.java

@@ -0,0 +1,38 @@
+package carpet.mixins;
+
+import carpet.network.CarpetClient;
+import carpet.script.utils.ShapesRenderer;
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.render.VertexConsumerProvider;
+import net.minecraft.client.render.debug.DebugRenderer;
+import net.minecraft.client.util.math.MatrixStack;
+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.callback.CallbackInfo;
+
+@Mixin(DebugRenderer.class)
+public class DebugRenderer_scarpetRenderMixin
+{
+    private ShapesRenderer shapes;
+
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void addRenderers(MinecraftClient client, CallbackInfo ci)
+    {
+        shapes = new ShapesRenderer(client);
+        CarpetClient.shapes = shapes;
+    }
+
+    @Inject(method = "reset", at = @At("HEAD"))
+    private void resetScarpetRenderes(CallbackInfo ci)
+    {
+        shapes.reset();
+    }
+
+    @Inject(method = "render", at = @At("HEAD"))
+    private void renderScarpetThings(MatrixStack matrices, VertexConsumerProvider.Immediate vertexConsumers, double cameraX, double cameraY, double cameraZ, CallbackInfo ci)
+    {
+        shapes.render(matrices, vertexConsumers, cameraX, cameraY, cameraZ);
+    }
+
+}

src/main/java/carpet/network/CarpetClient.java

@@ -1,6 +1,7 @@
 package carpet.network;
 
 import carpet.CarpetServer;
+import carpet.script.utils.ShapesRenderer;
 import net.minecraft.client.network.ClientPlayerEntity;
 import net.minecraft.util.Identifier;
 
@@ -10,6 +11,7 @@ public class CarpetClient
     public static final int HI = 69;
     public static final int HELLO = 420;
     public static final int DATA = 1;
+    public static ShapesRenderer shapes = null;
 
     private static ClientPlayerEntity clientPlayer = null;
     private static boolean isServerCarpet = false;

src/main/java/carpet/network/ClientNetworkHandler.java

@@ -11,6 +11,7 @@ import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.Tag;
 import net.minecraft.network.packet.c2s.play.CustomPayloadC2SPacket;
 import net.minecraft.util.PacketByteBuf;
+import net.minecraft.world.dimension.DimensionType;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -35,6 +36,17 @@ public class ClientNetworkHandler
             }
         });
         put("TickRate", (p, t) -> TickSpeed.tickrate(((AbstractNumberTag)t).getFloat(), false));
+        put("renderShape", (p, t) -> {
+            if (CarpetClient.shapes != null)
+            {
+                CompoundTag boxData = (CompoundTag)t;
+                CarpetClient.shapes.addShape(
+                        boxData.getString("type"),
+                        DimensionType.byRawId(boxData.getInt("dim")),
+                        boxData
+                );
+            }
+        });
     }};
 
 

src/main/java/carpet/network/ServerNetworkHandler.java

@@ -6,16 +6,18 @@ import carpet.helpers.TickSpeed;
 import carpet.settings.ParsedRule;
 import io.netty.buffer.Unpooled;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.Tag;
 import net.minecraft.network.packet.s2c.play.CustomPayloadS2CPacket;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.util.PacketByteBuf;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 
 public class ServerNetworkHandler
 {
-    private static List<ServerPlayerEntity> carpetPlayers = new ArrayList<>();
+    public static Set<ServerPlayerEntity> remoteCarpetPlayers = new HashSet<>();
+    public static Set<ServerPlayerEntity> validCarpetPlayers = new HashSet<>();
 
     public static void handleData(PacketByteBuf data, ServerPlayerEntity player)
     {
@@ -35,11 +37,17 @@ public class ServerNetworkHandler
                     (new PacketByteBuf(Unpooled.buffer())).writeVarInt(CarpetClient.HI).writeString(CarpetSettings.carpetVersion)
             ));
         }
+        else
+        {
+            validCarpetPlayers.add(playerEntity);
+        }
+
     }
 
     public static void onHello(ServerPlayerEntity playerEntity, PacketByteBuf packetData)
     {
-        carpetPlayers.add(playerEntity);
+        remoteCarpetPlayers.add(playerEntity);
+        validCarpetPlayers.add(playerEntity);
         String clientVersion = packetData.readString(64);
         if (clientVersion.equals(CarpetSettings.carpetVersion))
             CarpetSettings.LOG.info("Player "+playerEntity.getName().getString()+" joined with a matching carpet client");
@@ -52,7 +60,7 @@ public class ServerNetworkHandler
     
     public static void updateRuleWithConnectedClients(ParsedRule<?> rule)
     {
-        for (ServerPlayerEntity player : carpetPlayers)
+        for (ServerPlayerEntity player : remoteCarpetPlayers)
         {
             player.networkHandler.sendPacket(new CustomPayloadS2CPacket(
                     CarpetClient.CARPET_CHANNEL,
@@ -63,7 +71,7 @@ public class ServerNetworkHandler
     
     public static void updateTickSpeedToConnectedPlayers()
     {
-        for (ServerPlayerEntity player : carpetPlayers)
+        for (ServerPlayerEntity player : remoteCarpetPlayers)
         {
             player.networkHandler.sendPacket(new CustomPayloadS2CPacket(
                     CarpetClient.CARPET_CHANNEL,
@@ -72,15 +80,40 @@ public class ServerNetworkHandler
         }
     }
 
