René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"The face color of a patch affects its hatches in PDF viewed with Acrobat Reader","articleBody":"**Bug summary**\r\n\r\nOriginally reported in the thread of #8431.\r\n\r\nWhen using hatches with a patch and exporting to a PDF, the patch face color seems to also be applied to (or to overlay) the hatches when viewing the file with Acrobat Reader, which is neither the case in the Matplotlib interactive window nor when opening the same PDF with Evince. Not sure if it is the alpha value of the face color that is wrongly interpreted, or simply the z-order between the face color and the hatches.\r\n\r\n**Code for reproduction**\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport matplotlib.patches as mpatches\r\nimport matplotlib as mpl\r\n\r\nrect = mpatches.Rectangle((0.25, 0.25), 0.5, 0.5, hatch=\"x\",\r\n                          edgecolor=\"darkred\", facecolor=[0.5, 0.5, 0.5, 0.1])\r\n\r\nfig, ax = plt.subplots()\r\nax.add_patch(rect)\r\nfig.savefig(\"with_{0}.pdf\".format(mpl.__version__))\r\n```\r\n\r\n**Actual outcome**\r\n\r\nAn exemple of the PDF produced by the snippet above:\r\n[with_2.1.0.post933+gd046efbc2.pdf](https://github.com/matplotlib/matplotlib/files/1519769/with_2.1.0.post933.gd046efbc2.pdf)\r\n\r\nA screenshot comparing this file opened with Evince (on the left) and with Acrobat Reader (on the right):\r\n![evince_vs_acroread_with_master](https://user-images.githubusercontent.com/17270724/33459568-4821c460-d5df-11e7-8078-18a3634abf60.png)\r\n\r\nI get a similar output/behavior with Matplotlib 2.0.0. However, with Matplotlib 1.5.3, something is going wrong and I am thrown the following traceback below, so I do not know if it is really a kind of regression.\r\n\r\n```\r\n# Traceback when tryin to run the MWE with tags/v1.5.3\r\n\r\n---------------------------------------------------------------------------\r\nImportError                               Traceback (most recent call last)\r\n~/Playground/Matplotlib/transparent_hatches/mwe_issue.py in \u003cmodule\u003e()\r\n     10 fig, ax = plt.subplots()\r\n     11 ax.add_patch(rect)\r\n---\u003e 12 fig.savefig(\"with_{0}.pdf\".format(mpl.__version__))\r\n\r\n~/FOSS/matplotlib/lib/matplotlib/figure.py in savefig(self, *args, **kwargs)\r\n   1561             self.set_frameon(frameon)\r\n   1562 \r\n-\u003e 1563         self.canvas.print_figure(*args, **kwargs)\r\n   1564 \r\n   1565         if frameon:\r\n\r\n~/FOSS/matplotlib/lib/matplotlib/backends/backend_qt5agg.py in print_figure(self, *args, **kwargs)\r\n    201 \r\n    202     def print_figure(self, *args, **kwargs):\r\n--\u003e 203         FigureCanvasAgg.print_figure(self, *args, **kwargs)\r\n    204         self.draw()\r\n    205 \r\n\r\n~/FOSS/matplotlib/lib/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)\r\n   2137 \r\n   2138         # get canvas object and print method for format\r\n-\u003e 2139         canvas = self._get_output_canvas(format)\r\n   2140         print_method = getattr(canvas, 'print_%s' % format)\r\n   2141 \r\n\r\n~/FOSS/matplotlib/lib/matplotlib/backend_bases.py in _get_output_canvas(self, format)\r\n   2069 \r\n   2070         # check if there is a default canvas for the requested format\r\n-\u003e 2071         canvas_class = get_registered_canvas_class(format)\r\n   2072         if canvas_class:\r\n   2073             return self.switch_backends(canvas_class)\r\n\r\n~/FOSS/matplotlib/lib/matplotlib/backend_bases.py in get_registered_canvas_class(format)\r\n    135     backend_class = _default_backends[format]\r\n    136     if cbook.is_string_like(backend_class):\r\n--\u003e 137         backend_class = import_module(backend_class).FigureCanvas\r\n    138         _default_backends[format] = backend_class\r\n    139     return backend_class\r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/__init__.py in import_module(name, package)\r\n    124                 break\r\n    125             level += 1\r\n--\u003e 126     return _bootstrap._gcd_import(name[level:], package, level)\r\n    127 \r\n    128 \r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _gcd_import(name, package, level)\r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _find_and_load(name, import_)\r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _find_and_load_unlocked(name, import_)\r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _load_unlocked(spec)\r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap_external.py in exec_module(self, module)\r\n\r\n~/anaconda3/envs/matplotlib_dev/lib/python3.6/importlib/_bootstrap.py in _call_with_frames_removed(f, *args, **kwds)\r\n\r\n~/FOSS/matplotlib/lib/matplotlib/backends/backend_pdf.py in \u003cmodule\u003e()\r\n     32 from matplotlib.backend_bases import RendererBase, GraphicsContextBase,\\\r\n     33     FigureManagerBase, FigureCanvasBase\r\n---\u003e 34 from matplotlib.backends.backend_mixed import MixedModeRenderer\r\n     35 from matplotlib.cbook import Bunch, is_string_like, \\\r\n     36     get_realpath_and_stat, is_writable_file_like, maxdict\r\n\r\n~/FOSS/matplotlib/lib/matplotlib/backends/backend_mixed.py in \u003cmodule\u003e()\r\n      4 from matplotlib.externals import six\r\n      5 \r\n----\u003e 6 from matplotlib._image import frombuffer\r\n      7 from matplotlib.backends.backend_agg import RendererAgg\r\n      8 from matplotlib.tight_bbox import process_figure_for_rasterizing\r\n\r\nImportError: cannot import name 'frombuffer'\r\n```\r\n\r\n**Expected outcome**\r\n\r\nThe same behavior with both PDF viewers, i.e. the hatches not being affected by the the face color of the patch. \r\n\r\n**Matplotlib version**\r\n\r\n  * Operating system: Linux (Fedora 27)\r\n  * Matplotlib version: 1.5.3, 2.0.0 and master\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`):\r\n  * Python version: 3.6, from conda\r\n  * Jupyter version (if applicable):\r\n  * Other softwares: Acrobat Reader 9.5.5\r\n","author":{"url":"https://github.com/afvincent","@type":"Person","name":"afvincent"},"datePublished":"2017-11-30T23:09:30.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":14},"url":"https://github.com/9894/matplotlib/issues/9894"}