[pvcraven]

Summary

Fixes #2754: get_angle_degrees and get_angle_radians measure angles differently.

Target from (0, 0)	get_angle_degrees before	get_angle_radians before (as degrees)	Both, after
up (0, 1)	-90	0	0
right (1, 0)	0 (returned as -0.0)	90	90
down (0, -1)	90	180	180
left (-1, 0)	-180	-90	-90

Both functions used to measure clockwise from up. #2157 (June 2024) changed get_angle_degrees to measure clockwise from the right, and missed get_angle_radians.

Both now measure clockwise from straight up, like Sprite.angle: 0 is up and 90 is right. So a sprite whose image points up faces a point with sprite.angle = get_angle_degrees(...), and get_angle_radians is always math.radians of it. Only get_angle_degrees changes, which goes back to its pre-#2157 behavior. The docstrings now say which way the angles go.

Breaking: code using get_angle_degrees gets 90 more than before. The changelog entry is under Unreleased → Breaking Changes, and says to subtract 90 for the old value.

The issue proposes atan2(dy, dx) instead. That's counter-clockwise from the right, so it would have disagreed with Sprite.angle by direction.

Examples

• sprite_rotate_around_tank is the only user of get_angle_radians in the repo.
  • Its corrected barrel (correct = True) passed swapped arguments and sat 90° off from the mouse: with the mouse to the right, the barrel lay along the top edge of the tank. It now sticks out toward the mouse.
  • The default barrel compensation goes from -90 to -180 to match, and that mode behaves exactly as before.
• turn_and_move: the image offset and movement math were updated for the new angles.
  • Checked against development for six directions, the sprite faces and moves identically.
  • Its arrival check used <, so a sprite moving straight along an axis never registered arrival and kept turning. It now uses <=, and every direction stops facing the right way.

Tests

New in tests/unit/test_math.py; there were no tests for these functions before:

• get_angle_degrees returns the angle clockwise from up, for six directions.
• get_angle_radians matches math.radians(get_angle_degrees(...)).
• A sprite turned by get_angle_degrees faces its target.

12 of the 20 fail on development.

I compared both examples with development by simulation (barrel angle and offset; sprite angle, heading and arrival), and rendered the tank to check the barrel. Full suite: 1799 passed. ruff, mypy and pyright all pass.

🤖 Generated with Claude Code