matplotlib · mdboom · Apr 19, 2013 · Apr 15, 2013 · Apr 16, 2013 · Apr 16, 2013
diff --git a/doc/users/whats_new.rst b/doc/users/whats_new.rst
@@ -131,6 +131,17 @@ so that search results are printed prettily:
               'ytick.major.size': 4,
               'ytick.minor.size': 2})
 
+Better vertical text alignment
+------------------------------
+
+The vertical alignment of text is now consistent across backends.  You
+may see small differences in text placement, particularly with rotated
+text.
+
+If you are using a custom backend, note that the `draw_text` renderer
+method is now passed the location of the baseline, not the location of
+the bottom of the text bounding box.
+
 .. _whats-new-1-2-2:
 
 new in matplotlib 1.2.2

diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -475,7 +475,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
             the x location of the text in display coords
 
         *y*
-            the y location of the text in display coords
+            the y location of the text baseline in display coords
 
         *s*
             the text string
@@ -497,7 +497,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
 
             if 0: bbox_artist(self, renderer)
 
-        to if 1, and then the actual bounding box will be blotted along with
+        to if 1, and then the actual bounding box will be plotted along with
         your text.
         """
 

diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
@@ -154,8 +154,10 @@ def draw_mathtext(self, gc, x, y, s, prop, angle):
         ox, oy, width, height, descent, font_image, used_characters = \
             self.mathtext_parser.parse(s, self.dpi, prop)
 
-        x = np.round(x + ox)
-        y = np.round(y - oy)
+        xd = descent * np.sin(angle / (180.0 * np.pi))
+        yd = descent * np.cos(angle / (180.0 * np.pi))
+        x = np.round(x + ox - xd)
+        y = np.round(y - oy + yd)
         self._renderer.draw_text_image(font_image, x, y + 1, angle, gc)
 
     def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
@@ -177,10 +179,14 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
             # space) in the following call to draw_text_image).
             font.set_text(s, 0, flags=flags)
         font.draw_glyphs_to_bitmap(antialiased=rcParams['text.antialiased'])
+        d = font.get_descent() / 64.0
+        # The descent needs to be adjusted for the angle
+        xd = d * np.sin(np.deg2rad(angle))
+        yd = d * np.cos(np.deg2rad(angle))
 
         #print x, y, int(x), int(y), s
         self._renderer.draw_text_image(
-            font.get_image(), np.round(x), np.round(y) + 1, angle, gc)
+            font.get_image(), np.round(x - xd), np.round(y + yd) + 1, angle, gc)
 
     def get_text_width_height_descent(self, s, prop, ismath):
         """

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
@@ -1622,15 +1622,15 @@ def draw_gouraud_triangles(self, gc, points, colors, trans):
         self.check_gc(gc)
         self.file.output(name, Op.shading)
 
-    def _setup_textpos(self, x, y, descent, angle, oldx=0, oldy=0, olddescent=0, oldangle=0):
+    def _setup_textpos(self, x, y, angle, oldx=0, oldy=0, oldangle=0):
         if angle == oldangle == 0:
-            self.file.output(x - oldx, (y + descent) - (oldy + olddescent), Op.textpos)
+            self.file.output(x - oldx, y - oldy, Op.textpos)
         else:
             angle = angle / 180.0 * pi
             self.file.output( cos(angle), sin(angle),
                              -sin(angle), cos(angle),
                               x,        y,         Op.textmatrix)
-            self.file.output(0, descent, Op.textpos)
+            self.file.output(0, 0, Op.textpos)
 
     def draw_mathtext(self, gc, x, y, s, prop, angle):
         # TODO: fix positioning and encoding
@@ -1660,7 +1660,7 @@ def draw_mathtext(self, gc, x, y, s, prop, angle):
                 fonttype = global_fonttype
 
