Loop unit transfer command

core/assets/bundles/bundle.properties

@@ -359,6 +359,7 @@ command.enterPayload = Enter Payload Block
 command.loadUnits = Load Units
 command.loadBlocks = Load Blocks
 command.unloadPayload = Unload Payload
+command.loopPayload = Loop Unit Transfer
 stance.stop = Cancel Orders
 stance.shoot = Stance: Shoot
 stance.holdfire = Stance: Hold Fire
@@ -1274,6 +1275,7 @@ keybind.unit_command_load_units.name = Unit Command: Load Units
 keybind.unit_command_load_blocks.name = Unit Command: Load Blocks
 keybind.unit_command_unload_payload.name = Unit Command: Unload Payload
 keybind.unit_command_enter_payload.name = Unit Command: Enter Payload
+keybind.unit_command_loop_payload.name = Unit Command: Loop Unit Transfer
 
 keybind.rebuild_select.name = Rebuild Region
 keybind.schematic_select.name = Select Region

core/src/mindustry/ai/UnitCommand.java

@@ -17,7 +17,7 @@ public class UnitCommand extends MappableContent{
     @Deprecated
     public static final Seq<UnitCommand> all = new Seq<>();
 
-    public static UnitCommand moveCommand, repairCommand, rebuildCommand, assistCommand, mineCommand, boostCommand, enterPayloadCommand, loadUnitsCommand, loadBlocksCommand, unloadPayloadCommand;
+    public static UnitCommand moveCommand, repairCommand, rebuildCommand, assistCommand, mineCommand, boostCommand, enterPayloadCommand, loadUnitsCommand, loadBlocksCommand, unloadPayloadCommand, loopPayloadCommand;
 
     /** Name of UI icon (from Icon class). */
     public final String icon;
@@ -110,5 +110,10 @@ public class UnitCommand extends MappableContent{
             drawTarget = true;
             resetTarget = false;
         }};
+        loopPayloadCommand = new UnitCommand("loopPayload", "resize", Binding.unit_command_loop_payload, null){{
+            switchToMove = false;
+            drawTarget = true;
+            resetTarget = false;
+        }};
     }
 }

core/src/mindustry/ai/types/CommandAI.java

@@ -20,11 +20,12 @@ public class CommandAI extends AIController{
     protected static final Vec2 vecOut = new Vec2(), vecMovePos = new Vec2();
     protected static final boolean[] noFound = {false};
     protected static final UnitPayload tmpPayload = new UnitPayload(null);
+    protected static final int transferStateNone = 0, transferStateLoad = 1, transferStateUnload = 2;
 
     public Seq<Position> commandQueue = new Seq<>(5);
     public @Nullable Vec2 targetPos;
     public @Nullable Teamc attackTarget;
-    /** Group of units that were all commanded to reach the same point.. */
+    /** Group of units that were all commanded to reach the same point. */
     public @Nullable UnitGroup group;
     public int groupIndex = 0;
     /** All encountered unreachable buildings of this AI. Why a sequence? Because contains() is very rarely called on it. */
@@ -36,6 +37,7 @@ public class CommandAI extends AIController{
     protected Vec2 lastTargetPos;
     protected boolean blockingUnit;
     protected float timeSpentBlocked;
+    protected int transferState = transferStateNone;
 
     /** Stance, usually related to firing mode. */
     public UnitStance stance = UnitStance.shoot;
@@ -113,6 +115,13 @@ public class CommandAI extends AIController{
         attackTarget = null;
     }
 
+    void tryPickupUnit(Payloadc pay){
+        Unit target = Units.closest(unit.team, unit.x, unit.y, unit.type.hitSize * 2f, u -> u.isAI() && u != unit && u.isGrounded() && pay.canPickup(u) && u.within(unit, u.hitSize + unit.hitSize));
+        if(target != null){
+            Call.pickedUnitPayload(unit, target);
+        }
+    }
+
     public void defaultBehavior(){
 
         if(!net.client() && unit instanceof Payloadc pay){
@@ -123,10 +132,7 @@ public class CommandAI extends AIController{
 
             //try to pick up what's under it
             if(command == UnitCommand.loadUnitsCommand){
-                Unit target = Units.closest(unit.team, unit.x, unit.y, unit.type.hitSize * 2f, u -> u.isAI() && u != unit && u.isGrounded() && pay.canPickup(u) && u.within(unit, u.hitSize + unit.hitSize));
+                tryPickupUnit(pay);
-                if(target != null){
-                    Call.pickedUnitPayload(unit, target);
-                }
             }
 
             //try to pick up a block
@@ -223,7 +229,8 @@ public class CommandAI extends AIController{
             //TODO: should the unit stop when it finds a target?
             if(
                 (stance == UnitStance.patrol && target != null && unit.within(target, unit.type.range - 2f) && !unit.type.circleTarget) ||
-                (command == UnitCommand.enterPayloadCommand && unit.within(targetPos, 4f) || (targetBuild != null && unit.within(targetBuild, targetBuild.block.size * tilesize/2f * 0.9f)))
+                (command == UnitCommand.enterPayloadCommand && unit.within(targetPos, 4f) || (targetBuild != null && unit.within(targetBuild, targetBuild.block.size * tilesize/2f * 0.9f))) ||
+                (command == UnitCommand.loopPayloadCommand && unit.within(targetPos, 10f))
             ){
                 move = false;
             }
@@ -330,6 +337,46 @@ public class CommandAI extends AIController{
             return;
         }
 
