aboutsummaryrefslogtreecommitdiffstats
path: root/src/symbols.h
Commit message (Collapse)AuthorAgeFilesLines
* Name Vega's parts: lib/, surfaces/ and symbols/eunhhu2026-09-271-54/+0
| | | | | | | src/ held two parts, the surfaces that show modules to people and the symbol format with its CPU and GPU drawing. As in Pure (design 009), top level directories are now the parts, and the README says what each builds.
* Store symbol outlines as point chains, and keep glyph advances wholeeunhhu2026-09-271-11/+27
| | | | | | | | | | | | | | | | | | | | Format 2 (VEGASYM2) writes each contour as a chain of 4-byte points, on or off the curve as in TrueType: endpoints are shared, lines have no control point, and two off points imply the on point between them. A curve is still had from one point and its two neighbours, so a GPU can point at curves by point index and upload the table as it is. Cubics (CFF, SVG curves and arcs) become quadratic splines the cu2qu way, joins left implied, within a unit. Files are about half of format 1: 1.3-1.4x a TrueType font's glyf (the whole subset font's size), 2.0-2.9x CFF, 2.6x smaller than the SVG icons. Opening checks each symbol's first and last point instead of every curve: 0.34 ms rather than 19 ms for 11,172 Hangul syllables. Points decode without branching on their flags (9.7 ns a point), still 1.2-10x cheaper than FreeType's outline. Glyph advances were half their width since outlines are doubled for FreeType's implied points; they now match hmtx, and the check says so.
* Draw glyphs and icons from one symbol format, by exact pixel areaeunhhu2026-09-271-0/+38
Symbol files (VEGASYM1) hold glyphs and icons as quadratic curves, verified once per symbol and then read in place. vega-symbols builds them from fonts (through FreeType, losslessly: twice the font's units keeps TrueType's implied points whole) and from solid SVG paths (arcs included), refusing by name what an icon asks for that symbols cannot hold. The reference rasterizer computes each pixel's covered area exactly: every curve's integral of clamp(1 - x) dy inside the pixel, split where it crosses the pixel's sides. The Slug-style two-ray average first tried missed FreeType by 15.4 levels on average at 12 px; exact area is within 1.2-3.5 at 8-16 px, and where it differs most it matches 64x64 supersampling, not FreeType. Reaching an outline costs 4.6-29x less than through FreeType, but the files are 2.1-6.6x larger than glyf or CFF: design 002 has the numbers and the next question (points shared along contours, lines without control points).