matplotlib · jklymak · Jun 23, 2022 · Jun 16, 2022 · Jun 16, 2022 · Jun 16, 2022
diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
@@ -250,6 +250,57 @@ def _datetime_to_pdf(d):
     return r
 
 
+def _calculate_quad_point_coordinates(x, y, width, height, angle=0):
+    """
+    Uses matrix maths to calculate the coordinates of a
+    rectangle when rotated by angle around x, y
+    """
+
+    angle = math.radians(angle)
+    a = x + height * math.sin(angle)
+    b = y + height * math.cos(angle)
+    c = x + width * math.cos(angle) + height * math.sin(angle)
+    d = y - width * math.sin(angle) + height * math.cos(angle)
+    e = x + width * math.cos(angle)
+    f = y - width * math.sin(angle)
+    return ((x, y), (a, b), (c, d), (e, f))
+
+
+def _get_coordinates_of_block(x, y, width, height, angle=0):
+    """
+    Get the coordinates of a rectange that contains the URL text.
+    This is for use in PDF < v1.6
+    """
+
+    vertices = _calculate_quad_point_coordinates(x, y, width,
+                                                    height, angle)
+
+    min_x = min(vertices[0][0], vertices[1][0], vertices[2][0], vertices[3][0])
+    min_y = min(vertices[0][1], vertices[1][1], vertices[2][1], vertices[3][1])
+    max_x = max(vertices[0][0], vertices[1][0], vertices[2][0], vertices[3][0])
+    max_y = max(vertices[0][1], vertices[1][1], vertices[2][1], vertices[3][1])
+    return vertices, (min_x, min_y, max_x, max_y)
+
+
+def _get_link_annotation(gc, x, y, width, height, angle=0):
+    """
+    Create a link annotation object for embedding URLs.
+    """
+    quadpoints, rect = _get_coordinates_of_block(x, y, width, height, angle)
+    link_annotation = {
+        'Type': Name('Annot'),
+        'Subtype': Name('Link'),
+        'Rect': rect,
+        'QuadPoint': quadpoints,
+        'Border': [0, 0, 0],
+        'A': {
+            'S': Name('URI'),
+            'URI': gc.get_url(),
+        },
+    }
+    return link_annotation
+
+
 def pdfRepr(obj):
     """Map Python objects to PDF syntax."""
 
@@ -2154,17 +2205,8 @@ def draw_mathtext(self, gc, x, y, s, prop, angle):
             self._text2path.mathtext_parser.parse(s, 72, prop)
 
         if gc.get_url() is not None:
-            link_annotation = {
-                'Type': Name('Annot'),
-                'Subtype': Name('Link'),
-                'Rect': (x, y, x + width, y + height),
-                'Border': [0, 0, 0],
-                'A': {
-                    'S': Name('URI'),
-                    'URI': gc.get_url(),
-                },
-            }
-            self.file._annotations[-1][1].append(link_annotation)
+            self.file._annotations[-1][1].append(_get_link_annotation(
+                gc, x, y, width, height, angle))
 
         fonttype = mpl.rcParams['pdf.fonttype']
 
@@ -2220,17 +2262,8 @@ def draw_tex(self, gc, x, y, s, prop, angle, *, mtext=None):
             page, = dvi
 
         if gc.get_url() is not None:
-            link_annotation = {
-                'Type': Name('Annot'),
-                'Subtype': Name('Link'),
-                'Rect': (x, y, x + page.width, y + page.height),
-                'Border': [0, 0, 0],
-                'A': {
-                    'S': Name('URI'),
-                    'URI': gc.get_url(),
-                },
-            }
-            self.file._annotations[-1][1].append(link_annotation)
+            self.file._annotations[-1][1].append(_get_link_annotation(
+                gc, x, y, page.width, page.height, angle))

         # Gather font information and do some setup for combining
         # characters into strings. The variable seq will contain a
@@ -2330,17 +2363,8 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         if gc.get_url() is not None:
             font.set_text(s)
             width, height = font.get_width_height()
-            link_annotation = {
-                'Type': Name('Annot'),
-                'Subtype': Name('Link'),
-                'Rect': (x, y, x + width / 64, y + height / 64),
-                'Border': [0, 0, 0],
-                'A': {
-                    'S': Name('URI'),
-                    'URI': gc.get_url(),
-                },
-            }
-            self.file._annotations[-1][1].append(link_annotation)
+            self.file._annotations[-1][1].append(_get_link_annotation(
+                gc, x, y, width / 64, height / 64, angle))
 
         # If fonttype is neither 3 nor 42, emit the whole string at once
         # without manual kerning.