Curves: New tools for curves sculpt mode.

This commit contains various new features for curves sculpt mode
that have been developed in parallel.

* Selection:
  * Operator to select points/curves randomly.
  * Operator to select endpoints of curves.
  * Operator to grow/shrink an existing selection.
* New Brushes:
  * Pinch: Moves points towards the brush center.
  * Smooth: Makes individual curves straight without changing the root
    or tip position.
  * Puff: Makes curves stand up, aligning them with the surface normal.
  * Density: Add or remove curves to achieve a certain density defined
    by a minimum distance value.
  * Slide: Move root points on the surface.

Differential Revision: https://developer.blender.org/D15134

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_brush_types.h b/source/blender/makesdna/DNA_brush_types.h
index d13496b21f7..b24bb786593 100644
--- a/source/blender/makesdna/DNA_brush_types.h
+++ b/source/blender/makesdna/DNA_brush_types.h
@@ -148,6 +148,13 @@ typedef struct BrushCurvesSculptSettings {
   float minimum_length;
   /** Length of newly added curves when it is not interpolated from other curves. */
   float curve_length;
+  /** Minimum distance between curve root points used by the Density brush. */
+  float minimum_distance;
+  /** How often the Density brush tries to add a new curve. */
+  int density_add_attempts;
+  /** #eBrushCurvesSculptDensityMode. */
+  uint8_t density_mode;
+  char _pad[7];
 } BrushCurvesSculptSettings;
 
 typedef struct Brush {