             if fonttype == 42 or num <= 255:
-                self._setup_textpos(ox, oy, 0, 0, oldx, oldy)
+                self._setup_textpos(ox, oy, 0, oldx, oldy)
                 oldx, oldy = ox, oy
                 if (fontname, fontsize) != prev_font:
                     self.file.output(self.file.fontName(fontname), fontsize,
@@ -1762,7 +1762,7 @@ def draw_tex(self, gc, x, y, s, prop, angle, ismath='TeX!', mtext=None):
                 self.file.output(elt[1], elt[2], Op.selectfont)
             elif elt[0] == 'text':
                 curx, cury = mytrans.transform((elt[1], elt[2]))
-                self._setup_textpos(curx, cury, 0, angle, oldx, oldy)
+                self._setup_textpos(curx, cury, angle, oldx, oldy)
                 oldx, oldy = curx, cury
                 if len(elt[3]) == 1:
                     self.file.output(elt[3][0], Op.show)
@@ -1811,13 +1811,11 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         if rcParams['pdf.use14corefonts']:
             font = self._get_font_afm(prop)
             l, b, w, h = font.get_str_bbox(s)
-            descent = -b * fontsize / 1000
             fonttype = 1
         else:
             font = self._get_font_ttf(prop)
             self.track_characters(font, s)
             font.set_text(s, 0.0, flags=LOAD_NO_HINTING)
-            descent = font.get_descent() / 64.0
 
             fonttype = rcParams['pdf.fonttype']
 
@@ -1857,7 +1855,7 @@ def draw_text_simple():
                              self.file.fontName(prop),
                              fontsize,
                              Op.selectfont)
-            self._setup_textpos(x, y, descent, angle)
+            self._setup_textpos(x, y, angle)
             self.file.output(self.encode_string(s, fonttype), Op.show, Op.end_text)
 
         def draw_text_woven(chunks):
@@ -1878,7 +1876,6 @@ def draw_text_woven(chunks):
             # output all the 2-byte characters.
             for mode in (1, 2):
                 newx = oldx = 0
-                olddescent = 0
                 # Output a 1-byte character chunk
                 if mode == 1:
                     self.file.output(Op.begin_text,
@@ -1888,10 +1885,9 @@ def draw_text_woven(chunks):
 
                 for chunk_type, chunk in chunks:
                     if mode == 1 and chunk_type == 1:
-                        self._setup_textpos(newx, 0, descent, 0, oldx, 0, olddescent, 0)
+                        self._setup_textpos(newx, 0, 0, oldx, 0, 0)
                         self.file.output(self.encode_string(chunk, fonttype), Op.show)
                         oldx = newx
-                        olddescent = descent
 
                     lastgind = None
                     for c in chunk:

diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -643,7 +643,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
             text_args.append("x=%fin" % (x * f))
             text_args.append("y=%fin" % (y * f))
             text_args.append("left")
-            text_args.append("bottom")
+            text_args.append("base")
 
         if angle != 0:
             text_args.append("rotate=%f" % angle)

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -755,7 +755,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
             #print 'text', s
             lines = []
             thisx = 0
-            thisy = font.get_descent() / 64.0
+            thisy = 0
             for c in s:
                 ccode = ord(c)
                 gind = cmap.get(ccode)

diff --git a/lib/matplotlib/backends/backend_svg.py b/lib/matplotlib/backends/backend_svg.py
@@ -852,8 +852,6 @@ def _draw_text_as_path(self, gc, x, y, s, prop, angle, ismath, mtext=None):
             _glyphs = text2path.get_glyphs_with_font(
                 font, s, glyph_map=glyph_map, return_new_glyphs_only=True)
             glyph_info, glyph_map_new, rects = _glyphs
-            y -= ((font.get_descent() / 64.0) *
-                  (prop.get_size_in_points() / text2path.FONT_SCALE))
 
             if glyph_map_new:
                 writer.start(u'defs')
@@ -953,8 +951,6 @@ def _draw_text_as_text(self, gc, x, y, s, prop, angle, ismath, mtext=None):
         if not ismath:
             font = self._get_font(prop)
             font.set_text(s, 0.0, flags=LOAD_NO_HINTING)
-            descent = font.get_descent() / 64.0
-            y -= descent
 
             fontsize = prop.get_size_in_points()
 
