Apply a shader when player selects a country.

Author: telrikk

entities/countries/country.gd

@@ -4,6 +4,8 @@ class_name Country
 enum Keys { USA }
 
 @export var country_key: Keys
+@export var sprite: Sprite2D
+var selected_material: Material = preload("res://entities/countries/selected_country_material.tres")
 var country_name: String
 
 func _ready() -> void:
@@ -15,5 +17,9 @@ func _ready() -> void:
 
 func select() -> void:
 	var countries_vm = ViewModelRegistry.retrieve(ViewModelRegistry.Keys.COUNTRIES) as CountriesViewModel
+	sprite.material = selected_material
 	if countries_vm:
 		countries_vm.select_country(country_key)
+
+func unselect() -> void:
+	sprite.material = null

entities/countries/country.gdshader

@@ -0,0 +1,27 @@
+shader_type canvas_item;
+
+//void vertex() {
+	//// Called for every vertex the material is visible on.
+//}
+
+const float frequency = 750.00;
+
+void fragment() {
+    vec4 tex_color = texture(TEXTURE, UV);
+    vec4 overlay_color = vec4(.3, .3, .9, .8);
+    
+    // Create a diagonal striped pattern
+    float stripe = mod((UV.x + UV.y) * frequency, 2) > 1.00 ? 1.0 : 0.0;
+	
+    // Apply overlay only to non-transparent areas and within stripe pattern
+    if (tex_color.a > 0.0 && stripe == 1.0) {
+        COLOR = mix(tex_color, overlay_color, overlay_color.a);
+    } else {
+        COLOR = tex_color;
+    }
+}
+
+//void light() {
+	// Called for every pixel for every light affecting the CanvasItem.
+	// Uncomment to replace the default light processing function with this one.
+//}

entities/countries/country.tscn

@@ -3,8 +3,9 @@
 [ext_resource type="Script" path="res://entities/countries/country.gd" id="1_j7m2o"]
 [ext_resource type="Texture2D" uid="uid://5tcwuxorjhmw" path="res://art/usa.png" id="2_1k81q"]
 
-[node name="Country" type="Area2D"]
+[node name="Country" type="Area2D" node_paths=PackedStringArray("sprite")]
 script = ExtResource("1_j7m2o")
+sprite = NodePath("Sprite2D")
 
 [node name="Sprite2D" type="Sprite2D" parent="."]
 texture = ExtResource("2_1k81q")

entities/countries/selected_country_material.tres

@@ -0,0 +1,6 @@
+[gd_resource type="ShaderMaterial" load_steps=2 format=3 uid="uid://du3ukvaptkks8"]
+
+[ext_resource type="Shader" path="res://entities/countries/country.gdshader" id="1_bbqy0"]
+
+[resource]
+shader = ExtResource("1_bbqy0")

scenes/common/player_controller.gd

@@ -10,6 +10,7 @@ extends Node2D
 @export var menu_scene: PackedScene
 var is_dragging: bool = false
 var menu_instance: Control
+var selected_country: Country
 
 func _ready():
 	Input.mouse_mode = Input.MOUSE_MODE_CONFINED
@@ -26,6 +27,9 @@ func _unhandled_input(event: InputEvent) -> void:
 			for collision in collisions:
 				var country := collision.collider as Country
 				if country:
+					if selected_country:
+						selected_country.unselect()
+					selected_country = country
 					country.select()
 					return