add border to title screen logo

scenes/TitleScreen.tscn

@@ -1,7 +1,8 @@
-[gd_scene load_steps=6 format=3 uid="uid://42qq4ke7te0s"]
+[gd_scene load_steps=8 format=3 uid="uid://42qq4ke7te0s"]
 
 [ext_resource type="Theme" uid="uid://cw2jrsfudbjvg" path="res://default_theme.tres" id="1_clfqb"]
 [ext_resource type="Texture2D" uid="uid://c3wki3kjoisgc" path="res://assets/art/logo_transparent.PNG" id="2_3quqd"]
+[ext_resource type="Shader" path="res://shaders/logo.gdshader" id="2_ohgnl"]
 
 [sub_resource type="Theme" id="Theme_1ea38"]
 default_font_size = 50
@@ -12,6 +13,11 @@ default_font_size = 50
 [sub_resource type="Theme" id="Theme_py6c5"]
 default_font_size = 50
 
+[sub_resource type="ShaderMaterial" id="ShaderMaterial_nh4jm"]
+shader = ExtResource("2_ohgnl")
+shader_parameter/line_color = Color(0, 0, 0, 1)
+shader_parameter/line_thickness = 10.0
+
 [node name="TitleScreen" type="Panel"]
 offset_left = -2.0
 offset_top = -2.0
@@ -68,6 +74,7 @@ theme = SubResource("Theme_py6c5")
 text = "Fullscreen"
 
 [node name="Logo" type="Sprite2D" parent="."]
+material = SubResource("ShaderMaterial_nh4jm")
 position = Vector2(1500, 548)
 scale = Vector2(0.889648, 0.889648)
 texture = ExtResource("2_3quqd")

shaders/logo.gdshader

@@ -0,0 +1,22 @@
+shader_type canvas_item;
+
+uniform vec4 line_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);
+uniform float line_thickness : hint_range(0, 10) = 1.0;
+
+const vec2 OFFSETS[8] = {
+	vec2(-1, -1), vec2(-1, 0), vec2(-1, 1), vec2(0, -1), vec2(0, 1), 
+	vec2(1, -1), vec2(1, 0), vec2(1, 1)
+};
+
+void fragment() {
+	vec2 size = TEXTURE_PIXEL_SIZE * line_thickness;
+	float outline = 0.0;
+
+	for (int i = 0; i < OFFSETS.length(); i++) {
+		outline += texture(TEXTURE, UV + size * OFFSETS[i]).a;
+	}
+	outline = min(outline, 1.0);
+
+	vec4 color = texture(TEXTURE, UV);
+	COLOR = mix(color, line_color, outline - color.a);
+}