Added color keyword argument to math_to_image

oscargus · oscargus · commit d33ebe2988f8 · 2021-12-19T16:18:17.000+01:00
diff --git a/doc/users/next_whats_new/color_support_for_math_to_image.rst b/doc/users/next_whats_new/color_support_for_math_to_image.rst
@@ -0,0 +1,11 @@
+``math_to_image`` now has a ``color`` keyword argument
+--------------------------------------------------------
+
+To easily support external libraries that rely on the rendering of Matplotlib
+to generate figures, a ``color`` keyword argument was added to
+``math_to_image``.
+
+.. code-block:: python
+
+    from matplotlib import mathtext
+    mathtext.math_to_image('$x**2$', 'filename.png', color='Maroon')
diff --git a/lib/matplotlib/mathtext.py b/lib/matplotlib/mathtext.py
@@ -563,7 +563,8 @@ def get_depth(self, texstr, dpi=120, fontsize=14):
         return depth
 
 
-def math_to_image(s, filename_or_obj, prop=None, dpi=None, format=None):
+def math_to_image(s, filename_or_obj, prop=None, dpi=None, format=None,
+                  color=None):
     """
     Given a math expression, renders it in a closely-clipped bounding
     box to an image file.
@@ -582,14 +583,16 @@ def math_to_image(s, filename_or_obj, prop=None, dpi=None, format=None):
     format : str, optional
         The output format, e.g., 'svg', 'pdf', 'ps' or 'png'.  If not set, the
         format is determined as for `.Figure.savefig`.
+    color : str, optional
+        Foreground color, if not set the color is determined by rc params.
     """
     from matplotlib import figure
 
     parser = MathTextParser('path')
     width, height, depth, _, _ = parser.parse(s, dpi=72, prop=prop)
 
     fig = figure.Figure(figsize=(width / 72.0, height / 72.0))
-    fig.text(0, depth/height, s, fontproperties=prop)
+    fig.text(0, depth/height, s, fontproperties=prop, color=color)
     fig.savefig(filename_or_obj, dpi=dpi, format=format)
 
     return depth
diff --git a/lib/matplotlib/tests/test_mathtext.py b/lib/matplotlib/tests/test_mathtext.py
@@ -373,6 +373,7 @@ def test_mathtext_fallback(fallback, fontlist):
 def test_math_to_image(tmpdir):
     mathtext.math_to_image('$x^2$', str(tmpdir.join('example.png')))
     mathtext.math_to_image('$x^2$', io.BytesIO())
+    mathtext.math_to_image('$x^2$', io.BytesIO(), color='Maroon')
 
 
 def test_mathtext_to_png(tmpdir):
