Slug is distributed as a static library that has a basic C++ interface, and full source is included with every license. Slug is platform agnostic and runs on Windows, Mac, Linux, iOS, Android, and all major game consoles. It can be used with Vulkan, Direct3D 10/11/12, OpenGL 3.0–4.6, Metal, and WebGL2. The API is fully documented in the
Slug User Manual.
The primary function of Slug is to take a Unicode string (encoded as UTF-8), lay out the corresponding glyphs, and generate a vertex buffer containing the data needed to draw them. When text is rendered, your application binds the vertex buffer, one of our glyph shaders, and two texture maps associated with the font. One texture holds all of the Bézier curve data, and the other texture holds spatial data structures that Slug uses for efficient rendering.
Slug can render each glyph as a single quad. This has the advantage that it’s easy to clip to an irregular shape or project onto a curved surface in a 3D environment. It also means that vertex buffer storage requirements do not depend on the complexity of the glyphs. There is also an optimization that uses a tighter polygon having between three and six vertices that can be enabled to increase speed at moderate and large font sizes.)
