The SamsaFont object is the fundamental object in the Samsa Core library. It is created from a binary TrueType font stored in a SamsaBuffer. Note that SamsaBuffer is a subclass of the standard JavaScript DataView. The SamsaFont object is used to create SamsaInstance objects, which are then used to render text using the SamsaInstance.renderText() method.
SamsaFont()
SamsaFont.glyphIdFromUnicode()
Takes an integer argument that is the Unicode code point of a character, and returns the id of the glyph that, by default, represents the character. If the font does not contain a glyph for the character, return value is 0.
SamsaFont.loadGlyphById()
Takes an integer argument that is the id of the glyph to be loaded, and returns a new SamsaGlyph object. The returned SamsaGlyph may be simple or composite; if composite, it can be converted to a simple glyph using SamsaGlyph.decompose(). It is valid to load glyph 0, which, according to the TrueType specification, represents the missing glyph and is typically an empty square or a square with a cross inside it. Note that this method only returns the default form of the glyph. For variations, it is necessary to SamsaInstance object. When using this method directly, clients should keep track of those glyphs they have already loaded, thus not load the same glyph multiple times.
The essential steps are to obtain a SamsaBuffer that contains a TrueType font, and make a SamsaFont from it.
const buf = new SamsaBuffer(arrayBuffer); // arrayBuffer contains a TrueType font
const font = new SamsaFont(buf);
There are numerous ways to get a font file into an ArrayBuffer. Common ways on the web are fetch() and File drag and drop. Common ways in Node.js are fetch and fs.readFile().
Example using fetch() (works on the web and Node.js):
const fontUrl = "https://example.com/font.ttf";
fetch(fontUrl)
.then(response => {
if (!response.ok) {
throw new Error("Failed to fetch font");
}
const arrayBuffer = response.arrayBuffer();
const buf = new SamsaBuffer(arrayBuffer);
const font = new SamsaFont(buf);
// do stuff with the font here
});
Example using fs.readFileSync() (works in Node.js):
const fs = require("fs");
const fontPath = "path/to/font.ttf";
const data = fs.readFileSync(fontPath);
const buf = new SamsaBuffer(data.buffer);
const font = new SamsaFont(buf);
// do stuff with the font here