@@ -982,10 +978,9 @@ def _draw_text_as_text(self, gc, x, y, s, prop, angle, ismath, mtext=None):
                 # to the anchor point manually for now.
                 angle_rad = angle * np.pi / 180.
                 dir_vert = np.array([np.sin(angle_rad), np.cos(angle_rad)])
-                y += descent  # Undo inappropriate text descent handling
                 v_offset = np.dot(dir_vert, [(x - ax), (y - ay)])
-                ax = ax + (v_offset - descent) * dir_vert[0]
-                ay = ay + (v_offset - descent) * dir_vert[1]
+                ax = ax + v_offset * dir_vert[0]
+                ay = ay + v_offset * dir_vert[1]
 
                 ha_mpl_to_svg = {'left': 'start', 'right': 'end',
                                  'center': 'middle'}

diff --git a/lib/matplotlib/mathtext.py b/lib/matplotlib/mathtext.py
@@ -261,7 +261,7 @@ def render_rect_filled(self, x1, y1, x2, y2):
         self.pswriter.write(ps)
 
     def get_results(self, box, used_characters):
-        ship(0, -self.depth, box)
+        ship(0, 0, box)
         return (self.width,
                 self.height + self.depth,
                 self.depth,
@@ -288,7 +288,7 @@ def render_rect_filled(self, x1, y1, x2, y2):
         self.rects.append((x1, self.height - y2, x2 - x1, y2 - y1))
 
     def get_results(self, box, used_characters):
-        ship(0, -self.depth, box)
+        ship(0, 0, box)
         return (self.width,
                 self.height + self.depth,
                 self.depth,
@@ -316,7 +316,7 @@ def render_rect_filled(self, x1, y1, x2, y2):
             (x1, self.height - y1 + 1, x2 - x1, y2 - y1))
 
     def get_results(self, box, used_characters):
-        ship(0, -self.depth, box)
+        ship(0, 0, box)
         svg_elements = Bunch(svg_glyphs = self.svg_glyphs,
                              svg_rects = self.svg_rects)
         return (self.width,
@@ -346,7 +346,7 @@ def render_rect_filled(self, x1, y1, x2, y2):
             (x1, self.height-y2 , x2 - x1, y2 - y1))
 
     def get_results(self, box, used_characters):
-        ship(0, -self.depth, box)
+        ship(0, 0, box)
         return (self.width,
                 self.height + self.depth,
                 self.depth,
@@ -374,7 +374,7 @@ def render_rect_filled(self, x1, y1, x2, y2):
             (x1, y1 - self.height, x2 - x1, y2 - y1))
 
     def get_results(self, box, used_characters):
-        ship(0, -self.depth, box)
+        ship(0, 0, box)
         return (self.width,
                 self.height + self.depth,
                 self.depth,

diff --git a/lib/matplotlib/testing/decorators.py b/lib/matplotlib/testing/decorators.py
@@ -165,7 +165,7 @@ def do_test():
 
                 yield (do_test,)
 
-def image_comparison(baseline_images=None, extensions=None, tol=10,
+def image_comparison(baseline_images=None, extensions=None, tol=13,
                      freetype_version=None, remove_text=False,
                      savefig_kwarg=None):
     """
@@ -260,11 +260,11 @@ def _image_directories(func):
         subdir = os.path.splitext(os.path.split(script_name)[1])[0]
     else:
         mods = module_name.split('.')
-        mods.pop(0) # <- will be the name of the package being tested (in 
+        mods.pop(0) # <- will be the name of the package being tested (in
                     # most cases "matplotlib")
         assert mods.pop(0) == 'tests'
         subdir = os.path.join(*mods)
-        
+
         import imp
         def find_dotted_module(module_name, path=None):
             """A version of imp which can handle dots in the module name"""
@@ -273,7 +273,7 @@ def find_dotted_module(module_name, path=None):
                 res = _, path, _ = imp.find_module(sub_mod, path)
                 path = [path]
             return res
-        
+
         mod_file = find_dotted_module(func.__module__)[1]
         basedir = os.path.dirname(mod_file)
 

diff --git a/lib/matplotlib/tests/baseline_images/test_axes/axhspan_epoch.png b/lib/matplotlib/tests/baseline_images/test_axes/axhspan_epoch.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/const_xy.pdf b/lib/matplotlib/tests/baseline_images/test_axes/const_xy.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/const_xy.png b/lib/matplotlib/tests/baseline_images/test_axes/const_xy.png