+        if(!net.client() && command == UnitCommand.loopPayloadCommand && unit instanceof Payloadc pay){
+
+            if(transferState == transferStateNone){
+                transferState = pay.hasPayload() ? transferStateUnload : transferStateLoad;
+            }
+
+            if(transferState == transferStateUnload){
+                //drop until there's a failure
+                int prev = -1;
+                while(pay.hasPayload() && prev != pay.payloads().size){
+                    prev = pay.payloads().size;
+                    Call.payloadDropped(unit, unit.x, unit.y);
+                }
+
+                //wait for everything to unload before running code below
+                if(pay.hasPayload()){
+                    return;
+                }
+            }else if(transferState == transferStateLoad){
+                //pick up units until there's a failure
+                int prev = -1;
+                while(prev != pay.payloads().size){
+                    prev = pay.payloads().size;
+                    tryPickupUnit(pay);
+                }
+
+                //wait to load things before running code below
+                if(!pay.hasPayload()){
+                    return;
+                }
+            }
+
+            //it will never finish
+            if(commandQueue.size == 0){
+                return;
+            }
+        }
+
+        transferState = transferStateNone;
+
         Vec2 prev = targetPos;
         targetPos = null;
 
@@ -341,7 +388,7 @@ public class CommandAI extends AIController{
                 commandPosition(position);
             }
 
-            if(prev != null && stance == UnitStance.patrol){
+            if(prev != null && (stance == UnitStance.patrol || command == UnitCommand.loopPayloadCommand)){
                 commandQueue.add(prev.cpy());
             }
 

core/src/mindustry/entities/comp/PayloadComp.java

@@ -147,7 +147,8 @@ abstract class PayloadComp implements Posc, Rotc, Hitboxc, Unitc{
         Unit u = payload.unit;
 
         //can't drop ground units
-        if(!u.canPass(tileX(), tileY()) || Units.count(x, y, u.physicSize(), o -> o.isGrounded()) > 1){
+        //allow stacking for small units for now - otherwise, unit transfer would get annoying
+        if(!u.canPass(tileX(), tileY()) || Units.count(x, y, u.physicSize(), o -> o.isGrounded() && o.hitSize > 14f) > 1){
             return false;
         }
 

core/src/mindustry/input/Binding.java

@@ -60,6 +60,7 @@ public enum Binding implements KeyBind{
     unit_command_load_units(KeyCode.unset),
     unit_command_load_blocks(KeyCode.unset),
     unit_command_unload_payload(KeyCode.unset),
+    unit_command_loop_payload(KeyCode.unset),
 
     category_prev(KeyCode.comma, "blocks"),
     category_next(KeyCode.period),

core/src/mindustry/input/InputHandler.java

@@ -1088,6 +1088,20 @@ public abstract class InputHandler implements InputProcessor, GestureListener{
                         }
                     }
                 }
+
+                if(ai.targetPos != null && ai.currentCommand() == UnitCommand.loopPayloadCommand && unit instanceof Payloadc pay){
+                    Draw.color(Pal.accent, 0.4f + Mathf.absin(5f, 0.5f));
+                    TextureRegion region = pay.hasPayload() ? Icon.download.getRegion() : Icon.upload.getRegion();
+                    float offset = 11f;
+                    float size = 8f;
+                    Draw.rect(region, ai.targetPos.x, ai.targetPos.y + offset, size, size / region.ratio());
+
+                    if(ai.commandQueue.size > 0){
+                        region = !pay.hasPayload() ? Icon.download.getRegion() : Icon.upload.getRegion();
+                        Draw.rect(region, ai.commandQueue.first().getX(), ai.commandQueue.first().getY() + offset, size, size / region.ratio());
+                    }
+                    Draw.color();
+                }
             }
 
             for(var commandBuild : commandBuildings){

core/src/mindustry/io/TypeIO.java

@@ -581,7 +581,7 @@ public class TypeIO{
                 if(ai.command == null) ai.command = UnitCommand.moveCommand;
             }
 
-            //command queue only in type 7
+            //command queue only in type 7/8
             if(type == 7 || type == 8){
                 ai.commandQueue.clear();
                 int length = read.ub();

core/src/mindustry/type/UnitType.java

@@ -853,7 +853,7 @@ public class UnitType extends UnlockableContent implements Senseable{
                     cmds.add(UnitCommand.mineCommand);
                 }
                 if(example instanceof Payloadc){
-                    cmds.addAll(UnitCommand.loadUnitsCommand, UnitCommand.loadBlocksCommand, UnitCommand.unloadPayloadCommand);
+                    cmds.addAll(UnitCommand.loadUnitsCommand, UnitCommand.loadBlocksCommand, UnitCommand.unloadPayloadCommand, UnitCommand.loopPayloadCommand);
                 }
             }
 

core/src/mindustry/ui/fragments/PlacementFragment.java

@@ -529,6 +529,10 @@ public class PlacementFragment{
                                 if(stances.size > 1){
                                     u.row();
 
+                                    if(commands.size > 1){
+                                        u.add(new Image(Tex.whiteui)).height(3f).color(Pal.gray).pad(7f).growX().row();
+                                    }
+
                                     u.table(coms -> {
                                         coms.left();
                                         int scol = 0;