+    public static void sendCustomCommand(String command, Tag data)
+    {
+        for (ServerPlayerEntity player : validCarpetPlayers)
+        {
+            player.networkHandler.sendPacket(new CustomPayloadS2CPacket(
+                    CarpetClient.CARPET_CHANNEL,
+                    DataBuilder.create().withCustomNbt(command, data).build()
+            ));
+        }
+    }
+
+    public static void sendCustomCommand(ServerPlayerEntity player, String command, Tag data)
+    {
+        if (validCarpetPlayers.contains(player))
+        {
+            player.networkHandler.sendPacket(new CustomPayloadS2CPacket(
+                    CarpetClient.CARPET_CHANNEL,
+                    DataBuilder.create().withCustomNbt(command, data).build()
+            ));
+        }
+    }
+
+
     public static void onPlayerLoggedOut(ServerPlayerEntity player)
     {
+        validCarpetPlayers.remove(player);
         if (!player.networkHandler.connection.isLocal())
-            carpetPlayers.remove(player);
+            remoteCarpetPlayers.remove(player);
     }
 
     public static void close()
     {
-        carpetPlayers.clear();
+        remoteCarpetPlayers.clear();
+        validCarpetPlayers.clear();
     }
 
     private static class DataBuilder
@@ -112,6 +145,13 @@ public class ServerNetworkHandler
             rules.put(rule.name, ruleNBT);
             return this;
         }
+
+        public DataBuilder withCustomNbt(String key, Tag value)
+        {
+            tag.put(key, value);
+            return this;
+        }
+
         private PacketByteBuf build()
         {
             PacketByteBuf packetBuf = new PacketByteBuf(Unpooled.buffer());
@@ -119,5 +159,7 @@ public class ServerNetworkHandler
             packetBuf.writeCompoundTag(tag);
             return packetBuf;
         }
+
+
     }
 }

src/main/java/carpet/script/CarpetExpression.java

@@ -21,6 +21,7 @@ import carpet.script.exception.ContinueStatement;
 import carpet.script.exception.ExitStatement;
 import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InternalExpressionException;
+import carpet.script.utils.ShapeDispatcher;
 import carpet.script.value.BlockValue;
 import carpet.script.value.EntityValue;
 import carpet.script.value.FormattedTextValue;
@@ -63,7 +64,6 @@ import net.minecraft.item.TridentItem;
 import net.minecraft.network.packet.s2c.play.ContainerSlotUpdateS2CPacket;
 import net.minecraft.network.packet.s2c.play.PlaySoundIdS2CPacket;
 import net.minecraft.command.arguments.ItemStackArgument;
-import net.minecraft.command.arguments.ParticleArgumentType;
 import net.minecraft.enchantment.Enchantments;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
@@ -148,7 +148,6 @@ import static carpet.script.utils.WorldTools.canHasChunk;
 import static java.lang.Math.abs;
 import static java.lang.Math.max;
 import static java.lang.Math.min;
-import static java.lang.Math.sqrt;
 
 public class CarpetExpression
 {
@@ -261,90 +260,6 @@ public class CarpetExpression
         return bs;
     }
 
-    private static final Map<String, ParticleEffect> particleCache = new HashMap<>();
-    private ParticleEffect getParticleData(String name)
-    {
-        ParticleEffect particle = particleCache.get(name);
-        if (particle != null)
-            return particle;
-        try
-        {
-            particle = ParticleArgumentType.readParameters(new StringReader(name));
-        }
-        catch (CommandSyntaxException e)
-        {
-            throw new InternalExpressionException("No such particle: "+name);
-        }
-        particleCache.put(name, particle);
-        return particle;
-    }
-
-
-    private boolean isStraight(Vec3d from, Vec3d to, double density)
-    {
-        if ( (from.x == to.x && from.y == to.y) || (from.x == to.x && from.z == to.z) || (from.y == to.y && from.z == to.z))
-            return from.distanceTo(to) / density > 20;
-        return false;
-    }
-
-    private int drawOptimizedParticleLine(ServerWorld world, ParticleEffect particle, Vec3d from, Vec3d to, double density)
-    {
-        double distance = from.distanceTo(to);
-        int particles = (int)(distance/density);
-        Vec3d towards = to.subtract(from);
-        int parts = 0;
-        for (PlayerEntity player : world.getPlayers())
-        {
-            world.spawnParticles((ServerPlayerEntity)player, particle, true,
-                    (towards.x)/2+from.x, (towards.y)/2+from.y, (towards.z)/2+from.z, particles/3,
-                    towards.x/6, towards.y/6, towards.z/6, 0.0);
-            world.spawnParticles((ServerPlayerEntity)player, particle, true,
-                    from.x, from.y, from.z,1,0.0,0.0,0.0,0.0);
-            world.spawnParticles((ServerPlayerEntity)player, particle, true,
-                    to.x, to.y, to.z,1,0.0,0.0,0.0,0.0);
-            parts += particles/3+2;
-        }
-        int divider = 6;
-        while (particles/divider > 1)
-        {
-            int center = (divider*2)/3;
-            int dev = 2*divider;
-            for (PlayerEntity player : world.getPlayers())
-            {
-                world.spawnParticles((ServerPlayerEntity)player, particle, true,
-                        (towards.x)/center+from.x, (towards.y)/center+from.y, (towards.z)/center+from.z, particles/divider,
-                        towards.x/dev, towards.y/dev, towards.z/dev, 0.0);
-                world.spawnParticles((ServerPlayerEntity)player, particle, true,
-                        (towards.x)*(1.0-1.0/center)+from.x, (towards.y)*(1.0-1.0/center)+from.y, (towards.z)*(1.0-1.0/center)+from.z, particles/divider,
-                        towards.x/dev, towards.y/dev, towards.z/dev, 0.0);
-            }
-            parts += 2*particles/divider;
-            divider = 2*divider;
-        }
-        return parts;
-    }
-
-    private int drawParticleLine(ServerWorld world, ParticleEffect particle, Vec3d from, Vec3d to, double density)
-    {
-        if (isStraight(from, to, density)) return drawOptimizedParticleLine(world, particle, from, to, density);
-        double lineLengthSq = from.squaredDistanceTo(to);
-        if (lineLengthSq == 0) return 0;
-        Vec3d incvec = to.subtract(from).multiply(2*density/sqrt(lineLengthSq));
-        int pcount = 0;
-        for (Vec3d delta = new Vec3d(0.0,0.0,0.0);
-             delta.lengthSquared()<lineLengthSq;
-             delta = delta.add(incvec.multiply(Expression.randomizer.nextFloat())))
-        {
-            for (PlayerEntity player : world.getPlayers())
-            {
-                world.spawnParticles((ServerPlayerEntity)player, particle, true,
-                        delta.x+from.x, delta.y+from.y, delta.z+from.z, 1,
-                        0.0, 0.0, 0.0, 0.0);
-                pcount ++;
-            }
-        }
-        return pcount;
-    }
 
