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);
+    }
+
+}