Merge pull request #90786 from m4rr5/fix_flipped_line2d_joints

Fix `Line2D` joints with `joint_mode` set to Round rendered "flipped" for a 180 degree angle.
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Rémi Verschelde 2024-04-23 19:11:22 +02:00
commit 2463e42ea1
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@ -353,7 +353,20 @@ void LineBuilder::build() {
} else if (current_joint_mode == Line2D::LINE_JOINT_ROUND && !(wrap_around && i == segments_count)) {
Vector2 vbegin = cbegin - pos1;
Vector2 vend = cend - pos1;
strip_add_arc(pos1, vbegin.angle_to(vend), orientation);
// We want to use vbegin.angle_to(vend) below, which evaluates to
// Math::atan2(vbegin.cross(vend), vbegin.dot(vend)) but we need to
// calculate this ourselves as we need to check if the cross product
// in that calculation ends up being -0.f and flip it if so, effectively
// flipping the resulting angle_delta to not return -PI but +PI instead
float cross_product = vbegin.cross(vend);
float dot_product = vbegin.dot(vend);
// Note that we're comparing against -0.f for clarity but 0.f would
// match as well, therefore we need the explicit signbit check too.
if (cross_product == -0.f && signbit(cross_product)) {
cross_product = 0.f;
}
float angle_delta = Math::atan2(cross_product, dot_product);
strip_add_arc(pos1, angle_delta, orientation);
}
if (!is_intersecting) {