     private static void forceChunkUpdate(BlockPos pos, ServerWorld world)
     {
@@ -2625,7 +2540,7 @@ public class CarpetExpression
                     }
                 }
             }
-            ParticleEffect particle = getParticleData(particleName);
+            ParticleEffect particle = ShapeDispatcher.getParticleData(particleName);
             Vec3d vec = locator.vec;
             if (player == null)
             {
@@ -2650,36 +2565,73 @@ public class CarpetExpression
             CarpetContext cc = (CarpetContext)c;
             ServerWorld world = cc.s.getWorld();
             String particleName = lv.get(0).evalValue(c).getString();
-            ParticleEffect particle = getParticleData(particleName);
+            ParticleEffect particle = ShapeDispatcher.getParticleData(particleName);
             Vector3Argument pos1 = Vector3Argument.findIn(cc, lv, 1);
             Vector3Argument pos2 = Vector3Argument.findIn(cc, lv, pos1.offset);
-            int offset = pos2.offset;
-            double density = (lv.size() > offset)? NumericValue.asNumber(lv.get(offset).evalValue(c)).getDouble():1.0;
-            if (density <= 0)
+            double density = 1.0;
+            ServerPlayerEntity player = null;
+            if (lv.size() > pos2.offset+0 )
             {
-                throw new InternalExpressionException("Particle density should be positive");
+                density = NumericValue.asNumber(lv.get(pos2.offset+0).evalValue(c)).getDouble();
+                if (density <= 0)
+                {
+                    throw new InternalExpressionException("Particle density should be positive");
+                }
+                if (lv.size() > pos2.offset+1)
+                {
+                    Value playerValue = lv.get(pos2.offset+1).evalValue(c);
+                    if (playerValue instanceof EntityValue)
+                    {
+                        Entity e = ((EntityValue) playerValue).getEntity();
+                        if (!(e instanceof ServerPlayerEntity)) throw new InternalExpressionException("'particle_line' player argument has to be a player");
+                        player = (ServerPlayerEntity) e;
+                    }
+                    else
+                    {
+                        player = cc.s.getMinecraftServer().getPlayerManager().getPlayer(playerValue.getString());
+                    }
+                }
             }
-            Value retval = new NumericValue(drawParticleLine(world, particle, pos1.vec, pos2.vec, density));
+
+            Value retval = new NumericValue(ShapeDispatcher.drawParticleLine(
+                    (player == null)?world.getPlayers():Collections.singletonList(player),
+                    particle, pos1.vec, pos2.vec, density));
+
             return (c_, t_) -> retval;
         });
 
