PGF: Clip lines/markers to maximum LaTeX dimensions.

QuLogic · QuLogic · commit 447e578b06a7 · 2021-06-11T01:59:29.000-04:00
This has been open for many years without any change to LaTeX, so it seems unlikely they are going to change how their parsing works. Fixes #4482.
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -426,8 +426,12 @@ def draw_markers(self, gc, marker_path, marker_trans, path, trans,
                             fill=rgbFace is not None)
         writeln(self.fh, r"}")
 
+        maxcoord = 16383 / 72.27 * self.dpi  # Max dimensions in LaTeX.
+        clip = (-maxcoord, -maxcoord, maxcoord, maxcoord)
+
         # draw marker for each vertex
-        for point, code in path.iter_segments(trans, simplify=False):
+        for point, code in path.iter_segments(trans, simplify=False,
+                                              clip=clip):
             x, y = point[0] * f, point[1] * f
             writeln(self.fh, r"\begin{pgfscope}")
             writeln(self.fh, r"\pgfsys@transformshift{%fin}{%fin}" % (x, y))
@@ -564,11 +568,13 @@ def _print_pgf_path(self, gc, path, transform, rgbFace=None):
         f = 1. / self.dpi
         # check for clip box / ignore clip for filled paths
         bbox = gc.get_clip_rectangle() if gc else None
+        maxcoord = 16383 / 72.27 * self.dpi  # Max dimensions in LaTeX.
         if bbox and (rgbFace is None):
             p1, p2 = bbox.get_points()
-            clip = (p1[0], p1[1], p2[0], p2[1])
+            clip = (max(p1[0], -maxcoord), max(p1[1], -maxcoord),
+                    min(p2[0], maxcoord), min(p2[1], maxcoord))
         else:
-            clip = None
+            clip = (-maxcoord, -maxcoord, maxcoord, maxcoord)
         # build path
         for points, code in path.iter_segments(transform, clip=clip):
             if code == Path.MOVETO:
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
@@ -150,11 +150,19 @@ def test_rcupdate():
 @pytest.mark.style('default')
 @pytest.mark.backend('pgf')
 def test_pathclip():
+    np.random.seed(19680801)
     mpl.rcParams.update({'font.family': 'serif', 'pgf.rcfonts': False})
-    plt.plot([0., 1e100], [0., 1e100])
-    plt.xlim(0, 1)
-    plt.ylim(0, 1)
-    plt.savefig(BytesIO(), format="pdf")  # No image comparison.
+    fig, axs = plt.subplots(1, 2)
+
+    axs[0].plot([0., 1e100], [0., 1e100])
+    axs[0].set_xlim(0, 1)
+    axs[0].set_ylim(0, 1)
+
+    axs[1].scatter([0, 1], [1, 1])
+    axs[1].hist(np.random.normal(size=1000), bins=20, range=[-10, 10])
+    axs[1].set_xscale('log')
+
+    fig.savefig(BytesIO(), format="pdf")  # No image comparison.
 
 
 # test mixed mode rendering
