[Bf-blender-cvs] [4c66bd5da25] master: Curves: Use simpler "set" behavior for postion attribute

[Hans Goudey]

Commit: 4c66bd5da256779ef5a308d86abfe9b88f4a039b
Author: Hans Goudey
Date:   Thu Feb 24 12:17:22 2022 -0500
Branches: master
https://developer.blender.org/rB4c66bd5da256779ef5a308d86abfe9b88f4a039b

Curves: Use simpler "set" behavior for postion attribute

This is similar to f8fe0e831ec14cc521e03df, which made the change to the
handle position attributes. This commit removes the way that setting the
`position` attribute also changes the handle position attributes. Now,
the "Set Position" node still has this behavior, but changing the
attribute directly (with the modifier's output attributes) does not.

The previous behavior was a relic of the geometry nodes design
from before fields and the set position node existed.

This makes the transition to the new curves data structure simpler.
There is more room for optimizing the Bezier case of the set position
node in the future.

===================================================================

M	source/blender/blenkernel/intern/geometry_component_curve.cc
M	source/blender/nodes/geometry/nodes/node_geo_set_position.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/geometry_component_curve.cc b/source/blender/blenkernel/intern/geometry_component_curve.cc
index 9116ffc63a8..c22b6ff07ec 100644
--- a/source/blender/blenkernel/intern/geometry_component_curve.cc
+++ b/source/blender/blenkernel/intern/geometry_component_curve.cc
@@ -880,15 +880,7 @@ class VArrayImpl_For_SplinePosition final : public VMutableArrayImpl<float3> {
   {
     const PointIndices indices = lookup_point_indices(offsets_, index);
     Spline &spline = *splines_[indices.spline_index];
-    if (BezierSpline *bezier_spline = dynamic_cast<BezierSpline *>(&spline)) {
-      const float3 delta = value - bezier_spline->positions()[indices.point_index];
-      bezier_spline->handle_positions_left()[indices.point_index] += delta;
-      bezier_spline->handle_positions_right()[indices.point_index] += delta;
-      bezier_spline->positions()[indices.point_index] = value;
-    }
-    else {
-      spline.positions()[indices.point_index] = value;
-    }
+    spline.positions()[indices.point_index] = value;
   }
 
   void set_all(Span<float3> src) final
@@ -897,20 +889,7 @@ class VArrayImpl_For_SplinePosition final : public VMutableArrayImpl<float3> {
       Spline &spline = *splines_[spline_index];
       const int offset = offsets_[spline_index];
       const int next_offset = offsets_[spline_index + 1];
-      if (BezierSpline *bezier_spline = dynamic_cast<BezierSpline *>(&spline)) {
-        MutableSpan<float3> positions = bezier_spline->positions();
-        MutableSpan<float3> handle_positions_left = bezier_spline->handle_positions_left();
-        MutableSpan<float3> handle_positions_right = bezier_spline->handle_positions_right();
-        for (const int i : IndexRange(next_offset - offset)) {
-          const float3 delta = src[offset + i] - positions[i];
-          handle_positions_left[i] += delta;
-          handle_positions_right[i] += delta;
-          positions[i] = src[offset + i];
-        }
-      }
-      else {
-        spline.positions().copy_from(src.slice(offset, next_offset - offset));
-      }
+      spline.positions().copy_from(src.slice(offset, next_offset - offset));
     }
   }
 
diff --git a/source/blender/nodes/geometry/nodes/node_geo_set_position.cc b/source/blender/nodes/geometry/nodes/node_geo_set_position.cc
index 361a75ee0a8..eb035aa9b6b 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_set_position.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_set_position.cc
@@ -61,6 +61,41 @@ static void set_computed_position_and_offset(GeometryComponent &component,
       }
       break;
     }
+    case GEO_COMPONENT_TYPE_CURVE: {
+      if (component.attribute_exists("handle_right") &&
+          component.attribute_exists("handle_left")) {
+        OutputAttribute_Typed<float3> handle_right_attribute =
+            component.attribute_try_get_for_output<float3>(
+                "handle_right", ATTR_DOMAIN_POINT, {0, 0, 0});
+        OutputAttribute_Typed<float3> handle_left_attribute =
+            component.attribute_try_get_for_output<float3>(
+                "handle_left", ATTR_DOMAIN_POINT, {0, 0, 0});
+        MutableSpan<float3> handle_right = handle_right_attribute.as_span();
+        MutableSpan<float3> handle_left = handle_left_attribute.as_span();
+
+        MutableSpan<float3> out_positions_span = positions.as_span();
+        devirtualize_varray2(
+            in_positions, in_offsets, [&](const auto in_positions, const auto in_offsets) {
+              threading::parallel_for(
+                  selection.index_range(), grain_size, [&](const IndexRange range) {
+                    for (const int i : selection.slice(range)) {
+                      const float3 new_position = in_positions[i] + in_offsets[i];
+                      const float3 delta = new_position - out_positions_span[i];
+                      handle_right[i] += delta;
+                      handle_left[i] += delta;
+                      out_positions_span[i] = new_position;
+                    }
+                  });
+            });
+
+        handle_right_attribute.save();
+        handle_left_attribute.save();
+        break;
+      }
+      else {
+        ATTR_FALLTHROUGH;
+      }
+    }
     default: {
       MutableSpan<float3> out_positions_span = positions.as_span();
       if (in_positions.is_same(positions.varray())) {