Fix get_canvas_width_height() for pgf backend.

anntzer · anntzer · commit 871312553718 · 2019-07-22T10:37:05.000+02:00
The pgf backend's get_canvas_width_height returns the canvas size in inches, but it should return it in display units ("pixels", or inches*dpi) instead. get_canvas_width_height is actually barely used (only in text.py for some backends (not pgf), in collections.py as an optimization, and in BboxImage -- the only really relevant case), so to show the failure, apply diff --git i/examples/text_labels_and_annotations/demo_text_path.py w/examples/text_labels_and_annotations/demo_text_path.py index 47ed5dd..d45a922f4 100644 --- i/examples/text_labels_and_annotations/demo_text_path.py +++ w/examples/text_labels_and_annotations/demo_text_path.py @@ -61,6 +61,7 @@ class PathClippedImagePatch(mpatches.PathPatch): if __name__ == "__main__": + import matplotlib; matplotlib.use("pgf") usetex = plt.rcParams["text.usetex"] fig = plt.figure() @@ -156,4 +157,5 @@ if __name__ == "__main__": ax.set_xlim(0, 1) ax.set_ylim(0, 1) + plt.savefig("/tmp/test.pdf") plt.show() and observe that the image is incorrectly drawn before the patch, but correctly after.
diff --git a/doc/api/next_api_changes/2019-07-20-AL.rst b/doc/api/next_api_changes/2019-07-20-AL.rst
@@ -0,0 +1,4 @@
+The pgf backend's get_canvas_width_height now returns the canvas size in display units
+``````````````````````````````````````````````````````````````````````````````````````
+
+... rather than in inches, which it previously did.  The new behavior is the correct one given the uses of ``get_canvas_width_height`` in the rest of the codebase.
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -736,7 +736,8 @@ def flipy(self):
 
     def get_canvas_width_height(self):
         # docstring inherited
-        return self.figure.get_figwidth(), self.figure.get_figheight()
+        return (self.figure.get_figwidth() * self.dpi,
+                self.figure.get_figheight() * self.dpi)
 
     def points_to_pixels(self, points):
         # docstring inherited
