Use multi-font output for PS backend

aitikgupta · aitikgupta · commit 63e0f3adc2ee · 2021-08-13T16:29:09.000+05:30
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -640,6 +640,8 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         if ismath:
             return self.draw_mathtext(gc, x, y, s, prop, angle)
 
+        self.set_color(*gc.get_rgb())
+
         if mpl.rcParams['ps.useafm']:
             font = self._get_font_afm(prop)
             scale = 0.001 * prop.get_size_in_points()
@@ -662,18 +664,27 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
 
         else:
             font = self._get_font_ttf(prop)
-            font.set_text(s, 0, flags=LOAD_NO_HINTING)
-            self._character_tracker.track(font, s)
-            xs_names = [(item.x, font.get_glyph_name(item.glyph_idx))
-                        for item in _text_helpers.layout(s, font)]
-
-        self.set_color(*gc.get_rgb())
-        ps_name = (font.postscript_name
-                   .encode("ascii", "replace").decode("ascii"))
-        self.set_font(ps_name, prop.get_size_in_points())
-        thetext = "\n".join(f"{x:f} 0 m /{name:s} glyphshow"
-                            for x, name in xs_names)
-        self._pswriter.write(f"""\
+            char_to_font = font.fill_glyphs(s, 0, flags=LOAD_NO_HINTING)
+            for char, font in char_to_font.items():
+                self._character_tracker.track(font, chr(char))
+            stream = []
+            prev_font = curr_stream = None
+            for item in _text_helpers.layout(s, font):
+                ps_name = (item.ft_object.postscript_name.encode("ascii", "replace").decode("ascii"))
+                if item.ft_object is not prev_font:
+                    if curr_stream:
+                        stream.append(curr_stream)
+                    prev_font = item.ft_object
+                    curr_stream = [ps_name, []]
+                curr_stream[1].append((item.x, item.ft_object.get_glyph_name(item.glyph_idx)))
+            # append the last entry
+            stream.append(curr_stream)
+
+            for ps_name, xs_names in stream:
+                self.set_font(ps_name, prop.get_size_in_points(), False)
+                thetext = "\n".join(f"{x:f} 0 m /{name:s} glyphshow"
+                                    for x, name in xs_names)
+                self._pswriter.write(f"""\
 gsave
 {self._get_clip_cmd(gc)}
 {x:f} {y:f} translate
