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Physics Interpolation - Fix interpolated_transform_2d

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Uses the skew correct `Transform2D::interpolate_with()` function rather than the bugged 3.x version.
This commit is contained in:
lawnjelly 2024-07-02 08:10:55 +01:00
parent 9425535602
commit 0ed71f3e0c
1 changed files with 2 additions and 32 deletions
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34
core/math/transform_interpolator.cpp
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@ -33,44 +33,14 @@
#include "core/math/transform_2d.h"
void TransformInterpolator::interpolate_transform_2d(const Transform2D &p_prev, const Transform2D &p_curr, Transform2D &r_result, real_t p_fraction) {
// Extract parameters.
Vector2 p1 = p_prev.get_origin();
Vector2 p2 = p_curr.get_origin();
// Special case for physics interpolation, if flipping, don't interpolate basis.
// If the determinant polarity changes, the handedness of the coordinate system changes.
if (_sign(p_prev.determinant()) != _sign(p_curr.determinant())) {
r_result.columns[0] = p_curr.columns[0];
r_result.columns[1] = p_curr.columns[1];
r_result.set_origin(p1.lerp(p2, p_fraction));
r_result.set_origin(p_prev.get_origin().lerp(p_curr.get_origin(), p_fraction));
return;
}
real_t r1 = p_prev.get_rotation();
real_t r2 = p_curr.get_rotation();
Size2 s1 = p_prev.get_scale();
Size2 s2 = p_curr.get_scale();
// Slerp rotation.
Vector2 v1(Math::cos(r1), Math::sin(r1));
Vector2 v2(Math::cos(r2), Math::sin(r2));
real_t dot = v1.dot(v2);
dot = CLAMP(dot, -1, 1);
Vector2 v;
if (dot > 0.9995f) {
v = v1.lerp(v2, p_fraction).normalized(); // Linearly interpolate to avoid numerical precision issues.
} else {
real_t angle = p_fraction * Math::acos(dot);
Vector2 v3 = (v2 - v1 * dot).normalized();
v = v1 * Math::cos(angle) + v3 * Math::sin(angle);
}
// Construct matrix.
r_result = Transform2D(Math::atan2(v.y, v.x), p1.lerp(p2, p_fraction));
r_result.scale_basis(s1.lerp(s2, p_fraction));
r_result = p_prev.interpolate_with(p_curr, p_fraction);
}