selecting_units_and_issuing_commands.md

Selecting Units and Issuing Commands

Objective

Create a system where the player can:

1. Select units using a drag-selection or single-click.
2. Issue a movement command to selected units by clicking on the ground.

Step 1: Setting Up the Scene

1. Add RTSController:

   • Create a RTSController node in your scene.
   • Attach the RTSController.gd script to it.

   Screenshot Suggestion: Show the main scene with the RTSController node added and its inspector panel.

2. Add Managers:

   • As children of the RTSController, add:
     • A SelectionManager node and attach the SelectionManager.gd script.
     • A CommandManager node and attach the CommandManager.gd script.

   Screenshot Suggestion: Show the RTSController with SelectionManager and CommandManager as child nodes.

Step 2: Adding Units to the Scene

1. Create UnitEntity Scene:

   • Create a new UnitEntity scene with:
     • A Node3D as the root (with UnitEntity.gd attached).
     • A Sprite3D for the unit’s visual representation.
     • A SelectableComponent as a child of the root.

   Screenshot Suggestion: Show the UnitEntity scene hierarchy in the editor.

2. Place Units in the World:

   • Instance several UnitEntity scenes and position them in your game world.
   • Group them under a Units node for organization.
   • Ensure each unit has the SelectableComponent and is added to the "units" group.

   Screenshot Suggestion: Show units scattered in the world with the "units" group assigned in the inspector.

Step 3: Configuring Selection

1. Configure SelectionManager:

   • In the SelectionManager script, ensure raycast_manager is correctly assigned to the Raycaster node.
   • Add a ColorRect to the UI layer as the selection box and link it to the selection_box property in the inspector.

   Screenshot Suggestion: Show the SelectionManager with its raycast_manager and selection_box properties configured.

2. Input Mapping:

   • Add input actions in the Input Map for:
     • select: For left mouse button.
     • command: For right mouse button.

   Screenshot Suggestion: Show the input mappings in the project settings.

3. Enable Selection Visualization:

   • Ensure each unit’s SelectableComponent is configured with a Sprite3D and a shader for the selection ring.

   Screenshot Suggestion: Show the SelectableComponent setup in the unit’s scene.

Step 4: Configuring Commands

1. Raycaster Setup:

   • Add a Raycaster node to the main scene and attach the Raycaster.gd script.
   • Configure the raycaster’s collision layers to detect ground surfaces and units.

   Screenshot Suggestion: Show the Raycaster node configuration in the inspector.

2. Implement Commands:

   • In the CommandManager script:
     • Ensure the issue_command method supports move commands.
     • Connect the selected units to their StateMachine and transition to MoveState when a command is issued.

   Screenshot Suggestion: Highlight the issue_command logic in the CommandManager.gd script.

Step 5: Testing the System

1. Test Selection:

   • Run the game and test dragging the selection box or clicking on individual units to select them.
   • Verify that selected units visually highlight using the SelectableComponent.

   Screenshot Suggestion: Capture the drag-selection in action, highlighting units in the selection area.

2. Test Commands:

   • After selecting units, right-click on the ground to issue a move command.
   • Verify that the units move to the target position using NavigationAgent3D.

   Screenshot Suggestion: Capture units moving toward the clicked position.

Step 6: Debugging and Enhancements

1. Debug Logs:
   • Add debug prints in the RTSController, SelectionManager, and CommandManager to ensure the correct units are selected and commands are issued.
2. Enhancements:
   • Add command feedback, such as a visual marker at the target position.
   • Expand the command system to include additional commands like attack or patrol.