-        this.expr.addLazyFunction("particle_rect", -1, (c, t, lv) ->
+        this.expr.addLazyFunction("particle_box", -1, (c, t, lv) ->
         {
             CarpetContext cc = (CarpetContext)c;
             ServerWorld world = cc.s.getWorld();
             String particleName = lv.get(0).evalValue(c).getString();
-            ParticleEffect particle = getParticleData(particleName);
+            ParticleEffect particle = ShapeDispatcher.getParticleData(particleName);
             Vector3Argument pos1 = Vector3Argument.findIn(cc, lv, 1);
             Vector3Argument pos2 = Vector3Argument.findIn(cc, lv, pos1.offset);
-            int offset = pos2.offset;
+
             double density = 1.0;
-            if (lv.size() > offset)
+            ServerPlayerEntity player = null;
+            if (lv.size() > pos2.offset+0 )
             {
-                density = NumericValue.asNumber(lv.get(offset).evalValue(c)).getDouble();
-            }
-            if (density <= 0)
-            {
-                throw new InternalExpressionException("Particle density should be positive");
+                density = NumericValue.asNumber(lv.get(pos2.offset+0).evalValue(c)).getDouble();
+                if (density <= 0)
+                {
+                    throw new InternalExpressionException("Particle density should be positive");
+                }
+                if (lv.size() > pos2.offset+1)
+                {
+                    Value playerValue = lv.get(pos2.offset+1).evalValue(c);
+                    if (playerValue instanceof EntityValue)
+                    {
+                        Entity e = ((EntityValue) playerValue).getEntity();
+                        if (!(e instanceof ServerPlayerEntity)) throw new InternalExpressionException("'particle_box' player argument has to be a player");
+                        player = (ServerPlayerEntity) e;
+                    }
+                    else
+                    {
+                        player = cc.s.getMinecraftServer().getPlayerManager().getPlayer(playerValue.getString());
+                    }
+                }
             }
             Vec3d a = pos1.vec;
             Vec3d b = pos2.vec;
@@ -2689,24 +2641,107 @@ public class CarpetExpression
             double bx = max(a.x, b.x);
             double by = max(a.y, b.y);
             double bz = max(a.z, b.z);
-            int pc = 0;
-            pc += drawParticleLine(world, particle, new Vec3d(ax, ay, az), new Vec3d(ax, by, az), density);
-            pc += drawParticleLine(world, particle, new Vec3d(ax, by, az), new Vec3d(bx, by, az), density);
-            pc += drawParticleLine(world, particle, new Vec3d(bx, by, az), new Vec3d(bx, ay, az), density);
-            pc += drawParticleLine(world, particle, new Vec3d(bx, ay, az), new Vec3d(ax, ay, az), density);
-
-            pc += drawParticleLine(world, particle, new Vec3d(ax, ay, bz), new Vec3d(ax, by, bz), density);
-            pc += drawParticleLine(world, particle, new Vec3d(ax, by, bz), new Vec3d(bx, by, bz), density);
-            pc += drawParticleLine(world, particle, new Vec3d(bx, by, bz), new Vec3d(bx, ay, bz), density);
-            pc += drawParticleLine(world, particle, new Vec3d(bx, ay, bz), new Vec3d(ax, ay, bz), density);
-
-            pc += drawParticleLine(world, particle, new Vec3d(ax, ay, az), new Vec3d(ax, ay, bz), density);
-            pc += drawParticleLine(world, particle, new Vec3d(ax, by, az), new Vec3d(ax, by, bz), density);
-            pc += drawParticleLine(world, particle, new Vec3d(bx, by, az), new Vec3d(bx, by, bz), density);
-            pc += drawParticleLine(world, particle, new Vec3d(bx, ay, az), new Vec3d(bx, ay, bz), density);
-            int particleCount = pc;
+            int particleCount = ShapeDispatcher.Box.mesh(
+                    player==null?world.getPlayers():Collections.singletonList(player),
+                    particle, density, ax, ay, az, bx, by, bz
+            );
             return (c_, t_) -> new NumericValue(particleCount);
         });
+        // deprecated
+        this.expr.alias("particle_rect", "particle_box");
+
+
+        this.expr.addLazyFunction("marker_box", -1, (c, t, lv) ->
+        {
+            CarpetContext cc = (CarpetContext)c;
+            Vector3Argument from = Vector3Argument.findIn(cc, lv, 0);
+            Vector3Argument to = Vector3Argument.findIn(cc, lv, from.offset);
+            int duration = 10;
+            int color = -1; // hwite
+            ServerPlayerEntity player = null;
+
+            if (lv.size() > to.offset+0 )
+            {
+                duration = NumericValue.asNumber(lv.get(to.offset).evalValue(c)).getInt();
+                if (duration <= 0)
+                {
+                    throw new InternalExpressionException("Particle density should be positive");
+                }
+                if (lv.size() > to.offset + 1)
+                {
+                    color = NumericValue.asNumber(lv.get(to.offset+1).evalValue(c)).getInt();
+
+
+                    if (lv.size() > to.offset + 2)
+                    {
+                        Value playerValue = lv.get(to.offset + 2).evalValue(c);
+                        if (playerValue instanceof EntityValue)
+                        {
+                            Entity e = ((EntityValue) playerValue).getEntity();
+                            if (!(e instanceof ServerPlayerEntity))
+                                throw new InternalExpressionException("'particle_box' player argument has to be a player");
+                            player = (ServerPlayerEntity) e;
+                        }
+                        else
+                        {
+                            player = cc.s.getMinecraftServer().getPlayerManager().getPlayer(playerValue.getString());
+                        }
+                    }
+                }
+            }
+            ShapeDispatcher.sendShape(
+                    (player==null)?cc.s.getWorld().getPlayers():Collections.singletonList(player),
+                    cc.s.getWorld().getDimension().getType(),
+                    new ShapeDispatcher.Box(duration, from.vec, to.vec, color)
+            );
+            return LazyValue.TRUE;
+        });
+
+        this.expr.addLazyFunction("marker_line", -1, (c, t, lv) ->
+        {
+            CarpetContext cc = (CarpetContext)c;
+            Vector3Argument from = Vector3Argument.findIn(cc, lv, 0);
+            Vector3Argument to = Vector3Argument.findIn(cc, lv, from.offset);
+            int duration = 10;
+            int color = -1; // hwite
+            ServerPlayerEntity player = null;
+
+            if (lv.size() > to.offset+0 )
+            {
+                duration = NumericValue.asNumber(lv.get(to.offset).evalValue(c)).getInt();
+                if (duration <= 0)
+                {
+                    throw new InternalExpressionException("Particle density should be positive");
+                }
+                if (lv.size() > to.offset + 1)
+                {
+                    color = NumericValue.asNumber(lv.get(to.offset+1).evalValue(c)).getInt();
+
+
+                    if (lv.size() > to.offset + 2)
+                    {
+                        Value playerValue = lv.get(to.offset + 2).evalValue(c);
+                        if (playerValue instanceof EntityValue)
+                        {
+                            Entity e = ((EntityValue) playerValue).getEntity();
+                            if (!(e instanceof ServerPlayerEntity))
+                                throw new InternalExpressionException("'particle_box' player argument has to be a player");
+                            player = (ServerPlayerEntity) e;
+                        }
+                        else
+                        {
+                            player = cc.s.getMinecraftServer().getPlayerManager().getPlayer(playerValue.getString());
+                        }
+                    }
+                }
+            }
+            ShapeDispatcher.sendShape(
+                    (player==null)?cc.s.getWorld().getPlayers():Collections.singletonList(player),
+                    cc.s.getWorld().getDimension().getType(),
+                    new ShapeDispatcher.Line(duration, from.vec, to.vec, color)
+            );
+            return LazyValue.TRUE;
+        });
 
