@jsvision/core / fallbackGlyph

Function: fallbackGlyph()

fallbackGlyph(char, caps): string

Defined in: render/glyphs.ts:92

Substitute a glyph for the terminal's capabilities.

Resolution order: ASCII ambiguous-chrome fallback (when ambiguousWide is on, most specific — its keys collide with no other table) → ASCII box fallback (when boxDrawing is off) → # for block/shade glyphs (when halfBlocks is off) → ? for any other code point above U+007F (when utf8 is off) → the glyph unchanged.

Parameters

char

string

A single buffer glyph (a continuation cell's empty string passes straight through).

caps

CapabilityProfile

The resolved terminal capabilities.

Returns

string

The original glyph when supported, else its ASCII fallback.

Example

import { fallbackGlyph, resolveCapabilities } from '@jsvision/core';
const caps = resolveCapabilities().profile;

fallbackGlyph('│', caps); // '│' on a UTF-8 terminal; '|' when box-drawing is unavailable
fallbackGlyph('█', caps); // '█' normally; '#' when half/solid blocks are unavailable