gui_toolkit 0.14.0

Added

• Slug text: font.Settings.text_renderer = .Slug (default .Atlas, unchanged) draws glyphs on the GPU from their quadratic Bézier outlines (Eric Lengyel's Slug algorithm, MIT, patent in the public domain; shaders pinned in font/slug_ref, credit in NOTICE.md): sharp at any scale, rotation, skew or page zoom, exact subpixel positions, no bitmaps, nothing to re-rasterize when the scale changes (a picture of Slug text is never stale for its scale). Color glyphs (emoji) stay on the atlas path.
  • font: outlines come from a provider (font.Outline_Provider, slug_set_provider; DirectWrite's GetGlyphRunOutline on Windows, cubics turned into quadratics within Settings.slug_tolerance), slug_build makes the curve texels (RGBA16F) and band texels (RG16UI), slug_glyph caches them per (face, glyph) in pages of the two textures (Settings.slug_pages, least recently used page reused, pictures that drew from it go stale), slug_sync_page / slug_stats.
  • render: slug.hlsl (compiled after rect.hlsl, which it reuses for transforms, clips and the text correction), KIND_SLUG instances in the ordinary instance list drawn by their own pipeline (Frame_Data.slug_runs, Replay.slug_runs: a batch is drawn in pieces, in order), create_slug_textures, update_slug_page.
  • draw: glyph_run uses it when the setting says so; pictures remember their Slug pages.
  • tools/textcompare: atlas | Slug | difference images and measurements; tests/slug.