         this.expr.addLazyFunction("create_marker", -1, (c, t, lv) ->{
             CarpetContext cc = (CarpetContext)c;

src/main/java/carpet/script/Expression.java

@@ -418,6 +418,12 @@ public class Expression
         return result;
     }
 
+    public void alias(String copy, String original)
+    {
+        functions.put(copy, functions.get(original));
+    }
+
+
     private void UserDefinedFunctionsAndControlFlow() // public just to get the javadoc right
     {
         // artificial construct to handle user defined functions and function definitions

src/main/java/carpet/script/utils/ShapeDispatcher.java

@@ -0,0 +1,289 @@
+package carpet.script.utils;
+
+import carpet.network.ServerNetworkHandler;
+import carpet.script.Expression;
+import carpet.script.exception.InternalExpressionException;
+import com.mojang.brigadier.StringReader;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import net.minecraft.command.arguments.ParticleArgumentType;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.particle.ParticleEffect;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.world.dimension.DimensionType;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.function.Consumer;
+
+import static java.lang.Math.sqrt;
+
+public class ShapeDispatcher
+{
+    private static final Map<String, ParticleEffect> particleCache = new HashMap<>();
+
+    public static void sendShape(List<ServerPlayerEntity> players, DimensionType dim, ExpiringShape shape)
+    {
+        Consumer<ServerPlayerEntity> alternative = null;
+        CompoundTag tag = null;
+        for (ServerPlayerEntity player : players)
+        {
+            if (ServerNetworkHandler.validCarpetPlayers.contains(player))
+            {
+                if (tag == null) tag = shape.toTag();
+                tag.putInt("dim", dim.getRawId());
+                ServerNetworkHandler.sendCustomCommand(player,"renderShape", tag);
+            }
+            else
+            {
+                if (alternative == null) alternative = shape.alternative();
+                alternative.accept(player);
+            }
+        }
+    }
+
+    public static void sendBox(ServerPlayerEntity player, int duration, Vec3d from, Vec3d to, int color)
+    {
+
+    }
+
+    public static ParticleEffect getParticleData(String name)
+    {
+        ParticleEffect particle = particleCache.get(name);
+        if (particle != null)
+            return particle;
+        try
+        {
+            particle = ParticleArgumentType.readParameters(new StringReader(name));
+        }
+        catch (CommandSyntaxException e)
+        {
+            throw new InternalExpressionException("No such particle: "+name);
+        }
+        particleCache.put(name, particle);
+        return particle;
+    }
+
+
+    public abstract static class ExpiringShape
+    {
+        protected float r, g, b, a;
+        protected int color;
+        protected int duration = 0;
+        public ExpiringShape(int duration, int color)
+        {
+            this.r = (float)(color >> 24 & 0xFF) / 255.0F;
+            this.g = (float)(color >> 16 & 0xFF) / 255.0F;
+            this.b = (float)(color >>  8 & 0xFF) / 255.0F;
+            this.a = (float)(color & 0xFF) / 255.0F;
+            this.color = color;
+            this.duration = duration;
+        };
+
+        public int getExpiry() { return duration; };
+        public CompoundTag toTag()
+        {
+            CompoundTag tag = new CompoundTag();
+            tag.putInt("color", color);
+            tag.putInt("duration", duration);
+            return tag;
+        };
+        public abstract Consumer<ServerPlayerEntity> alternative();
+    }
+
+    public static class Box extends ExpiringShape
+    {
+        float x1, y1, z1;
+        float x2, y2, z2;
+        public Box(int duration, Vec3d from, Vec3d to, int color)
+        {
+            super(duration, color);
+            x1 = (float)from.x;
+            y1 = (float)from.y;
+            z1 = (float)from.z;
+            x2 = (float)to.x;
+            y2 = (float)to.y;
+            z2 = (float)to.z;
+        }
+
+
+        public static ExpiringShape fromTag(CompoundTag tag)
+        {
+            return new Box(tag.getInt("duration"),
+                    new Vec3d(tag.getFloat("x1"), tag.getFloat("y1"), tag.getFloat("z1")),
+                    new Vec3d(tag.getFloat("x2"), tag.getFloat("y2"), tag.getFloat("z2")),
+                    tag.getInt("color")
+            );
+        }
+
+        @Override
+        public CompoundTag toTag()
+        {
+            CompoundTag tag = super.toTag();
+            tag.putFloat("x1", x1);
+            tag.putFloat("y1", y1);
+            tag.putFloat("z1", z1);
+            tag.putFloat("x2", x2);
+            tag.putFloat("y2", y2);
+            tag.putFloat("z2", z2);
+            tag.putString("type", "debugBox");
+            return tag;
+        }
+
+        @Override
+        public Consumer<ServerPlayerEntity> alternative()
+        {
+            String particleName = String.format(Locale.ROOT , "dust %.1f %.1f %.1f 1.0", r, g, b);
+            ParticleEffect particle = getParticleData(particleName);
+            double dx = x1-x2;
+            double dy = y1-y2;
+            double dz = z1-z2;
+            double density = Math.max(2.0, Math.sqrt(dx*dx+dy*dy+dz*dz) /50) / (a+0.1);
+            return p -> mesh(Collections.singletonList(p), particle, density, x1, y1, z1, x2, y2, z2);
+        }
+
+        public static int mesh(List<ServerPlayerEntity> playerList, ParticleEffect particle, double density,
+                               double x1, double y1, double z1, double x2, double y2, double z2 )
+        {
+            return
+            drawParticleLine(playerList, particle, new Vec3d(x1, y1, z1), new Vec3d(x1, y2, z1), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x1, y2, z1), new Vec3d(x2, y2, z1), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x2, y2, z1), new Vec3d(x2, y1, z1), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x2, y1, z1), new Vec3d(x1, y1, z1), density)+
