Rename the confusingly named dviread._mul2012.

anntzer · anntzer · commit b49c6dc99bd8 · 2025-03-27T16:07:35.000+01:00
Dvi fixed-point values are in 12.20 format (12 bits before the decimal
point, 20 bits after -- see e.g. the 20-bit bitshifts scattered in the
dviread module), not 20.12.  Rename the helper function accordingly.
diff --git a/lib/matplotlib/dviread.py b/lib/matplotlib/dviread.py
@@ -398,14 +398,14 @@ def _put_char_real(self, char):
         else:
             scale = font._scale
             for x, y, f, g, w in font._vf[char].text:
-                newf = DviFont(scale=_mul2012(scale, f._scale),
+                newf = DviFont(scale=_mul1220(scale, f._scale),
                                tfm=f._tfm, texname=f.texname, vf=f._vf)
-                self.text.append(Text(self.h + _mul2012(x, scale),
-                                      self.v + _mul2012(y, scale),
+                self.text.append(Text(self.h + _mul1220(x, scale),
+                                      self.v + _mul1220(y, scale),
                                       newf, g, newf._width_of(g)))
-            self.boxes.extend([Box(self.h + _mul2012(x, scale),
-                                   self.v + _mul2012(y, scale),
-                                   _mul2012(a, scale), _mul2012(b, scale))
+            self.boxes.extend([Box(self.h + _mul1220(x, scale),
+                                   self.v + _mul1220(y, scale),
+                                   _mul1220(a, scale), _mul1220(b, scale))
                                for x, y, a, b in font._vf[char].boxes])
 
     @_dispatch(137, state=_dvistate.inpage, args=('s4', 's4'))
@@ -606,7 +606,7 @@ def _width_of(self, char):
         """Width of char in dvi units."""
         width = self._tfm.width.get(char, None)
         if width is not None:
-            return _mul2012(width, self._scale)
+            return _mul1220(width, self._scale)
         _log.debug('No width for char %d in font %s.', char, self.texname)
         return 0
 
@@ -621,7 +621,7 @@ def _height_depth_of(self, char):
                            name, char, self.texname)
                 result.append(0)
             else:
-                result.append(_mul2012(value, self._scale))
+                result.append(_mul1220(value, self._scale))
         # cmsyXX (symbols font) glyph 0 ("minus") has a nonzero descent
         # so that TeX aligns equations properly
         # (https://tex.stackexchange.com/q/526103/)
@@ -755,8 +755,8 @@ def _pre(self, i, x, cs, ds):
         # cs = checksum, ds = design size
 
 
-def _mul2012(num1, num2):
-    """Multiply two numbers in 20.12 fixed point format."""
+def _mul1220(num1, num2):
+    """Multiply two numbers in 12.20 fixed point format."""
     # Separated into a function because >> has surprising precedence
     return (num1*num2) >> 20
 
diff --git a/lib/matplotlib/dviread.pyi b/lib/matplotlib/dviread.pyi
@@ -56,12 +56,13 @@ class Dvi:
 class DviFont:
     texname: bytes
     size: float
-    widths: list[int]
     def __init__(
         self, scale: float, tfm: Tfm, texname: bytes, vf: Vf | None
     ) -> None: ...
     def __eq__(self, other: object) -> bool: ...
     def __ne__(self, other: object) -> bool: ...
+    @property
+    def widths(self) -> list[int]: ...
 
 class Vf(Dvi):
     def __init__(self, filename: str | os.PathLike) -> None: ...
