Curves: new Grow/Shrink brush

This adds a new Grow/Shrink brush which is similar to the Length
brush in the old hair system.
* It's possible to switch between growing and shrinking by hold
  down ctrl and/or by changing the direction enum.
* 3d brush is supported.
* Different brush falloffs are supported.
* Supports scaling curves uniformly or shrinking/extrapolating
  them. Extrapolation is linear only in this patch.
* A minimum length settings helps to avoid creating zero-sized curves.

Differential Revision: https://developer.blender.org/D14474

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_brush_types.h b/source/blender/makesdna/DNA_brush_types.h
index 1382efca409..2d879f5afa0 100644
--- a/source/blender/makesdna/DNA_brush_types.h
+++ b/source/blender/makesdna/DNA_brush_types.h
@@ -140,6 +140,10 @@ typedef struct BrushGpencilSettings {
 typedef struct BrushCurvesSculptSettings {
   /** Number of curves added by the add brush. */
   int add_amount;
+  /* eBrushCurvesSculptFlag. */
+  uint32_t flag;
+  /** When shrinking curves, they shouldn't become shorter than this length. */
+  float minimum_length;
 } BrushCurvesSculptSettings;
 
 typedef struct Brush {