+
+            drawParticleLine(playerList, particle, new Vec3d(x1, y1, z2), new Vec3d(x1, y2, z2), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x1, y2, z2), new Vec3d(x2, y2, z2), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x2, y2, z2), new Vec3d(x2, y1, z2), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x2, y1, z2), new Vec3d(x1, y1, z2), density)+
+
+            drawParticleLine(playerList, particle, new Vec3d(x1, y1, z1), new Vec3d(x1, y1, z2), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x1, y2, z1), new Vec3d(x1, y2, z2), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x2, y2, z1), new Vec3d(x2, y2, z2), density)+
+            drawParticleLine(playerList, particle, new Vec3d(x2, y1, z1), new Vec3d(x2, y1, z2), density);
+        }
+    }
+
+    public static class Line extends ExpiringShape
+    {
+        float x1, y1, z1;
+        float x2, y2, z2;
+        public Line(int duration, Vec3d from, Vec3d to, int color)
+        {
+            super(duration, color);
+            x1 = (float)from.x;
+            y1 = (float)from.y;
+            z1 = (float)from.z;
+            x2 = (float)to.x;
+            y2 = (float)to.y;
+            z2 = (float)to.z;
+
+        }
+        @Override
+        public CompoundTag toTag()
+        {
+            CompoundTag tag = super.toTag();
+            tag.putFloat("x1", x1);
+            tag.putFloat("y1", y1);
+            tag.putFloat("z1", z1);
+            tag.putFloat("x2", x2);
+            tag.putFloat("y2", y2);
+            tag.putFloat("z2", z2);
+            tag.putString("type", "debugLine");
+            return tag;
+        }
+
+        public static ExpiringShape fromTag(CompoundTag tag)
+        {
+            return new Line(tag.getInt("duration"),
+                    new Vec3d(tag.getFloat("x1"), tag.getFloat("y1"), tag.getFloat("z1")),
+                    new Vec3d(tag.getFloat("x2"), tag.getFloat("y2"), tag.getFloat("z2")),
+                    tag.getInt("color")
+            );
+        }
+        @Override
+        public Consumer<ServerPlayerEntity> alternative()
+        {
+            String particleName = String.format(Locale.ROOT , "dust %.1f %.1f %.1f 1.0", r, g, b);
+            ParticleEffect particle = getParticleData(particleName);
+            Vec3d pos1 = new Vec3d(x1, y1, z1);
+            Vec3d pos2 = new Vec3d(x2, y2, z2);
+            double dx = x1-x2;
+            double dy = y1-y2;
+            double dz = z1-z2;
+            double density = Math.max(2.0, Math.sqrt(dx*dx+dy*dy+dz*dz) /50) / (a+0.1);
+            return p -> drawParticleLine(Collections.singletonList(p), particle, pos1, pos2, density);
+        }
+    }
+
+    private static boolean isStraight(Vec3d from, Vec3d to, double density)
+    {
+        if ( (from.x == to.x && from.y == to.y) || (from.x == to.x && from.z == to.z) || (from.y == to.y && from.z == to.z))
+            return from.distanceTo(to) / density > 20;
+        return false;
+    }
+
+    private static int drawOptimizedParticleLine(List<ServerPlayerEntity> playerList, ParticleEffect particle, Vec3d from, Vec3d to, double density)
+    {
+        double distance = from.distanceTo(to);
+        int particles = (int)(distance/density);
+        Vec3d towards = to.subtract(from);
+        int parts = 0;
+        for (ServerPlayerEntity player : playerList)
+        {
+            ServerWorld world = player.getServerWorld();
+            world.spawnParticles(player, particle, true,
+                    (towards.x)/2+from.x, (towards.y)/2+from.y, (towards.z)/2+from.z, particles/3,
+                    towards.x/6, towards.y/6, towards.z/6, 0.0);
+            world.spawnParticles(player, particle, true,
+                    from.x, from.y, from.z,1,0.0,0.0,0.0,0.0);
+            world.spawnParticles(player, particle, true,
+                    to.x, to.y, to.z,1,0.0,0.0,0.0,0.0);
+            parts += particles/3+2;
+        }
+        int divider = 6;
+        while (particles/divider > 1)
+        {
+            int center = (divider*2)/3;
+            int dev = 2*divider;
+            for (ServerPlayerEntity player : playerList)
+            {
+                ServerWorld world = player.getServerWorld();
+                world.spawnParticles(player, particle, true,
+                        (towards.x)/center+from.x, (towards.y)/center+from.y, (towards.z)/center+from.z, particles/divider,
+                        towards.x/dev, towards.y/dev, towards.z/dev, 0.0);
+                world.spawnParticles(player, particle, true,
+                        (towards.x)*(1.0-1.0/center)+from.x, (towards.y)*(1.0-1.0/center)+from.y, (towards.z)*(1.0-1.0/center)+from.z, particles/divider,
+                        towards.x/dev, towards.y/dev, towards.z/dev, 0.0);
+            }
+            parts += 2*particles/divider;
+            divider = 2*divider;
+        }
+        return parts;
+    }
+
+    public static int drawParticleLine(List<ServerPlayerEntity> players, ParticleEffect particle, Vec3d from, Vec3d to, double density)
+    {
+        if (isStraight(from, to, density)) return drawOptimizedParticleLine(players, particle, from, to, density);
+        double lineLengthSq = from.squaredDistanceTo(to);
+        if (lineLengthSq == 0) return 0;
+        Vec3d incvec = to.subtract(from).multiply(2*density/sqrt(lineLengthSq));
+        int pcount = 0;
+        for (Vec3d delta = new Vec3d(0.0,0.0,0.0);
+             delta.lengthSquared()<lineLengthSq;
+             delta = delta.add(incvec.multiply(Expression.randomizer.nextFloat())))
+        {
+            for (ServerPlayerEntity player : players)
+            {
+                player.getServerWorld().spawnParticles(player, particle, true,
+                        delta.x+from.x, delta.y+from.y, delta.z+from.z, 1,
+                        0.0, 0.0, 0.0, 0.0);
+                pcount ++;
+            }
+        }
+        return pcount;
+    }
+}

