added add_chunk_ticket

docs/scarpet/api/BlocksAndWorldAccess.md

@@ -712,3 +712,10 @@ It returns a `map` with a report indicating how many chunks were affected, and h
  * `layer_count_<status>`: number of chunks for which a `<status>` generation step has been performed
  * `layer_time_<status>`: cumulative time for all chunks spent on generating `<status>` step
  
+### add_chunk_ticket(pos, type, radius)
+
+Adds a chunk ticket at a position, which makes the game to keep the designated area centered around
+`pos` with radius of `radius` loaded for a predefined amount of ticks, defined by `type`. Allowed types
+are `portal`: 300 ticks, `teleport`: 5 ticks, and `unknown`: 1 tick. Radius can be from 1 to 32 ticks.
+
+This function is tentative - will likely change when chunk ticket API is properly fleshed out.

docs/scarpet/resources/editors/idea/2.txt

@@ -1,4 +1,5 @@
 air
+add_chunk_ticket
 biome
 blast_resistance
 block

docs/scarpet/resources/editors/npp/scarpet.xml

@@ -56,6 +56,7 @@
                 blocks_movement block_sound material map_colour property block_properties block_data poi set_poi
                 place_item set_biome biome loaded_status generation_status inhabited_time spawn_potential chunk_tickets
                 structure_eligibility structures structure_references set_structure reset_chunk reload_chunk
+                add_chunk_ticket
 
                 scoreboard scoreboard_add scoreboard_remove scoreboard_display
 

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

@@ -88,6 +88,7 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.server.world.ChunkTicket;
+import net.minecraft.server.world.ChunkTicketType;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.sound.BlockSoundGroup;
 import net.minecraft.sound.SoundCategory;
@@ -1383,7 +1384,35 @@ public class CarpetExpression
             return (_c, _t) -> ret;
         });
 
+        this.expr.addLazyFunction("add_chunk_ticket", -1, (c, t, lv) ->
+        {
+            CarpetContext cc = (CarpetContext)c;
+            BlockArgument locator = BlockArgument.findIn(cc, lv, 0);
+            BlockPos pos = locator.block.getPos();
+            if (lv.size() != locator.offset+2) throw new InternalExpressionException("'add_chunk_ticket' requires block position, ticket type and radius");
+            String type = lv.get(locator.offset).evalValue(c).getString();
+            ChunkTicketType ticket = ticketTypes.get(type.toLowerCase(Locale.ROOT));
+            if (ticket == null) throw new InternalExpressionException("Unknown ticket type: "+type);
+            int radius = NumericValue.asNumber(lv.get(locator.offset+1).evalValue(c)).getInt();
+            if (radius < 1 || radius > 32) throw new InternalExpressionException("Ticket radius should be between 1 and 32 chunks");
+            // due to types we will wing it:
+            ChunkPos target = new ChunkPos(pos);
+            if (ticket == ChunkTicketType.PORTAL)
+                cc.s.getWorld().getChunkManager().addTicket(ChunkTicketType.PORTAL, target, radius, pos);
+            else if (ticket == ChunkTicketType.POST_TELEPORT)
+                cc.s.getWorld().getChunkManager().addTicket(ChunkTicketType.POST_TELEPORT, target, radius, 1);
+            else
+                cc.s.getWorld().getChunkManager().addTicket(ChunkTicketType.UNKNOWN, target, radius, target);
+            Value ret = new NumericValue(ticket.getExpiryTicks());
+            return (_c, _t) -> ret;
+        });
+
     }
+    private Map<String, ChunkTicketType<?>> ticketTypes = new HashMap<String, ChunkTicketType<?>>(){{
+        put("portal", ChunkTicketType.PORTAL);
+        put("teleport", ChunkTicketType.POST_TELEPORT);
+        put("unknown", ChunkTicketType.UNKNOWN);
+    }};
 
     private static String getScoreboardKeyFromValue(Value keyValue)
     {