gdd.md

@@ -8,6 +8,19 @@
 * Education
 * Supply chains
 
+## Interaction Modes
+
+Interaction modes can be changed via keyboard shortcut.
+
+### Selection Mode
+
+This is the default interaction mode.
+It can be accessed at any time by pressing the `esc` key.
+
+### Build Mode
+
+Build mode can be entered by pressing the `b` key.
+
 ## Critical Path
 
 ### Grid

half-earth/nodes/debug_ui.tscn

@@ -8,6 +8,22 @@ anchor_bottom = 1.0
 script = ExtResource( 1 )
 TicksLabelPath = NodePath("Ticks")
 PauseLabelPath = NodePath("Paused")
+InteractionModeLabelPath = NodePath("Interaction Mode")
+
+[node name="Interaction Mode" type="Label" parent="."]
+anchor_left = 1.0
+anchor_top = 1.0
+anchor_right = 1.0
+anchor_bottom = 1.0
+margin_left = -94.0
+margin_top = -64.0
+margin_right = -10.0
+margin_bottom = -50.0
+grow_horizontal = 0
+grow_vertical = 0
+text = "mode: SELECT"
+align = 2
+valign = 2
 
 [node name="Ticks" type="Label" parent="."]
 anchor_left = 1.0

half-earth/nodes/game.tscn

@@ -1,9 +1,10 @@
-[gd_scene load_steps=5 format=2]
+[gd_scene load_steps=6 format=2]
 
 [ext_resource path="res://nodes/grid.tscn" type="PackedScene" id=1]
 [ext_resource path="res://nodes/grid_cursor.tscn" type="PackedScene" id=2]
 [ext_resource path="res://nodes/debug_ui.tscn" type="PackedScene" id=3]
 [ext_resource path="res://nodes/clock.tscn" type="PackedScene" id=4]
+[ext_resource path="res://nodes/interaction_mode.tscn" type="PackedScene" id=5]
 
 [node name="Root" type="Node"]
 
@@ -18,6 +19,9 @@ Grid = NodePath("../Grid")
 [node name="Clock" parent="." instance=ExtResource( 4 )]
 _autoTick = true
 
+[node name="Interaction Mode" parent="." instance=ExtResource( 5 )]
+
 [connection signal="OnPauseChanged" from="Clock" to="Debug UI" method="_on_Clock_OnPauseChanged"]
 [connection signal="OnTick" from="Clock" to="Grid" method="_on_Clock_OnTick"]
 [connection signal="OnTick" from="Clock" to="Debug UI" method="_on_Clock_OnTick"]
+[connection signal="OnInteractionModeChanged" from="Interaction Mode" to="Debug UI" method="_on_Interaction_Mode_OnInteractionModeChanged"]

half-earth/nodes/interaction_mode.tscn

@@ -0,0 +1,7 @@
+[gd_scene load_steps=2 format=2]
+
+[ext_resource path="res://scripts/InteractionMode.cs" type="Script" id=1]
+
+[node name="Interaction Mode" type="Node"]
+script = ExtResource( 1 )
+_buildMode = 66

half-earth/scripts/DebugUI.cs

@@ -11,27 +11,29 @@ public class DebugUI : Control
     public NodePath PauseLabelPath { private get; set; }
     private Label _pauseLabel;
 
+    [Export]
+    public NodePath InteractionModeLabelPath { private get; set; }
+    private Label _interactionModeLabel;
     public override void _Ready()
     {
         _ticksLabel = GetNode<Label>(TicksLabelPath);
         _pauseLabel = GetNode<Label>(PauseLabelPath);
-
-        SetTicksText(0);
-        SetPauseText(false);
+        _interactionModeLabel = GetNode<Label>(InteractionModeLabelPath);
     }
 
     #region Signals
-    public void _on_Clock_OnPauseChanged(bool paused) => SetPauseText(paused);
-    public void _on_Clock_OnTick(int ticks) => SetTicksText(ticks);
+    public void _on_Clock_OnPauseChanged(bool paused) =>
+        SetLabelText(_pauseLabel, "pause", paused);
+
+    public void _on_Clock_OnTick(int ticks) =>
+        SetLabelText(_ticksLabel, "ticks", ticks);
+
+    public void _on_Interaction_Mode_OnInteractionModeChanged(InteractionMode.Mode oldMode, InteractionMode.Mode newMode) =>
+        SetLabelText(_interactionModeLabel, "mode", newMode);
     #endregion
 
-    private void SetTicksText(int ticks)
+    private void SetLabelText(Label label, string key, object value)
     {
-        _ticksLabel.Text = $"ticks: {ticks}";
-    }
-
-    private void SetPauseText(bool paused)
-    {
-        _pauseLabel.Text = $"pause: {paused}";
+        label.Text = $"{key}: {value}";
     }
 }

half-earth/scripts/InteractionMode.cs

@@ -0,0 +1,58 @@
+using Godot;
+using System;
+
+public class InteractionMode : Node
+{
+    [Export]
+    private KeyList _buildMode;
+
+    [Signal]
+    delegate void OnInteractionModeChanged(Mode oldMode, Mode newMode);
+
+    public enum Mode
+    {
+        SELECT = 0,
+        BUILD = 1
+    }
+
+    public Mode Current
+    {
+        get => _current;
+        set
+        {
+            if (_current == value)
+                return;
+
+            var old = _current;
+            _current = value;
+
+            EmitSignal(nameof(OnInteractionModeChanged), old, _current);
+        }
+    }
+    private Mode _current = Mode.SELECT;
+
+    public override void _Input(InputEvent @event)
+    {
+        base._Input(@event);
+
+        if (!(@event is InputEventKey keyEvent))
+            return;
+
+        if (!keyEvent.Pressed)
+            return;
+
+        var key = (KeyList)keyEvent.Scancode;
+
+        // TODO: this should be developed into a UI stack
+        if (key == KeyList.Escape)
+        {
+            Current = Mode.SELECT;
+            return;
+        }
+
+        if (key == _buildMode)
+        {
+            Current = Mode.BUILD;
+        }
+    }
+}