src/main/java/carpet/script/utils/ShapesRenderer.java

@@ -1,53 +1,171 @@
 package carpet.script.utils;
 
+import carpet.CarpetSettings;
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.render.RenderLayer;
 import net.minecraft.client.render.VertexConsumer;
 import net.minecraft.client.render.VertexConsumerProvider;
+import net.minecraft.client.util.math.Matrix4f;
 import net.minecraft.client.util.math.MatrixStack;
-import net.minecraft.util.math.Vec3d;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.IWorld;
+import net.minecraft.world.dimension.DimensionType;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
+import java.util.function.BiFunction;
 
 public class ShapesRenderer
 {
-    List<ExpiringShape> shapes;
+    private final Map<DimensionType, List<RenderedShape<? extends ShapeDispatcher.ExpiringShape>>> shapes;
+    private MinecraftClient client;
 
-    void render(MatrixStack matrices, VertexConsumerProvider vertexConsumers, double cameraX, double cameraY, double cameraZ){
+    private Map<String, BiFunction<MinecraftClient, CompoundTag, RenderedShape<? extends ShapeDispatcher.ExpiringShape >>> renderedShapes
+            = new HashMap<String, BiFunction<MinecraftClient, CompoundTag, RenderedShape<? extends ShapeDispatcher.ExpiringShape>>>()
+    {{
+        put("debugBox", RenderedBox::new);
+        put("debugLine", RenderedLine::new);
+    }};
 
