Free Godot Shader: 2D Outline and Inline Stroke (Juulpower)

Overview

Juulpower shares a 2D outline/inline shader on Godot Shaders that adds an outer or inner stroke to a texture. The shader is attached to a material on a canvas item such as a sprite and is configurable in color, width, pattern and placement, with the ability to add margins to the texture to make room for an outline.

The page notes that for Godot 3, source_color at line 3 should be replaced by hint_color. The shader code is published on the page under the CC0 license and is free to copy.