From 5945a90df99b919229c876c2fd294f035e24831a Mon Sep 17 00:00:00 2001 From: Jacques Lucke Date: Tue, 26 Jul 2022 15:25:59 +0200 Subject: Fix T98788: bad first curve tangent when first points have same position --- source/blender/blenkernel/intern/curve_poly.cc | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/source/blender/blenkernel/intern/curve_poly.cc b/source/blender/blenkernel/intern/curve_poly.cc index 7ab92068d81..2b2cf9adeee 100644 --- a/source/blender/blenkernel/intern/curve_poly.cc +++ b/source/blender/blenkernel/intern/curve_poly.cc @@ -65,8 +65,21 @@ void calculate_tangents(const Span positions, tangents.last() = direction_bisect(second_to_last, last, first, used_fallback); } else { - tangents.first() = math::normalize(positions[1] - positions.first()); - tangents.last() = math::normalize(positions.last() - positions[positions.size() - 2]); + const float epsilon = 1e-6f; + if (math::almost_equal_relative(positions[0], positions[1], epsilon)) { + tangents.first() = {0.0f, 0.0f, 0.0f}; + used_fallback = true; + } + else { + tangents.first() = math::normalize(positions[1] - positions[0]); + } + if (math::almost_equal_relative(positions.last(0), positions.last(1), epsilon)) { + tangents.last() = {0.0f, 0.0f, 0.0f}; + used_fallback = true; + } + else { + tangents.last() = math::normalize(positions.last(0) - positions.last(1)); + } } if (!used_fallback) { -- cgit v1.2.3