Geometry Noes: Curve Resample Node

This node generates a naturally parametarized (even length edge) poly
spline version of every spline in the input. There are two modes,
"Count", and "Length". These are similar to the same options for the
line primitive node in end points mode.

I implemented this instead of a "Sample Points" node, because for this
operation it's trivial to keep the result as a curve, which is nice
since it increases flexibility, and because it can make instancing
simpler, i.e. using the transforms of each evaluated point rather than
requiring the construction of a "rotation" attribute.

Differential Revision: https://developer.blender.org/D11173

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_spline.hh b/source/blender/blenkernel/BKE_spline.hh
index 098abf6de65..fda603d57bf 100644
--- a/source/blender/blenkernel/BKE_spline.hh
+++ b/source/blender/blenkernel/BKE_spline.hh
@@ -113,6 +113,7 @@ class Spline {
   bool is_cyclic() const;
   void set_cyclic(const bool value);
 
+  virtual void resize(const int size) = 0;
   virtual blender::MutableSpan<blender::float3> positions() = 0;
   virtual blender::Span<blender::float3> positions() const = 0;
   virtual blender::MutableSpan<float> radii() = 0;
@@ -163,6 +164,9 @@ class Spline {
   LookupResult lookup_evaluated_factor(const float factor) const;
   LookupResult lookup_evaluated_length(const float length) const;
 
+  blender::Array<float> sample_uniform_index_factors(const int samples_size) const;
+  LookupResult lookup_data_from_index_factor(const float index_factor) const;
+
   /**
    * Interpolate a virtual array of data with the size of the number of control points to the
    * evaluated points. For poly splines, the lifetime of the returned virtual array must not
@@ -248,6 +252,7 @@ class BezierSpline final : public Spline {
                  const float radius,
                  const float tilt);
 
+  void resize(const int size) final;
   blender::MutableSpan<blender::float3> positions() final;
   blender::Span<blender::float3> positions() const final;
   blender::MutableSpan<float> radii() final;
@@ -387,6 +392,7 @@ class NURBSpline final : public Spline {
   bool check_valid_size_and_order() const;
   int knots_size() const;
 
+  void resize(const int size) final;
   blender::MutableSpan<blender::float3> positions() final;
   blender::Span<blender::float3> positions() const final;
   blender::MutableSpan<float> radii() final;
@@ -441,6 +447,7 @@ class PolySpline final : public Spline {
 
   void add_point(const blender::float3 position, const float radius, const float tilt);
 
+  void resize(const int size) final;
   blender::MutableSpan<blender::float3> positions() final;
   blender::Span<blender::float3> positions() const final;
   blender::MutableSpan<float> radii() final;