Support luatex-generated dvi.

To be used together with the same-named branch on Matplotlib.

Author: anntzer

ext/_mplcairo.cpp

@@ -1670,11 +1670,11 @@ void GraphicsContextRenderer::restore_region(Region& region)
 
 MathtextBackend::Glyph::Glyph(
   std::string path, double size,
-  std::variant<char32_t, std::string, FT_ULong> codepoint_or_name_or_index,
+  std::variant<char32_t, FT_ULong> codepoint_or_index,
   double x, double y,
   double slant, double extend) :
   path{path}, size{size},
-  codepoint_or_name_or_index{codepoint_or_name_or_index},
+  codepoint_or_index{codepoint_or_index},
   x{x}, y{y},
   slant{slant}, extend{extend}
 {}
@@ -1689,16 +1689,9 @@ void MathtextBackend::add_glyph(
 
 void MathtextBackend::add_usetex_glyph(
   double ox, double oy, std::string filename, double size,
-  std::variant<std::string, FT_ULong> name_or_index,
-  double slant, double extend)
+  FT_ULong index, double slant, double extend)
 {
-  auto codepoint_or_name_or_index =
-    std::variant<char32_t, std::string, FT_ULong>{};
-  std::visit(
-    [&](auto name_or_index) { codepoint_or_name_or_index = name_or_index; },
-    name_or_index);
-  glyphs_.emplace_back(
-    filename, size, codepoint_or_name_or_index, ox, oy, slant, extend);
+  glyphs_.emplace_back(filename, size, index, ox, oy, slant, extend);
 }
 
 void MathtextBackend::add_rect(
@@ -1746,37 +1739,16 @@ void MathtextBackend::draw(
         }
         return FT_Get_Char_Index(ft_face, codepoint);
       },
-      [&](std::string name) {
-        return FT_Get_Name_Index(ft_face, name.data());
-      },
       [&](FT_ULong idx) {
-        // For classic fonts, the index maps to the "native" font charmap,
-        // which typically has an ADOBE_STANDARD or ADOBE_CUSTOM encoding,
-        // unlike the FreeType-synthesized one which has a UNICODE encoding.
-        auto found = false;
-        for (auto i = 0; i < ft_face->num_charmaps; ++i) {
-          auto const& cmap = ft_face->charmaps[i];
-          if (cmap->encoding == FT_ENCODING_ADOBE_STANDARD
-              || cmap->encoding == FT_ENCODING_ADOBE_CUSTOM) {
-            if (found) {
-              throw std::runtime_error{"multiple Adobe charmaps found"};
-            }
-            FT_CHECK(FT_Set_Charmap, ft_face, cmap);
-            found = true;
-          }
-        }
-        if (!found) {
-          throw std::runtime_error{"no builtin charmap found"};
-        }
-        return FT_Get_Char_Index(ft_face, idx);
+        return FT_UInt(idx);
       }
-    }, glyph.codepoint_or_name_or_index);
+    }, glyph.codepoint_or_index);
     if (!index) {
       auto glyph_ref = std::visit(overloaded {
         [&](char32_t codepoint) { return "#" + std::to_string(codepoint); },
         [&](std::string name) { return name; },
         [&](FT_ULong idx) { return "#" + std::to_string(idx); }
-      }, glyph.codepoint_or_name_or_index);
+      }, glyph.codepoint_or_index);
       warn_on_missing_glyph(glyph_ref);
     }
     auto const& raw_glyph = cairo_glyph_t{index, glyph.x, glyph.y};

ext/_mplcairo.h

@@ -175,15 +175,15 @@ class MathtextBackend {
     // that will wait for the ft2 rewrite in Matplotlib itself.
     std::string path;
     double size;
-    std::variant<char32_t, std::string, FT_ULong> codepoint_or_name_or_index;
+    std::variant<char32_t, FT_ULong> codepoint_or_index;
     double x, y;
     double slant;
     double extend;
 
     Glyph(
       std::string path,
       double size,
-      std::variant<char32_t, std::string, FT_ULong> codepoint_or_name_or_index,
+      std::variant<char32_t, FT_ULong> codepoint_or_index,
       double x, double y,
       double slant = 0, double extend = 1);
   };
@@ -200,8 +200,7 @@ class MathtextBackend {
     char32_t codepoint);
   void add_usetex_glyph(
     double ox, double oy, std::string filename, double size,
-    std::variant<std::string, FT_ULong> name_or_index,
-    double slant, double extend);
+    FT_ULong index, double slant, double extend);
   void add_rect(double x1, double y1, double x2, double y2);
   void draw(
     GraphicsContextRenderer& gcr, double x, double y, double angle) const;

src/mplcairo/_backports.py

@@ -6,8 +6,6 @@
 import matplotlib as mpl
 import numpy as np
 
-from . import _backports
-
 
 def detect_buffer_format(buf):
     return {
@@ -22,17 +20,6 @@ def detect_buffer_format(buf):
     }[buf.dtype.type, buf.shape[2:]]
 
 
-@functools.lru_cache(1)
-def get_tex_font_map():
-    return mpl.dviread.PsfontsMap(mpl.dviread.find_tex_file("pdftex.map"))
-
-
-def get_glyph_name(dvitext):
-    ps_font = get_tex_font_map()[dvitext.font.texname]
-    return (_backports._parse_enc(ps_font.encoding)[dvitext.glyph]
-            if ps_font.encoding is not None else None)
-
-
 def get_matplotlib_gtk_backend():
     import gi
     required = gi.get_required_version("Gtk")

src/mplcairo/_util.py

@@ -142,18 +142,10 @@ def draw_tex(self, gc, x, y, s, prop, angle, ismath="TeX!", mtext=None):
             page = next(iter(dvi))
         mb = _mplcairo.MathtextBackendCairo()
         for text in page.text:
-            texfont = _util.get_tex_font_map()[text.font.texname]
-            if texfont.filename is None:
-                # Not TypeError:
-                # :mpltest:`test_backend_svg.test_missing_psfont`.
-                raise ValueError(f"No font file found for {texfont.psname} "
-                                 f"({texfont.texname!a})")
             mb.add_usetex_glyph(
-                text.x, -text.y,
-                texfont.filename, text.font.size,
-                _util.get_glyph_name(text) or text.glyph,
-                texfont.effects.get("slant", 0),
-                texfont.effects.get("extend", 1))
+                text.x, -text.y, text.font.path, text.font.size, text.index,
+                text.font.effects.get("slant", 0),
+                text.font.effects.get("extend", 1))
         for x1, y1, h, w in page.boxes:
             mb.add_rect(x1, -y1, x1 + w, -(y1 + h))
         mb.draw(self, x, y, angle)