Sync Cairo's usetex measurement with base class.

QuLogic · QuLogic · commit bcaa26b0d52d · 2020-07-15T21:01:15.000-04:00
diff --git a/lib/matplotlib/backends/backend_cairo.py b/lib/matplotlib/backends/backend_cairo.py
@@ -286,10 +286,18 @@ def get_canvas_width_height(self):
     def get_text_width_height_descent(self, s, prop, ismath):
         # docstring inherited
 
+        if ismath == 'TeX':
+            # todo: handle props
+            texmanager = self._text2path.get_texmanager()
+            fontsize = prop.get_size_in_points()
+            w, h, d = texmanager.get_text_width_height_descent(
+                s, fontsize, renderer=self)
+            return w, h, d
+
+        dpi = self.points_to_pixels(72)
         if ismath:
-            width, height, descent, fonts, used_characters = \
-                self.mathtext_parser.parse(s, self.dpi, prop)
-            return width, height, descent
+            dims = self._text2path.mathtext_parser.parse(s, dpi, prop)
+            return dims[0:3]  # return width, height, descent
 
         ctx = self.text_ctx
         # problem - scale remembers last setting and font can become
