Start 3.2.0 API changes page

dstansby · dstansby · commit 933a93e8196e · 2019-08-27T11:00:53.000+01:00
diff --git a/doc/api/api_changes.rst b/doc/api/api_changes.rst
@@ -37,5 +37,4 @@ added to Matplotlib, see :ref:`whats-new`.
 
       next_api_changes/*
 
-.. include:: prev_api_changes/api_changes_3.1.1.rst
-.. include:: prev_api_changes/api_changes_3.1.0.rst
+.. include:: prev_api_changes/api_changes_3.2.0.rst
diff --git a/doc/api/next_api_changes/2019-01-02-AL.rst b/doc/api/next_api_changes/2019-01-02-AL.rst
diff --git a/doc/api/prev_api_changes/api_changes_3.2.0.rst b/doc/api/prev_api_changes/api_changes_3.2.0.rst
@@ -1,6 +1,19 @@
+API Changes for 3.2.0
+=====================
+
+.. contents::
+   :local:
+   :depth: 1
+
+
+Behavior changes
+----------------
+
 Deprecations
-````````````
+------------
 
+``axes_grid1`` colorbar
+~~~~~~~~~~~~~~~~~~~~~~~
 The ``mpl_toolkits.axes_grid1.colorbar`` module and its colorbar implementation
 are deprecated in favor of :mod:`matplotlib.colorbar`, as the former is
 essentially abandoned and the latter is a more featureful replacement with a
@@ -25,3 +38,26 @@ During the deprecation period, the ``mpl_toolkits.legacy_colorbar``
 rcParam can be set to True to use ``mpl_toolkits.axes_grid1.colorbar`` in
 :mod:`mpl_toolkits.axes_grid1` code with a deprecation warning (the default),
 or to False to use ``matplotlib.colorbar``.
+
+
+Development changes
+-------------------
+
+Windows build
+~~~~~~~~~~~~~
+Previously, when building the :mod:`matplotlib._png` extension, the build
+script would add "png" and "z" to the extensions ``.libraries`` attribute (if
+pkg-config information is not available, which is in particular the case on
+Windows).
+
+In particular, this implies that the Windows build would look up files named
+``png.lib`` and ``z.lib``; but neither libpng upstream nor zlib upstream
+provides these files by default.  (On Linux, this would look up ``libpng.so``
+and ``libz.so``, which are indeed standard names.)
+
+Instead, on Windows, we now look up ``libpng16.lib`` and ``zlib.lib``, which
+*are* the upstream names for the shared libraries (as of libpng 1.6.x).
+
+For a statically-linked build, the upstream names are ``libpng16_static.lib``
+and ``zlibstatic.lib``; one still needs to manually rename them if such a build
+is desired.
