Generate Makepad Font and Text Rendering Code

Makepad Font Skill is an expert reference for text and font rendering in the Makepad Rust UI framework, covering font configuration, text layout/shaping, and GPU-based text rendering via signed distance fields (SDF) (tracks the makepad-widgets dev branch). It generates font/text DSL and Rust code and explains the underlying font module architecture.

Before answering, it is instructed to read a local font-system.md reference file and incorporate its content, falling back to SKILL.md patterns plus built-in knowledge if the file is missing or empty (surfacing a documentation-sync command to the user in that case). It maps the text module's internal file structure - font.rs (handle/metrics), font_atlas.rs (GPU glyph texture atlas), font_face.rs, font_family.rs, fonts.rs (built-ins), glyph_outline.rs/glyph_raster_image.rs, layouter.rs (layout engine), rasterizer.rs, sdfer.rs (SDF generator), selection.rs, and shaper.rs (harfbuzz-based text shaping).

<Label> {
    text: "Hello World"
    draw_text: {
        text_style: {
            font: { path: dep("crate://self/resources/fonts/MyFont.ttf") }
            font_size: 16.0
            line_spacing: 1.5
            letter_spacing: 0.0
        }
        color: #FFFFFF
    }
}

It covers using fonts in DSL three ways: inline text_style configuration, theme fonts (<THEME_FONT_REGULAR> with a theme font-size variable), and defining reusable named font prototypes (FONT_REGULAR, FONT_BOLD) that reference embedded font paths via dep("crate://..."). The Layouter API is documented with its constructor and methods (define_font_family, define_font, get_or_layout, is_font_family_known) plus its layout parameter structs - OwnedLayoutParams (text, spans, options), Span/Style (font family, size, color per span), and LayoutOptions (max width for wrapping, wrap toggle, first-line indent). Rasterizer settings cover the default glyph cache size (4096), and SDF-specific tuning (padding, radius, cutoff) plus grayscale (4096x4096) and color/emoji (2048x2048) atlas dimensions.

It distinguishes the simple Label widget (plain text with a single style) from TextFlow for rich text composition with Bold, Italic, and Link (with an href) child elements. A text-properties table covers eight configurable properties: text, font, font_size, line_spacing, letter_spacing, color, brightness, and curve (a text-curve visual effect).

Six conceptual points guide question-answering: Makepad uses SDF for crisp text at any scale, fonts are loaded once and cached in GPU texture atlases, text shaping uses harfbuzz for correct glyph positioning, dep("crate://...") is the syntax for embedded font resources, the default font cache holds 4096 glyphs, and atlas sizes are 4096x4096 grayscale versus 2048x2048 for color/emoji glyphs.

Use this skill for Makepad font configuration (families, sizes, styles), text layout and shaping questions, or GPU-based SDF text rendering tasks.

It is scoped to Makepad's text/font rendering system specifically, not DSL composition, layout containers, animation, events, or shaders covered by sibling Makepad skills. It is not a substitute for environment-specific validation, testing, or expert review - if local reference documentation is missing, it flags this explicitly rather than silently guessing beyond its built-in knowledge.

Inputs: a request to configure font styling, define reusable font prototypes, or understand text layout/rasterization behavior in a Makepad app.

Outputs: DSL text_style blocks, font prototype definitions, and Layouter/rasterizer configuration matching the requested text behavior.

Part of the Makepad skill family alongside basics, DSL, layout, animation, event/action, shader, deployment, and reference skills; references local font-system.md documentation kept in sync via a /sync-crate-skills makepad command; text shaping is powered by harfbuzz.

Makepad developers configuring fonts, tuning text rendering quality/performance, or building rich-text widgets who need the correct DSL and Layouter/rasterizer API usage.