Squares squares squares

Author: pelson

xkcd-script/font/xkcd-script.otf

@@ -154,6 +154,8 @@ def extract_symbol(arr, y0, y1, x0, x1, name, exclude=None):
 
 # Each entry is (output_name, source_filename_stem).
 EXTRAS = [
+    ('notdef', '1913_i_2x__notdef'),            # .notdef fallback glyph source
+    ('square', '2251_alignment_chart_2x__square'),  # □ U+25A1 source
     ('eszett', 'eszett'),                       # ß U+00DF / ẞ U+1E9E source
     ('lambda', '1145_sky_color_2x__lambda'),    # λ U+03BB source
     ('tau', '2520_symbols_2x__tau'),            # τ U+03C4 source

xkcd-script/font/xkcd-script.sfd

@@ -317,26 +317,9 @@ def charname(char):
 c = font.createMappedChar(32)
 c.width = 256
 
-# recommended by OpenType specification
-c = font.createChar(-1, '.notdef')
-c.addReference('question', psMat.compose(psMat.scale(0.5), psMat.translate(font.ascent * 0.25, font.ascent * 0.25)))
-c.unlinkRef()
-c.width = round(font.em * 0.6)
-pen = c.glyphPen(replace=False)
-pen.moveTo(20, 20)
-pen.lineTo((c.width - 20, 20))
-pen.lineTo((c.width - 20, font.ascent - 20))
-pen.lineTo((20, font.ascent - 20))
-pen.lineTo((20, 20))
-pen.lineTo((60, 60))
-pen.lineTo((60, font.ascent - 60))
-pen.lineTo((c.width - 60, font.ascent - 60))
-pen.lineTo((c.width - 60, 60))
-pen.lineTo((60, 60))
-pen.closePath()
-c = font.createChar(0x0000, '.null')
+c = font.createChar(0x0000, '.null')   # U+0000: null, zero-width; required by OpenType
 c.width = 256
-c = font.createChar(0x000D, 'nonmarkingreturn')
+c = font.createChar(0x000D, 'nonmarkingreturn')  # U+000D: carriage return, zero-width; required by OpenType
 c.width = 256
 
 
@@ -413,6 +396,23 @@ def _import_comic_glyph(font, name, svg_path, target_top, weight_delta=0):
     return g
 
 
+# .notdef is shown for any codepoint the font doesn't cover; OpenType requires it.
+# Hand-drawn source: xkcd #1913 (I), a sketchy question-mark-in-a-box.
+_notdef_svg = os.path.join(_COMIC_CHARS_DIR, 'notdef.svg')
+_notdef_src = _import_comic_glyph(font, 'notdef', _notdef_svg, target_top=font.ascent, weight_delta=20)
+_bb = _notdef_src.boundingBox()
+_notdef_src.transform(psMat.translate(0, -_bb[1]))
+_bb = _notdef_src.boundingBox()
+if _bb[3] > 0:
+    _notdef_src.transform(psMat.scale(font.ascent / _bb[3]))
+    _notdef_src.width = int(round(_notdef_src.boundingBox()[2] + 20))
+c = font.createChar(-1, '.notdef')
+c.clear()
+for _cont in _notdef_src.foreground:
+    c.foreground += _cont
+c.width = _notdef_src.width
+
+
 # Greek letters vectorised by pt4 from xkcd comic images.
 # Each entry: (svg_name, unicode_cp, ref_char_for_height, baseline_snap)
 # baseline_snap=True  → translate so bb[1]=0 (letters that sit on the baseline).
@@ -614,6 +614,23 @@ def _import_comic_glyph(font, name, svg_path, target_top, weight_delta=0):
     _ch.width = _g.width
 
 
+# □ U+25A1 WHITE SQUARE — hand-drawn source from extras/square.png.
+_square_svg = os.path.join(_COMIC_CHARS_DIR, 'square.svg')
+_target_top_sq = font['H'].boundingBox()[3]
+_square_src = _import_comic_glyph(font, 'square', _square_svg, target_top=_target_top_sq, weight_delta=45)
+_bb = _square_src.boundingBox()
+_square_src.transform(psMat.translate(0, -_bb[1]))
+_bb = _square_src.boundingBox()
+if _bb[3] > 0:
+    _square_src.transform(psMat.scale(_target_top_sq / _bb[3]))
+    _square_src.width = int(round(_square_src.boundingBox()[2] + 20))
+_ch = font.createMappedChar(0x25A1)
+_ch.clear()
+for _cont in _square_src.foreground:
+    _ch.foreground += _cont
+_ch.width = _square_src.width
+
+
 # ---------------------------------------------------------------------------
 # Save
 # ---------------------------------------------------------------------------

xkcd-script/font/xkcd-script.ttf

@@ -212,12 +212,29 @@ def _accented(cp, base_name, mark_name, gap=20, x_adj=0):
 # Glyph aliases and re-uses
 # ---------------------------------------------------------------------------
 
+# U+20DE COMBINING ENCLOSING SQUARE — zero-width mark sized and positioned to
+# enclose '?' with a small margin.  GPOS would be needed for full generality.
+_sq = font[0x25A1]
+_sq_bb = _sq.boundingBox()
+_sq_cx = (_sq_bb[0] + _sq_bb[2]) / 2
+_sq_h = _sq_bb[3] - _sq_bb[1]   # sq_bb[1] == 0 after baseline snap
+_q_bb = font[ord('?')].boundingBox()
+_q_adv = font[ord('?')].width
+_margin = 20
+_scale_y = (_q_bb[3] - _q_bb[1] + 2 * _margin) / _sq_h
+_x_offset = -_q_adv / 2 - _sq_cx
+_y_offset = _q_bb[1] - _margin
+c = font.createMappedChar(0x20DE)
+c.addReference(_sq.glyphname, psMat.compose(
+    psMat.scale(1, _scale_y),
+    psMat.translate(_x_offset, _y_offset),
+))
+c.width = 0
+
 # Vertical pipe: re-use the I glyph (same stroke, same weight).
-font.selection.select('I')
-font.copy()
 c = font.createChar(-1, 'I.sansserif')
-font.selection.select(c)
-font.paste()
+c.addReference('I')
+c.width = font['I'].width
 pipe = font.createMappedChar(ord('|'))
 pipe.clear()
 pipe.addReference('I.sansserif', psMat.compose(psMat.scale(1, 1.3), psMat.translate(0, -0.2 * font.ascent)))