Drop support for dvipng 1.5; drop dvipnghack.

dvipng 1.5 was released on 2005-02-04 and 1.6 on 2005-04-04
(http://git.savannah.nongnu.org/cgit/dvipng.git), so it isn't really
worth carrying a hack just to support two more months.

Author: anntzer

lib/matplotlib/__init__.py

@@ -496,7 +496,7 @@ def checkdep_usetex(s):
         return False
 
     gs_req = '8.60'
-    dvipng_req = '1.5'
+    dvipng_req = '1.6'
     flag = True
 
     if _backports.which("tex") is None:
@@ -508,8 +508,8 @@ def checkdep_usetex(s):
     if not compare_versions(dvipng_v, dvipng_req):
         flag = False
         warnings.warn('matplotlibrc text.usetex can not be used with *Agg '
-                      'backend unless dvipng-1.5 or later is installed on '
-                      'your system')
+                      'backend unless dvipng-%s or later is installed on '
+                      'your system' % dvipng_req)
 
     gs_exec, gs_v = checkdep_ghostscript()
     if not compare_versions(gs_v, gs_req):
@@ -812,7 +812,7 @@ def gen_candidates():
 
 _deprecated_ignore_map = {}
 
-_obsolete_set = {'legend.isaxes'}
+_obsolete_set = {'text.dvipnghack', 'legend.isaxes'}
 
 # The following may use a value of None to suppress the warning.
 _deprecated_set = {'axes.hold'}  # do NOT include in _all_deprecated

lib/matplotlib/mpl-data/stylelib/_classic_test.mplstyle

@@ -124,13 +124,6 @@ text.latex.preamble :  # IMPROPER USE OF THIS FEATURE WILL LEAD TO LATEX FAILURE
                            # may also be loaded, depending on your font settings
 text.latex.preview : False
 
-text.dvipnghack : None      # some versions of dvipng don't handle alpha
-                            # channel properly.  Use True to correct
-                            # and flush ~/.matplotlib/tex.cache
-                            # before testing and False to force
-                            # correction off.  None will try and
-                            # guess based on your dvipng version
-
 text.hinting : auto   # May be one of the following:
                       #   'none': Perform no hinting
                       #   'auto': Use freetype's autohinter

lib/matplotlib/mpl-data/stylelib/classic.mplstyle

@@ -124,13 +124,6 @@ text.latex.preamble :  # IMPROPER USE OF THIS FEATURE WILL LEAD TO LATEX FAILURE
                            # may also be loaded, depending on your font settings
 text.latex.preview : False
 
-text.dvipnghack : None      # some versions of dvipng don't handle alpha
-                            # channel properly.  Use True to correct
-                            # and flush ~/.matplotlib/tex.cache
-                            # before testing and False to force
-                            # correction off.  None will try and
-                            # guess based on your dvipng version
-
 text.hinting : auto   # May be one of the following:
                       #   'none': Perform no hinting
                       #   'auto': Use freetype's autohinter

lib/matplotlib/tests/test_backend_pdf.py

@@ -12,7 +12,7 @@
 import pytest
 
 import numpy as np
-from matplotlib import checkdep_tex, cm, rcParams
+from matplotlib import checkdep_usetex, cm, rcParams
 from matplotlib.backends.backend_pdf import PdfPages
 from matplotlib import pyplot as plt
 from matplotlib.testing.determinism import (_determinism_source_date_epoch,

lib/matplotlib/texmanager.py

@@ -65,6 +65,7 @@
     cmd_split = ';'
 
 
+@mpl.cbook.deprecated("2.1")
 def dvipng_hack_alpha():
     try:
         p = Popen([str('dvipng'), '-version'], stdin=PIPE, stdout=PIPE,
@@ -122,8 +123,6 @@ class TexManager(object):
     if texcache is not None:
         mkdirs(texcache)
 
-    _dvipng_hack_alpha = None
-    #_dvipng_hack_alpha = dvipng_hack_alpha()
     # mappable cache of
     rgba_arrayd = {}
     grey_arrayd = {}
@@ -542,46 +541,10 @@ def get_grey(self, tex, fontsize=None, dpi=None):
         """returns the alpha channel"""
         key = tex, self.get_font_config(), fontsize, dpi
         alpha = self.grey_arrayd.get(key)
-
         if alpha is None:
             pngfile = self.make_png(tex, fontsize, dpi)
             X = read_png(os.path.join(self.texcache, pngfile))
-
-            if rcParams['text.dvipnghack'] is not None:
-                hack = rcParams['text.dvipnghack']
-            else:
-                if TexManager._dvipng_hack_alpha is None:
-                    TexManager._dvipng_hack_alpha = dvipng_hack_alpha()
-                hack = TexManager._dvipng_hack_alpha
-
-            if hack:
-                # hack the alpha channel
-                # dvipng assumed a constant background, whereas we want to
-                # overlay these rasters with antialiasing over arbitrary
-                # backgrounds that may have other figure elements under them.
-                # When you set dvipng -bg Transparent, it actually makes the
-                # alpha channel 1 and does the background compositing and
-                # antialiasing itself and puts the blended data in the rgb
-                # channels.  So what we do is extract the alpha information
-                # from the red channel, which is a blend of the default dvipng
-                # background (white) and foreground (black).  So the amount of
-                # red (or green or blue for that matter since white and black
-                # blend to a grayscale) is the alpha intensity.  Once we
-                # extract the correct alpha information, we assign it to the
-                # alpha channel properly and let the users pick their rgb.  In
-                # this way, we can overlay tex strings on arbitrary
-                # backgrounds with antialiasing
-                #
-                # red = alpha*red_foreground + (1-alpha)*red_background
-                #
-                # Since the foreground is black (0) and the background is
-                # white (1) this reduces to red = 1-alpha or alpha = 1-red
-                #alpha = npy.sqrt(1-X[:,:,0]) # should this be sqrt here?
-                alpha = 1 - X[:, :, 0]
-            else:
-                alpha = X[:, :, -1]
-
-            self.grey_arrayd[key] = alpha
+            self.grey_arrayd[key] = alpha = X[:, :, -1]
         return alpha
 
     def get_rgba(self, tex, fontsize=None, dpi=None, rgb=(0, 0, 0)):

matplotlibrc.template

@@ -243,14 +243,6 @@ backend      : $TEMPLATE_BACKEND
                             # beware of package collisions: color, geometry, graphicx,
                             # type1cm, textcomp. Adobe Postscript (PSSNFS) font packages
                             # may also be loaded, depending on your font settings
-
-#text.dvipnghack : None      # some versions of dvipng don't handle alpha
-                             # channel properly.  Use True to correct
-                             # and flush ~/.matplotlib/tex.cache
-                             # before testing and False to force
-                             # correction off.  None will try and
-                             # guess based on your dvipng version
-
 #text.hinting : auto   # May be one of the following:
                        #   'none': Perform no hinting
                        #   'auto': Use FreeType's autohinter

tutorials/text/usetex.py

@@ -119,10 +119,6 @@
 * Using MiKTeX with Computer Modern fonts, if you get odd \*Agg and PNG
   results, go to MiKTeX/Options and update your format files
 
-* The fonts look terrible on screen. You are probably running Mac OS, and there
-  is some funny business with older versions of dvipng on the mac. Set
-  ``text.dvipnghack : True`` in your matplotlibrc file.
-
 * On Ubuntu and Gentoo, the base texlive install does not ship with
   the type1cm package. You may need to install some of the extra
   packages to get all the goodies that come bundled with other latex