PR summary

I've been having a lot of fun profiling the past two days. This PR is the result of optimizing slow bits of the text rendering code paths that are called downstream of axis3d._draw_ticks(). None of these changes are 3D specific, so they should speed up 2D draw times as well. The non-agg-rendering code in this part of the stack is sped up by a cumulative 2.2x, which is an 8% reduction in the total draw time for my test script of an empty 3D plot.

The commits are all self-contained, so I can break them apart if that's easier to review.

The font property cache is the change where I'm least confident in my understanding of the original design decisions, but it's simpler and 2x faster. The new __copy__ method does help partially speed things up if we want to keep the original structure instead

Summary of the changes:

text.py:

• Rework the font property cache to use a plain dict instead of lru_cache
• Add @lru_cache for rotation transforms via a _rotate(theta) helper function (common case is only a few angles)
• Add fast path to skip rotation transform operations when rotation=0 (the most common case)
• Use direct indexing instead of numpy array operations for several small lists

font_manager.py:

• Implement __copy__ method on FontProperties that bypasses __init__ validation
• Make __hash__ more robust to new attrs

lines.py

• Add fast path for same-shape x/y arrays using direct assignment instead of broadcast_arrays
• Replace .T unpacking with column slicing for views

path.py

• Inline shape validation instead of calling _api.check_shape

transforms.py

• Type the array construction in Bbox.from_extents

Before:

After (less time on things that aren't draw_text):

Test script:

import time
import matplotlib.pyplot as plt

print("Starting...")

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

print("Timing...")

start_time = time.perf_counter()
for i in range(250):
    ax.view_init(elev=i, azim=i)
    fig.canvas.draw()
end_time = time.perf_counter()

plt.close()

print(f"Time taken: {end_time - start_time:.4f} seconds")

PR checklist

• [n/a] "closes #0000" is in the body of the PR description to link the related issue
• new and changed code is tested
• [n/a] Plotting related features are demonstrated in an example
• [n/a] New Features and API Changes are noted with a directive and release note
• [n/a] Documentation complies with general and docstring guidelines