diff options
author | Jacques Lucke <jacques@blender.org> | 2022-05-30 11:14:00 +0300 |
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committer | Jacques Lucke <jacques@blender.org> | 2022-05-30 11:14:00 +0300 |
commit | fc3c589b18080640d483ed91c5be6efb945fc4c3 (patch) | |
tree | 766cc0f4b3a5f87cdbceb8d002454e91b8ca4f6b /source/blender/blenkernel/intern/curve_poly.cc | |
parent | 16746e8ec2831937771daf488b1c2fd444dbd8dd (diff) | |
parent | a7bda30ca890d1a76b1a1f0be23cb08a4bd1b5f5 (diff) |
Merge branch 'blender-v3.2-release'
Diffstat (limited to 'source/blender/blenkernel/intern/curve_poly.cc')
-rw-r--r-- | source/blender/blenkernel/intern/curve_poly.cc | 65 |
1 files changed, 57 insertions, 8 deletions
diff --git a/source/blender/blenkernel/intern/curve_poly.cc b/source/blender/blenkernel/intern/curve_poly.cc index 1b337379604..7ab92068d81 100644 --- a/source/blender/blenkernel/intern/curve_poly.cc +++ b/source/blender/blenkernel/intern/curve_poly.cc @@ -13,15 +13,28 @@ namespace blender::bke::curves::poly { -static float3 direction_bisect(const float3 &prev, const float3 &middle, const float3 &next) +static float3 direction_bisect(const float3 &prev, + const float3 &middle, + const float3 &next, + bool &r_used_fallback) { + const float epsilon = 1e-6f; + const bool prev_equal = math::almost_equal_relative(prev, middle, epsilon); + const bool next_equal = math::almost_equal_relative(middle, next, epsilon); + if (prev_equal && next_equal) { + r_used_fallback = true; + return {0.0f, 0.0f, 0.0f}; + } + if (prev_equal) { + return math::normalize(next - middle); + } + if (next_equal) { + return math::normalize(middle - prev); + } + const float3 dir_prev = math::normalize(middle - prev); const float3 dir_next = math::normalize(next - middle); - const float3 result = math::normalize(dir_prev + dir_next); - if (UNLIKELY(math::is_zero(result))) { - return float3(0.0f, 0.0f, 1.0f); - } return result; } @@ -36,8 +49,11 @@ void calculate_tangents(const Span<float3> positions, return; } + bool used_fallback = false; + for (const int i : IndexRange(1, positions.size() - 2)) { - tangents[i] = direction_bisect(positions[i - 1], positions[i], positions[i + 1]); + tangents[i] = direction_bisect( + positions[i - 1], positions[i], positions[i + 1], used_fallback); } if (is_cyclic) { @@ -45,13 +61,46 @@ void calculate_tangents(const Span<float3> positions, const float3 &last = positions.last(); const float3 &first = positions.first(); const float3 &second = positions[1]; - tangents.first() = direction_bisect(last, first, second); - tangents.last() = direction_bisect(second_to_last, last, first); + tangents.first() = direction_bisect(last, first, second, used_fallback); + 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]); } + + if (!used_fallback) { + return; + } + + /* Find the first tangent that does not use the fallback. */ + int first_valid_tangent_index = -1; + for (const int i : tangents.index_range()) { + if (!math::is_zero(tangents[i])) { + first_valid_tangent_index = i; + break; + } + } + if (first_valid_tangent_index == -1) { + /* If all tangents used the fallback, it means that all positions are (almost) the same. Just + * use the up-vector as default tangent. */ + const float3 up_vector{0.0f, 0.0f, 1.0f}; + tangents.fill(up_vector); + } + else { + const float3 &first_valid_tangent = tangents[first_valid_tangent_index]; + /* If the first few tangents are invalid, use the tangent from the first point with a valid + * tangent. */ + tangents.take_front(first_valid_tangent_index).fill(first_valid_tangent); + /* Use the previous valid tangent for points that had no valid tangent. */ + for (const int i : tangents.index_range().drop_front(first_valid_tangent_index + 1)) { + float3 &tangent = tangents[i]; + if (math::is_zero(tangent)) { + const float3 &prev_tangent = tangents[i - 1]; + tangent = prev_tangent; + } + } + } } void calculate_normals_z_up(const Span<float3> tangents, MutableSpan<float3> normals) |