Path: change the type of the code type constants to match the type of the codes array

lazka · lazka · commit 3b8689afe346 · 2018-12-23T20:09:12.000+01:00
The matching types make comparisons between the constants and values of the codes array faster.

Using the Gtk3Cairo backend with wire3d_animation_sgskip.py:
Before: 9.95 fps
After: 15.26 fps

The main areas where this helps for the cairo case is the faster comparisons in
Path.iter_segments() and in _append_paths() of the cairo backend.
diff --git a/doc/api/next_api_changes/2018-12-23-path-code-types.rst b/doc/api/next_api_changes/2018-12-23-path-code-types.rst
@@ -0,0 +1,7 @@
+Path code types like ``Path.MOVETO`` are now ``np.uint8`` instead of ``int``
+````````````````````````````````````````````````````````````````````````````
+
+``Path.STOP``, ``Path.MOVETO``, ``Path.LINETO``, ``Path.CURVE3``,
+``Path.CURVE4`` and ``Path.CLOSEPOLY`` are now of the type ``Path.code_type``
+(``np.uint8`` by default) instead of plain ``int``. This makes their type
+match the array value type of the ``Path.codes`` array.
diff --git a/lib/matplotlib/path.py b/lib/matplotlib/path.py
@@ -74,13 +74,15 @@ class Path(object):
 
     """
 
+    code_type = np.uint8
+
     # Path codes
-    STOP = 0         # 1 vertex
-    MOVETO = 1       # 1 vertex
-    LINETO = 2       # 1 vertex
-    CURVE3 = 3       # 2 vertices
-    CURVE4 = 4       # 3 vertices
-    CLOSEPOLY = 79   # 1 vertex
+    STOP = code_type(0)         # 1 vertex
+    MOVETO = code_type(1)       # 1 vertex
+    LINETO = code_type(2)       # 1 vertex
+    CURVE3 = code_type(3)       # 2 vertices
+    CURVE4 = code_type(4)       # 3 vertices
+    CLOSEPOLY = code_type(79)   # 1 vertex
 
     #: A dictionary mapping Path codes to the number of vertices that the
     #: code expects.
@@ -91,8 +93,6 @@ class Path(object):
                              CURVE4: 3,
                              CLOSEPOLY: 1}
 
-    code_type = np.uint8
-
     def __init__(self, vertices, codes=None, _interpolation_steps=1,
                  closed=False, readonly=False):
         """
