Add alpha change for cell based on hp left to restore the cell

Author: Overkane

game/ship_skeleton/cell/cell.gd

@@ -14,6 +14,7 @@ var _related_movemenet_collision_shape: CollisionShape2D
 
 @onready var hurtbox_2d: ComponentHurtbox2D = %Hurtbox2D
 @onready var health_component: ComponentHealth = %Health
+@onready var sprite_2d: Sprite2D = %Sprite2D
 
 
 func _ready() -> void:
@@ -29,11 +30,12 @@ func _physics_process(delta: float) -> void:
 
 		if can_restore:
 			health_component.current_health += repair_rate * delta
+			(sprite_2d.material as ShaderMaterial).set_shader_parameter("hp_ratio", health_component.get_current_health_percentage())
+
 			if health_component.current_health >= health_component.max_health:
 				restored.emit()
 				_related_movemenet_collision_shape.disabled = false
 				hurtbox_2d.monitorable = true
-				modulate.a = 1.0
 				is_destroyed = false
 		elif health_component.current_health > 0:
 			health_component.current_health = 0
@@ -57,6 +59,8 @@ func _on_health_depleted() -> void:
 	modulate.a = 0.5
 	hurtbox_2d.monitorable = false
 	is_destroyed = true
+	(sprite_2d.material as ShaderMaterial).set_shader_parameter("hp_ratio", 0.0)
+
 	for child_cell: Cell in core_children:
 		child_cell.health_component.current_health = 0
 

game/ship_skeleton/cell/cell.gdshader

@@ -0,0 +1,30 @@
+shader_type canvas_item;
+
+uniform float hp_ratio = 1.0;
+
+void vertex() {
+	// Called for every vertex the material is visible on.
+}
+
+void fragment() {
+	// Called for every pixel the material is visible on.
+	vec4 tex_color = texture(TEXTURE, UV);
+
+	float dist = distance(UV, vec2(0.5));
+
+	if (tex_color.a > 0.0) {
+		if (dist < 0.5 * hp_ratio) {
+			tex_color.a = 1.0;
+		} else {
+			tex_color.a = 0.3;
+		}
+	}
+	//tex_color.a = mix(tex_color.a, 1.0, boost_factor);
+
+	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.
+//}

game/ship_skeleton/cell/cell.gdshader.uid

@@ -0,0 +1 @@
+uid://4ojyrld7fshk

game/ship_skeleton/cell/cell.tscn

@@ -1,27 +1,35 @@
 [gd_scene format=3 uid="uid://73o17dpehsvx"]
 
 [ext_resource type="Script" uid="uid://bt6o8bkpam2te" path="res://game/ship_skeleton/cell/cell.gd" id="1_cjhyy"]
+[ext_resource type="Shader" uid="uid://4ojyrld7fshk" path="res://game/ship_skeleton/cell/cell.gdshader" id="2_mnm1f"]
 [ext_resource type="Texture2D" uid="uid://bcuoljnurrnwp" path="res://game/ship_skeleton/cell/cells/basic_cell/medium_basic_cell.svg" id="2_ruldg"]
 [ext_resource type="PackedScene" uid="uid://b4154adjjbvvc" path="res://components/hurtbox/component_hurtbox_2d.tscn" id="3_mnm1f"]
 [ext_resource type="PackedScene" uid="uid://cc0xm7ql0sgut" path="res://components/health/component_health.tscn" id="4_ruldg"]
 
+[sub_resource type="ShaderMaterial" id="ShaderMaterial_0jsgn"]
+resource_local_to_scene = true
+shader = ExtResource("2_mnm1f")
+shader_parameter/hp_ratio = 1.0
+
 [sub_resource type="CircleShape2D" id="CircleShape2D_ruldg"]
-radius = 31.016125
+radius = 25.0
 
 [node name="Cell" type="Node2D" unique_id=1435320636]
 script = ExtResource("1_cjhyy")
-health = 5.0
 repair_rate = 1.0
 metadata/_edit_group_ = true
 
 [node name="Sprite2D" type="Sprite2D" parent="." unique_id=1975990942]
+unique_name_in_owner = true
+material = SubResource("ShaderMaterial_0jsgn")
 texture = ExtResource("2_ruldg")
 
 [node name="Hurtbox2D" parent="." unique_id=146611675 instance=ExtResource("3_mnm1f")]
 unique_name_in_owner = true
 collision_layer = 524288
 
 [node name="CollisionShape2D" parent="Hurtbox2D" index="0" unique_id=2074960276]
+visible = false
 shape = SubResource("CircleShape2D_ruldg")
 
 [node name="Health" parent="." unique_id=562956058 instance=ExtResource("4_ruldg")]