typesetting/fontland/fontland/test/subset.rkt

#lang racket
(require rackunit racket/runtime-path fontland fontland/subset)

#|
approximates
https://github.com/mbutterick/fontkit/blob/master/test/subset.js
|#

(define-runtime-path open-sans-ttf "data/OpenSans/OpenSans-Regular.ttf")

(define font (open-font open-sans-ttf))

(test-case
 "should create a TTFSubset instance"
 (define subset (create-subset font))
 (check-true (ttf-subset? subset)))

(test-case
 "should produce a subset"
 (define subset (create-subset font))
 (for ([glyph (in-vector (vector-map glyph-id (glyphrun-glyphs (layout font "hello"))))])
   (subset-add-glyph! subset glyph))
 (define f (encode-to-port subset))
 f
 (void))

#|

    it('should produce a subset', function(done) {
      let subset = font.createSubset();
      for (let glyph of font.glyphsForString('hello')) {
        subset.includeGlyph(glyph);
      }

      subset.encodeStream().pipe(concat(function(buf) {
        let f = fontkit.create(buf);
        assert.equal(f.numGlyphs, 5);
        assert.equal(f.getGlyph(1).path.toSVG(), font.glyphsForString('h')[0].path.toSVG());
        done();
      }));
    });
    
    it('should re-encode variation glyphs', function(done) {
      if (!fs.existsSync('/Library/Fonts/Skia.ttf')) return done();
      
      let font = fontkit.openSync('/Library/Fonts/Skia.ttf', 'Bold');
      let subset = font.createSubset();
      for (let glyph of font.glyphsForString('e')) {
        subset.includeGlyph(glyph);
      }

      subset.encodeStream().pipe(concat(function(buf) {
        let f = fontkit.create(buf);
        assert.equal(f.getGlyph(1).path.toSVG(), font.glyphsForString('e')[0].path.toSVG());
        done();
      }));
    });

    it('should handle composite glyphs', function(done) {
      let subset = font.createSubset();
      subset.includeGlyph(font.glyphsForString('é')[0]);

      subset.encodeStream().pipe(concat(function(buf) {
        let f = fontkit.create(buf);
        assert.equal(f.numGlyphs, 4);
        assert.equal(f.getGlyph(1).path.toSVG(), font.glyphsForString('é')[0].path.toSVG());
        done();
      }));
    });

    it('should handle fonts with long index to location format (indexToLocFormat = 1)', function(done) {
      let font = fontkit.openSync(__dirname + '/data/FiraSans/FiraSans-Regular.ttf');
      let subset = font.createSubset();
      for (let glyph of font.glyphsForString('abcd')) {
        subset.includeGlyph(glyph);
      }

      subset.encodeStream().pipe(concat(function(buf) {
        let f = fontkit.create(buf);
        assert.equal(f.numGlyphs, 5);
        assert.equal(f.getGlyph(1).path.toSVG(), font.glyphsForString('a')[0].path.toSVG());
        // must test also second glyph which has an odd loca index
        assert.equal(f.getGlyph(2).path.toSVG(), font.glyphsForString('b')[0].path.toSVG());
        done();
      }));
    });
  });

  describe('CFF subsetting', function() {
    let font = fontkit.openSync(__dirname + '/data/SourceSansPro/SourceSansPro-Regular.otf');

    it('should create a CFFSubset instance', function() {
      let subset = font.createSubset();
      return assert.equal(subset.constructor.name, 'CFFSubset');
    });

    it('should produce a subset', function(done) {
      let subset = font.createSubset();
      let iterable = font.glyphsForString('hello');
      for (let i = 0; i < iterable.length; i++) {
        let glyph = iterable[i];
        subset.includeGlyph(glyph);
      }

      return subset.encodeStream().pipe(concat(function(buf) {
        let stream = new r.DecodeStream(buf);
        let cff = new CFFFont(stream);
        let glyph = new CFFGlyph(1, [], { stream, 'CFF ': cff });
        assert.equal(glyph.path.toSVG(), font.glyphsForString('h')[0].path.toSVG());
        return done();
      }));
    });

    it('should handle CID fonts', function(done) {
      let f = fontkit.openSync(__dirname + '/data/NotoSansCJK/NotoSansCJKkr-Regular.otf');
      let subset = f.createSubset();
      let iterable = f.glyphsForString('갈휸');
      for (let i = 0; i < iterable.length; i++) {
        let glyph = iterable[i];
        subset.includeGlyph(glyph);
      }

      return subset.encodeStream().pipe(concat(function(buf) {
        let stream = new r.DecodeStream(buf);
        let cff = new CFFFont(stream);
        let glyph = new CFFGlyph(1, [], { stream, 'CFF ': cff });
        assert.equal(glyph.path.toSVG(), f.glyphsForString('갈')[0].path.toSVG());
        assert.equal(cff.topDict.FDArray.length, 2);
        assert.deepEqual(cff.topDict.FDSelect.fds, [0, 1, 1]);
        return done();
      }));
    });
  });
});

|#