-    }
-    void addShape() {}
-
-
-    public abstract static class ExpiringShape
+    public ShapesRenderer(MinecraftClient minecraftClient)
     {
-        protected int r;
-        protected int g;
-        protected int b;
-        protected int a;
-        protected int expiryTick = 0;
-        public abstract void render(MatrixStack matrix, VertexConsumer vertexConsumer);
-        public ExpiringShape expiresIn(int ticks)
+        this.client = minecraftClient;
+        shapes = new HashMap<>();
+        shapes.put(DimensionType.OVERWORLD, new ArrayList<>());
+        shapes.put(DimensionType.THE_NETHER, new ArrayList<>());
+        shapes.put(DimensionType.THE_END, new ArrayList<>());
+    }
+
+    public void render(MatrixStack matrices, VertexConsumerProvider vertexConsumers, double cameraX, double cameraY, double cameraZ)
+    {
+        //Camera camera = this.client.gameRenderer.getCamera();
+        IWorld iWorld = this.client.world;
+        DimensionType dimensionType = iWorld.getDimension().getType();
+        if (shapes.get(dimensionType).isEmpty()) return;
+        //BlockPos blockPos = new BlockPos(camera.getPos().x, 0.0D, camera.getPos().z);
+        VertexConsumer vertexConsumer = vertexConsumers.getBuffer(RenderLayer.getLines());
+        long currentTime = client.world.getTime();
+
+        synchronized (shapes)
         {
-            expiryTick = ticks;
-            return this;
+            Iterator<RenderedShape<? extends ShapeDispatcher.ExpiringShape>> it = shapes.get(dimensionType).iterator();
+            while (it.hasNext())
+            {
+                RenderedShape shape = it.next();
+                if (shape.isExpired(currentTime)) it.remove();
+                shape.render(matrices, vertexConsumer, (float) cameraX, (float) cameraY, (float) cameraZ);
+            }
+        }
+    }
+    public void addShape(String type, DimensionType dim, CompoundTag tag)
+    {
+        BiFunction<MinecraftClient, CompoundTag, RenderedShape<? extends ShapeDispatcher.ExpiringShape >> shapeFactory;
+        shapeFactory = renderedShapes.get(type);
+        if (shapeFactory == null)
+        {
+            CarpetSettings.LOG.error("Unrecognized shape: "+type);
+        }
+        else
+        {
+            synchronized (shapes) { shapes.get(dim).add(shapeFactory.apply(client, tag)); }
+        }
+    }
+    public void reset()
+    {
+        synchronized (shapes)
+        {
+            shapes.values().forEach(List::clear);
+        }
+    }
+
+
+    public abstract static class RenderedShape<T extends ShapeDispatcher.ExpiringShape>
+    {
+        T shape;
+        long expiryTick;
+        public abstract void render(MatrixStack matrices, VertexConsumer vertexConsumer, float cx, float cy, float cz );
+        protected RenderedShape(MinecraftClient client, T shape)
+        {
+            this.shape = shape;
+            expiryTick = client.world.getTime()+shape.getExpiry();
         }
 
+        public boolean isExpired(long currentTick)
+        {
+            return  expiryTick < currentTick;
+        }
     }
 
-    public static class SolidLine extends ExpiringShape
+    public static class RenderedBox extends RenderedShape<ShapeDispatcher.Box>
     {
-        public SolidLine(Vec3d from, Vec3d to, int r, int g, int b, int a)
+        public RenderedBox(MinecraftClient client, CompoundTag boxData)
         {
-            this.r = r;
-            this.g = g;
-            this.b = b;
-            this.a = a;
-
+            super(client, (ShapeDispatcher.Box)ShapeDispatcher.Box.fromTag(boxData));
         }
         @Override
-        public void render(MatrixStack matrix, VertexConsumer vertexConsumer)
+        public void render(MatrixStack matrices, VertexConsumer vertexConsumer, float cx, float cy, float cz)
         {
-
+            drawBox(matrices, vertexConsumer,
+                    shape.x1-cx, shape.y1-cy, shape.z1-cz,
+                    shape.x2-cx, shape.y2-cy, shape.z2-cz,
+                    shape.r, shape.g, shape.b, shape.a, shape.r, shape.g, shape.b
+            );
         }
     }
 
+    public static class RenderedLine extends RenderedShape<ShapeDispatcher.Line>
+    {
+        public RenderedLine(MinecraftClient client, CompoundTag boxData)
+        {
+            super(client, (ShapeDispatcher.Line)ShapeDispatcher.Line.fromTag(boxData));
+        }
+        @Override
+        public void render(MatrixStack matrices, VertexConsumer vertexConsumer, float cx, float cy, float cz)
+        {
+            drawLine(matrices, vertexConsumer,
+                    shape.x1-cx, shape.y1-cy, shape.z1-cz,
+                    shape.x2-cx, shape.y2-cy, shape.z2-cz,
+                    shape.r, shape.g, shape.b, shape.a
+            );
+        }
+    }
+
+    // some raw shit
+
+    public static void drawLine(MatrixStack matrix, VertexConsumer vertexConsumer, float x1, float y1, float z1, float x2, float y2, float z2, float red1, float grn1, float blu1, float alpha) {
+        Matrix4f matrix4f = matrix.peek().getModel();
+        vertexConsumer.vertex(matrix4f, x1, y1, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z2).color(red1, grn1, blu1, alpha).next();
+    }
+
+    public static void drawBox(MatrixStack matrix, VertexConsumer vertexConsumer, float x1, float y1, float z1, float x2, float y2, float z2, float red1, float grn1, float blu1, float alpha, float red2, float grn2, float blu2) {
+        Matrix4f matrix4f = matrix.peek().getModel();
+        vertexConsumer.vertex(matrix4f, x1, y1, z1).color(red1, grn2, blu2, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y1, z1).color(red1, grn2, blu2, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y1, z1).color(red2, grn1, blu2, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y2, z1).color(red2, grn1, blu2, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y1, z1).color(red2, grn2, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y1, z2).color(red2, grn2, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y1, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y2, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y2, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y2, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y2, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y1, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y1, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y1, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y1, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y1, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x1, y2, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y1, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z2).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z1).color(red1, grn1, blu1, alpha).next();
+        vertexConsumer.vertex(matrix4f, x2, y2, z2).color(red1, grn1, blu1, alpha).next();
+    }
 }