Partial fix for Matplotlib 3.9's test suite.

ext/_mplcairo.cpp

@@ -618,6 +618,14 @@ void GraphicsContextRenderer::_set_size(
   }
 }
 
+void GraphicsContextRenderer::_set_init_translation(double x, double y)
+{
+  auto mtx = cairo_matrix_t{1, 0, 0, 1, x, y};
+  cairo_set_matrix(cr_, &mtx);
+  CAIRO_CHECK_SET_USER_DATA_NEW(
+    cairo_set_user_data, cr_, &detail::INIT_MATRIX_KEY, mtx);
+}
+
 void GraphicsContextRenderer::_show_page()
 {
   cairo_show_page(cr_);
@@ -1588,10 +1596,12 @@ void GraphicsContextRenderer::draw_text(
                   next_glyphs_pos = glyphs_pos + cluster.num_glyphs;
       for (auto j = glyphs_pos; j < next_glyphs_pos; ++j) {
         if (!gac.glyphs[j].index) {
-          auto missing =
-            py::cast(s.substr(bytes_pos, cluster.num_bytes))
-            .attr("encode")("ascii", "namereplace");
-          warn_on_missing_glyph(missing.cast<std::string>());
+          auto missing = py::cast(s.substr(bytes_pos, cluster.num_bytes));
+          warn_on_missing_glyph(  // Format forced by test_mathtext_ticks.
+            "{} ({})"_format(
+              py::module::import("builtins").attr("ord")(missing),
+              missing.attr("encode")("ascii", "namereplace").attr("decode")())
+            .cast<std::string>());
         }
       }
       bytes_pos = next_bytes_pos;
@@ -2158,6 +2168,7 @@ Only intended for debugging purposes.
     .def("_set_path", &GraphicsContextRenderer::_set_path)
     .def("_set_metadata", &GraphicsContextRenderer::_set_metadata)
     .def("_set_size", &GraphicsContextRenderer::_set_size)
+    .def("_set_init_translation", &GraphicsContextRenderer::_set_init_translation)
     .def("_show_page", &GraphicsContextRenderer::_show_page)
     .def("_get_context", &GraphicsContextRenderer::_get_context)
     .def("_get_buffer", &GraphicsContextRenderer::_get_buffer)

ext/_mplcairo.h

@@ -77,6 +77,7 @@ class GraphicsContextRenderer {
   void _set_path(std::optional<std::string> path);
   void _set_metadata(std::optional<py::dict> metadata);
   void _set_size(double width, double height, double dpi);
+  void _set_init_translation(double x, double y);
   void _show_page();
   py::object _get_context();
   py::array _get_buffer();

ext/_util.cpp

@@ -903,8 +903,8 @@ void warn_on_missing_glyph(std::string s)
 {
   PY_CHECK(
     PyErr_WarnEx,
-    nullptr,
-    "Requested glyph ({}) missing from current font."_format(s)
+    PyExc_UserWarning,
+    "Glyph {} missing from current font."_format(s)
     .cast<std::string>().c_str(),
     1);
 }

src/mplcairo/base.py

@@ -264,7 +264,7 @@ def restore_region(self, region):
 
     def _print_vector(self, renderer_factory,
                       path_or_stream, *, metadata=None,
-                      _fixed_72dpi=True,
+                      _fixed_72dpi=True, _forced_size=None, _offset=None,
                       **kwargs):
         _check_print_extra_kwargs(**kwargs)
         dpi = self.figure.get_dpi()
@@ -273,6 +273,10 @@ def _print_vector(self, renderer_factory,
         draw_raises_done = False
         with cbook.open_file_cm(path_or_stream, "wb") as stream:
             renderer = renderer_factory(stream, *self.figure.bbox.size, dpi)
+            if _forced_size is not None:
+                renderer._set_size(*_forced_size, dpi)
+            if _offset is not None:
+                renderer._set_init_translation(*_offset)
             try:
                 # Setting invalid metadata can also throw, in which case the
                 # rendered needs to be _finish()ed (to avoid later writing to a
@@ -332,21 +336,33 @@ def _print_ps_impl(self, is_eps, path_or_stream, *,
             f"%%Orientation: {orientation}"]
         if "Title" in metadata:
             dsc_comments.append("%%Title: {}".format(metadata.pop("Title")))
+        fig_wh = self.figure.get_size_inches() * np.array(72)
         if not is_eps and papertype != "figure":
             dsc_comments.append(f"%%DocumentPaperSizes: {papertype}")
-        print_method = partial(self._print_vector,
-                               GraphicsContextRendererCairo._for_eps_output
-                               if is_eps else
-                               GraphicsContextRendererCairo._for_ps_output)
+            paper_wh = backend_ps.papersize[papertype] * np.array(72)
+            if orientation == "landscape":
+                paper_wh = paper_wh[::-1]
+                fig_wh = fig_wh[::-1]
+            offset = (paper_wh - fig_wh) / 2 * [1, -1]
+            # FIXME: We should set the init transform, including the rotation
+            # for landscape orientation, instead of just the offset.
+        else:
+            paper_wh = offset = None
+        print_method = partial(
+            self._print_vector,
+            GraphicsContextRendererCairo._for_eps_output if is_eps else
+            GraphicsContextRendererCairo._for_ps_output,
+            _forced_size=paper_wh, _offset=offset)
         if mpl.rcParams["ps.usedistiller"]:
             with TemporaryDirectory() as tmp_dirname:
                 tmp_name = Path(tmp_dirname, "tmp")
                 print_method(tmp_name, metadata=metadata, **kwargs)
-                # Assume we can get away without passing the bbox.
                 {"ghostscript": backend_ps.gs_distill,
                  "xpdf": backend_ps.xpdf_distill}[
                      mpl.rcParams["ps.usedistiller"]](
-                         str(tmp_name), is_eps, ptype=papertype)
+                         str(tmp_name), is_eps, ptype=papertype,
+                        # Assume we can get away with just bbox width/height.
+                         bbox=(None, None, *fig_wh))
                 # If path_or_stream is *already* a text-mode stream then
                 # tmp_name needs to be opened in text-mode too.
                 with cbook.open_file_cm(path_or_stream, "wb") as stream, \