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Add ability to normalize a Vector of length zero #3157
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I'm not sure that it was actually determined for sure that this needs to be implemented in pygame-ce. I'm still partially against it because there are several nonintuitive things that could break if you expect normalizing to return a vector of magnitude 1
@@ -237,6 +237,11 @@ Multiple coordinates can be set using slices or swizzling | |||
Returns a new vector that has ``length`` equal to ``1`` and the same |
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You should update this if we're gonna go this route, as well as the sluglines above
@@ -247,6 +252,11 @@ Multiple coordinates can be set using slices or swizzling | |||
Normalizes the vector so that it has ``length`` equal to ``1``. |
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Update this and the sluglines above
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Also, you still need to update the Vector3
docs with these changes as well
self.assertRaises(ValueError, lambda: self.zeroVec.normalize()) | ||
# 0 vector | ||
self.assertEqual(self.zeroVec.normalize(), Vector2()) | ||
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def test_normalize_ip(self): | ||
v = +self.v1 | ||
# v has length != 1 before normalizing | ||
self.assertNotEqual(v.x * v.x + v.y * v.y, 1.0) | ||
# inplace operations should return None | ||
self.assertEqual(v.normalize_ip(), None) | ||
self.assertEqual(self.zeroVec.normalize_ip(), None) | ||
# length is 1 | ||
self.assertAlmostEqual(v.x * v.x + v.y * v.y, 1.0) | ||
# v2 is parallel to v1 | ||
self.assertAlmostEqual(self.v1.x * v.y - self.v1.y * v.x, 0.0) | ||
self.assertRaises(ValueError, lambda: self.zeroVec.normalize_ip()) |
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These changes also need to be applied to the Vector3
tests
Good point -- this adds the possibility of |
@oddbookworm Could you provide an example ? If we merge this, it will not break any code as the following structure : if vector:
vector.normalize_ip() Would still work. (which is what people are currently doing / supposed to do) |
@Doublestuf So the test can pass, you'll have to update the test for |
In issue #2269, it's been decided that pygame-ce should follow game engines such as Unity and Godot in allowing users to normalize zero-vectors for convenience.
Update the function in
math_test.c
, tests inmath_test.py
, and documentation inmath.rst
accordingly.